Chemotherapy-free treatment targeting fusions and driver mutations in KRAS wild-type pancreatic ductal adenocarcinoma, a case series

Background

KRAS wild-type (WT) pancreatic ductal adenocarcinoma (PDAC) represents a distinct entity with unique biology. The therapeutic impact of matched targeted therapy in these patients in a real-world setting, to date, is less established.

Objectives

The aim of our study was to review our institutional database to identify the prevalence of actionable genomic alterations in patients with KRAS-WT tumors and to evaluate the therapeutic impact of matched targeted therapy in these patients.

Design

We reviewed electronic medical records of patients with KRAS-WT PDAC and advanced disease (n = 14) who underwent clinical-grade tissue ± liquid next-generation sequencing (315-648 genes for tissue) between years 2015 and 2021.

Methods

Demographic and disease characteristics were summarized using descriptive parameters. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method.

Results

Of 236 PDAC patients, 14 had advanced/metastatic disease with KRAS-WT tumors. Median age at diagnosis was 66 years. There was a high frequency of potentially actionable genomic alterations, including three (21%) with BRAF alterations, two (14%) with fusions [RET-PCM1 and FGFR2-POC1B (N = 1 each)]; and one with a druggable EGFR (EGFR E746_A755delISERD) variant; two other patients had an STK11 and a MUTYH alteration. Five patients were treated with matched targeted therapy, with three having durable benefit: (i) erlotinib for EGFR-altered tumor, followed by osimertinib/capmatinib when MET amplification emerged (first-line therapy); (ii) pralsetinib for RET fusion (fifth line); and (iii) dabrafenib/trametinib for BRAF N486_P490del (third line). Duration of time on chemotherapy-free matched targeted therapy for these patients was 17+, 11, and 18+ months, respectively.

Conclusion

Sustained therapeutic benefit can be achieved in a real-world setting in a subset of patients with advanced/metastatic KRAS-WT PDAC treated with chemotherapy-free matched targeted agents. Prospective studies are warranted.

Transcriptomic-Based Microenvironment Classification Reveals Precision Medicine Strategies for Pancreatic Ductal Adenocarcinoma

BACKGROUND & AIMS

The complex tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) has hindered the development of reliable predictive biomarkers for targeted therapy and immunomodulatory strategies. A comprehensive characterization of the TME is necessary to advance precision therapeutics in PDAC.

METHODS

A transcriptomic profiling platform for TME classification based on functional gene signatures was applied to 14 publicly available PDAC datasets (n = 1657) and validated in a clinically annotated independent cohort of patients with PDAC (n = 79). Four distinct subtypes were identified using unsupervised clustering and assessed to evaluate predictive and prognostic utility.

RESULTS

TME classification using transcriptomic profiling identified 4 biologically distinct subtypes based on their TME immune composition: immune enriched (IE); immune enriched, fibrotic (IE/F); fibrotic (F); and immune depleted (D). The IE and IE/F subtypes demonstrated a more favorable prognosis and potential for response to immunotherapy compared with the F and D subtypes. Most lung metastases and liver metastases were subtypes IE and D, respectively, indicating the role of clonal phenotype and immune milieu in developing personalized therapeutic strategies. In addition, distinct TMEs with potential therapeutic implications were identified in treatment-naive primary tumors compared with tumors that underwent neoadjuvant therapy.

CONCLUSIONS

This novel approach defines a distinct subgroup of PADC patients that may benefit from immunotherapeutic strategies based on their TME subtype and provides a framework to select patients for prospective clinical trials investigating precision immunotherapy in PDAC. Further, the predictive utility and real-world clinical applicability espoused by this transcriptomic-based TME classification approach will accelerate the advancement of precision medicine in PDAC.

Pancreatic Adenocarcinoma with Co-Occurrence of KRAS and EGFR Mutations: Case Report and Literature Review

Introduction

Mutation in Kristin ras sarcoma virus (KRAS) oncogene is the main driver in pancreatic ductal adenocarcinoma (PDAC) and is present in nearly 90% of patients with PDAC. Epidermal growth factor receptor (EGFR) mutation is rare in PDAC and is mostly present in the absence of KRAS mutation. Co-occurrence of KRAS and EGFR mutations is extremely rare, and the value of EGFR inhibition in these cases is unknown.

Case Presentation

Here, we present a case of metastatic PDAC with co-occurrence of KRAS G12V and EGFR L730R. Despite primary resistance to folinic acid, fluorouracil, irinotecan, oxaliplatin, and gemcitabine/nab-paclitaxel, this patient had a biochemical response (decrease in carbohydrate antigen 19-9) and disease control of 7 months on gemcitabine/erlotinib (an EGFR inhibitor). This outcome is remarkable in the late-line PDAC treatment setting and is unusual after the progression of the tumor on gemcitabine/nab-paclitaxel chemotherapy.

Conclusion

This case suggests that gemcitabine/erlotinib could be an effective treatment in patients with PDAC and co-occurrence of EGFR and KRAS mutations.

Characterization of an oligometastatic state in patients with metastatic pancreatic adenocarcinoma undergoing systemic chemotherapy

PURPOSE/OBJECTIVES

Most patients with pancreatic adenocarcinoma (PDAC) will present with distant metastatic disease at diagnosis. We sought to identify clinical characteristics associated with prolonged overall survival (OS) in patients presenting with metastatic PDAC.

MATERIALS/METHODS

Patients presenting with metastatic PDAC that received treatment at our institution with FOLFIRINOX or gemcitabine-based chemotherapies between August 1, 2011 and September 1, 2017 were included in the study. Metastatic disease burden was comprehensively characterized radiologically via individual diagnostic imaging segmentation. Landmark analysis was performed at 18 months, and survival curves were estimated using the Kaplan-Meier method and compared between groups via the log-rank test. ECOG and Charlson Comorbidity Index (CCI) were calculated for all patients.

RESULTS

121 patients were included with a median age of 62 years (37-86), 40% were female, 25% had ECOG 0 at presentation. Of the 121 patients included, 33% (n = 41) were alive at 12 months and 25% (n = 31) were alive at 18 months. Landmark analysis demonstrated a significant difference between patients surviving <18 months and ≥18 months regarding the presence of lung only metastases (36% vs. 16%, p = 0.04), number of organs with metastases (≥2 vs. 1, p = 0.04), and disease volume (mean of 19.1 cc vs. 1.4 cc, p = 0.04). At Year 1, predictors for improved OS included ECOG status at diagnosis (ECOG 0 vs. ECOG 1, p = 0.04), metastatic disease volume at diagnosis (≤0.1 cc vs. >60 cc, p = 0.004), metastasis only in the liver (p = 0.04), and normalization of CA 19-9 (p < 0.001). At Year 2, the only predictor of improved OS was normalization of the CA 19-9 (p = 0.03). In those patients that normalized their CA 19-9, median overall survival was 16 months.

CONCLUSIONS

In this exploratory analysis normalization of CA-19-9 or volumetric metastatic disease burden less than 0.2 cc demonstrated a remarkable OS, similar to that of patients with non-metastatic disease. These metrics are useful for counseling patients and identifying cohorts that may be optimal for trials exploring metastatic and/or local tumor-directed interventions.

Biliary Adverse Events During Neoadjuvant Therapy for Pancreatic Cancer

OBJECTIVE

To describe a high-volume experience with biliary drainage before neoadjuvant therapy (NAT) for patients with operable pancreatic cancer (PC) and characterize the association between biliary adverse events (BAEs) and patient outcome.

BACKGROUND

Patients with PC presenting with biliary obstruction require durable decompression before NAT.

METHODS

Patients with operable PC and tumor-associated biliary obstruction were examined and grouped by the presence or absence of a BAE during NAT. The incidence, timing, and management of BAEs are described, and outcomes, including the completion of all treatment and overall survival (OS), were compared.

RESULTS

Of 426 patients who received pretreatment biliary decompression, 92 (22%) experienced at least 1 BAE during NAT, and 56 (13%) required repeat intervention on their biliary stent. The median duration of NAT was 161 days for all patients and was not different in the group that experienced BAEs. The median time from initial stent placement to BAE was 64 days. An interruption in the delivery of NAT (median 7 days) occurred in 25 (6%) of 426 patients. Among 426 patients, 290 (68%) completed all NAT, including surgery: 60 (65%) of 92 patients with BAE and 230 (69%) of 334 patients without BAE ( P =0.51). Among 290 patients who completed NAT and surgery, the median OS was 39 months, 26 months for the 60 patients with BAE, and 43 months for the 230 patients without BAE ( P =0.02).

CONCLUSIONS

During extended multimodal NAT for PC, 22% of patients experienced a BAE. Although BAEs were not associated with a significant interruption of treatment, patients who experienced a BAE had worse OS.

Patterns of Locoregional Pancreatic Cancer Recurrence after Total Neoadjuvant Therapy and Implications on Optimal Neoadjuvant Radiation Treatment Volumes

PURPOSE/OBJECTIVE(S)

Neoadjuvant treatment for patients with localized pancreatic adenocarcinoma (PDAC) has improved survival duration. As survival increases, local disease control becomes even more important. We sought to understand the patterns of locoregional recurrence following total neoadjuvant therapy (TNT) and determine the impact of treatment volumes on recurrence.

MATERIALS/METHODS

Patients with PDAC managed with neoadjuvant chemotherapy and chemoradiation (TNT) followed by surgery who developed an isolated locoregional or simultaneously locoregional and distant recurrence were identified. Locoregional recurrences were individually contoured utilizing commercially available software. When available, original neoadjuvant dose distributions were registered to the scans on which the locoregional recurrences were contoured. Recurrences where then classified as in-field (> 95% of prescription dose), marginal (50-95% of prescription dose), or out of field (< 50% of prescription dose). Target volumes were created using four commonly utilized PDAC contouring guidelines to characterize the relationship of the local recurrence to the RT dose distribution.

RESULTS

Of 474 patients treated with TNT and surgery, 80 (17%) patients developed a locoregional recurrence with or without distant recurrence, visible on diagnostic imaging. Of the 80 patients, 56 (70%) had tumors in the pancreatic head; 46 (57.5%) were borderline resectable, 23 (28.8%) locally advanced, and 11 (13.6%) resectable. The most common initial neoadjuvant therapies were FOLFIRINOX (57.5%) and gemcitabine/nab-paclitaxel (18.8%). Chemoradiation included concurrent gemcitabine (47.5%) or 5-fluorouracil (26.3%). RT dose distributions were available for 38 patients; 22 (57.9%) had in-field failures, 9 (23.7%) marginal failures, and 7 (18.4%) out of field failures. Each published contouring atlas covered a relatively low percentage of recurrences, which are summarized in Table 1. Regions at particularly high likelihood of recurrence that were under covered on existing atlases included: aortic-diaphragmic junction, retro-pancreatic duodenal nodal basin, and the region to the right of the superior mesenteric artery (SMA).

CONCLUSION

We present the largest series (to our knowledge) of mapped locoregional recurrences for patients being treated with TNT in PDAC. These recurrences differ substantially from established atlases and highlight anatomical regions of highest priority for RT coverage. A novel visual contouring volume highlighting these regions will be presented which will strive to advance the use of RT in the TNT setting.

Neoadjuvant Chemotherapy for Pancreatic Cancer: Quality over Quantity

BACKGROUND AND OBJECTIVES

The ideal duration of neoadjuvant chemotherapy (NACT) in patients with localized pancreatic adenocarcinoma (PDAC) treated with curative intent is unclear. We sought to determine the prognostic significance of both duration of NACT and Carbohydrate Antigen 19-9 (CA19-9) normalization to NACT.

METHODS

We examined patients with resectable and borderline resectable PDAC treated with NACT and chemoradiation. Patients were compared by NACT duration (2 vs 4 months) and by CA19-9 normalization after NACT.

RESULTS

Among 171 patients, 83 (49%) received two months of NACT and 88 (51%) received four months. After NACT completion, 115 (67%) patients had persistently elevated CA19-9 and 56 (33%) had normalized. Of the 125 patients who had successful surgery, 73 (58%) had normalized CA19-9 postoperatively. Duration of NACT was not associated with overall survival (OS) while CA19-9 normalization after NACT (regardless of duration) was associated with improved OS (HR 0.56, 95% CI 0.35-0.89, p=0.02). Adjuvant chemotherapy was associated with improved OS among patients without CA19-9 normalization after NACT (HR 0.42, CI 0.20-0.86, p=0.02) but not among those that normalized, independent of duration.

CONCLUSIONS

CA19-9 normalization after NACT is a clinically significant endpoint of treatment; patients without CA19-9 normalization may benefit from additional therapy. This article is protected by copyright. All rights reserved.

Chemotherapy-induced peripheral neuropathy in the detroit research on cancer survivors (ROCS) cohort

PURPOSE

Improved life expectancy has increased the likelihood for long-term complications from chemotherapy among cancer survivors. One burdensome complication is chemotherapy-induced peripheral neuropathy (CIPN). We evaluated rates of CIPN outcomes in the Detroit Research on Cancer Survivorship (ROCS) cohort.

METHODS

The population included 1,034 African American (AA) survivors who received chemotherapy for breast, colorectal, lung or prostate cancer. CIPN prevalence was based on initial occurrence of worsening of self-reported pain, numbness or tingling after chemotherapy. Current CIPN included symptoms still present at the time of the survey, and persistent CIPN symptoms were present 12 or more months post-chemotherapy. CIPN severity was ranked as mild, moderate or severe. Logistic regression was utilized to evaluate sociodemographic and clinical factors associated with the various categories of CIPN.

RESULTS

CIPN prevalence was 68%, with 53% current and 52% persistent. The symptom severity distribution based on prevalent CIPN included 32.2% mild, 30.8% moderate, and 36.9% severe. Factors associated with prevalent CIPN (odds ratio, 95% confidence interval) included primary cancer site (breast: 3.88, 2.02-7.46); and (colorectal: 5.37, 2.69-10.73), lower risk for older age at diagnosis (0.66, 0.53-0.83) and divorced/separated marital status (2.13, 1.42-3.21). Current CIPN was in addition, associated with more advanced stage disease trend (1.34, 1.08-1.66) and greater number of co-morbid medical conditions trend (1.23, 1.09-1.40), as was persistent CIPN. Severity of prevalent CIPN was associated with history of arthritis (1.55, 1.06-2.26) and severity of persistent CIPN with higher BMI (1.58, 1.07-2.35).

CONCLUSIONS

CIPN is a common and persistent complication in AA cancer survivors. Further research is needed to improve our understanding of CIPN predictors in all groups of cancer survivors.

CA19-9 Response to First-Line Neoadjuvant FOLFIRINOX and Second-Line Gemcitabine/Nab-Paclitaxel for Patients with Operable Pancreatic Cancer

BACKGROUND

Response to second-line (2L) neoadjuvant therapy for operable pancreatic cancer (PC) is understudied. This study examined carbohydrate antigen 19-9 (CA19-9) response to first-line (1L) and 2L chemotherapy.

METHODS

The study identified patients with operable PC and elevated CA19-9 (≥ 35 U/mL with total bilirubin < 2 mg/dL) who received 1L FOLFIRINOX (FFX). The patients were restaged after 2 months and based on response, received additional FFX or gemcitabine/nab-paclitaxel (GnP) as part of total neoadjuvant therapy. Response was defined as a decrease in tumor size on computed tomography (CT) imaging or a decline in CA19-9 of 50% or more and preserved performance status.

RESULTS

For operable PC with an elevated CA19-9, 108 patients received 1L FFX. After 2 months of chemotherapy, the decision was made to continue FFX (FFX ≥ FFX) for 76 (70%) of the 108 patients and switch to GnP (FFX ≥ GnP)) for 32 (30%) of the patients. Of the 32 FFX ≥ GnP patients, 27 had no evidence of radiographic or biochemical (CA19-9) response to 1L FFX. Of these 27 patients, 26 (96%) demonstrated a response to 2L GnP. After 4 months of chemotherapy, 62 (82%) of the 76 FFX ≥ FFX patients had a CA19-9 response compared with 31 (97%) of the 32 FFX ≥ GnP patients (p = 0.04).

CONCLUSIONS

Lack of biochemical response to 2 months of 1L FFX may identify a subgroup of patients with a very high rate of response to 2L GnP, emphasizing the importance of assessing treatment response at 2-month intervals.

Comprehensive genomic profiling: Does timing matter?

Purpose

There is variability in utilization of Comprehensive Genomic Profiling (CGP) in most of the metastatic solid tumors (MST). We evaluated the CGP utilization patterns and its impact on outcomes at an academic tertiary center.

Patients and Methods

Institutional database was reviewed for CGP data in adult patients with MST between 01/2012 - 04/2020. Patients were categorized based on interval between CGP and metastatic diagnosis; 3 tertiles of distribution (T1-earliest to the diagnosis, T3-furthest), and pre-mets (CGP performed prior to diagnosis of metastasis). Overall survival (OS) was estimated from the time of metastatic diagnosis with left truncation at the time of CGP. Cox regression model was used to estimate the impact of timing of CGP on survival.

Results

Among 1,358 patients, 710 were female, 1,109 Caucasian, 186 Afro-Americans, and 36 Hispanic. The common histologies were lung cancer (254; 19%), colorectal cancer (203; 15%), gynecologic cancers (121; 8.9%), and pancreatic cancer (106; 7.8%). Time interval between diagnosis of metastatic disease and CGP was not statistically significantly different based on sex, race and ethnicity after adjusting for histologic diagnoses with 2 exceptions - Hispanics with lung cancer had delayed CGP compared to non-Hispanics (p =0.019) and females with pancreas cancer had delayed CGP compared to males (p =0.025). Lung cancer, gastro-esophageal cancer and gynecologic malignancies had better survival if they had CGP performed during the first tertile after metastatic diagnosis.

Conclusion

CGP utilization across cancer types was equitable irrespective of sex, race and ethnicity. Early CGP after metastatic diagnosis might have effect on treatment delivery and clinical outcomes in cancer type with more actionable targets.

Treatment sequencing for patients with localized duodenal and ampullary adenocarcinoma

783

Background: Duodenal adenocarcinomas (DA) and ampullary adenocarcinoma (AA) are rare, comprising less than 1% of all gastrointestinal cancers. Optimal treatment sequencing strategies for patients with localized DA and AA have not been prospectively validated. We analyzed the clinical outcomes of patients with localized DA and AA treated with curative intent, multimodality therapy based on treatment sequencing – upfront surgery versus neoadjuvant therapy. Methods: Our institutional database was interrogated to identify adult patients with localized DA and AA diagnosed between January 2000 to December 2019. Adjusted survival analyses were performed to compare outcomes of patients that received neoadjuvant therapy (NAT - concurrent chemo-radiation +/-induction chemotherapy) versus upfront surgery (+/- adjuvant chemotherapy). Survival time was calculated from date of diagnosis to either death (overall survival; OS) or relapse/death (relapse free survival; RFS). Log-rank test and multiple Cox proportional hazards regression were performed to compare survival between treatment groups and adjust for relevant variables. Results: We identified 79 patients – 32 (41%) with DA and 47 (59%) with AA; Median age at diagnosis was 67. Forty two patients (53%) were male. Sixty-two patients underwent surgery – 27 (43.6%) patients with DA and 35 patients (56.4%) with AA. Among patients with DA, 18 (67%) were treated with upfront surgery, while 9 (33%) were treated with NAT. Among patients with AA, 32 (91%) were treated with upfront surgery while 3 (9%) were treated with NAT. Lymph node (LN) positivity rate in DA and AA patients treated with upfront surgery was 15% and 46% respectively, compared to 50% and 0% respectively, in patients treated with NAT (p = 0.26, p > 0.99 respectively). DA patients treated with upfront surgery had a median relapse free survival (mRFS) of 3.8 years compared to 1.4 years for those treated with NAT (p = 0.370). The median overall survival m(OS) was not reached (NR) for DA patients treated with upfront surgery (4 years +) or NAT (2.6 years +) p = 0.875). AA patients treated with upfront surgery had a median RFS of 4.7 years compared to NR for patients treated with NAT (p = 0.117) while the mOS of AA patients treated with upfront surgery and NAT were 5.9 years and NR respectively (p = 0.158). Conclusions: Among DA patients, there was no difference in outcome based on sequence of treatment delivery – NAT versus upfront surgery. DA patients with more aggressive clinical phenotype were likely treated with NAT, hence similar outcomes in both groups should prompt consideration of NAT for all patients with DA. Role of NAT in AA is not clear considering the small sample size.

ATM or CHEK2 alterations: Potential biomarkers of improved outcomes with irinotecan-containing chemotherapy in advanced pancreatic ductal adenocarcinoma

754

Background: ATM and CHEK2 mutations are linked to homologous recombination DNA repair deficiency, with the potential for improved therapeutic response to DNA damaging agents. To investigate our clinical observation of improved outcomes with irinotecan (IRI) based chemotherapy in advanced/metastatic pancreatic ductal adenocarcinoma (PDAC) patients (pts) with somatic or germline ATM/ CHEK2 mutations, we examined our institutional real world experience. Methods: Between 2015-2021, 33 pts with ATM or CHEK2 mutations treated with chemotherapy were identified, of which 16 pts had advanced/metastatic disease. Progression-free survival (PFS) was calculated and compared (Kaplan Meier, log-rank test) in several ways to assess the impact of IRI vs platinum or other regimens. The event for PFS was progression (or death), and pts without progression were censored at treatment end, or at last follow up if treatment was ongoing. Results: Among 16 pts with advanced/metastatic PDAC, 8 (50%) had ATM (5 germline, 3 somatic) and 8 (50%), CHEK2 alterations (4 germline, 4 somatic). Overall, pts received 48 lines of chemotherapy (platinum-based-(No-IRI) N=14; IRI-based-(No-Platinum) N=8; both N=4; none N=22). For best-PFS among pts analysis, median line of best-PFS therapy for IRI-Ever (N=9 pts) was 2nd line (range 1-7) and for IRI-Never (N=7 pts) was 1st (range, 1-1); median PFS was 13 vs 3 months (mo) (IRI-Ever vs IRI-Never; p=0.0076). For PFS analysis within lines of treatment of each pt, median therapy line for both IRI-containing and No-IRI lines was 2nd line (range 1-7); median PFS for IRI-containing (N=12 lines of therapy) vs No-IRI (N=36) was 12.1 vs 3 mo (p<0.001). Median PFS for best IRI-based-(No-Platinum) line (N=7) was 13 mo; for best platinum-based-(No-IRI) line (N=9) was 2.8 mo; and for best treatment containing no IRI or platinum (N=13) was 5.1 mo (P= 0.003) (median therapy line for each was 3, 2 and 1.5, respectively). Conclusions: Irinotecan is a topoisomerase 1 inhibitor that induces DNA strand breaks, potentially causing synthetic lethality in tumors with DNA damage repair deficits due to ATM or CHEK2 alterations. IRI-containing therapy out-performed other treatment types, including platinum-containing regimens, in pts with ATM or CHEK2-mutated advanced/metastatic PDAC. Prospective trials are warranted.

A phase I study of CPI-613 (devimistat) in combination with chemoradiation in patients with pancreatic adenocarcinoma

TPS760

Background: Local tumor progression is a cause of significant mortality and morbidity in patients with unresectable pancreatic ductal adenocarcinoma (PDAC). Effective approaches to achieve durable local control are urgently needed. Metabolic reprogramming and enhanced mitochondrial function, both hallmarks of PDAC, are known contributors to chemo- and radio-resistance. CPI-613, a lipoic acid analog that selectively inhibits components of the Krebs cycle in tumors, showed promising preclinical synergy in combination with gemcitabine and radiation therapy (gem-RT). Methods: We describe a single-arm, single-center, open-label, phase I study designed to determine the maximum tolerated dose of CPI-613 when used concomitantly with gemcitabine and intensity modulated radiation therapy (IMRT) for local control of PDAC. CPI-613 will be administered once weekly by intravenous infusion over approximately 2 hours at a starting dose of 500 mg/m2 and dose-escalated/de-escalated using a Bayesian optimal interval design. Gemcitabine will be given once weekly at 400 mg/m2 dosage and IMRT as 54 Gray (Gy) in 30 fractions (1.8 Gy per fraction) with five fractions given per week. Up to 24 patients will be enrolled for the study after meeting the following main eligibility criteria, which include: pathologically confirmed PDAC; inoperable disease that by institutional pancreatic multidisciplinary tumor board or multidisciplinary review are considered to benefit from definitive local control of the primary tumor; ECOG of 0-2; and adequate organ and marrow function after completion of intended systemic chemotherapy. The secondary objectives are to determine the recommended phase II dose of CPI-613 when used with gem-RT, safety and tolerability of CPI-613-gem-RT, overall survival, local progression-free survival (PFS), overall PFS, patient-reported quality of life after treatment, and late gastrointestinal toxicities following treatment with CPI-613-gem-RT. Clinical trial information: NCT05325281 . Support: Cornerstone Pharmaceuticals. [Table: see text]

Neoadjuvant radiation case volume and associated with margin-negative resection rates in patients with pancreatic cancer

e16281

Background: High surgical case volume (SCV) is associated with improved outcomes. Whether radiation case volume (RCV) is associated with outcomes is unknown, but of potentially increased importance given the recent results of the PREOPANC trial. We examined the impact of RCV on pathologic outcomes among patients (pts) with pancreatic cancer (PC) receiving neoadjuvant therapy (NAT). Methods: Pts with PC who received any NAT between 2009-2018 were identified from the National Cancer Database. Institutions were defined by SCV (low: < 9, medium:9-35, high:≥36 pts/year) and by RCV (nil:none, low:1-6, high:≥7 pts/year). Pathologic outcomes were node (N0/N1) and margin (R0/R1) status. Results: In total, 10,893 pts received NAT at 890 institutions; 3,522 (32%) received radiation at 562 (63%) institutions. Among all 10,893 pts, 2,896 (26%) were treated at low-SCV, 5,421 (50%) at medium-SCV, and 2,576 (24%) at high-SCV institutions. Among all 10,893 pts, 904 (8%) were treated at nil-RCV institutions, 7,736 (71%) at low-RCV, and 2,253 (21%) at high-RCV institutions. N0 resections were accomplished in 1,210 (54%) of 2,253 pts at high-RCV institutions, 3,732 (48%) of 7,736 at low-RCV, and 339 (38%) of 904 at nil-RCV institutions ( p values < 0.001). Similarly, R0 margins were achieved in 1,979 (88%) of 2,253 pts at high-RCV, 6,380 (82%) of 7,736 at low-RCV, and 671 (74%) of 904 at nil-RCV institutions ( p values < 0.001). Among 3,522 pts that received radiation, N0 resections were not different by RCV: 769 (62%) of 1,241 at high-RCV institutions and 1,461 (64%) of 2,281 at low-RCV institutions ( p= 0.22). Pts treated with radiation at high-RCV institutions had higher proportions of R0 margins: 1,120 (90%) of 1,241 at high-RCV and 1,931 (85%) of 2,281 at low-RCV institutions ( p< 0.001). High-RCV and low-RCV institutions were each associated with N0 resections (Table) and were not different from each other ( p= 0.33). High-RCV and low-RCV institutions were each associated with R0 margins, however high-RCV was more strongly associated than low-RCV ( p< 0.001). Conclusions: Pts at high-RCV facilities had greater odds of R0 margins independent of surgical case volume. As radiation techniques evolve, the value of high-RCV experience is likely to become increasingly important.[Table: see text]

MEK-inhibitor (inh) and hydroxychloroquine (HCQ) in KRAS-mutated advanced pancreatic ductal adenocarcinoma (PDAC)

e16260

Background: Therapeutic inhibition of constitutive signaling mediated by mutated KRAS in PDAC remains a challenge except for modest success reported with KRAS G12C inhibition. A combinatorial strategy utilizing simultaneous MEK and autophagy inhibition holds therapeutic promise based on mechanism of action and preclinical data. We described characteristics and outcomes of patients (pts) treated with MEK-inh and HCQ at our institution. Methods: Ten KRAS-mutated advanced PDAC pts were treated with trametinib-HCQ (n = 9) or cobimetinib-HCQ (n = 1) off label due to lack of standard treatment options or toxicity concerns with cytotoxic systemic therapy. Trametinib dose was 2 mg once daily orally, Cobimetinib dose was 20 mg BID orally for 3/4 weeks cycles. HCQ was started at 200 mg BID and up-titrated weekly to 600 mg BID. Description of baseline and treatment (tx) characteristics, safety and efficacy is provided. Results: Median age at diagnosis was 61.3 years, and 7 pts were female. The number of prior lines of tx were 0/1/2/3/4 in 3/2/1/2/2 pts, respectively. KRAS mutations were: G12R/G12D/G12V/Q61H in 6/2/1/1 pts. Median overall survival was 6.6 months (m) in all pts, and 6.6/1.7 m in KRAS G12R/other KRAS (p = 0.31). Median progression-free survival was 5.7/6.2/1.5 m in all/ KRAS G12R/other KRAS (p = 0.16). Among 8 pts with evaluable response, 1 (12%) had partial response ( KRAS G12R) and 4 (50%) stable disease (3/4 KRAS G12R) as best response with disease control rate of 63%/80%/33% in total/ KRAS G12R/other KRAS (p = 0.29). Toxicity data are summarized in table 1. Conclusions: MEK-inh-HCQ demonstrated modest efficacy and manageable toxicities among KRAS G12R PDAC pts. Unlike G12D and G12V mutations in the KRAS gene, G12R is defective of conductive interactions for both PI3Ka and NF1. This ultimately results in a weakened signal being shunted through MAPK cascade and provides a unique opportunity where MEK inh can ablate signaling without the alternate pathways and WT-RAS isoforms compensating. Furthermore, as activation of PI3Ka is known to suppress autophagy, its lack of activation by KRAS G12R further sensitizes cells to HCQ. The combination therapy MEK-inh-HCQ is therefore mechanistically-rationale and warrants the further investigation of KRAS G12R as an actionable biomarker.[Table: see text]

Systemic Therapy of Metastatic Pancreatic Adenocarcinoma: Current Status, Challenges, and Opportunities

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy characterized by nonspecific presenting symptoms, lack of a screening test, rapidly progressive clinical course, and presentation with an advanced-stage disease in the majority of patients. PDAC is essentially a systemic disease irrespective of the initial stage, as most patients with non-metastatic PDAC undergoing curative-intent treatment eventually experience metastatic relapse. Currently, cytotoxic chemotherapy remains the cornerstone of treatment in patients with advanced disease. However, the current standard treatment with multiagent chemotherapy has modest efficacy and results in median overall survival (OS) of less than a year and a 5-year OS of about 10%. The pathobiology of PDAC poses many challenges, including a unique tumor microenvironment interfering with drug delivery, intratumoral heterogeneity, and a strongly immunosuppressive microenvironment that supports cancer growth. Recent research is exploring a wide range of novel therapeutic targets, including genomic alterations, tumor microenvironment, and tumor metabolism. The rapid evolution of tumor genome sequencing technologies paves the way for personalized, targeted therapies. The present review summarizes the current chemotherapeutic treatment paradigm of advanced PDAC and discusses the evolving novel targets that are being investigated in a myriad of clinical trials.

Targeted therapy (TT) in patients with KRAS wildtype (WT) pancreatic ductal adenocarcinoma (PDAC) produces durable response

596

Background: Genomic alterations (GA) that drive cancer development and predict therapeutic response remain elusive in patients (pts) with KRAS WT PDAC. We interrogated our institutional database to identify actionable GAs in pts with metastatic, KRAS WT PDAC and analyzed the therapeutic impact of matched TT. Methods: We reviewed electronic medical records of KRAS WT PDAC pts (n=24) who underwent comprehensive genomic profiling (CGP) utilizing Foundation One CDx (25.0%) or Tempus (75.0%) between 2015-2021. Duration of response (DOR) was calculated from date of treatment (Tx) initiation to Tx discontinuation. Overall survival (OS) was measured from the date of the diagnosis (Dx) of advanced disease (AD) to death or last follow-up. OS was estimated using the Kaplan-Meier method, with at-risk periods left-truncated at the time of CGP. The effect of covariates on survival was evaluated using Cox proportional hazards regression. Results: Of the 24 KRAS WT pts, 14 (58%) had AD: 8 (57%) pts had metastatic disease at or shortly after Dx, 6 (43%) pts developed metachronous recurrence. Median age at Dx for pts with AD was 65, and 57% were female. Seven of 14 pts with AD (50%) had highly actionable GA (HAGA), (Table). Pts with HAGA demonstrated durable responses to TT (Table) with manageable toxicities. Pts with HAGA had a median OS of 28 mo compared to 5.9 mo for those without (Hazard Ratio = 0.47, p = 0.33). Conclusions: The sustained therapeutic benefit noted with TT matched to HAGA in pts with KRAS WT PDAC underscores the need for systematic interrogation of the somatic genome in PDAC pts. Optimal sequencing of cytotoxic therapy with TT and its impact on modulating clonal selection pressure in pts with KRAS WT PDAC merits prospective evaluation.[Table: see text]

Reconstructing the tumor microenvironment to unlock therapeutic options in pancreatic cancer

589

Background: Spatiotemporal heterogeneity, paucity of actionable targets, and complexity of the tumor microenvironment (TME) are major barriers to therapeutic advances in pancreatic ductal adenocarcinoma (PDAC). We reconstructed the transcriptomic data from a heterogeneous cohort of PDAC patients (pts) to examine the TME and identify putative therapeutic strategies. Methods: Transcriptomic profiling and targeted gene sequencing data (Tempus) on primary or metastatic specimens from PDAC pts treated at the Medical College of Wisconsin (MCW) between 2015-2020 were analyzed. Mutation calling, expression analysis, cell type deconvolution from the transcriptome, and TME reconstruction were performed using BostonGene’s automated pipelines. Mann-Whitney U test and Fisher's exact test were used to assess statistical significance. Results: The cohort (N = 79) comprised of resectable (19%), borderline resectable (37%), locally advanced (24%) and metastatic (20%) PDAC pts. The most frequently used tumor sites for transcriptomic profiling were pancreas primary (59%), liver (16%), lung (10%) and peritoneum (10%). Four distinct subtypes were identified based on the BostonGene classification of the transcriptomic TME– Immune Enriched (IE; 14%), Fibrotic (F; 28%), Immune Enriched & Fibrotic (IEF; 36%), and Immune Depleted (ID; 22%). Analyses of the cellular composition of the TME subtypes with RNA-seq-based deconvolution showed that T-cell fractions (CD4, CD8) were higher in the IE/IEF subtypes compared to the F/ID subtypes (CD8 means: 6.4% vs 2.9%, p < 0.001; CD4 means: 15.1% vs. 7.6%, p < 0.001), while fibroblast content was higher in the F/IEF subtypes compared to the IE/ID subtypes (37.4% vs 18.4%; p < 0.001). KRAS wild-type (WT) tumors were enriched in the IEF subtype (58%), while KRAS mutated tumors comprised all four transcriptomic subtypes. Primary PDACs that underwent radiotherapy were significantly more enriched in fibroblasts compared to samples from the TCGA cohort that did not undergo radiotherapy (means: 30%(MCW) vs. 20% (TCGA), p < 0.001). Primary PDACs were enriched in the IEF subtype (46%), while liver and lung metastases were enriched in the ID (74%) and IE subtypes (70%), respectively. When pts were dichotomized to short (< 400 days) versus long (> 800 days) survivors, tumors from pts with longer survival demonstrated a trend towards enrichment in CD4/CD8 T cells and IE subtype that did not meet statistical significance. Conclusions: Lung metastases and KRAS WT PDACs harbor an immunogenic TME while liver metastases harbor an immune-cold TME, highlighting the biologic heterogeneity of PDAC. The efficacy of immunotherapeutic strategies in PDAC pts who demonstrate an IE/IEF transcriptomic subtype merits prospective evaluation. The four distinct subtypes identified by TME transcriptomic classification highlight the possibility of personalized immunotherapeutic strategies in PDAC.

Clinical course and outcome of patients developing capecitabine-induced non-neutropenic enterocolitis (NNEC): An institutional analysis

656

Background: Non-neutropenic enterocolitis (NNEC), a potentially fatal toxicity of capecitabine (CAPE), is under-reported in the literature. An institutional review was performed to determine the incidence, clinical course, and outcome of patients developing CAPE-induced NNEC. Methods: After the institutional review board approval, a database search identified patients requiring inpatient care for CAPE-induced diarrhea over a period of 6 years (between 01/2015 and 12/2020). Among the patients requiring hospital admission, patients with radiologic features of enterocolitis were included in the analysis. Data on patient characteristics, imaging study results, clinical course, and outcomes were gathered by electronic chart review. Results: Among the 789 patients treated with CAPE, 25 patients (3%) developed grade 3 or higher diarrhea requiring hospital admission, and 13 out of these 25 patients (1.6 % of patients treated with CAPE) had evidence of enterocolitis on CT scan: ileitis in 7/13 (54%), colitis in 1/13 (8%), and both in 5/13 (38%) patients. The median age of the patient cohort was 64 years (range, 31-81), 8/13 (62%) were female, and all patients were Caucasian. CAPE was administered for the following indications: breast cancer in 6 patients, colorectal cancer in 4 patients, cholangiocarcinoma in 2 patients, and neuroendocrine tumor in 1 patient. ECOG performance status at the time of CAPE initiation was 0 in 7 patients and 1 in 6 patients. Most patients (7/13, 54%) received single-agent CAPE, and the majority (10/13, 77%) developed diarrhea with the first cycle after a median of 21 days (range, 10-50). Patients were hospitalized after a median of 27 days (range, 13-51), and the median hospital stay was 12 days (range, 4-25). None of the 13 patients demonstrated neutropenia at the time of hospital admission. The associated adverse effects at the time of admission included grade 3 abdominal pain in 8 (62%) patients, grade 3 nausea in 7 (54%) patients, and grade 3 vomiting in 3 (23%) patients. Hypokalemia and oral mucositis were present at admission in 6 (46%) and 2 (15%) patients, respectively. Stool studies performed in 11 (85%) patients ruled out infection. Testing for dihydropyrimidine dehydrogenase deficiency performed in 4 (31%) patients was negative. All patients were treated with supportive measures, and 2 (15%) patients required total parenteral nutrition. All but 1 patient recovered fully; 1 patient died due to a condition unrelated to CAPE. Intravenous infusional 5-fluorouracil (5-FU) administration in 3 patients after the recovery was tolerated well. Conclusions: CAPE-induced NNEC is uncommon and generally occurs after the first cycle of therapy. Most patients developing CAPE-induced NNEC recover fully with appropriate supportive measures. Infusional 5-FU-based regimens appear to be safe in this patient group.

Comprehensive genomic profiling (CGP) of fibrolamellar oncocytic hepatoma (FLO) and conventional hepatocellular carcinomas (HCC): An observational study

474

Background: FLO is a rare variant of liver cancer that disproportionately affects young adults and is frequently progressive and fatal as it is often detected in a clinically advanced stage. It is seldom associated with cirrhosis of liver, viral hepatitis or other risk factors associated with conventional HCC. Treatment options are largely limited to surgical resection, and there is dearth of effective targeted therapies for FLO. Methods: Comprehensive genomic profiling (CGP) was performed using the Foundation Medicine Inc. (FMI) data base on 63 FLO and 1,793 HCC clinically advanced cases between 6/2013-12/2020 using a hybrid capture-based assay of up to 324 genes a to detect genomic alterations (GA), tumor mutational burden (TMB) and microsatellite instability (MSI). PD-L1 expression in tumor cells (Dako 22C3) was measured by IHC and scored using the tumor proportion score (TPS) method. Results: The FLO patients (pts) were significantly younger than HCC pts (median age 20 vs. 64, respectively) and the male preponderance was similar. The HCC group featured significantly more GA/tumor than FLO group (3.74 vs 1.31 p<.0001). In the currently untargetable GA group, CTNNB1, TERT and TP53 GA were significantly more frequent in HCC than FLO. GA in potentially targetable genes were extremely uncommon in both FLO and HCC with HCC featuring slightly more MTOR pathway targets ( PTEN, TSC2, NF1). GA in DNA damage and repair (DDR) pathway including BRCA2 were infrequent in both groups. GA in targetable kinases including EGFR, ERBB2, ALK, RET and PIK3CA were extremely uncommon in both groups. GA associated with intrahepatic cholangiocarcinoma (IDH1, FGFR2) were extremely uncommon in these tumors. Although the mean TMB was significantly higher in HCC than FLO, overall TMB was low with very few cases having TMB > 10 mutations/Mb. PD-L1 expression was relatively low in both groups. GA in genes associated with immune checkpoint inhibitors (ICPI) drug response like PBRM1, CD274, MDM2, STK11 were rarely identified in both groups. Additional details are illustrated in the table. Conclusions: Comparison of CGP of FLO with HCC illustrates the multifarious nature of these cancers. In HCC, there is a high prevalence of GA in TERT, CTNNB1 and TP53. CGP identified certain targetable GA in the MTOR and DDR pathways and TMB was higher in HCC. These findings warrant further evaluation of clinically advanced FLO and HCC pts by CGP to identify possible targetable genomic pathways. [Table: see text]

Survival outcome and treatment response of patients with young-onset locally advanced rectal cancer (YO-LARC) receiving total neoadjuvant therapy (TNT)

44

Background: Despite an alarming rise in incidence, data on survival outcome and treatment response of young-onset (age < 50 years) locally advanced rectal cancer (YO-LARC) patients receiving total neoadjuvant therapy (TNT) are sparse. We retrospectively compared the outcome between YO-LARC and later-onset (aged 50 years or older) LARC (LO-LARC) patients treated with TNT. Methods: After the institutional review board approval, electronic medical records of the LARC (T3/T4 or node-positive) patients treated with TNT at a tertiary care cancer center between January 1, 2015, and June 30, 2020, were reviewed for data collection. TNT consisted of systemic chemotherapy with oxaliplatin-based regimens for 16 weeks followed by long-course radiation with concurrent capecitabine or 5-fluorouracil (CRT). Patients receiving only preoperative CRT were excluded. Most patients underwent surgical resection following the TNT. Non-operative management was offered to patients if TNT resulted in clinical complete response (cCR). The following comparisons between the YO-LARC and the LO-LARC patients were performed: patient characteristics, pathological complete response (pCR) rate, combined pCR + cCR rate, disease-free survival (DFS), and overall survival (OS). Results: Of 72 patients included in the analysis, 44(61%) were male, 49 (68%) were Caucasian, and 62 (86%) had clinical stage III disease. The study included 26 (36%) patients with YO-LARC (median age, 43 years) and 46 (64%) patients with LO-LARC (median age, 64 years). The comparison of patient characteristics that included gender, clinical stage, baseline carcinoembryonic antigen level, the distance of the tumor from the anal verge, presence of high-risk features, and histologic grade did not differ significantly between the groups. There were no statistically significant differences in pCR and combined pCR+cCR rates (p = 0.16) between the groups: YO-LARC, 12 % (3/26) and 15 % (4/26), respectively; LO-LARC, 22% (10/46) and 30% (14/46), respectively. Either group did not reach median DFS and OS after a median follow-up of 38 months for survivors. The estimated 5-year OS rates in patients with YO-LARC and LO-LARC were 86 % (95% confidence interval [CI], 69% to 100%) and 84% (95% CI, 68% to 100%), respectively (p = 0.92). The estimated 3-year DFS rates in patients with YO-LARC and LO-LARC were 67 % (95% CI, 50% to 89%) and 83% (95% CI, 72% to 95%), respectively (p = 0.19). Conclusions: The current retrospective analysis did not demonstrate significant differences in the pCR rates, combined pCR +cCR rates, DFS, or OS between the YO-LARC and LO-LARC patients treated with TNT.

Prognostic effect of RAS/BRAF mutations in patients (pts) with metastatic colorectal cancer (mCRC)

191

Background: Somatic alterations in KRAS and BRAF have prognostic as well as predictive impact in pts with mCRC; however, the differential impact of various somatic alterations in these genes need further characterization. We analyzed the prognostic impact of specific somatic mutations in K RAS and BRAF in mCRC pts. Methods: We retrospectively reviewed the electronic medical records of pts with mCRC at our institution who underwent comprehensive genomic profiling (CGP) utilizing the Foundation One assay. Prevalence of genetic alterations was estimated using proportions and compared between groups using a chi-squared test. Patients were followed for survival from metastatic diagnosis until death or last follow-up, with left truncation at the time of CGP. Kaplan-Meier estimates were used to estimate overall survival, and groups were compared using a Cox-regression based likelihood ratio test. Results: 192 pts were identified - median age at diagnosis was 55 years, 62% (119/192) presented with metachronous metastatic disease, and 28% (54/192) had a rectal primary. Somatic mutations in KRAS were found in 49% (95/192) pts, and 53% (50/95) had a left sided primary (p = 0.3). Majority of the KRAS mutations localized to codon 12 (72/95 -76%), KRAS G12C comprised 12% (11/95). Median Overall Survival (mOS) of KRAS mutated pts was 3.0 years compared to 3.5 years for KRAS wild type (WT) pts (p = 0.5). Median OS of pts with different KRAS mutations were as follows: codon 12 mutations (excluding G12C) - 2.7 years; KRAS G12C – 5.2 years; non-codon 12 KRAS mutations - 4.8 years. BRAF mutations were identified in 7.8% (15/192) pts, and 67% (10/15) had a right sided primary (p = 0.062). BRAF V600E represented the most common alteration in BRAF – 87% (13/15). Patients with BRAF mutation had a mOS of 1.8 years compared to 3.1 years for BRAF WT pts (p = 0.2). Median OS of pts with different BRAF mutations were as follows: BRAF V600E – 1.8 years and BRAF non V600E - 2.1 years (p = 0.4). Conclusions: The numerically higher mOS in pts with KRAS G12C and non-codon 12 KRAS mutations merit further biologic characterization with functional assays. Individualized therapeutic strategies must be conceptualized for mCRC pts with specific RAS/BRAF mutations, considering their widely disparate prognosis and putative downstream signaling mechanisms. Dynamic molecular simulation to understand conformational changes in proteins associated with specific mutations will be pivotal to optimizing precision therapeutic strategies.

Abstract PO-055: Phase II clinical trial of subtype directed neoadjuvant therapy in patients with localized pancreatic cancer

Background: Preoperative (neoadjuvant) therapy has become the preferred treatment sequencing strategy for patients with localized pancreatic cancer. During neoadjuvant therapy, approximately 30% of patients will experience metastatic disease progression while on treatment. Therefore, tools to aid clinicians to select efficacious first-line chemotherapeutic regimens is a critical unmet need. The most common neoadjuvant chemotherapy regimens used are 5-fluorouracil/irinotecan/oxaliplatin (mFOLFIRINOX) and gemcitabine/nab-paclitaxel (GnP). There is growing data to suggest an association of pancreatic cancer subtype (classical versus basal-like) with treatment response to therapy. Recently, the translation of tumor subtyping to the clinic has been successfully achieved using the Purity Independent Subtyping of Tumors (PurIST) single sample classifier. We aim to assess the clinical response to pancreatic cancer subtype-directed therapy in patients with localized pancreatic cancer. Methods: This is a phase II, multicenter, single-arm clinical trial for previously untreated patients with localized (resectable or borderline resectable) pancreatic cancer. Patients will undergo endoscopic ultrasound guided biopsy of the primary tumor and PurIST classifier to determine classical versus basal-like subtype. Patients with classical subtype will be assigned to mFOLFIRINOX and patients with basal-like tumors will be assigned to GnP. Following two months of therapy, patients will be restaged with a computed tomography scan, carbohydrate antigen (CA19-9) levels, performance status assessment, and a repeat endoscopic ultrasound guided biopsy for research. The primary endpoint is composite clinical response as measured by radiographic response, CA19-9 decline, and performance status following two months of treatment. Correlative endpoints include blood-based biomarkers for association with clinical response and stroma-specific response to therapy. The study has enrolled 4 of the anticipated 41 patients at the time of submission. Clinical Trial information: NCT 04683315.

Citation Format: Susan Tsai, Erkut Borazanci, Margaret Gulley, Naim Rashid, Jason Merker, Abdul H. Khan, Phillip Chisholm, Bryan Hunt, Tamara Giorgadze, William Hall, Mandana Kamgar, Douglas B. Evans, Jen Jen Yeh. Phase II clinical trial of subtype directed neoadjuvant therapy in patients with localized pancreatic cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-055.

Abstract PO-024: Targeting cellular metabolism with CPI-613 sensitizes pancreatic cancer cells to radiotherapy

Novel treatment strategies for pancreatic ductal adenocarcinoma (PDAC) are desperately needed. Local tumor progression is a cause of significant morbidity and mortality in patients with surgically unresectable disease. Often, regional anatomic structures limit the total doses of radiation therapy (RT) that can be safely delivered. Conventional doses of concurrent chemotherapy and RT (chemo-RT) have shown suboptimal results in local control of disease, progression free survival, and overall survival. Therefore, novel and effective approaches to enhance the efficacy of RT are urgently needed to improve overall survival in unresectable PDAC. Metabolic reprogramming enables cancer cells to adjust their metabolism to support increased energy requirements associated with continuous growth and proliferation. Indeed, metabolic reprogramming is a hallmark of PDAC and is associated with increased tumor cell plasticity and chemo-RT resistance. Cancer-cell mitochondria are key regulators of deranged tumor metabolism and have been shown to guide molecular pathways involved in radio-resistance. There is also expanding data that the presence of metabolites modulates the response of cancer cells to RT primarily by impacting the ability to repair DNA. This makes them an optimal candidate for novel radiosensitization strategies, as these characteristics are unique to PDAC cells, and are limited in normal cells. CPI-613, is an analog of lipoic acid which inhibits pyruvate dehydrogenase (PDH) and α-ketoglutarate dehydrogenase (α-KGDH), thereby disrupting mitochondrial metabolism leading to selective tumor cell killing. The drug has demonstrated significant clinical activity in patients with metastatic PDAC in combination with standard of care chemotherapies. It remains unknown as to the efficacy in patients treated with concurrent chemo-RT. Here we show that combined treatment of RT (2 and 10 Gy) with CPI-613 (used at 200 and 300 μM) causes superior inhibition of pancreatic cancer cell growth (MTT assay and colony formation assay). In addition, we demonstrate enhanced apoptosis (Annexin V FITC and 7AAD assay) of PDAC cells when treated with a combination of RT and CPI-613. Molecular analysis revealed superior inhibition of PDH and α-KGDH at the protein level. Targeted metabolomic analysis on PDAC cells post CPI-613-RT treatment revealed alterations in key mitochondrial metabolites, leading to these findings. These results indicate broader target engagement by this combination treatment, indicating the sensitization of CPI-613 treated PDAC cells to radiotherapy at doses as low as 2 Gy. Furthermore, in our preclinical cellular models, a combination treatment of CPI-613 with either Gemcitabine or 5-FU has shown synergistic effects on the proliferation of PDAC cells. Pre-clinical anti-tumor efficacy of the CPI-613-RT and CPI-613-RT-chemo using subcutaneous and orthotopic PDAC models is planned. Our results bring forward a novel combination of CPI-613-RT that warrants further pre-clinical and early phase clinical investigations.

Citation Format: William A. Hall, Husain Y. Khan, Mandana Kamgar, Susan Tsai, Kathleen Christians, Douglas B. Evans, Philip Philip, Callisia Clarke, Ben George, Beth Erickson, Asfar S. Azmi. Targeting cellular metabolism with CPI-613 sensitizes pancreatic cancer cells to radiotherapy [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-024.

Evolution of Systemic Therapy in Metastatic Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma is characterized by early systemic dissemination, a complex tumor microenvironment, as well as significant intratumoral and intertumoral heterogeneity. Treatment options and survival in pancreatic ductal adenocarcinoma have improved steadily over the last 3 decades. Although cytotoxic chemotherapy is currently the mainstay of treatment for pancreatic ductal adenocarcinoma, evolving therapeutic strategies are aimed at targeting the tumor microenvironment, metabolism, and the tumor-host immune balance.

Prevalence and predictors of peripheral neuropathy after breast cancer treatment

Background

Many of the 3.8 million breast cancer survivors in the United States experience long‐term side effects of cancer therapy including peripheral neuropathy (PN). We assessed the prevalence and predictors of PN among women with breast cancer followed in the Women's Health Initiative's Life and Longevity After Cancer survivorship cohort.

Methods

The study population included 2420 women with local (79%) or regional (21%) stage disease. Presence of PN was based on the reports of “nerve problems and/or tingling sensations” after treatment and PN severity was assessed using the Functional Assessment of Cancer Therapy‐Gynecologic Oncology Group/Neurotoxicity instrument. Logistic regression analysis was used to evaluate the socio‐demographic and clinical factors associated with PN prevalence and severity.

Results

Initial breast cancer treatment included surgery‐only (21%), surgery and radiation (53%), or surgery and chemotherapy (±radiation) (26%). Overall, 17% of women reported PN occurring within days (30%), months (46%), or years (24%) after treatment and 74% reported ongoing symptoms at a median of 6.5 years since diagnosis. PN was reported by a larger proportion of chemotherapy recipients (33%) compared to those who had surgery alone (12%) or surgery+radiation (11%) (p < 0.0001). PN was reported more commonly by women treated with paclitaxel (52%) and docetaxel (39%), versus other chemotherapy (17%) (p < 0.0001). In multivariable analyses, treatment type (chemotherapy vs. none; OR, 95% CI: 3.31, 2.4–4.6), chemotherapy type (taxane vs. no‐taxane; 4.74, 3.1–7.3), and taxane type (paclitaxel vs. docetaxel; 1.59, 1.0–2.5) were associated with higher odds of PN.

Conclusion

PN is an important long‐term consequence of taxane‐based chemotherapy in breast cancer survivors.

Prevalence and predictors of peripheral neuropathy after chemotherapy: Outcomes from the Detroit Research on Cancer Survivorship (ROCS) cohort

12069

Background: Increased life expectancy for cancer survivors following advances in treatment has led to a greater likelihood of developing long-term complications. Among them is chemotherapy-induced peripheral neuropathy (CIPN), which adversely impacts the functional capacity of survivors. We assessed prevalence and predictors of CIPN in a cohort of African-American (AA) cancer survivors. Methods: The study population included 633 breast, colorectal, prostate and lung cancer survivors who received chemotherapy and participated in the Detroit Research on Cancer Survivorship (ROCS) study. Presence of CIPN was based on self-reported pain, numbness or tingling in the hands or feet, occurring either for the first time or worsening after chemotherapy. If participants reported continued CIPN at the time of survey, their symptoms were reported as persistent. CIPN severity was self-reported as mild, moderate or severe. Logistic regression analysis was used to evaluate socio-demographic and clinical factors (including 12 common comorbid conditions) associated with CIPN prevalence, persistence and severity. Results: Overall, 67% of the cohort reported CIPN at a mean time of 25.3 months (range 2-74 months) after cancer diagnosis, and 51% reported persistent CIPN. The distribution of CIPN severity consisted of 32.2% with mild, 30.8% with moderate, and 36.9% with moderate to severe symptoms. Diagnosis of primary breast (OR 3.99, 95% CI 1.52-10.46) or colorectal cancers (OR 5.24, 95% CI 2.17-12.69) conferred greater CIPN prevalence relative to a diagnosis of prostate cancer. The presence of each additional comorbid condition among those outlined in the survey also conferred a 20% greater prevalence of CIPN (OR 1.2, 95% CI 1.03-1.39). Similar trends were seen among those who reported persistent CIPN. Using age > 65 at diagnosis as the reference group, age < 50 (OR 2.64, 95% CI 1.43-4.88) and age 51-64 (OR 1.96, 95% CI 1.14-3.35) resulted in an increased risk of moderate or severe compared to mild CIPN. Conclusions: In the Detroit ROCS cohort, CIPN was reported in two-thirds of cancer survivors receiving chemotherapy. Out of them, more than one-third reported moderate to severe symptoms, more commonly seen among those age < 65. Consideration of CIPN as a prominent long-term complication of cancer treatment should play a role in treatment decisions and development of new chemotherapy regimens.

Impact of KRAS alterations in pancreatic ductal adenocarcinoma (PDAC)

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Background: The genomic alterations which characterize PDAC holds great promise for novel therapeutic interventions. Constitutive signaling via mutated KRAS is considered the signature pathognomonic alteration in PDAC, less than 10% of patients (pts) have tumors which are KRAS wild type (WT). We retrospectively reviewed our institutional genomic database to characterize PDAC pts with KRAS WT tumors. Methods: We reviewed electronic medical records of PDAC pts who underwent comprehensive genomic profiling (CPG) utilizing Foundation One CDx (50.6%) or TEMPUS (49.4%) between 2015-2020. Demographic and disease characteristics were compared between cohorts using Wilcoxon rank-sum test or chi-square tests. Left truncation at the time of CGP was used to account for the time of entry into the study cohort. Kaplan-Meier method was used for survival curve estimation, and log-rank test was used for between-group comparison. Cox regression was used to adjust for confounders. Results: We identified 235 patients: median age at diagnosis was 65 years and 52% were male. Clinical stages at diagnosis were localized (resectable/borderline resectable), locally advanced, or metastatic in 105 (44.7%), 61 (26.0%), and 69 (29.4%) patients, respectively. KRAS status was mutated in 212 (90%) patients: the most common alterations being G12D (48%), G12V (28%) and G12R (14%). KRAS WT status was noted in 23 (9.8%) pts, actionable genomic alterations in this subgroup are summarized in the table. Baseline demographic and treatment characteristics were similar between patients with KRAS mutated and WT tumors. Of the 23 patients with KRAS WT tumors, 16 (69.6%) completed all planned curative intent therapy compared to 121 (57.3%) of the 212 KRAS mutated pts (p=0.26). Median Overall Survival of patients with KRAS mutated tumors was 18.6 months compared to 44.1 months for WT pts (p=0.03). Adjusting for stage, WT vs. mutated status was associated with a 62% decreased hazard of death (HR 0.38 [0.18-0.83]; p=0.016). Conclusions: Patients with KRAS WT PDAC appear to have a distinct biology compared to those with KRAS mutations, meriting exploration in larger data sets. Further, comprehensive whole genome or transcriptomic characterization of KRAS WT tumors is necessary to identify putative driver alterations as well as actionable therapeutic targets.[Table: see text]

Clinical outcomes in pancreatic ductal adenocarcinoma (PDAC) patients with underlying autoimmune disease (AID)

e16233

Background: Chronic inflammation from AID and the resultant immunosuppression from treatment increases the risk of various malignancies. Risk of PDAC is increased in patients (pts) with AID, however, there is paucity of cancer specific outcome data in these pts. We retrospectively reviewed the outcomes of pts with PDAC and AIDs to include Crohn’s disease (CD), ulcerative colitis (UC) and rheumatoid arthritis (RA). Methods: All pts aged 18 or older, diagnosed with PDAC in the setting of CD, UC and RA between January 2010 and December 2019 were included. Patients were identified using our institutional Clinical Research Data Warehouse (CRDW) and chart review. Clinical data was obtained by querying a cohort discovery tool (i2b2) from the CRDW with IRB approval. Pts with incomplete documentation were excluded. Descriptive statistics were used to report demographics. Overall survival (OS) was calculated from the time of diagnosis of PDAC to the date of death or last follow-up. Deaths from any cause were included in the survival analysis. OS and relapse free survival (RFS) were estimated using Kaplan-Meier methods. Results: We identified 51 pts who met inclusion criteria; 26 (51%) had RA, 15 (29.4%) had UC and 10 (19.6%) had CD. Median age at diagnosis of PDAC was 55.2 years, 49% were male (Table 1). Median duration from diagnosis of AID to PDAC for pts with CD, RA and UC was 173, 107 and 105 months, respectively. Metastatic disease at diagnosis was present in 19 (37.3%) of the 51 pts and 32 (62.7%) had localized disease (LD). Among the 17 pts with LD who underwent surgery, 6 (35.3%) experienced relapse with a median RFS of 14 months. The median OS of pts with LD who underwent surgery was 44 months compared to 8.25 months for those who did not. Among the 19 pts with metastatic disease at diagnosis, 0, 1, 2 & 3 lines of chemotherapy was received by 4 (21.1%), 8 (78.9%), 3 (36.8%) and 2 (21.1%) of pts, respectively. Median OS of patients with metastatic disease at diagnosis was 8.9 months. Conclusions: The inflammatory milieu and immunosuppression associated with AID treatment may be responsible for the early onset of PDAC in these pts. Although our sample size is small, pts with AID and PDAC who complete all planned curative intent therapy appear to have excellent outcomes, emphasizing the importance of early diagnosis and perhaps routine screening in pts with AID. Receipt of chemotherapy and OS of pts with metastatic PDAC in the setting of AID does not appear to be significantly compromised despite their exclusion from several clinical trials. Demographics.[Table: see text]

Impact of KRAS alterations in localized pancreatic cancer (PC)

431

Background: Patients (pts) with localized PC do not routinely undergo comprehensive genomic profiling (CGP) unless they develop recurrent or metastatic disease. KRAS is the most frequently mutated gene in PC, however, the impact of different KRAS mutations in localized PC has not been well characterized. We interrogated our genomic database to analyze the KRAS status in PC pts who presented with localized disease at diagnosis (Dx). Methods: We identified PC pts at our institution who underwent CGP utilizing the Foundation One CDx assay and had localized disease at initial Dx; these pts were categorized into resectable/borderline resectable PC (LPC) and locally advanced PC (LAPC). All pts with LPC and LAPC underwent neoadjuvant chemotherapy and chemoradiation prior to possible surgery (all intended therapy - AIT). Tissue from metastatic sites was used for CGP in pts who developed recurrent/metastatic disease before or after completion of AIT. The primary tumor was used for CGP in pts who completed AIT without subsequent relapse or in the absence of adequate metastatic tissue. Effect of each gene on response and survival outcomes was estimated using proportional odds and Cox regression analysis, respectively, adjusting for stage. Results: 75 pts were identified, median age at Dx was 65 years, 59% were male, 65% had a primary tumor in the pancreatic head. 38 (86%) pts with LPC completed AIT compared to 21 (68%) pts with LAPC (p<0.001). KRAS mutation was detected in 95% (71/75) of pts– 94% (67/71) in codon 12 and 6% (4/71) in codon 61. The various KRAS mutations and their association with completion of AIT is summarized in the table. The likelihood of completing AIT did not differ based on KRAS wildtype (WT) vs mutated status (p =1.00), the mutated codon (codon 12 vs. codon 61; p =1.00) or the individual KRAS point mutations (p = 0.7); however, all patients with G12A (N= 1), G12C (N=1), G12L (N=1) and G12R (N=11) mutations completed AIT. KRAS status (mutated vs. WT) and the individual KRAS mutations were not associated with overall survival (OS) after adjusting for stage (p= 0.13 and p = 0.26 respectively). Median OS for patients with LPC and LAPC, was 39 months (mos) and 29 mos respectively. Conclusions: KRAS status and individual KRAS mutations did not have an impact on completing AIT or mOS; however, these findings need to be interpreted with caution due to the inherent biases involved in such analyses. The clinical significance and functional relevance of KRAS G12A, G12C, G12L and G12R mutations, though relatively rare, needs further characterization as well as mechanistic elucidation. [Table: see text]

Association of total neoadjuvant therapy with favorable clinical outcomes in patients with locally advanced esophageal and gastroesophageal junction adenocarcinomas (LA-GEJ CA)

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Background: Both peri-operative chemotherapy and neoadjuvant chemoradiation have been shown to improve outcomes in patients (pts) with LA-GEJ CA compared to surgery alone. Rates of post-operative chemotherapy delivery remain suboptimal. Total neo-adjuvant therapy (TNT) in LA-GEJ CA - induction chemotherapy (IC) followed by concurrent chemoradiation (CRT) - may improve systematic delivery of neoadjuvant therapy and result in favorable clinical outcomes. Methods: We retrospectively reviewed medical records of 135 pts with LA-GEJ CA at our institution between 2/2007 and 11/2019; pertinent clinical data were abstracted with Institutional Review Board approval. Patients treated with IC and curative-intent CRT with ≥40 Gy dose of radiation for adenocarcinoma were included in this analysis (N = 59). Doublet or triplet IC regimens utilizing 5-Flurouracil(5-FU), Cisplatin/Oxaliplatin and Docetaxel were commonly administered while combinations of Carboplatin +Paclitaxel or 5-FU + Oxaliplatin were used in CRT. Clinical complete response (CCR) was defined as metabolic imaging and endoscopic biopsies negative for residual malignancy after completion of TNT. Patients were followed from diagnosis to recurrence and overall survival. Survival probabilities were estimated using the Kaplan-Meier method and compared between groups using a log-rank test. Results: Out of 59 evaluable pts, 69% were clinical stage T3, 71% were node positive. 37 pts (63%) underwent surgery, R0 resection rate was 89% (33/37), pathologic complete response (pCR) rate was 19% (7/37). Among the pts who did not undergo surgery, 41% (9/22) opted to forego surgery since they attained a CCR. For the entire cohort, median Disease-Free Survival (mDFS), median Overall Survival (mOS), and 3-yr OS were 2.4 yrs, 4.7 yrs, and 67% respectively. Pts who did not undergo surgery had a mDFS, mOS, and 3-yr OS of 1.5 yrs, 4.2 yrs, and 59% respectively. Median DFS, mOS, and 3-yr OS of patients who underwent surgery were 3.5 yrs, 5.8 yrs and 72% respectively. Patients who achieved a CCR and opted to forego surgery (N = 9) had a 3 -yr DFS of 42% vs 83% for pts (N = 7) who demonstrated a pCR after curative intent tri-modality therapy. (P = 0.0099) Interestingly, the same group that achieved CCR and opted out of surgery had 3yr OS of 89% vs 83% of those who demonstrated a pCR (p = 0.0042). Conclusions: TNT for pts with LA-GEJ CA is associated with high rates of R0 resection as well as excellent DFS and OS compared to historical controls, warranting prospective evaluation. The remarkable DFS and OS in patients who opted to forego surgery due to achieving CCR is reflective of the local and systemic control rendered by this approach. Careful characterization and close longitudinal follow-up of patients who achieve CCR may help identify a subgroup of LA-GEJ CA pts who may benefit from surgery sparing approaches.

Total Neoadjuvant Therapy for Operable Pancreatic Cancer

BACKGROUND

Overall survival (OS) for operable pancreatic cancer (PC) is optimized when 4-6 months of nonsurgical therapy is combined with pancreatectomy. Because surgery renders the delivery of postoperative therapy uncertain, total neoadjuvant therapy (TNT) is gaining popularity.

METHODS

We performed a retrospective cohort study of patients with operable PC and compared TNT with shorter course neoadjuvant therapy (SNT). Primary outcomes of interest included completion of neoadjuvant therapy (NT) and resection of the primary tumor, receipt of 5 months of nonsurgical therapy, and median OS.

RESULTS

We reviewed 541 consecutive patients from 2009 to 2019 including 226 (42%) with resectable PC and 315 (58%) with borderline resectable (BLR) PC. The median age was 66 years (IQR [59, 72]), and 260 (48%) patients were female. TNT was administered to 89 (16%) patients and SNT was administered to 452 (84%). Both groups were equally likely to complete intended NT and surgery (p = 0.90). Patients who received TNT and surgical resection were more likely to have a complete pathologic response (8% vs 4%, p < 0.01) and were more likely to receive at least 5 months of nonsurgical therapy (67% vs 45%, p < 0.01). The median OS was 26 months [IQR (15, 57)]; not reached among patients treated with TNT, and 25 months [IQR (15, 56)] among patients treated with SNT (p = 0.19).

CONCLUSIONS

TNT ensures the delivery of intended systemic therapy prior to a complicated operation without decreasing the chance of successful surgery; a window of operability was not lost. Patients who can tolerate SNT will likely benefit from TNT.

Cost-effectiveness analysis of universal germline testing for patients with pancreatic cancer

BACKGROUND

Historically, germline testing of patients with pancreatic cancer was performed selectively in patients with a strong family history of cancer. Current guidelines recommend universal testing because some patients may have actionable germline pathogenic variants without family history.

METHODS

We conducted a cost-effectiveness analysis using a decision-tree model to compare universal versus selective testing strategies for patients with pancreatic cancer. Costs, probabilities, and overall survival were estimated from the published literature and institutional data. One-way and probabilistic sensitivity analyses explored model uncertainty.

RESULTS

Universal germline genetic testing had an incremental cost of $310 with an increase of 0.003 life-years. The incremental cost-effectiveness ratio was $121,924/life-years. Parameters which were most impactful (sensitivity analysis) included the median overall survival of patients with advanced disease treated with personalized therapy, cost of personalized therapy for advanced disease, and the probability of receiving personalized therapy in advanced disease. A strategy of selective testing was more cost-effective in 59% of iterations when the willingness-to-pay threshold was set to $100,000/life-years.

CONCLUSION

Our model suggested that selective germline testing of patients with newly diagnosed pancreatic cancer is more cost-effective than universal testing. Additional research is needed to explore the impact of cascade testing of relatives on cost-effectiveness.

Targeted Therapies in Advanced Biliary Tract Cancer: An Evolving Paradigm

Biliary tract cancers (BTCs) are a heterogeneous group of adenocarcinomas that originate from the epithelial lining of the biliary tree. BTCs are characterized by presentation with advanced disease precluding curative surgery, rising global incidence, and a poor prognosis. Chemotherapy is the mainstay of the current treatment, which results in a median overall survival of less than one year, underscoring the need for novel therapeutic agents and strategies. Next-generation sequencing-based molecular profiling has shed light on the underpinnings of the complex pathophysiology of BTC and has uncovered numerous actionable targets, leading to the discovery of new therapies tailored to the molecular targets. Therapies targeting fibroblast growth factor receptor (FGFR) fusion, isocitrate dehydrogenase (IDH) mutations, the human epidermal growth factor receptor (HER) family, DNA damage repair (DDR) pathways, and BRAF mutations have produced early encouraging results in selected patients. Current clinical trials evaluating targeted therapies, as monotherapies and in combination with other agents, are paving the way for novel treatment options. Genomic profiling of cell-free circulating tumor DNA that can assist in the identification of an actionable target is another exciting area of development. In this review, we provide a contemporaneous appraisal of the evolving targeted therapies and the ongoing clinical trials that will likely transform the therapeutic paradigm of BTC.

Prognostic effect of specific RAS/BRAF mutations in patients (pts) with metastatic colorectal cancer (mCRC)

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Background: Somatic mutations in KRAS, HRAS, NRAS (extended RAS) and BRAF have prognostic and predictive impact in pts with mCRC. We analyzed the prognostic impact of specific somatic mutations in extended RAS and BRAF. Methods: We retrospectively reviewed the electronic medical records of pts with mCRC at our institution who underwent comprehensive genomic profiling (CGP) utilizing the Foundation One assay. DNA was extracted from clinical specimens and CGP was performed on hybrid-capture, adaptor ligation-based libraries for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. BRAF mutations were classified as class I, II and III according to accepted nomenclature. Fisher’s exact test and Kaplan Meier estimates were used for statistical analyses. This project was approved by the Medical College of Wisconsin Institutional Review Board. Results: 273 pts were identified - median age at diagnosis was 57, 48% were male. Somatic mutations in extended RAS were found in 138 (50%) pts, majority being mutations in KRAS (46%). Among pts with KRAS mutations, codon 12, 13, 61 and 146 mutations accounted for 73%, 11%, 4% and 6% respectively while KRAS G12C mutations accounted for 9%. BRAF mutations were detected in 22 (8%) pts - BRAF V600E and non–V600E mutations accounting for 4.4% and 3.6% respectively. Among pts with BRAF mutations, 17 (77%) were kinase domain mutations, 16 of which could be further classified as class I (12/16), II (1/16) and III (3/16). Median overall survival (mOS) for the entire cohort was 26.4 months (mo). KRAS mutated pts had a mOS of 25.8 mo; pts with KRAS G12C mutation had a mOS of 23 mo compared to 27.1 mo for pts with other KRAS mutations (p < 0.001).Pts with BRAF mutation had a mOS of 26.2 mo; pts with BRAF V600E mutation had a mOS of 14.1 mo compared to 30.6 mo for pts with BRAF non-V600E mutations (p = 0.1). Conclusions: The poor prognosis of pts with KRAS G12C and BRAF V600E mutations compared to pts with other KRAS and BRAF mutations merit further biologic characterization with functional assays. Individualized therapeutic strategies must be conceptualized for mCRC pts with specific RAS/BRAF mutations, considering their widely disparate prognosis and putative downstream signaling mechanisms. Dynamic molecular simulation to understand conformational changes in proteins associated with specific mutations will be pivotal to optimizing precision therapeutic strategies.

Impact of tumor histology and socioeconomic factors on survival of patients suffering from malignant vascular tumors of liver and hepatocellular carcinomas: A SEER database analysis

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Background: Primary malignant vascular tumors of the liver are rare, aggressive and poorly understood subtypes of liver cancers. In this analysis, we aim to determine the impact of tumor histology and other socio economic factors on survival of these tumors and hepatocellular carcinomas. Methods: Patients with malignant histopathological diagnoses of hepatocellular carcinoma not otherwise specified (HCC NOS), hepatocellular carcinoma with spindle cell (HCC SP), fibrolamellar (HCC F), clear cell (HCC CL), scirrhous (HCC SC) and pleomorphic variants ( HCC PL), combined hepatocellular carcinoma and cholangiocarcinoma (Mixed), hepatic angiosarcoma (AS), hemangioendothelioma (HE), its epithelioid variant (EHE) and hemangiopericytoma (HP) were identified using the SEER (version 2018) database. Overall survival was studied with Kaplan–Meier with the log rank method. Multivariable analysis was performed to assess the impact of race, ethnicity, marital and insurance status on survival of these patients. Results: We analyzed de-identified data of 104502 patients from the year 1973 to 2016 with hepatocellular carcinomas and malignant vascular tumors of liver (including 101851 patients with HCCNOS, 70 with HCC SP, 378 with HCC F, 104 with HCC SC, 593 with HCC CL, 23 with HCC PL, 950 with Mixed, 367 with AS, 36 with HE, 120 with EHE and 10 with HP ) respectively. Median overall survival (OS) of HCC NOS was calculated to be 7 months. Among hepatocellular carcinoma patients HCC F had the longest median OS of 29 months and HCC SP had the shortest median OS of 3months (P < 0.001). Additionally, among patients with malignant vascular tumors, AS had the shortest median OS (1 month) while patients with EHE had the longest median OS of 81 months (P < 0.001). Overall, married and insured patients had a better overall survival than unmarried and uninsured patients (P < 0.04). Conclusions: Malignant vascular tumors of liver are rare in comparison to hepatocellular carcinomas. Spindle cell variant of HCC and liver angiosarcomas carry the worst prognosis and fibrolamellar variant of HCC, hemangioendothelioma (HE) and its epithelioid variant (EHE) have the best prognosis. Insurance and marital status has a positive impact on overall survival of liver cancer patients.

Peripheral neuropathy after breast cancer: An analysis of data from the Women’s Health Initiative Life and Longevity After Cancer cohort

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Background: There are over 3.8 million breast cancer survivors in the United States, and many experience long-term side effects from chemotherapy. Factors associated with peripheral neuropathy (PN), one troubling side effect, following breast cancer among women are unknown. Methods: We included 2,420 women enrolled in the Women’s Health Initiative and diagnosed prospectively with local or regional stage breast cancer and followed in the Life and Longevity After Cancer (LILAC) study. PN was assessed by response to the baseline LILAC questionnaire regarding the presence of “nerve problems, tingling sensations” after treatment. Data were collected on initial course of therapy (surgery, radiation, and chemotherapy) through Medicare linkage or the LILAC staging and treatment form. Chi-square and Wilcoxon rank-sum tests were used for univariate comparison of socio-demographics, clinical and diagnosis characteristics associated with the presence or absence of PN. Results: The sample included 1,913 women (79%) with local and 507 women (21%) with regional stage disease. Initial course of therapy included either surgery alone (21%), surgery and radiation (53%), or surgery and chemotherapy (+/- radiation) (26%). Seventeen percent of women reported experiencing PN days (30%), months (46%) or years (24%) following treatment. Three-quarters (74%) reported ongoing symptoms at the time of the LILAC survey. PN was reported by 33% of chemotherapy recipients, compared to 12% in the surgery alone group, and 11% in the group that received surgery and radiation (p<0.0001). The prevalence of PN was higher among women receiving regimens containing paclitaxel (52%) and docetaxel (39%), compared to those receiving other chemotherapy (17%) (p<0.0001). Conclusions: PN is an important complication of taxane-based chemotherapy. Further analysis will explore the relationship between socio-demographic, clinical and treatment on the development, timing of, and severity of PN after cancer directed therapy.

Preclinical Assessment with Clinical Validation of Selinexor with Gemcitabine and Nab-Paclitaxel for the Treatment of Pancreatic Ductal Adenocarcinoma

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) remains a deadly disease urgently requiring new treatments. Overexpression of the protein transporter exportin-1 (XPO1) leads to mislocalization of tumor-suppressor proteins (TSP) and their inactivation. Earlier, we showed that blocking XPO1 by CRISPR/Cas9 validated Selective Inhibitor of Nuclear Export (SINE) compounds (selinexor and analogs) restores the antitumor activity of multiple TSPs leading to suppression of PDAC in vitro and in orthotopic models.

EXPERIMENTAL DESIGN

We evaluate the synergy between SINE compounds and standard-of-care treatments in preclinical models and in a PDAC Phase Ib trial.

RESULTS

SINE compounds synergize with gemcitabine (GEM) and nanoparticle albumin-bound (nab)-paclitaxel leading to suppression of PDAC cellular growth and cancer stem cell (CSC) spheroids disintegration. Label-free quantitative proteome profiling with nuclear and cytoplasmic enrichment showed superior enhancement in nuclear protein fraction in combination treatment. Selinexor inhibited the growth of PDAC CSC and two patient-derived (PDX) subcutaneous xenografts. Selinexor-GEM-nab-paclitaxel blocked PDX and orthotopic tumor growth. In a phase 1b study (NCT02178436), 9 patients were exposed to selinexor (60 mg oral) with GEM (1,000 mg/m2 i.v.) and nab-paclitaxel (125 mg/m2 i.v.) on days 1, 8, and 15 of 28-day cycle. Two patients showed partial response, and 2 had stable disease. An outstanding, durable objective response was observed in one of the responders with progression-free survival of 16 months and overall survival of 22 months.

CONCLUSIONS

Our preclinical and ongoing clinical study lends support to the use of selinexor-GEM-nab-paclitaxel as an effective therapy for metastatic PDAC.

Impact of CDKN2A/b status in pancreatic cancer (PC)

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Background: PC is a lethal disease with limited treatment options. We utilized Comprehensive Genomic Profiling (CGP) to identify putative prognostic and/or predictive biomarkers. Methods: We retrospectively reviewed PC patients (pts) at our institution who underwent CGP utilizing the Foundation One assay. CGP was performed on hybrid-capture, adaptor ligation-based libraries for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. PC pts were categorized by clinical stage – localized (resectable and borderline resectable PC; LPC), locally advanced (LAPC) and metastatic (mPC). Effect of gene alterations (GAs) with at least 10% prevalence were analyzed. The marginal effect of each gene on radiographic response and survival outcomes was estimated using proportional odds and multivariate Cox regression analysis, respectively, adjusting for stage. Results: Ninety-three pts were identified - median age was 63, 55% were male, and 50% were smokers. Clinical stage at diagnosis was LPC, LAPC and mPC in 42 (45%), 23 (25%) and 28 (30%) pts, respectively. The most commonly altered genes were KRAS (94%), TP53 (75%), CDKN2A (41.2%) and SMAD4 (32.9%). All patients were microsatellite stable and the median tumor mutational burden was 1.7. 5-FU (52%) or Gemcitabine (46%) based chemotherapy combinations were utilized as the first systemic therapy. Median overall survival for patients with LPC, LAPC and mPC were 30.7, 28.8 and 9.6 months respectively. Thirty-eight (91%) pts with LPC underwent curative intent surgery compared to 15 (65%) pts with LAPC (p = 0.019). Thirty-five (95%) pts with wild type (WT) CDKN2A and 47 (94%) pts with WT CDKN2B underwent curative intent surgery compared to 13 (65%) and 1(14%) pt(s) with GAs in CDKN2A and CDKN2B respectively (p = 0.003 and p < 0.0001 respectively). The response to chemotherapy was statistically significantly higher in pts with WT CDKN2A (53%) and CDKN2B (48%) compared to pts with GAs in CDKN2A (19%) and CDKN2B (12%) (p = 0.03 and p = 0.05, respectively). Conclusions: GAs in CDKN2A/B may have a predictive and possibly a prognostic impact. The clinical validity and biological relevance of these findings need to be further explored in larger studies.

Utilization of somatic comprehensive genomic profiling (CGP) to identify patients (pts) with pancreatic cancer (PC) that harbor germline DNA damage repair (DDR) gene alterations

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Background: Somatic and germline DDR gene alterations in PC have been postulated to positively predict response to DNA damaging cytotoxic agents. Due to the relatively high prevalence of germline DDR gene alterations, germline testing is recommended in all pts with PC. We examined whether somatic CGP can be used to reliably identify PC pts that merit germline testing. Methods: We retrospectively reviewed the electronic medical records of PC pts who underwent both somatic CGP (utilizing the Foundation One assay) and germline testing. DDR gene mutations were categorized as somatic-pathogenic, somatic-variant of uncertain significance (VUS), germline-pathogenic and germline-VUS. For somatic testing, DNA was extracted from formalin fixed paraffin embedded (FFPE) clinical specimens and CGP was done on hybrid-capture, adaptor ligation based libraries to a mean coverage depth of > 600 for up to 315 genes plus 47 introns from 19 genes frequently rearranged in cancer. Germline genetic testing was performed on submitted blood or saliva samples, utilizing commercial assays; next generation or Sanger sequencing of all coding regions and adjacent intronic nucleotides were performed. Results: Ninety-three pts had somatic CGP data, 51 (55%) pts had both somatic CGP and germline data available. Among the 51 pts with both germline and somatic data available, DDR gene alterations that were somatic-pathogenic, germline-pathogenic, somatic-VUS and germline-VUS were present in 7 (13.7%), 7 (13.7%), 23 (45.1%) and 16 (31.4%) pts, respectively. Of the 7 pts with somatic-pathogenic alterations, 5 (71%) had a concordant germline alteration and of the 7 pts with germline-pathogenic alterations, 5 (71%) had a concordant somatic alteration. Of the 23 pts with somatic-VUSs, 12 (52%) had a concordant germline VUS and of the 16 pts with germline-VUSs, 12 (75%) had a concordant somatic VUS. Conclusions: Both somatic and germline DDR gene alterations are common in PC pts. Despite the relatively high concordance rate between somatic and germline pathogenic DDR gene alterations, somatic CGP will miss approximately one fourth of the germline DDR gene alterations.

Abstract 3476: Evaluable antitumor activity in metastatic pancreatic adenocarcinoma with specific inhibitor of nuclear export based treatment

Background: Pancreatic ductal adenocarcinoma (PDAC) remains a deadly disease in urgent need of newer therapeutic modalities. Earlier we have shown that in PDAC, the over-expression of the nuclear exporter protein Exportin-1 (XPO1) leads to functional inactivation of tumor suppressor proteins (TSPs; FOXO3a, p27, Par-4 etc.) through mis-localization. We demonstrated that inhibition of XPO1 by CRISPR/Cas9 validated Selective Inhibitor of Nuclear Export (SINE) Selinexor and analogs restores the anti-tumor function of multiple TSPs leading to PDAC cell death and tumor inhibition in orthotopic models.

Methods: Here we evaluate the synergy between SINE compounds and standard of care gemcitabine-nab-paclitaxel in PDAC models in vitro, in vivo and in a Phase Ib/2 trial (NCT02178436).

Results: Selinexor and second generation SINE compound eltanexor synergized with gemcitabine (GEM) and nab-paclitaxel leading to suppression of PDAC growth, induction of apoptosis, and superior spheroid disintegration of PDAC derived cancer stem cells (CSCs). The observed synergy was due in part to enhanced nuclear localization of TSPs and suppression of both CSCs and epithelial-to-mesenchymal transition (EMT) markers. Label-Free quantitative (LFQ) proteome profiling with nuclear and cytoplasmic enrichment showed superior enhancement in nuclear protein fraction in combination treatment. The protein class with highest percent of nuclear retention were DNA binders. Selinexor and eltanexor as single agent (used at MTD) inhibited the growth of PDAC-CSC and two patient derived (Pdx) sub-cutaneous xenografts (p&lt;0.01). In combination experiment, selinexor-GEM-nab-paclitaxel used at sub-MTD dose could significantly suppress the growth of PDx tumors. Molecularly, we observed down-regulation of CRM1 and target TSPs ex vivo. In a Phase 1b/2 study examining patients with metastatic pancreatic cancer, 9 patients were exposed to selinexor (60 mg oral) with GEM (1000 mg/m2 IV) and nab-paclitaxel (125 mg/m2 IV) once weekly (Mondays) for 3 weeks. Evaluable responses were observed in patients on this trial. 2 patients showed partial response (PR) and 2 had stable disease. Outstanding objective response was observed in 1 patient who demonstrated remission for 16 months and remained alive for 22 months. Remarkable and sustained reduction in CA19-9 levels were observed in the responding patient.

Conclusions: These results rationally fortify selinexor-gemcitabine-nab-paclitaxel as new and effective therapy for metastatic PDAC and strengthen our ongoing Phase II study.

Citation Format: Asfar S. Azmi, Yosef Landesman, Michael Kauffman, Sharon Shacham, Gabriel Mpilla, Amro Aboukameel, Steve Kim, Mandana Kamgar, Anteneh Tesfaye, Ramzi M. Mohammad, Philip A. Philip. Evaluable antitumor activity in metastatic pancreatic adenocarcinoma with specific inhibitor of nuclear export based treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3476.

Comprehensive genomic profiling in metastatic pancreatic adenocarcinoma, correlation with early death versus prolonged survival

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Background: PDAC has a very poor prognosis and around 50% of the patients die within two months of their diagnosis and around 10% live beyond one year. In this study we sought to find biomarkers differentiating patients with early death from those with more prolonged survival. Methods: Tumors from our patients with PDAC were examined using NexGen sequencing (evaluating somatic mutations in 592 genes), immunohistochemistry, and in-situ hybridization (Caris Life Sciences). Tumor mutational burden, microsatellite instability, copy number variation, and gene fusion assessment were done in a subset of samples. Extremes in clinical outcome were defined as death in < 4 months and > 12 months from metastasis diagnosis. Fischer’s exact tests were used to associate the categorical clinical data and genomic factors with the extremes of clinical outcome. A t-test was used to associate the continuous clinical factors with the extreme outcomes. Hierarchical clustering using the Ward amalgamation and binary distance metric was used to define cluster based upon the genomic factors. Results: From October 2014 to August 2018, we evaluated 115 patients. 15 patients with PDAC died < 4 months and 39 died > 12 month from the time of metastasis diagnosis. Compared to the patients with prolonged survival, patients with an early death were significantly older (Average 67.5 vs. 60.5 years old, P = 0.03) and had significantly higher neutrophil counts (average 9.6 vs. 5.1, P = 0.001) and monocyte counts (average 1 vs. 0.6, P = 0.01). No genomic alteration differentiated the groups with extreme outcomes. None of the clusters defined upon the genomic factors differentiated the two outcome groups. Using classification model to predict early death vs prolonged survival, no factor evaluated by the genomic profiling was discriminatory between the groups. Conclusions: We did not find a pattern of genomic alteration difference in PDAC patients between the short-term versus the long-term survivals using Next Generation Sequencing. The short-term survivals were older and had higher neutrophil and monocyte counts at the time of metastatic disease diagnosis.

Case Report: First Reported Combined Heart-Liver Transplant in a Patient With a Congenital Solitary Kidney

We report a case of successful combined heart liver transplant in a patient with a congenital solitary kidney. The patient had normal renal function before combined heart-liver transplantation and developed acute kidney injury requiring slow continuous dialysis and subsequent intermittent dialysis for almost 8 weeks post transplantation. Her renal function recovered and she remains off dialysis now 7 months post transplantation. She only currently has mild chronic renal insufficiency. We believe this is the first reported case of successful heart liver transplant in a patient with a congenital solitary kidney.

The evolution into personalized therapies in pancreatic ductal adenocarcinoma: challenges and opportunities

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is projected to be the second leading cause of cancer related mortality in the United States in 2030, with a 5-year overall survival of less than 10% despite decades of extensive research. Pancreatic cancer is marked by the accumulation of complex molecular changes, complex tumor-stroma interaction, and an immunosuppressive tumor microenvironment. PDAC has proven to be resistant to many cytotoxic, targeted and immunologic treatment approaches. Areas covered: In this paper, we review the major areas of research in PDAC, with highlights on the challenges and areas of opportunity for personalized treatment approaches. Expert commentary: The focus of research in pancreatic cancer has moved away from developing conventional cytotoxic combinations. The marked advances in understanding the molecular biology of this disease especially in the areas of the microenvironment, metabolism, and DNA repair have opened new opportunities for developing novel treatment strategies. Improved understanding of molecular abnormalities allows the development of personalized treatment approaches.

Comparative analysis of the effect of bevacizumab maintenance regimens after first-line chemotherapy in patients with metastatic colorectal cancer (MCRC): A single institution experience

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Background: The majority of patients with metastatic colorectal cancer (MCRC) will ultimately experience disease progression following initial therapy. Although phase III clinical trials show that continued maintenance therapy improves progression free and overall survival in MCRC, the optimal maintenance regimen with an acceptable safety profile is still undetermined. This study aimed to assess outcomes of bevacizumab-containing maintenance therapy after first line chemotherapy for MCRC. Methods: One hundred thirteen patients (46 males, 67 females) with MCRC diagnosed between 2005 and 2014 who received chemotherapy at Karmanos Cancer Institute were included in this retrospective analysis. Induction treatment for most patients consisted of either 5-FU or capecitabine-based chemotherapy with either oxaliplatin or irinotecan and with or without bevacizumab. Eighty percent of patients who received bevacizumab with induction also received it as part of maintenance therapy. Results: After stratifying for age (dichotomized at 65 years) and induction therapy bevacizumab, there was no difference in PFS for induction regimens with or without bevacizumab (p = 0.67). For patients who received capecitabine as maintenance chemotherapy, the addition of bevacizumab resulted in non-significant larger hazard of a PFS event (HR = 1.46, p = 0.36). Among those who received 5-FU maintenance, the addition of bevacizumab resulted in non-significant smaller hazard of a PFS event (HR = 0.48, p = 0.11). There was no difference in observed toxicities between patients who received bevacizumab and those who did not (p = 0.38), with further sub-set analysis showing no increased toxicities among those who received 5-FU (p = 0.76) and those who received capecitabine (p = 0.16). Conclusions: In patients with metastatic colorectal cancer, there was no difference in efficacy or safety when adding bevacizumab to either 5-FU or capecitabine for maintenance after first line chemotherapy. Based on our results, tolerability and compliance with oral capecitabine ought to be a key factor in determining the choice of maintenance in patients with MCRC.