Clinician overconfidence in visual estimation of the posthepatectomy liver remnant volume: A proximal source of liver failure after major hepatic resection?

BACKGROUND

Post-hepatectomy liver failure is a source of morbidity and mortality after major hepatectomy and is related to the volume of the future liver remnant. The accuracy of a clinician's ability to visually estimate the future liver remnant without formal computed tomography liver volumetry is unknown.

METHODS

Twenty physicians in diagnostic radiology, interventional radiology, and hepatopancreatobiliary surgery reviewed 20 computed tomography scans of patients without underlying liver pathology who were not scheduled for liver resection. We evaluated clinician accuracy to estimate the future liver remnant for 3 hypothetical major hepatic resections: left hepatectomy, right hepatectomy, and right trisectionectomy. The percent-difference between the mean and actual computed tomography liver volumetry (mean percent difference) was tested along with specialty differences using mixed-effects regression analysis.

RESULTS

The actual future liver remnant (computed tomography liver volumetry) remaining after a hypothetical left hepatectomy ranged from 59% to 75% (physician estimated range: 50%-85%), 23% to 40% right hepatectomy (15%-50%), and 13% to 29% right trisectionectomy (8%-39%). For right hepatectomy, the mean future liver remnant was overestimated by 95% of clinicians with a mean percent difference of 22% (6%-45%; P < .001). For right trisectionectomy, 90% overestimated the future liver remnant by a mean percent difference of 25% (6%-50%; P < .001). Hepatopancreatobiliary surgeons overestimated the future liver remnant for proposed right hepatectomy and right trisectionectomy by a mean percent difference of 25% and 34%, respectively. Based on years of experience, providers with <10 years of experience had a greater mean percent difference than providers with 10+ years of experience for hypothetical major hepatic resections, but was only significantly higher for left hepatectomy (9% vs 6%, P = .002).

CONCLUSION

A clinician's ability to visually estimate the future liver remnant volume is inaccurate when compared to computed tomography liver volumetry. Clinicians tend to overestimate the future liver remnant volume, especially in patients with a small future liver remnant where the risk of posthepatectomy liver failure is greatest.

Safety and effectiveness of portal vein embolization after hepatic arterial infusion therapy

Portal vein embolization (PVE) is a potential tool useful for inducing future liver remnant (FLR) hypertrophy in patients with advanced hepatic malignancies who are at high risk of hepatic insufficiency if treated by surgical resection. However, the safety and effectiveness of PVE in the context of patients who have undergone hepatic arterial infusion (HAI) is unknown. This retrospective, single-center study identified nine patients who underwent PVE after HAI between January 2015 and December 2022. There were no major adverse events, including biliary, or high-grade liver failure. Analysis showed an increase in standardized FLR from 21.1 ± 2.4% to 34.8 ± 2.1% over 9.8 ± 1.2 weeks, with a mean kinetic growth rate of 2.2 ± 0.6%. The study suggested compatibility of PVE after HAI. Patients who have undergone HAI therapy should not be excluded from consideration of PVE as part of their operative clearance strategy.

Outcomes of Late-Line Systemic Treatment in GIST: Does Sequence Matter?

Ripretinib and avapritinib have demonstrated activity in the late-line treatment of gastrointestinal stomal tumors (GISTs). We investigated whether patients previously treated with ripretinib benefit from avapritinib, and vice versa. Patients diagnosed with metastatic/unresectable GIST and treated with both drugs at two institutions in 2000-2021 were included. Patients were grouped by drug sequence: ripretinib-avapritinib (RA) or avapritinib-ripretinib (AR). Radiographic response was evaluated using RECIST 1.1. Kaplan-Meier and log-rank tests were used to compare time-to-progression (TTP) and overall survival (OS). Thirty-four patients (17 per group) were identified, with a median age of 48 years. The most common primary site was the small bowel (17/34, 50%), followed by the stomach (10/34, 29.4%). Baseline characteristics and tumor mutations were not significantly different between groups. Response rates (RRs) for ripretinib were 18% for RA and 12% for AR; RRs for avapritinib were 12% for AR and 18% for RA. Median TTPs for ripretinib were 3.65 months (95%CI 2-5.95) for RA and 4.73 months (1.87-15.84) for AR. Median TTPs for avapritinib were 5.39 months (2.86-18.99) for AR and 4.11 months (1.91-11.4) for RA. Median OS rates following RA or AR initiation were 29.63 (95%CI 13.8-50.53) and 33.7 (20.03-50.57) months, respectively. Both ripretinib and avapritinib were efficacious in the late-line treatment of GIST, with no evidence that efficacy depended on sequencing.

Imaging of the hepatic arterial infusion pump: Primer for radiologists

Hepatic arterial infusion (HAI) pumps are used to deliver liver-directed therapy by allowing the administration of selective chemotherapy to the liver via a catheter implanted most commonly into the gastroduodenal artery connected to a subcutaneous pump. This selective administration helps maximize the chemotherapeutic effect within the hepatic tumors while minimizing systemic toxicity. While HAI therapy has primarily been used to treat liver-only metastatic colorectal cancer, the indications have expanded to other malignancies, including intrahepatic cholangiocarcinoma. Radiologists play an important role in pre-operative planning, assessment of treatment response, and evaluation for potential complications using various imaging studies, including computed tomography angiography, magnetic resonance imaging, and perfusion scintigraphy. This article describes the radiologist's role as part of a multi-disciplinary oncology team to help maximize the success of HAI therapy and also helps radiologists familiarize themselves with various aspects of HAI pumps.

Current Practices in Hepatic Artery Infusion (HAI) Chemotherapy: An International Survey of the HAI Consortium Research Network

BACKGROUND

An increasing number of hepatic artery infusion (HAI) programs have been established worldwide. Practice patterns for this complex therapy across these programs have not been reported. This survey aimed to identify current practice patterns in HAI therapy with the long-term goal of defining best practices and performing prospective studies.

METHODS

Using SurveyMonkeyTM, a 28-question survey assessing current practices in HAI was developed by 12 HAI Consortium Research Network (HCRN) surgical oncologists. Content analysis was used to code textual responses, and the frequency of categories was calculated. Scores for rank-order questions were generated by calculating average ranking for each answer choice.

RESULTS

Thirty-six (72%) HCRN members responded to the survey. The most common intended initial indications for HAI at new programs were unresectable colorectal liver metastases (uCRLM; 100%) and unresectable intrahepatic cholangiocarcinoma (uIHC; 56%). Practice patterns evolved such that uCRLM (94%) and adjuvant therapy for CRLM (adjCRLM; 72%) have become the most common current indications for HAI at established centers. Referral patterns for pump placement differed between uCRLM and uIHC, with most patients referred while receiving second- and first-line therapy, respectively, with physicians preferring to evaluate patients for HAI while receiving first-line therapy for CRLM. Concern for extrahepatic disease was ranked as the most important factor when considering a patient for HAI.

CONCLUSIONS

Indication and patient selection factors for HAI therapy are relatively uniform across most HCRN centers. The increasing use of adjuvant HAI therapy and overall consistency of practice patterns among HCRN centers provides a robust environment for prospective data collection and randomized clinical trials.

Updated Management of Colorectal Cancer Liver Metastases: Scientific Advances Driving Modern Therapeutic Innovations

Colorectal cancer is the second leading cause of cancer-related deaths in the United States and accounts for an estimated 1 million deaths annually worldwide. The liver is the most common site of metastatic spread from colorectal cancer, significantly driving both morbidity and mortality. Although remarkable advances have been made in recent years in the management for patients with colorectal cancer liver metastases, significant challenges remain in early detection, prevention of progression and recurrence, and in the development of more effective therapeutics. In 2017, our group held a multidisciplinary state-of-the-science symposium to discuss the rapidly evolving clinical and scientific advances in the field of colorectal liver metastases, including novel early detection and prognostic liquid biomarkers, identification of high-risk cohorts, advances in tumor-immune therapy, and different regional and systemic therapeutic strategies. Since that time, there have been scientific discoveries translating into therapeutic innovations addressing the current management challenges. These innovations are currently reshaping the treatment paradigms and spurring further scientific discovery. Herein, we present an updated discussion of both the scientific and clinical advances and future directions in the management of colorectal liver metastases, including adoptive T-cell therapies, novel blood-based biomarkers, and the role of the tumor microbiome. In addition, we provide a comprehensive overview detailing the role of modern multidisciplinary clinical approaches used in the management of patients with colorectal liver metastases, including considerations toward specific molecular tumor profiles identified on next generation sequencing, as well as quality of life implications for these innovative treatments.

The genomics of liver metastases from colon and rectal cancer: An Invited Commentary (invitation from Lee Ocuin, MD and Kevin Behrns, MD) for the special issue of "Management of Advanced Primary and Secondary Liver Malignancies"

Over the past two decades, the treatment of patients with cancer has become increasingly structured around the identification of cancer mutations genetically driving the disease. Upfront knowledge of these data has implications for both the selection and omission of certain cytotoxic and targeted therapies. For patients with colon or rectal cancer metastatic to the liver, next-generation sequencing to identify these key mutational drivers should be done at the outset of diagnosis to understand the full spectrum of treatment options available to a patient. Mutational profiling for patients with colorectal liver metastasis initially led to the recognition of treatment resistance to epidermal growth factor inhibitors in patients with a KRAS mutation and now has expanded to include other targeted options. As the treatment options for patients with colorectal liver metastasis continue to evolve, it is increasingly important to integrate genomic data into selecting patients who will benefit from hepatic resection, ablative techniques, and liver-directed therapy. Herein, we review the most common mutations encountered in treating patients with colorectal liver metastasis, focusing specifically on epidermal growth factor receptor, KRAS/NRAS, BRAF, and the mismatch repair pathway with resultant implications to the medical and surgical treatment for these patients.

Phase 2 study of preoperative chemotherapy with nab-paclitaxel and gemcitabine followed by chemoradiation for borderline resectable or node-positive pancreatic ductal adenocarcinoma

BACKGROUND

Neoadjuvant treatment with nab-paclitaxel and gemcitabine for potentially operable pancreatic adenocarcinoma has not been well studied in a prospective interventional trial and could down-stage tumors to achieve negative surgical margins.

METHODS

A single-arm, open-label phase 2 trial (NCT02427841) enrolled patients with pancreatic adenocarcinoma deemed to be borderline resectable or clinically node-positive from March 17, 2016 to October 5, 2019. Patients received preoperative gemcitabine 1000 mg/m² and nab-paclitaxel 125 mg/m² on Days 1, 8, 15, every 28 days for two cycles followed by chemoradiation with 50.4 Gy intensity-modulated radiation over 28 fractions with concurrent fluoropyrimidine chemotherapy. After definitive resection, patients received four additional cycles of gemcitabine and nab-paclitaxel. The primary endpoint was R0 resection rate. Other endpoints included treatment completion rate, resection rate, radiographic response rate, survival, and adverse events.

RESULTS

Nineteen patients were enrolled, with the majority having head of pancreas primary tumors, both arterial and venous vasculature involvement, and clinically positive nodes on imaging. Among them, 11 (58%) underwent definitive resection and eight of 19 (42%) achieved R0 resection. Disease progression and functional decline were primary reasons for deferring surgical resection after neoadjuvant treatment. Pathologic near-complete response was observed in two of 11 (18%) resection specimens. Among the 19 patients, the 12-month progression-free survival was 58%, and 12-month overall survival was 79%. Common adverse events were alopecia, nausea, vomiting, fatigue, myalgia, peripheral neuropathy, rash, and neutropenia.

CONCLUSION

Gemcitabine and nab-paclitaxel followed by long-course chemoradiation represents a feasible neoadjuvant treatment strategy for borderline resectable or node-positive pancreatic cancer.

Socioeconomic and Geographic Disparities in the Referral and Treatment of Pancreatic Cancer at High-Volume Centers

Importance

Treatment at high-volume centers (HVCs) has been associated with improved overall survival (OS) in patients with pancreatic ductal adenocarcinoma (PDAC); however, it is unclear how patterns of referral affect these findings.

Objective

To understand the relative contributions of treatment site and selection bias in driving differences in outcomes in patients with PDAC and to characterize socioeconomic factors associated with referral to HVCs.

Design, Setting, Participants

A population-based retrospective review of the Oregon State Cancer Registry was performed from 1997 to 2019 with a median 4.3 months of follow-up. Study participants were all patients diagnosed with PDAC in Oregon from 1997 to 2018 (n = 8026).

Exposures

The primary exposures studied were diagnosis and treatment at HVCs (20 or more pancreatectomies for PDAC per year), low-volume centers ([LVCs] less than 20 per year), or both.

Main Outcomes and Measures

OS and treatment patterns (eg, receipt of chemotherapy and primary site surgery) were evaluated with Kaplan-Meier analysis and logistic regression, respectively.

Results

Eight thousand twenty-six patients (male, 4142 [52%]; mean age, 71 years) were identified (n = 3419 locoregional, n = 4607 metastatic). Patients receiving first-course treatment at a combination of HVCs and LVCs demonstrated improved median OS for locoregional and metastatic disease (16.6 [95% CI, 15.3-17.9] and 6.1 [95% CI, 4.9-7.3] months, respectively) vs patients receiving HVC only (11.5 [95% CI, 10.7-12.3] and 3.9 [95% CI, 3.5-4.3] months, respectively) or LVC-only treatment (8.2 [95% CI, 7.7-8.7] and 2.1 [95% CI, 1.9-2.3] months, respectively; all P < .001). No differences existed in disease burden by volume status of diagnosing institution. When stratifying by site of diagnosis, HVC-associated improvements in median OS were smaller (locoregional: 10.4 [95% CI, 9.5-11.2] vs 9.9 [95% CI, 9.4-10.4] months; P = .03; metastatic: 3.6 vs 2.7 months, P < .001) than when stratifying by the volume status of treating centers, indicating selection bias during referral. A total of 94% (n = 1103) of patients diagnosed at an HVC received HVC treatment vs 18% (n = 985) of LVC diagnoses. Among patients diagnosed at LVCs, later year of diagnosis and higher estimated income were independently associated with higher odds of subsequent HVC treatment, while older age, metastatic disease, and farther distance from HVC were independently associated with lower odds.

Conclusions and Relevance

LVC-to-HVC referrals for PDAC experienced improved OS vs HVC- or LVC-only care. While disease-related features prompting referral may partially account for this finding, socioeconomic and geographic disparities in referral worsen OS for disadvantaged patients. Measures to improve access to HVCs are encouraged.

Updates to NeoOPTIMIZE: An open-label, phase II trial and biomarker discovery platform to assess the efficacy of adaptive switching of modified FOLFIRINOX (mFFX) or gemcitabine/nab-paclitaxel (GA) as a neoadjuvant strategy for patients with resectable/borderline resectable and locally advanced unresectable pancreatic ductal adenocarcinoma (PDAC)

TPS776

Background: Neoadjuvant chemotherapy (NAC) and/or chemo-RT may confer benefit to patients with localized PDAC, by better tolerability, tumor down-staging, and increased R0 resections. mFFX or GA are the current NAC backbones; however, a lack of robust predictive biomarker(s) hampers identification of patients most likely to benefit from mFFX or GA. Further, desmoplastic stroma/poor vascularity compromise NAC efficacy, but angiotensin II receptor inhibitor, losartan, might remodel vascular perfusion to enhance chemotherapy activity. We designed the NeoOPTIMIZE trial for patients with newly diagnosed localized PDAC to provide a flexible clinical platform to: 1) evaluate the feasibility and efficacy of early switching of mFFX to GA, and 2) establish a robust biomarker/imaging discovery platform to optimize the NAC backbone. Methods: NeoOPTIMIZE (NCT04539808) is an open-label, non-randomized, phase II trial assessing the preliminary efficacy of an adaptive treatment strategy that allows for early switching of NAC in patients with localized PDAC. Sixty patients (n = 40 resectable/BRCP; n = 20 locally advanced unresectable [uLAPC]) will be enrolled to receive 2 months of preoperative mFFX (oxaliplatin, 85 mg/m2; folinic acid, 400 mg/m2; irinotecan, 150 mg/m2; 5-FU, 2400 mg/m2), then restaging by a multidisciplinary tumor board (multiD-TB). Absent progression (by panc protocol CT and CA19-9 decline/increase < 30% from baseline), patients continue mFFX (4 cycles). If progression (by panc protocol CT; CA19-9 increase > 30%), patients switch to GA (nab-paclitaxel, 125 mg/m2; gemcitabine, 1000 mg/m2) for 2 months. After 4 months of mFFX or mFFX/GA, another restaging multiD-TB will decide to proceed with: a) RT (if vascular involvement) then resection, b) resection, or c) continued chemo (if unresectable). Losartan (50 mg PO QD) is given throughout NAC and RT regimens. The primary endpoint estimates the proportion of resectable/BRPC patients with R0 resection. Assuming that the proportion of R0 is 60%, a sample size of 32 will provide a 95% CI (0.41, 076). To account for a 20% dropout, 40 patients will be enrolled towards primary endpoint. A separate exploratory cohort of 20 uLAPC patients will be enrolled. Secondary endpoints include DFS, PFS, OS, and AEs. Exploratory objectives include correlating clinical outcomes data with changes in blood-based biomarkers (CA19-9, ctDNA, circulating tumor cells etc.) and research DCE-MRI. To date, the trial has enrolled 19 patients: 8 resectable, 7 BRCP, and 4 uLAPC. Clinical trial information: NCT04539808 .

HCRN GI16-288: A phase II trial of perioperative CV301 vaccination in combination with nivolumab and systemic chemotherapy for resectable hepatic-limited metastatic colorectal cancer—Preliminary efficacy and correlative results

103

Background: Novel strategies to improve the efficacy of immune checkpoint inhibitors in microsatellite stable (MSS) mCRC are needed. CV301 is a vector-based vaccine that expresses carcinoembryonic antigen (CEA) and mucin 1 (MUC1), and in a phase II study in resected hepatic limited mCRC significantly improved OS compared with unvaccinated contemporary controls. Methods: In this multi-center randomized phase II study, patients with previously untreated resectable hepatic-limited mCRC were randomized to perioperative nivolumab + mFOLFOX +/- CV301 (Arm B) with a primary endpoint of 3-year OS. Treatment included mFOLFOX-nivo (+/- CV) x 4 cycles followed by resection, then 8 more cycles of mFOLFOX-nivo followed by maintenance nivo monthly for two years in both arms, and CV boosters concurrently with mFOLFOX, and then every 3 months for two years in arm B. Secondary endpoints of ORR (following induction pre-resection), PRR, and safety were determined. Correlative analyses included immune cell quantification using Immunoscore and T-cell clonality. Results: 17 patients were enrolled prior to premature closure for slow accrual (8 arm A, 9 arm B). At the time of data cutoff, 5 patients remained on treatment and no deaths had occurred. One patient was removed from study due to protocol non-compliance. The median age was 61, majority were male (59% vs 41%), and ECOG PS 0-1 (71% 0, 17% 1). All patients had complete surgical resection. Four patients (24%) experienced a SAE related to drug. The TRAE rate was 40.3%,. No AEs delayed/prevented surgical resection. The ORR in arm A was 50% (including 4 CR) and 87.5% in arm B (including 7 CR) (p=0.129, NS). There was no significant difference in pathologic response (p=0.9047). Correlative analyses demonstrated the Immunoscore CD3/CD8 predicted response to mFOLFOX + nivolumab, but did not correlate with response to CV301, though CV301 may induce a shift to predominantly cytotoxic CD8+ T cells. While there was no significant difference in T cell repertoire, clonality, fraction (TCFr) or richness, patients in arm B had significant decreases in blood TCFr and increase in tumor TCFr with treatment; those with CR had higher TCFr and clonality. Conclusions: The addition of CV301 to perioperative nivolumab and mFOLFOX was safe, did not delay or prevent surgical resection, and gave a higher response (p=ns due to sample size). Changes in T cells suggest a vaccine response. Clinical trial information: NCT03547999 . [Table: see text]

Phase 1b study to assess the safety of neoadjuvant trifluridine/tipiracil with concurrent radiation in resectable stage II/III rectal cancer

TPS274

Background: Treatment of locally advanced rectal cancer currently involves tri-modal therapy with pre-operative chemo-radiation (CRT), surgery, and combination chemotherapy. Total neoadjuvant therapy (TNT) is emerging as an important treatment pathway that can increase rates of complete response (CR) leading to better overall outcomes. Novel radio-sensitizing agents may improve rates of CR. Trifluridine/tipiracil (TFD/TPI) is a novel fluoropyrimidine that has demonstrated clinical efficacy in patients with treatment-refractory metastatic colorectal cancer. Importantly, TFD/TPI has superior radio-sensitization in vitro compared to 5-fluorouracil, and we hypothesize that this can improve the tumor response of patients. This phase 1 study assesses the safety and preliminary efficacy of using TFD/TPI for long-course CRT for rectal cancer followed by FOLFOX chemotherapy in the TNT setting. Methods: NCT04104139 is a prospective, dose-finding phase I study using Bayesian Optimal Interval (BOIN) design to determine the maximum tolerated dose (MTD) of TFD/TPI with concurrent standard dose/fractionation radiation for resectable rectal cancer. Adults with previously untreated rectal adenocarcinoma, with clinical stage II (T3-4aN0) and stage III (T1-4aN1+) by MRI and endoscopy are eligible. Patients must first receive CRT with standard radiation (45-50 Gy over 25-28 fractions) followed by up to 8 cycles of standard FOLFOX, or alternatively 5 cycles of CAPOX chemotherapy. During CRT, the first dose level of TFD/TPI is PO 25mg/m2 twice a day from Mon to Fri (5 weekdays) alternating on weeks 1, 3, and 5 concurrent with 5-6 weeks of radiation. The second dose level is 30mg/m2, and third dose level is 35mg/m2. The MTD of TFD/TPI in combination with radiation is the dose corresponding to a dose limiting toxicity (DLT) probability of 30% using the BOIN design with escalation/de-escalation of each dose level occurring in cohorts of 3 participants until a maximum total of 18 participants, sub-total of 12 patients within one dose level, or another stopping rule based on serious toxicities. The primary endpoint is proportion of DLTs for TFD/TPI at MTD. Secondary endpoints include overall tolerability profile, delayed toxicities during FOLFOX, rates of clinical CR, rates of pathologic CR, and correlative biomarkers. The study was activated December 2019 and has accrued 8 of intended 18 patients. Clinical trial information: NCT04104139 .

The multidisciplinary management of cholangiocarcinoma

Cholangiocarcinoma is a lethal malignancy of the biliary epithelium that can arise anywhere along the biliary tract. Surgical resection confers the greatest likelihood of long-term survivability. However, its insidious onset, difficult diagnostics, and resultant advanced presentation render the majority of patients unresectable, highlighting the importance of early detection with novel biomarkers. Developing liver-directed therapies and emerging targeted therapeutics may offer improved survivability for patients with unresectable or advanced disease. In this article, the authors review the current multidisciplinary standards of care in resectable and unresectable cholangiocarcinoma, with an emphasis on novel biomarkers for early detection and nonsurgical locoregional therapy options.

Past, Present, and Future Management of Localized Biliary Tract Malignancies

Most of the patients with gallbladder cancer (GBC), intrahepatic cholangiocarcinoma (iCCA), and peri-hilar cholangiocarcinoma (pCCA) present with advanced disease. Complete staging with multiphasic liver imaging is essential to determine the extent of disease. Operative goals should include a margin-negative resection, portal lymphadenectomy for staging, and sufficient remnant liver volume. Biliary tract malignancies have distinct mutational drivers (GBC and pCCA = ERBB2 in 20%; iCCA = fibroblast growth factor receptor 2 or isocitrate dehydrogenase 1 in 20%) amenable to therapy with inhibitors. Clinical trials assessing neoadjuvant, peri-operative, and adjuvant treatments continue to evolve and now include targeted inhibitors and the integration of hepatic arterial infusion.

Considerations and barriers to starting a new HAI pump program: an international survey of the HAI Consortium Research Network

BACKGROUND

Widespread implementation of HAI pump chemotherapy has been limited by logistic and feasibility concerns. Recent studies demonstrating excellent outcomes have fueled renewed enthusiasm and multiple new programs have emerged. This survey aims to identify barriers critical to establish a successful HAI program.

METHODS

Using SurveyMonkey™, a 17-question survey assessing factors required for establishing a successful program was developed by 12 HAI Consortium Research Network (HCRN) surgical oncologists. Content analysis was used to code textual responses. Frequency of categories and average rank scores for each choice were calculated.

RESULTS

Twenty-eight HCRN members responded to the survey. Implementation time varied, with 15 institutions requiring less than a year. Most programs (n = 17) became active in the past 5 years. Medical and surgical oncology were ranked most important for building a program (average ranking scores: 7.96 and 6.59/8). Administrative or regulatory approval was required at half of the institutions. The top 3 challenges faced when building a program were related to regulatory approval (6.65/9), device/equipment access (6.33/9), and drug (FUDR) access (6.25/9).

CONCLUSION

Development of successful programs outside of historically established centers is feasible and requires a multidisciplinary team. Future collaborative efforts are critical for sustainability of safe/effective new programs.

Imaging Breast Microcalcifications Using Dark-Field Signal in Propagation-Based Phase-Contrast Tomography

Breast microcalcifications are an important primary radiological indicator of breast cancer. However, microcalcification classification and diagnosis may be still challenging for radiologists due to limitations of the standard 2D mammography technique, including spatial and contrast resolution. In this study, we propose an approach to improve the detection of microcalcifications in propagation-based phase-contrast X-ray computed tomography of breast tissues. Five fresh mastectomies containing microcalcifications were scanned at different X-ray energies and radiation doses using synchrotron radiation. Both bright-field (i.e. conventional phase-retrieved images) and dark-field images were extracted from the same data sets using different image processing methods. A quantitative analysis was performed in terms of visibility and contrast-to-noise ratio of microcalcifications. The results show that while the signal-to-noise and the contrast-to-noise ratios are lower, the visibility of the microcalcifications is more than two times higher in the dark-field images compared to the bright-field images. Dark-field images have also provided more accurate information about the size and shape of the microcalcifications.

Ten-Year Survivorship in Patients with Metastatic Gastrointestinal Stromal Tumors

INTRODUCTION

Patients developing metastatic gastrointestinal stromal tumors (mGIST) have heterogenous disease biology and oncologic outcomes; prognostic factors are incompletely characterized. We sought to evaluate predictors of 10-year metastatic survivorship in the era of tyrosine kinase inhibitor (TKI) therapy.

METHODS

We reviewed patients with mGIST treated at our Comprehensive Cancer Center from 2003 to 2019, including only patients with either mortality or 10 years of follow-up. Ten-year survivorship was evaluated with logistic regression.

RESULTS

We identified 109 patients with a median age of 57 years at mGIST diagnosis. Synchronous disease was present in 57% (n = 62) of patients; liver (n = 48, 44%), peritoneum (n = 40, 37%), and liver + peritoneum (n = 18, 17%) were the most common sites. Forty-six (42%) patients were 10-year mGIST survivors. Following mGIST diagnosis, radiographic progression occurred within 2 years in 53% (n = 58) of patients, 2-5 years in 16% (n = 17), and 5-10 years in 16% (n = 17), with median survival of 32, 76, and 173 months, respectively. Seventeen (16%) patients had not progressed by 10 years. Fifty-two (47%) patients underwent metastasectomy, which was associated with improved progression-free survival (hazard ratio 0.63, p = 0.04). In patients experiencing progression, factors independently associated with 10-year survivorship were age (odds ratio [OR] 0.96, p = 0.03) and time to progression (OR 1.71/year, p < 0.001).

CONCLUSIONS

Ten-year survivorship is achievable in mGIST in the era of TKIs and is associated with younger age and longer time to first progression, while metastasectomy is associated with longer time to first progression. The role of metastasectomy in the management of patients with disease progression receiving TKI therapy merits further study.

Complications in Distal Pancreatectomy versus Radical Antegrade Modular Pancreatosplenectomy: A Disease Risk Score Analysis Utilizing National Surgical Quality Improvement Project Data

INTRODUCTION

Radical antegrade modular pancreatosplenectomy (RAMPS) was developed to improve R0 resections and lymph node harvests versus distal pancreatectomy (DP) in pancreatic adenocarcinoma (PDAC); relative complication rates are understudied.

METHODS

Patients undergoing distal pancreas resections from 2006 to 2020 were identified from our institutional NSQIP database, grouped by resection method, and evaluated for the following outcomes: postoperative pancreatic fistula (POPF), clinically relevant POPF (crPOPF), incisional surgical site infection (iSSI), organ space SSI (osSSI), and Clavien-Dindo grade ≥ 3 (CD ≥ 3) complications using logistic regression. Patients were matched 1:1 based on disease risk score.

RESULTS

Two-hundred-thirty-six and 117 patients underwent DP and RAMPS, respectively. POPF, crPOPF, CD ≥ 3 complications, iSSI, and osSSIs occurred in 105 (30%), 43 (12%), 74 (21%), 34 (10%) and 52 (15%) patients, respectively. Disease risk score matching yielded 89 similar patients per group. On multivariable analysis, patients undergoing RAMPS were not significantly more likely to experience POPF (OR 0.69, P = 0.26), crPOPF (OR 0.41, P = 0.72), CD ≥ 3 complication (OR 0.78, P = 0.44), iSSI (OR 0.58, P = 0.27), or osSSI (OR 0.93, P = 0.86). Of patients with PDAC (n = 108) mean nodal harvest were 14.8 (SD 11.30) and 19.4 (SD 7.19) nodes for patients undergoing DP and RAMPS, respectively (P = 0.01). Six patients (20%) undergoing DP had positive margins versus 12 (15%) undergoing RAMPS (P = 0.56). At a median follow-up of 17 months, there was no difference in locoregional recurrence-free survival (P = 0.32) or overall survival (P = 0.92) on Kaplan-Meier analysis.

CONCLUSION

RAMPS does not result in increased complications compared to DP and routine use is encouraged in pancreatic malignancies.

Neoadjuvant tyrosine kinase inhibitor therapy for patients with gastrointestinal stromal tumor: A propensity-matched analysis

BACKGROUND

Tyrosine kinase inhibitor (TKI) neoadjuvant therapy (NAT) is often given in gastrointestinal stromal tumors (GISTs) with the goal to facilitate less morbid resections and improve oncologic outcomes; however, the use of NAT for GIST is poorly studied.

METHODS

We reviewed patients with resected nonmetastatic GIST from 2003 to 2019. Overall (OS) and recurrence-free survival (RFS) were assessed with Kaplan-Meier modeling. We performed 1:1 propensity-matching for relevant clinicopathologic variables for receipt of NAT.

RESULTS

We identified 254 patients. Propensity 1:1 matching resulted in 33 patients per group. The median follow-up was 77 months with no difference in 10-year OS (68% vs. 73%), 5-year RFS (13% vs. 10%), or median RFS (24 vs. 27 months) for patients treated with NAT versus upfront resection (all P > 0.9). Hospital length-of-stay (both median 7 days) and Clavien-Dindo ≥ III complications (12% vs. 3%) were not different between groups (both P ≥ 0.35).

DISCUSSION

TKI NAT can be used to facilitate resection in select patients with surgically higher-risk GIST, however it does not result in an independent oncologic benefit.

Hepatic metastases in gastrointestinal stromal tumors: oncologic outcomes with curative-intent hepatectomy, resection of treatment-resistant disease, and tyrosine kinase inhibitor therapy alone

BACKGROUND

Hepatic resection for metastatic GIST (mGIST) is often performed with either curative-intent or for tyrosine kinase inhibitor (TKI)-resistant lesions. The efficacy of hepatectomy for treatment-resistant lesions (TRL) is uncertain.

METHODS

We reviewed patients with liver-mGIST treated from 2003 to 2018. Oncologic outcomes including overall (OS), post-operative progression-free survival (PFS), and post-progression OS were evaluated using Kaplan-Meier and Cox proportional hazards modeling.

RESULTS

We identified n = 91 patients; 31 (34%) underwent curative-intent hepatectomy, 60 (66%) were initially managed with TKI alone, and 17 (19%) had resection of a TRL. The median follow-up for resected patients was 102 months (range 5-209 months) with 23 (25%) managed with a major hepatectomy. Patients having curative-intent hepatectomy had 72% 10-year OS following diagnosis of liver-mGIST, compared with 58% (P = 0.50) for TRL resection and 41% (P = 0.01) for non-resected patients. Curative-intent hepatectomy (HR 0.39, P = 0.03) and age (HR 1.04, P = 0.004) were independently associated with 10-year OS, but not TRL resection. TRL resection was not associated with improved post-progression OS compared to second-line TKI therapy (HR 0.61, P = 0.21).

CONCLUSIONS

Curative-intent hepatectomy is associated with improved OS in liver-mGIST. The oncologic benefit of resecting treatment-resistant liver-mGIST compared to second-line TKI therapy alone remains unclear in the era of multi-line TKI therapy.

Hepatic arterial infusion pump chemotherapy combined with systemic therapy for patients with advanced colorectal liver metastases: Outcomes in a newly established program

BACKGROUND AND OBJECTIVES

Colorectal liver metastasis (CRLM) is a leading cause of morbidity and mortality in patients with colorectal cancer. Hepatic arterial infusion (HAI) chemotherapy has been demonstrated to improve survival in patients with resected CRLM and to facilitate conversion of technically unresectable disease.

METHODS

Between 2016 and 2018, n = 22 HAI pumps were placed for CRLM. All patients received systemic chemotherapy concurrently with HAI floxuridine/dexamethasone. Overall survival (OS) and progression-free survival (PFS) were assessed using the Kaplan-Meier method.

RESULTS

HAI pumps were placed in seven patients with completely resected CRLM and 15 patients with unresectable disease. Twenty-one patients received HAI floxuridine with a median of 5 total HAI cycles (interquartile range: 4-7). Biliary sclerosis was the most common HAI-related complication (n = 5, 24%). Of the 13 patients treated to convert unresectable CRLM, 3 (23%) underwent hepatic resection with curative intent after a median of 7 HAI cycles (range: 4-10). For all HAI patients, the mean OS was 26.7 months from CRLM diagnosis, while the median PFS and hepatic PFS from pump placement were 9 and 13 months, respectively.

CONCLUSION

Concomitant HAI and systemic therapy can be utilized at multidisciplinary programs for patients with advanced CRLM, both in the adjuvant setting and to facilitate conversion of unresectable disease.

Tomographic phase and attenuation extraction for a sample composed of unknown materials using x-ray propagation-based phase-contrast imaging

Propagation-based phase-contrast x-ray imaging (PB-PCXI) generates image contrast by utilizing sample-imposed phase-shifts. This has proven useful when imaging weakly attenuating samples, as conventional attenuation-based imaging does not always provide adequate contrast. We present a PB-PCXI algorithm capable of extracting the x-ray attenuation  β and refraction  δ, components of the complex refractive index of distinct materials within an unknown sample. The method involves curve fitting an error-function-based model to a phase-retrieved interface in a PB-PCXI tomographic reconstruction, which is obtained when Paganin-type phase retrieval is applied with incorrect values of δ and β. The fit parameters can then be used to calculate true δ and β values for composite materials. This approach requires no a priori sample information, making it broadly applicable. Our PB-PCXI reconstruction is single-distance, requiring only one exposure per tomographic angle, which is important for radiosensitive samples. We apply this approach to a breast-tissue sample, recovering the refraction component  δ, with 0.6-2.4% accuracy compared with theoretical values.

Similar Outcomes in Minimally Invasive versus Open Management of Primary Pancreatic Neuroendocrine Tumors: A Regional, Multi-Institutional Collaborative Analysis

In pancreatic neuroendocrine tumors (PNETs), the impact of minimally invasive (MI) versus open resection on outcomes remains poorly studied. We queried a multi-institutional pancreatic cancer registry for patients with resected non-metastatic PNET from 1996−2020. Recurrence-free (RFS), disease-specific survival (DSS), and operative complications were evaluated. Two hundred and eighty-two patients were identified. Operations were open in 139 (49%) and MI in 143 (51%). Pancreaticoduodenectomy was performed in 77 (27%, n = 23 MI), distal pancreatectomy in 184 (65%, n = 109 MI), enucleation in 13 (5%), and total pancreatectomy in eight (3%). Median follow-up was 50 months. Thirty-six recurrences and 13 deaths from recurrent disease yielded 5-year RFS and DSS of 85% and 95%, respectively. On multivariable analysis, grade 1 (HR 0.07, p < 0.001) and grade 2 (HR 0.20, p = 0.002) tumors were associated with improved RFS, while T3/T4 tumors were associated with worse RFS (OR 2.78, p = 0.04). MI resection was not associated with RFS (HR 0.53, p = 0.14). There was insufficient mortality to evaluate DSS with multivariable analysis. Of 159 patients with available NSQIP data, incisional surgical site infections (SSIs), organ space SSIs, Grade B/C pancreatic fistulas, reoperations, and need for percutaneous drainage did not differ by operative approach (all p > 0.2). Nodal harvest was similar for MI versus open distal pancreatectomies (p = 0.16) and pancreaticoduodenectomies (p = 0.28). Minimally invasive surgical management of PNETs is equivalent for oncologic and postoperative outcomes.

Surgical timing after preoperative chemotherapy is associated with oncologic outcomes in resectable colorectal liver metastases

INTRODUCTION

Preoperative chemotherapy (POC) is often employed for patients with resectable colorectal liver metastasis (CRLM). The time to resection (TTR) following the end of chemotherapy may impact oncologic outcomes; this phenomenon has not been studied in CRLM.

METHODS

We queried our institutional cancer database for patients with resected CRLM after POC from 2003 to 2019. TTR was calculated from date of last cytotoxic chemotherapy. Kaplan-Meier analysis and multivariable Cox proportional hazards modeling were used to analyze recurrence-free survival (RFS) and overall survival (OS).

RESULTS

We identified n = 187 patients. One hundred twenty-four (66%) patients had a TTR of <2 months, while 63 (33%) had a TTR of ≥2 months. Median follow-up was 36 months. On Kaplan-Meier analysis, patients with TTR ≥ 2 months had shorter RFS (median 11 vs. 17 months, p = 0.002) and OS (median 44 vs. 62 months, p < 0.001). On multivariable analysis, TTR ≥ 2 months was independently associated with worse RFS (hazard ratio [HR] = 1.54, 95% confidence interval [CI] = 1.06-2.22, p = 0.02) and OS (HR = 1.75, 95% CI = 1.11-2.77, p = 0.01).

CONCLUSION

TTR ≥ 2 months following POC is independently associated with worse oncologic outcomes in patients with resectable CRLM. We therefore recommend consideration for hepatic resection of CRLM within this window whenever feasible.

NeoOPTIMIZE: An open-label, phase II trial and biomarker discovery platform to assess the efficacy of adaptive switching of modified FOLFIRINOX (mFFX) or gemcitabine/nab-paclitaxel (GA) as a neoadjuvant strategy for patients with resectable/borderline resectable and locally advanced unresectable pancreatic ductal adenocarcinoma (PDAC)

TPS630

Background: Neoadjuvant chemotherapy (NAC) and/or chemo-RT may confer benefit to patients with localized PDAC, by better tolerability, tumor down-staging, and increased R0 resections. mFFX or GA are the current NAC backbones; however, a lack of robust predictive biomarker(s) hampers identification of patients most likely to benefit from mFFX or GA. Further, desmoplastic stroma/poor vascularity compromise NAC efficacy, but angiotensin II receptor inhibitor, losartan, might remodel vascular perfusion to enhance chemotherapy activity. We designed the NeoOPTIMIZE trial for patients with newly diagnosed localized PDAC to provide a flexible clinical platform to: 1) evaluate the feasibility and efficacy of early switching of mFFX to GA, and 2) establish a robust biomarker/imaging discovery platform to optimize the NAC backbone. Methods: NeoOPTIMIZE is an open-label, non-randomized, phase II trial to assess the efficacy of an adaptive treatment strategy that allows for early switching of NAC in patients with localized PDAC. Sixty patients (n = 40 resectable/BRCP; n = 20 locally advanced unresectable [uLAPC]) will be enrolled to receive 2 months of preoperative mFFX (oxaliplatin, 85 mg/m2; folinic acid, 400 mg/m2; irinotecan, 150 mg/m2; 5-FU, 2400 mg/m2), then restaging by a multidisciplinary tumor board (multiD-TB). Absent progression (by panc protocol CT and CA19-9 decline/increase < 30% from baseline), patients continue mFFX (4 cycles). If progression (by panc protocol CT; CA19-9 increase > 30%), patients switch to GA (nab-paclitaxel, 125 mg/m2; gemcitabine, 1000 mg/m2) for 2 months. After 4 months of mFFX or mFFX/GA, another restaging multiD-TB will decide to proceed with: a) RT (if vascular involvement) then resection, b) resection, or c) continued chemo (if unresectable). Losartan (50 mg PO QD) is given throughout NAC and RT regimens. The primary endpoint estimates the proportion of resectable/BRPC patients with R0 resection. Assuming that the proportion of R0 is 60%, a sample size of 32 will provide a 95% CI of 0.41 - 076. To account for a 20% dropout, 40 patients will be enrolled towards primary endpoint. A separate exploratory cohort of 20 uLAPC patients will be enrolled. Secondary endpoints include DFS, PFS, OS, and AEs. Exploratory objectives include correlating clinical outcomes data with changes in blood-based biomarkers (CA19-9, ctDNA, circulating tumor cells etc.) and research DCE-MRI. We are collecting tumors to correlate deep multi-omic analytics with clinical data. The study is open with 6 patients enrolled at time of submission. Clinical trial information: NCT04539808.

HELIX-ICC: An-open label phase II trial of induction systemic mFOLFIRINOX followed by concurrent hepatic arterial infusion of floxuridine and systemic mFOLFIRI for unresectable intrahepatic cholangiocarcinoma

TPS500

Background: The majority of patients with intrahepatic cholangiocarcinoma (ICC) present with advanced liver dominant disease rendering them unresectable. The current standard of care supports palliative treatment of unresectable ICC with gemcitabine plus cisplatin. Alternatively, continuous liver-directed therapy using a surgically implanted hepatic arterial infusion (HAI) pump allows for maximal treatment of liver tumors with limited systemic side-effects and can facilitate conversion to a resectable status. No prospective clinical trial has utilized FOLFIRINOX in combination with HAI floxuridine-dexamethasone for ICC. Methods: HELIX-ICC is a first-line, single-center, single-arm, phase II clinical trial enrolling patients with liver-dominant unresectable or multifocal ICC. Only patients with microsatellite stable cancer and no prior liver radiotherapy will be included. Patients are administered dose-modified FOLFIRINOX systemically for 4 cycles over 8 weeks. Those with evidence of disease control on restaging imaging and laparoscopy will proceed to HAI pump placement. Treatment continues with two 28-day cycles of combined HAI floxuridine (1.08 mg/kg) with dexamethasone for 14 days and systemic dose-modified FOLFIRI starting on day 15. The primary objectives are to evaluate the safety and efficacy (disease control rate [DCR] at 6 months) of this novel treatment approach that utilizes our institutional dose-reduced HAI floxuridine protocol in combination with modified systemic regimens to facilitate control of liver disease and maximize patient quality of life (QoL). HELIX-ICC includes many exploratory analyses through longitudinal collection of blood samples, liver biopsies (including an end of trial research biopsy), and QoL metrics (Table). The study is open to n = 30 with an initial safety run-in of 6 patients, of which 4 have enrolled at the time of submission. This study is designed to allow for drop out of 9 patients, with total accrual of 21 patients to protocol completion achieving 80.2% power at 0.05 significance to detect a 25% increase in DCR at 6 months. Clinical trial information: NCT04251715. [Table: see text]

Early Versus Late Recurrence in Rectal Cancer: Does Timing Matter?

BACKGROUND

The definition of early recurrence (ER) in rectal cancer is unclear, and the association of ER with post-recurrence survival (PRS) is poorly described. We therefore sought to identify if time to recurrence (TTR) is associated with PRS.

METHODS

We reviewed all curative-intent resections of nonmetastatic rectal cancer from 2003 to 2018 in our institutional registry within an NCI-Designated Comprehensive Cancer Center. Clinicopathologic data at diagnosis and first recurrence were collected and analyzed. ER was pre-specified at < 24 months and late recurrence (LR) at ≥ 24 months. PRS was evaluated by the Kaplan-Meier method and Cox proportional hazards modeling.

RESULTS

At a median follow-up of 53 months, 61 out of 548 (11.1%) patients undergoing resection experienced recurrence. Median TTR was 14 months (IQR 10-18) with 45 of 61 patients (74%) classified as ER. There were no significant baseline differences between patients with ER and LR. Most recurrences were isolated to the liver (26%) or lung (31%), and 16% were locoregional. ER was not associated with worse PRS compared to LR (P > 0.99). On multivariable analysis, detection of recurrence via workup for symptoms, CEA > 10 ng/mL at recurrence, and site of recurrence were independently associated with PRS.

CONCLUSION

ER is not associated with PRS in patients with resected rectal cancer. Symptomatic recurrences and those accompanied by CEA elevations are associated with worse PRS, while metastatic disease confined to the liver or lung is associated with improved PRS. Attention should be directed away from TTR and instead toward determining therapy for patients with treatable oligometastatic disease.

The patient's perspective: a qualitative study of individual experience with decision-making, treatment, and recovery for resectable pancreatic cancer

INTRODUCTION

Pancreatic ductal adenocarcinoma cancer (PDAC) remains a challenging diagnosis. The likelihood of long-term survival is limited even for patients who undergo maximal medical therapy with systemic chemotherapy and surgical resection. Within this intensive process, there remains limited understanding of patients' pretreatment expectations of PDAC treatment experience and their decision-making process.

METHODS

PDAC patients who underwent chemotherapy and surgical resection were retrospectively identified. Semi-structured phone interviews were completed regarding patient experience with therapy. Qualitative descriptive analysis was performed, and categories, subcategories, and themes were determined.

RESULTS

Fifteen patients were interviewed regarding their experience with PDAC treatment. An overall personal disease trajectory experience was identified with two phases. The first phase encompassed the patients' treatment. In this phase, patients expressed a choice, non-choice regarding therapy decisions, viewing therapy as the only option. Misconceptions about the roles of therapies and expected experience of treatment were observed. The second phase focused on life after therapy. Patients reported persistent physical changes secondary to therapy. An overall realistic understanding of the patient's limited prognosis was observed, with patients expressing appreciation of the life time gained as a benefit of treatment.

CONCLUSIONS

There remains critical areas for improvement in communication and care of patients with PDAC. Physicians should continue to ensure that patient's goals and wishes are respected when making treatment decisions and confirm that patients understand the roles and limitations of prescribed therapies. Additionally, patients continue to have significant physical changes post treatment which should be assessed for and managed as appropriate to maintain quality of life.

Detection of Tumor Multifocality in Resectable Intrahepatic Cholangiocarcinoma: Defining the Optimal Pre-operative Imaging Modality

BACKGROUND

Multiple tumor foci (MTF) in intrahepatic cholangiocarcinoma (ICC), including satellitosis and true multifocality, is a known negative prognostic factor and can inform pre-operative decision-making. Lack of standardized pre-operative liver staging practices may contribute to undiagnosed MTF and poor outcomes. We sought to investigate the sensitivity of different cross-sectional imaging modalities for MTF at our institution.

METHODS

We identified n = 52 patients with ICC who underwent curative-intent resection from 2004 to 2017 in a multidisciplinary hepato-pancreato-biliary cancer program. Timing and modality of pre-operative imaging were recorded. Blinded review of imaging was performed and modalities were evaluated for false-negative rate (FNR) in detecting MTF, satellitosis, and true multifocality.

RESULTS

Forty-one (79%) patients underwent CT and 20 (38%) underwent MRI prior to hepatectomy. MTF was pre-operatively identified in six (12%) patients. An additional seven patients had MTF discovered on final surgical pathology, despite a median interval from CT/MRI to surgery of 20 days. On blinded review the FNR of MRI compared to CT for multifocality was 0% vs. 38%, 50% vs 80% for satellitosis, and 22% vs 46% for MTF as a whole.

CONCLUSION

CT is inadequate for pre-operative diagnosis of MTF in resectable ICC, even when performed within 30 days of hepatectomy. We recommend liver-protocol MRI as the standard pre-operative imaging modality in non-metastatic ICC.

Geographic Disparities in Referral Rates and Oncologic Outcomes of Intrahepatic Cholangiocarcinoma: A Population-Based Study

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is a rare cancer. Patients in rural areas may face reduced access to advanced treatments often only available at referral centers. We evaluated the association of referral center treatment with treatment patterns, outcomes, and geography in patients with ICC.

METHODS

We queried the Oregon State Cancer Registry for ICC between 1997 and 2016, collecting clinicopathologic, demographic, and oncologic data. Patients were classified by treatment at a referral center or non-referral center. 'Crowfly' distance to the nearest referral center (DRC) was calculated. Outcomes were evaluated using Kaplan-Meier, Cox proportional hazards modeling, and logistic regression.

RESULTS

Over 20 years, 740 patients with ICC had a median age of 66 years. Slightly more than half (n = 424, 57%) were non-referral center treated and 316 (43%) were referral center treated. Referral center treatment increased over time (odds ratio [OR] 1.03/year, p < 0.05). Referral center-treated patients had improved overall survival in all patients (median 9 vs. 4 months, p < 0.001), in the non-metastatic group (median 13 vs. 6 months, p < 0.001), and in patients not receiving liver resection (median 6 vs. 3 months, p < 0.05). On multivariable analysis, referral center-treated patients more often underwent chemotherapy, resection, or radiation (all p < 0.05). Increasing DRC (OR 0.98/20 km, p < 0.05) was independently associated with non-referral center treatment.

CONCLUSION

Patients with ICC who are evaluated at a referral center are more likely to receive treatments associated with better oncologic outcomes, including patients who are not managed with hepatic resection. Increasing the DRC is associated with treatment at a non-referral center; interventions to facilitate referral, such as telemedicine, may lead to improved outcomes for patients with ICC in rural states.

Circulating Hybrid Cells: A Novel Liquid Biomarker of Treatment Response in Gastrointestinal Cancers

BACKGROUND

Real-time monitoring of treatment response with a liquid biomarker has potential to inform treatment decisions for patients with rectal adenocarcinoma (RAC), esophageal adenocarcinoma (EAC), and colorectal liver metastasis (CRLM). Circulating hybrid cells (CHCs), which have both immune and tumor cell phenotypes, are detectable in the peripheral blood of patients with gastrointestinal cancers, but their potential as an indicator of treatment response is unexplored.

METHODS

Peripheral blood specimens were collected from RAC and EAC patients after neoadjuvant therapy (NAT) or longitudinally during therapy and evaluated for CHC levels by immunostaining. Receiver operating characteristics (ROCs) and the Kaplan-Meier method were used to analyze the CHC level as a predictor of pathologic response to NAT and disease-specific survival (DSS), respectively.

RESULTS

Patients with RAC (n = 23) and EAC (n = 34) were sampled on the day of resection, and 11 patients (32%) demonstrated a pathologic complete response (pCR) to NAT. On ROC analysis, CHC levels successfully discriminated pCR from non-pCR with an area under the curve of 0.82 (95% confidence interval [CI], 0.71-0.92; P < 0.001). Additionally, CHC levels in the EAC patients correlated with residual nodal involvement (P = 0.026) and 1-year DSS (P = 0.029). The patients with RAC who were followed longitudinally during NAT (n = 2) and hepatic arterial infusion therapy for CRLM (n = 2) had CHC levels that decreased with therapy response and increased before clinical evidence of disease progression.

CONCLUSION

Circulating hybrid cells are a novel blood-based biomarker with potential for monitoring treatment response and disease progression to help guide decisions for further systemic therapy, definitive resection, and post-therapy surveillance. Additional validation studies of CHCs are warranted.

Location of Gastrointestinal Stromal Tumor (GIST) in the Stomach Predicts Tumor Mutation Profile and Drug Sensitivity

PURPOSE

Gastrointestinal stromal tumors (GIST) commonly arise in different regions of the stomach and are driven by various mutations (most often in KIT, PDGFRA, and SDHx). We hypothesized that the anatomic location of gastric GIST is associated with unique genomic profiles and distinct driver mutations.

EXPERIMENTAL DESIGN

We compared KIT versus non-KIT status with tumor location within the National Cancer Database (NCDB) for 2,418 patients with primary gastric GIST. Additionally, we compiled an international cohort (TransAtlantic GIST Collaborative, TAGC) of 236 patients and reviewed sequencing results, cross-sectional imaging, and operative reports. Subgroup analyses were performed for tumors located proximally versus distally. Risk factors for KIT versus non-KIT tumors were identified using multivariate regression analysis. A random forest machine learning model was then developed to determine feature importance.

RESULTS

Within the NCDB cohort, non-KIT mutants dominated distal tumor locations (P < 0.03). Proximal GIST were almost exclusively KIT mutant (96%) in the TAGC cohort, whereas 100% of PDGFRA and SDH-mutant GIST occurred in the distal stomach. On multivariate regression analysis, tumor location was associated with KIT versus non-KIT mutations. Using random forest machine learning analysis, stomach location was the most important feature for predicting mutation status.

CONCLUSIONS

We provide the first evidence that the mutational landscape of gastric GIST is related to tumor location. Proximal gastric GIST are overwhelmingly KIT mutant, irrespective of morphology or age, whereas distal tumors display non-KIT genomic diversity. Anatomic location of gastric GIST may therefore provide immediate guidance for clinical treatment decisions and selective confirmatory genomic testing when resources are limited.

Relevance of circulating hybrid cells as a non-invasive biomarker for myriad solid tumors

Metastatic progression defines the final stages of tumor evolution and underlies the majority of cancer-related deaths. The heterogeneity in disseminated tumor cell populations capable of seeding and growing in distant organ sites contributes to the development of treatment resistant disease. We recently reported the identification of a novel tumor-derived cell population, circulating hybrid cells (CHCs), harboring attributes from both macrophages and neoplastic cells, including functional characteristics important to metastatic spread. These disseminated hybrids outnumber conventionally defined circulating tumor cells (CTCs) in cancer patients. It is unknown if CHCs represent a generalized cancer mechanism for cell dissemination, or if this population is relevant to the metastatic cascade. Herein, we detect CHCs in the peripheral blood of patients with cancer in myriad disease sites encompassing epithelial and non-epithelial malignancies. Further, we demonstrate that in vivo-derived hybrid cells harbor tumor-initiating capacity in murine cancer models and that CHCs from human breast cancer patients express stem cell antigens, features consistent with the potential to seed and grow at metastatic sites. Finally, we reveal heterogeneity of CHC phenotypes reflect key tumor features, including oncogenic mutations and functional protein expression. Importantly, this novel population of disseminated neoplastic cells opens a new area in cancer biology and renewed opportunity for battling metastatic disease.

Degree of biliary tract violation during treatment of gallbladder adenocarcinoma is independently associated with development of peritoneal carcinomatosis

BACKGROUND

Gallbladder cancer (GBC) is often incidentally diagnosed after cholecystectomy. Intra-operative biliary tract violations (BTV) have been recently associated with development of peritoneal disease (PD). The degree of BTV may be associated with PD risk, but has not been previously investigated.

METHODS

We reviewed patients with initially non-metastatic GBC treated at our institution from 2003 to 2018. Patients were grouped based on degree of BTV during their treatment: major (e.g., cholecystotomy with bile spillage, n = 27, 29%), minor (e.g., intra-operative cholangiogram, n = 18, 19%), and no violations (n = 48, 55%). Overall survival (OS) and peritoneal disease-free survival (PDFS) were evaluated with Kaplan-Meier and Cox proportional hazards modeling.

RESULTS

Ninety-three patients were identified; the median age was 64 years (range 31-87 years). Seventy-six (82%) were incidentally diagnosed. The median follow-up was 23 months; 20 (22%) patients developed PD. The 3-year PDFS for patients with major, minor, and no BTV was 52%, 83%, and 98%, respectively (major vs. none: p <  0.001; minor vs. none: p <  0.01). BTV was not associated with 5-year OS (HR 1.53, p =  0.16).

CONCLUSION

Increasing degree of BTV is associated with higher risk of peritoneal carcinomatosis in patients with GBC and should be considered during preoperative risk stratification. Reporting biliary tract violations during cholecystectomy is encouraged.

Effect of Time to Surgery of Colorectal Liver Metastases on Survival

Purpose

Resection of liver-only colorectal liver metastases (CRLM) with perioperative chemotherapy is potentially curative. Specific primary tumor and liver metastasis characteristics have been validated to estimate the risk of recurrence. We hypothesize that the time interval from diagnosis of CRLM to surgery, or time to surgery (TTS), is clinically prognostic.

Methods

Patients from a prospectively maintained institutional database at a Comprehensive Cancer Center from May 2003 to January 2018 were reviewed. Clinicopathologic, perioperative treatment, and TTS data were collected. TTS was categorized into short (< 3 months), intermediate (3–6 months), and long (> 6 months) intervals.

Results

Two hundred eighty-one patients were identified. While overall survival (OS) was similar across TTS, postoperative overall survival (postoperative OS) of long TTS was associated with worse survival, 44 months (95% CI, 34–52) compared to short TTS, 59 months (95% CI, 43–79), and intermediate TTS, 63 months (95% CI, 52–108), both p < 0.01. With regard to long-term OS, intermediate TTS had 5-year OS of 59% and 8-year OS of 43% compared to long TTS (5-year OS 53% and 8-year OS 18%) and short TTS (5-year OS 54% and 8-year OS 29%). Long TTS was negatively associated with postoperative OS on multivariate analysis (HR 1.6, p < 0.01) when adjusting for resection margin, CRLM size, age, and use of postoperative chemotherapy.

Conclusion

Short and intermediate TTS had similar survival although patients with intermediate TTS may have better odds of long-term OS. While long TTS was associated with worse survival, likely due to higher disease burden, long-term survivors were still observed.

Electronic supplementary material

The online version of this article (10.1007/s12029-020-00372-5) contains supplementary material, which is available to authorized users.