Impact of travel distance on timeliness of adjuvant chemotherapy in veterans with colorectal cancer

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Background: Rural patients have well described disparities in quality cancer care. The VA Budget and Choice Improvement Act (2015) and VA Mission Act (2018) were passed to increase timely access to cancer care for veterans living at greater distances from VA facilities by paying for community oncology care. We sought to evaluate the baseline timeliness of adjuvant colorectal cancer (CRC) chemotherapy among patients living at increased distances from the Veterans Health Administration Tennessee Valley Healthcare System (VHA-TVHS) to determine local metrics for quality improvement initiatives. Methods: We reviewed 1,107 electronic medical records of patients with colorectal surgeries from January 1, 2000 to December 31, 2015 at the VHA-TVHS. We included patients with NCCN eligible pathologic high-risk stage II (T4/perf, R1, < 12LN, LVI) or stage III CRC and excluded those age ≥80, age ≥75 hospitalized in the prior year with a major co-morbidity, and death or hospice within 30 days of surgery. Primary exposure was travel distance from central zip code of patient residence to VHA-TVHS, categorized < 50 miles (N = 64), 55-99 miles (N = 60), and ≥ 100 miles (N = 56) to account for changes in referral patterns. Outcomes were days from surgery to first chemotherapy treatment and achieving a VHA timeliness standard of 56 days. Eligible patients not receiving chemotherapy were capped at 120 days per Commission on Cancer standard. Results: Of 1,107 colorectal resections, we excluded 623 for non-cancer, 212 for stage I or low risk stage II, 47 for metastases, and 45 for age, co-morbidity, death, and hospice, yielding a final cohort of 121 colon and 59 rectal cancer patients. Patients were predominantly male (96%), white (79%), and median age 64 years [Interquartile Range 60, 70]. Median days to chemotherapy were 62.5 days [48.5, 120] for those who lived < 50 miles, 58.5 days[46.5, 120] for distance 50-99 miles, and 84 days [50.5, 120]) for distance ≥ 100 miles. There were only 41%, 48%, and 32% in each distance group meeting the 56-day standard, respectively. Adjusting for known correlates, time to chemotherapy was 10.6 days longer for patients living ≥ 100 miles compared to < 50 miles (p = 0.08). Conclusions: Distance to care may influence timeliness of chemotherapy among southeast regional veterans. Given the observed overall low rate of timely chemotherapy, understanding modifiable health system factors associated with omissions and delays, as well as the impact of recent VA legislation merits further exploration.

Clinical and pathologic factors associated with survival in BRAFV600E colorectal cancers

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Background: BRAFV600E mutations occur in fewer than 10% of all patients (pts) with metastatic colorectal cancer (mCRC) and arise from sessile serrated adenomas. Despite efficacy with targeted therapies against MAPK signaling and with immunotherapies in this population, survival outcomes for pts with BRAFV600E mCRC in general are poor. Characteristics distinguishing pts with BRAFV600E mCRC with favorable versus unfavorable outcomes have not been well annotated. Methods: Records of 188 pts with BRAFV600E mCRC evaluated at MD Anderson Cancer Center between 3/2010-1/2020 were reviewed. Pts with the shortest and longest metastatic survival (N = 25 for each group) were compared. Associations between prognostic group and clinical/pathologic features were measured by odds ratio and for median survival by log-rank testing. Results: Median metastatic survival differed between the 2 BRAFV600E mCRC populations (8.6 vs 84 months, p < .0001). Pts with poor survival more commonly had primary tumors arising from the hepatic flexure/proximal transverse colon (44% vs 16%, p = .04) and more frequent hepatic involvement (75% vs 28%, p = .001). Pts with favorable survival were more likely to develop metachronous metastases (52% vs 16%, p = .01), have fewer distant organ involvement (median 1 vs 2, p = .02), and undergo definitive locoregional therapy to metastatic disease (44% vs 0%, p = .01). Microsatellite instability (36% vs 4%, p = .008) and a history of tobacco use (44% vs 16%, p = .04) were associated with a favorable prognosis. Durable responses to MAPK-targeted therapies (5/25) and immunotherapy (3/25) were noted in the favorable group. Conclusions: Pts with BRAFV600E mCRC can achieve excellent long-term survival which belies conventional context and is driven by locoregional and systemic treatment options alike. Anatomic localization of the primary tumor and prior exposures may highlight environmental influences on tumor biology which account for the clinical heterogeneity of pts with BRAFV600E mCRC.

Temporal trends in receipt of adjuvant chemotherapy for veterans with colorectal cancer

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Background: For patients with National Comprehensive Cancer Network (NCCN) high risk stage II or stage III colorectal cancer (CRC), adjuvant chemotherapy improves disease free (DFS) and overall survival (OS). Rates of use vary significantly across health care settings. Several demographic and healthcare factors are associated with decreased receipt of chemotherapy; however, few studies have assessed utilization patterns over time. We evaluated receipt of chemotherapy from 2000-2015 among patients treated at a Southeast Regional Veterans Health Administration (VHA) facility to determine local targets for quality improvement initiatives. Methods: We reviewed 1,107 electronic medical records of patients undergoing colorectal surgery from January 1, 2000 to December 31, 2015 at VHA Tennessee Valley Healthcare System. We included patients with NCCN eligible pathologic high risk stage II (T4/perf, R1, < 12LN, LVI) or stage III CRC and excluded for age ≥80, age ≥75 hospitalized in the prior year with a major co-morbidity, and death or hospice within 30 days of surgery. The primary predictor was year of surgery, partitioned 2000-2005 (N = 60), 2006-2010 (N = 64), 2011-2015 (N = 56) to reflect changes in NCCN guidelines. The primary outcome was receipt of any chemotherapy. Results: Of 1,107 colorectal surgeries, we excluded 623 for non-cancers, 212 for stage I or low-risk stage II cancer, 47 for metastatic disease, and 45 for age, co-morbidity, death, and hospice, yielding a final cohort of 121 colon and 59 rectal cancers. Most patients were male (96%), white (79%), with median age 64 years [Interquartile Range 60, 70]. Overall, 117 of 180 (65%) received chemotherapy with a median time to treatment of 50.5 days [40,64]. Adjusting for known correlates, receipt of chemotherapy decreased over time; 2000-2005 (72%), 2006-2010 (69%), 2011-2015 (53%) p = 0.02. Regardless of CRC stage, more patients declined chemotherapy in 2011-2015 (27%) compared to 2000-2005 (6%) and 2006-2010 (8%) p < 0.01. Conclusions: We identified decreased utilization of adjuvant chemotherapy in a non-elderly veteran cohort, which appeared to be due to patients declining chemotherapy regardless of cancer stage. Understanding patient and provider decisions around adjuvant chemotherapy and evaluating trends outside the VHA may offer important insights to implementing quality improvement measures.

In Reply

This letter to the editor remarks on additional considerations for the management of febrile neutropenia during the COVID‐19 pandemic, in response to the letter by Boutayeb et al.

Phase I study of DFP-11207, a novel oral fluoropyrimidine with reasonable AUC and low Cmax and improved tolerability, in patients with solid tumors

5-fluorouracil (5-FU) and 5-FU derivatives, such as capecitabine, UFT, and S-1, are the mainstay of chemotherapy treatment for gastrointestinal cancers, and other solid tumors. Compared with other cytotoxic chemotherapies, these drugs generally have a favorable safety profile, but hematologic and gastrointestinal toxicities remain common. DFP-11207 is a novel oral cytotoxic agent that combines a 5-FU pro-drug with a reversible DPD inhibitor and a potent inhibitor of OPRT, resulting in enhanced pharmacological activity of 5-FU with decreased gastrointestinal and myelosuppressive toxicities. In this Phase I study (NCT02171221), DFP-11207 was administered orally daily, in doses escalating from 40 mg/m²/day to 400 mg/m²/day in patients with esophageal, colorectal, gastric, pancreatic or gallbladder cancer (n = 23). It was determined that DFP-11207 at the dose of 330 mg/m²/day administered every 12 hours was well-tolerated with mild myelosuppressive and gastrointestinal toxicities. The pharmacokinetic analysis determined that the 5-FU levels were in the therapeutic range at this dose. In addition, fasted or fed states had no influence on the 5-FU levels (patients serving as their own controls). Among 21 efficacy evaluable patients, 7 patients had stable disease (33.3%), of which two had prolonged stable disease of >6 months duration. DFP-11207 can be explored as monotherapy or easily substitute 5-FU, capecitabine, or S-1 in combination regimens.

Cell-free Circulating Tumor DNA Variant Allele Frequency Associates with Survival in Metastatic Cancer

PURPOSE

Physicians are expected to assess prognosis both for patient counseling and for determining suitability for clinical trials. Increasingly, cell-free circulating tumor DNA (cfDNA) sequencing is being performed for clinical decision making. We sought to determine whether variant allele frequency (VAF) in cfDNA is associated with prognosis.

EXPERIMENTAL DESIGN

We performed a retrospective analysis of 298 patients with metastatic disease who underwent clinical comprehensive cfDNA analysis and assessed association between VAF and overall survival.

RESULTS

cfDNA mutations were detected in 240 patients (80.5%). Median overall survival (OS) was 11.5 months. cfDNA mutation detection and number of nonsynonymous mutations (NSM) significantly differed between tumor types, being lowest in appendiceal cancer and highest in colon cancer. Having more than one NSM detected was associated with significantly worse OS (HR = 2.3; P < 0.0001). VAF was classified by quartiles, Q1 lowest, Q4 highest VAF. Higher VAF levels were associated with a significantly worse overall survival (VAF Q3 HR 2.3, P = 0.0069; VAF Q4 HR = 3.8, P < 0.0001) on univariate analysis. On multivariate analysis, VAF Q4, male sex, albumin level <3.5 g/dL, number of nonvisceral metastatic sites >0 and number of prior therapies >4 were independent predictors of worse OS.

CONCLUSIONS

Higher levels of cfDNA VAF and a higher number of NSMs were associated with worse OS in patients with metastatic disease. Further study is needed to determine optimal VAF thresholds for clinical decision making and the utility of cfDNA VAF as a prognostic marker in different tumor types.

A phase II study of axalimogene filolisbac for patients with previously treated, unresectable, persistent/recurrent loco-regional or metastatic anal cancer

Squamous cell carcinoma of the anorectal canal (SCCA) is a rare HPV-related malignancy that is steadily increasing in incidence. A high unmet need exists for patients with persistent loco-regional and metastatic disease. Axalimogene filolisbac (ADXS11-001) is an investigational immunotherapy that stimulates tumor-specific responses against HPV-associated cancers, and has demonstrated benefit in metastatic cervical cancer. We conducted this single-arm, multicenter, phase 2 trial in patients with persistent/recurrent, loco-regional or metastatic SCCA. Patients received ADXS11-001, 1 × 10⁹ colony-forming units intravenously every 3 weeks. A Simon 2-stage design was used to test primary co-endpoints of overall response rate (ORR) and 6-month progression-free survival (PFS) rate. Study would proceed to full enrollment if ORR ≥ 10% or 6-month PFS rate ≥ 20%. Thirty-six patients were treated; 29 patients were evaluable for response. One patient had a prolonged partial response (3.4% ORR). The 6-month PFS rate was 15.5%. Grade 3 adverse event were noted in 10 patients, with the majority being cytokine-release symptoms; one grade 4 adverse event was noted. No grade 5 adverse events occurred. ADXS11-001 was safe and well-tolerated in patients with SCCA. However, this study did not meet either primary endpoint. ADXS11-001 may be more beneficial when administered in combination with other cytotoxic or targeted agents.

A phase II study of durvalumab (MEDI4736) (anti-PD-L1) and trametinib (MEKi) in microsatellite stable (MSS) metastatic colorectal cancer (mCRC)

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Background: Monotherapy with immune checkpoint blockade (ICB) is ineffective for patients (pts) with MSS mCRC. Novel approaches to modulate the tumor microenvironment (TME) are needed. Here, we investigate whether the combination of trametinib (T) with durvalumab (D) can alter the immune TME by successfully priming and activating T-cells. Methods: An open-label, single center phase II trial with primary endpoint of immune-related response rate for T+D in refractory MSS mCRC pts (NCT03428126). T is 2mg/day orally starting 1 week prior to D, which is given 1500mg intravenously every 4 weeks. Dose de-escalation strategy performed to identify maximum tolerated dose (MTD). Simon 2-stage design utilized with plans to enroll 29 pts into the first stage, requiring response in 2 or more pts to proceed to stage 2 (n = 15). Results: Demographics for 29 treated pts: 48% female, median age 48 years (range 28-75), and median prior therapies was 2 (range 1-5). No grade (G) 4 treatment-related adverse events (TRAE). The most common G3 TRAE included autoimmune hepatitis (14%) and acneiform rash (10%). G1/2 TRAE included acneiform rash (69%), fatigue (24%) and anemia (21%). No fatal TRAE and 4 pts discontinued treatment due to TRAE. 1 of 29 pts had confirmed partial response (PR) lasting 9.3 months (mo) for an ORR of 3.4%. This pt had an ATM E221fs*14 mutation. 7 pts had stable disease (SD) with median time to progression (TTP) of 5.4 mo (range 3.9-9.3 mo). 1 pt remains on active therapy with SD ( > 10 mo). 5 pts (1 PR, 4 SD) demonstrated decrease in total CEA ng/mL (best percentage reduction: 94%, 95%, 42%, 34% and 21.6% respectively). Median TTP for the entire cohort was 3.2 mo (range 1.1-9.3 mo). Consensus molecular subtypes (CMS) were performed on the primary CRC in 23 pts: 12 CMS2, 2 CMS3, and 9 CMS4. 4 SD pts were CMS2, 1 SD pt was CMS4 and the CMS status of the pt with a PR was unknown. Conclusions: The combination of T+D did not meet efficacy criteria to proceed to the second stage of the study. Analysis of 15 paired on-treatment biopsies is ongoing and will be presented. Utilization of CMS characterization in mCRC clinical trials is feasible and may provide an improved biological understanding of treatment activity. Clinical trial information: NCT03428126.

A phase Ib/II study of the anti-CD47 antibody magrolimab with cetuximab in solid tumor and colorectal cancer patients

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Background: Magrolimab (M, Hu5F9-G4) is an antibody targeting CD47, a macrophage “don’t eat me” signal that demonstrates preclinical synergy with cetuximab (C) in refractory KRAS wild type (KRASwt) and KRAS mutant (KRASm) colorectal (CRC) tumors. Methods: Phase (Ph) 1 doses of M+C were escalated in solid tumor patients (pts) and Ph 2 efficacy was explored in previously treated KRASwt and KRASm CRC patients. Day 1 priming with 1 mg/kg of M was used to mitigate on-target anemia followed by maintenance doses ranging from 10 to 45 mg/kg in combination with C. Ph 2 pts were treated with 30 or 45 mg/kg of M and 400/250 mg/m2 of C. Results: In 78 treated pts (32 Ph 1 and 46 Ph 2), the median age was 59 years (range 19-82), and median prior therapies was 5 (range 1-14). No maximum tolerated dose was reached. Treatment-related adverse events (TRAEs) of any Grade (G) included dermatitis acneiform 36%, dry skin 33%, fatigue 32%, infusion reactions 31%, headache 30%, diarrhea 23%, nausea 23%, chills 23%, and anemia 22%. There were no fatal TRAEs and 3/78 (4%) discontinued M treatment due to any adverse events. In the combined Ph 1+2 study, 2 of 30 evaluable KRASwt CRC pts had confirmed PRs for 7.0 and 12.5 months (mo), for a 6.7% objective response rate (ORR). Both had prior C treatment. The median progression-free survival (mPFS) and median overall survival (mOS) was 3.6 mo (95%CI 1.8-5.4) and 10.1 mo (95%CI: 6.9-14.4), respectively. In 40 evaluable KRASm pts, there were no responses but 45% had stable disease (SD) and the mPFS and mOS were 1.9 mo (95%CI: 1.8-3.5) and 10.4 mo (95%CI: 5.7-16.4), respectively. In 28 KRASm pts who were TAS102/regorafenib naïve, preliminary mOS was 12.4 mo (95%CI: 5.9-not reached) which is longer than that reported for historical controls. Tumor biopsies showed treatment-related increases in macrophage immune cell infiltrates in SD pts, and baseline T cell infiltration was associated with longer OS. Pharmacokinetic profiles will be presented. Conclusions: M+C is a novel, well-tolerated combination immunotherapeutic treatment regimen. Responses were observed in two previously treated CRC pts and survival is encouraging in KRASm pts. Funded by Forty Seven and California Institute for Regenerative Medicine. Clinical trial information: NCT02953782.

A pilot study of oncology massage to treat chemotherapy-induced peripheral neuropathy (CIPN)

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Background: Short- and long-term toxicity of platinum compounds and taxanes includes development of CIPN. With an increased interest regarding the role of complementary approaches for symptom control, we investigated massage therapy for symptomatic relief of chronic CIPN. Methods: This pilot study evaluated the optimum treatment schedule and initial efficacy of a standardized Swedish massage technique to treat lower extremity (LE) CIPN. Inclusion criteria: LE neuropathy attributed to oxaliplatin, paclitaxel, or docetaxel, no other history of attributable causes; self-reported neuropathy score ≥3, 0-10 scale; ≥ 6 months since last chemotherapy treatment; age ≥ 18. Patients (pts) were randomized to one of four groups: 1) LE massage 3 times (3X) week for 4 weeks; LE massage 2X week for 6 weeks; 3) head/neck/shoulder (control) massage 3X week for 4 weeks; or 4) control massage 2X week for 6 weeks. Massage completion rate was examined and symptoms of CIPN measured with the Pain Quality Assessment Scale [PQAS (Range: 0-10); subscales of SP (surface pain), DP (deep pain), and PP (paroxysmal pain)] at baseline and at 10 weeks. Results: 71 pts fulfilled inclusion criteria: 77.5% women; 57.7% (breast cancer), and 42.3% (GI cancer); mean age 60.3 y/o (range: 40-77). Average length of time since the end of chemotherapy was > 3 yrs. Mean massage completion rates (max = 12) were 8.9 (SD 4.2) for 3X week and 9.8 (4.0) for 2X week with no statistical differences. There were no statistically significant differences in PQAS scores at follow-up between site-specific massage groups (lower extremity vs controls). Pts who had massage 3X week reported statistically and clinically significantly improved PQAS scores versus those who had massage 2X week (change scores: PQAS-SP: -2.3 vs. -0.6, p = 0.001; PQAS-DP: -2.1 vs. -0.9, p = 0.008; PQAS-PP: -2.3 vs. -1.0, p = 0.025), with sustained improvement in the 3X week group, but minimal change in the 2X week group. Conclusions: We observed sustained reduction in pts with long-term CIPN up to 6 weeks after treatment completion for the more intensive 3X week massage group, regardless of treatment site. A large-scale efficacy trial is warranted to validate the role of oncology massage therapy for CIPN. Clinical trial information: NCT02221700.

Role of Immunotherapy in the Treatment of Squamous Cell Carcinoma of the Anal Canal

Anal cancer is a rare malignancy for which cisplatin with 5-fluorouracil is the recommended treatment for patients with metastatic disease. Because most cases of anal cancer are linked to prior infection with oncogenic strands of the human papillomavirus, immunotherapeutic approaches have been of great interest in the development of new treatments for this virally driven tumor. This article reviews the early successes of anti-PD-1 therapies and adoptive T-cell therapies for metastatic anal cancer as a potential foundation for novel combination immunotherapy trials in the future.

Minocycline for Symptom Reduction During Oxaliplatin-Based Chemotherapy for Colorectal Cancer: A Phase II Randomized Clinical Trial

CONTEXT

The most debilitating symptoms during oxaliplatin-based chemotherapy in patients with colorectal cancer (CRC) are neuropathy and fatigue. Inflammation has been suggested to contribute to these symptoms, and the anti-inflammatory agent minocycline is safe and readily available.

OBJECTIVES

This proof-of-concept study investigated minocycline's capacity to reduce treatment-related neuropathy and fatigue and its impact on inflammatory markers during chemotherapy in a Phase II randomized, double-blind, placebo-controlled clinical trial.

METHODS

Patients with locally advanced or metastatic CRC who were scheduled for oxaliplatin-based chemotherapy were randomly assigned to receive either minocycline (100 mg twice daily) or placebo over four months from started chemotherapy. Toxicity assessments and blood samples were prospectively collected monthly. The severity of fatigue and numbness/tingling was assessed weekly using the MD Anderson Symptom Inventory. The primary endpoint, area under the curve for numbness/tingling and fatigue over approximately four months, was compared between the two arms.

RESULTS

Of 66 evaluable participants, 32 received minocycline and 34 placebo. There was no observed significant symptom reduction on both fatigue and numbness/tingling in either arm, nor was there a difference in levels of serum proinflammatory and anti-inflammatory markers between arms. No Grade 3 adverse events nor disparity mediating effects on intervention were observed.

CONCLUSION

Minocycline treatment is feasible and has a low-toxicity profile. However, with 200 mg/day, it did not reduce numbness/tingling or fatigue nor moderate inflammatory biomarkers from this Phase II randomized study. Our results do not support further exploration of minocycline for fatigue or neuropathy symptom intervention in patients treated for CRC.

Identification of Actionable Genomic Alterations Using Circulating Cell-Free DNA

PURPOSE

Cell-free DNA (cfDNA) next-generation sequencing is a noninvasive approach for genomic testing. We report the frequency of identifying alterations and their clinical actionability in patients with advanced/metastatic cancer.

PATIENTS AND METHODS

Prospectively consented patients had cfDNA testing performed. Alterations were assessed for therapeutic implications.

RESULTS

We enrolled 575 patients with 37 tumor types. Of these patients, 438 (76.2%) had at least one alteration detected, and 205 (35.7%) had one or more alterations of high potential for clinical action. In diseases with 10 or more patients enrolled, 50% or more had at least one alteration deemed of high potential for clinical action. Trials were identified in 80% of patients (286 of 357) with any alteration and in 92% of patients (188 of 205) with one or more alterations of high potential for clinical action of whom 57.6% (118 of 205) had 6 or more months of follow-up available. Of these patients, 10% (12 of 118) had received genomically matched therapy through enrollment in clinical trials (n = 8), off-label drug use (n = 3), or standard of care (n = 1). Although 88.6% of all patients had a performance status of 0 or 1 upon enrollment, the primary reason for not acting on alterations was poor performance status at next treatment change (28.1%; 27 of 96).

CONCLUSION

cfDNA testing represents a readily accessible method for genomic testing and allows for detection of genomic alterations in most patients with advanced disease. Utility may be higher in patients interested in investigational therapeutics with adequate performance status. Additional study is needed to determine whether utility is enhanced by testing earlier in the treatment course.

Pharmacotherapeutic considerations for elderly patients with colorectal cancer

Introduction: Oncology care in the elderly presents a dilemma. The majority of cancer cases are diagnosed in the elderly yet they are underrepresented in clinical trials. In addition to limited evidence-based medicine, the elderly is a heterogeneous population filled with pharmacotherapeutic challenges and barriers. Elderly metastatic colorectal cancer (mCRC) treatment decisions encompass these challenges.Areas covered: Treatment based solely on chronological age is an unacceptable practice. Physiologic factors such as function, cognition, comorbidities, polypharmacy, among others must be considered. Oncology guidelines emphasize using a geriatric assessment (GA) as opposed to traditional oncology performance status measures to best identify risks. Our review shines light on these issues as they pertain to elderly unresectable metastatic colorectal cancer (mCRC).Expert opinion: The practical use of GA tools in oncology remain to be determined. Current barriers are the lack of a consistent tool to unify decision-making, provider education, and evidence-based use/outcomes in specific cancers. mCRC antineoplastic data surrounding GAs are scarce, and current mCRC national treatment algorithms are not stratified to encompass GA-driven therapy. Therefore, providers lack clear guidance or practicality of use. We hope mCRC trial designs will abandon age cutoffs and instead place more focus on GAs for inclusion and outcomes.

Atypical, Non-V600 BRAF Mutations as a Potential Mechanism of Resistance to EGFR Inhibition in Metastatic Colorectal Cancer

PURPOSE

Atypical, non-V600 BRAF (aBRAF) mutations represent a rare molecular subtype of metastatic colorectal cancer (mCRC). Preclinical data are used to categorize aBRAF mutations into class II (intermediate to high levels of kinase activity, RAS independent) and III (low kinase activity level, RAS dependent). The clinical impact of these mutations on anti-EGFR treatment efficacy is unknown.

PATIENTS AND METHODS

Data from 2,084 patients with mCRC at a single institution and from an external cohort of 5,257 circulating tumor DNA (ctDNA) samples were retrospectively analyzed. Overall survival (OS) was calculated using Kaplan-Meier and log-rank tests. Statistical tests were two-sided.

RESULTS

BRAF mutations were harbored by 257 patients, including 36 with aBRAF mutations: 22 class III, 10 class II, four unclassified. For patients with aBRAF mCRC, median OS was 36.1 months, without a difference between classes, and median OS was 21.0 months for patients with BRAF^V600E mCRC. In contrast to right-sided predominance of tumors with BRAF^V600E mutation, 53% of patients with aBRAF mCRC had left-sided primary tumors. Concurrent RAS mutations were noted in 33% of patients with aBRAF mCRC, and 67% of patients had microsatellite stable disease. Among patients with aBRAF RAS wild-type mCRC who received anti-EGFR antibodies (monotherapy, n = 1; combination therapy, n = 10), no responses to anti-EGFR therapy were reported, and six patients (four with class III aBRAF mutations, one with class II, and one unclassified) achieved stable disease as best response. Median time receiving therapy was 4 months (range, 1 to 16). In the ctDNA cohort, there was an increased prevalence of aBRAF mutations and subclonal aBRAF mutations (P < .001 for both) among predicted anti-EGFR exposed compared with nonexposed patients.

CONCLUSION

Efficacy of anti-EGFR therapy is limited in class II and III aBRAF mCRC. Detection of aBRAF mutations in ctDNA after EGFR inhibition may represent a novel mechanism of resistance.

A Phase II Study of Capecitabine/Oxaliplatin With Concurrent Radiotherapy in Locally Advanced Squamous Cell Carcinoma of the Anal Canal

INTRODUCTION

Squamous cell carcinoma of the anal canal (SCCA) presents a rising incidence in the United States. Standard of care for locally advanced disease is comprised of infusional 5-fluorouracil with mitomycin C or cisplatin concurrent with radiation therapy (RT). We designed this trial to evaluate the efficacy and safety of a more convenient regimen composed of capecitabine and oxaliplatin.

PATIENTS AND METHODS

This was a single-arm, phase II trial, with treatment-naive stage II to IIIB (TX,1-4NxM0) SCCA patients. The regimen was composed of capecitabine (825 mg/m² twice per day for 5 days) and oxaliplatin (50 mg/m² weekly) during weeks 1 through 6, concurrent with RT (XELOX-XRT; group 1). After the first 11 patients, the study was amended to omit chemotherapy during the third and sixth weeks (group 2). The primary objective was 3-year time to treatment failure (TTF) and safety. Secondary objectives were complete response (CR) rate, locoregional control, colostomy-free survival (CFS), and overall survival (OS).

RESULTS

Twenty patients were enrolled. Seven patients of group 1 (63%) developed Grade 3 toxicity, which reduced to 22% in Group 2. No Grade 4 toxicities were noted. The median RT dose was 55 Gy. CR occurred in 100% of the 19 patients evaluable for response at 12 to 14 weeks. After a median follow-up of 47.6 months, 2 patients had local recurrence and 1 had distant recurrence. Three-year TTF was 90.0%, with similar rates between groups 1 and 2 (respectively, 90.9% vs. 88.8%, P = .984). Three-year CFS was 90.0%. The median OS has not been reached.

CONCLUSION

The XELOX-XRT regimen is safe, with promising efficacy, and should be explored in larger trials for the treatment of locally advanced SCCA.

Comprehensive Genomic Landscapes in Early and Later Onset Colorectal Cancer

PURPOSE

The incidence rates of colorectal cancers are increasing in young adults. The objective of this study was to investigate genomic differences between tumor samples collected from younger and older patients with colorectal cancer.

EXPERIMENTAL DESIGN

DNA was extracted from 18,218 clinical specimens, followed by hybridization capture of 3,769 exons from 403 cancer-related genes and 47 introns of 19 genes commonly rearranged in cancer. Genomic alterations (GA) were determined, and association with patient age and microsatellite stable/microsatellite instability high (MSS/MSI-H) status established.

RESULTS

Overall genomic alteration rates in the younger (<40) and older (≥50) cohorts were similar in the majority of the genes analyzed. Gene alteration rates in the microsatellite stable (MSS) younger and older cohorts were largely similar, with several notable differences. In particular, TP53 (FDR < 0.01) and CTNNB1 (FDR = 0.01) alterations were more common in younger patients with colorectal cancer, and APC (FDR < 0.01), KRAS (FDR < 0.01), BRAF (FDR < 0.01), and FAM123B (FDR < 0.01) were more commonly altered in older patients with colorectal cancer. In the MSI-H cohort, the majority of genes showed similar rate of alterations in all age groups, but with significant differences seen in APC (FDR < 0.01), BRAF (FDR < 0.01), and KRAS (FDR < 0.01).

CONCLUSIONS

Tumors from younger and older patients with colorectal cancer demonstrated similar overall rates of genomic alteration. However, differences were noted in several genes relevant to biology and response to therapy. Further study will need to be conducted to determine whether the differences in gene alteration rates can be leveraged to provide personalized therapies for young patients with early-onset sporadic colorectal cancer.

FOLFOXIRI versus doublet-regimens in the first-line therapy of MSI-S right-sided (RS) metastatic colorectal cancer (mCRC): A survival analysis

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Background: Microsatellite stable (MSI-S) RS mCRC patients (pts) have a worse prognosis relative to left sided tumors for overall survival (OS). The present analysis aims to test the hypothesis that a triplet-regimen is superior compared to doublet-regimens (DR; FOLFOX or FOLFIRI) for OS. Methods: Pts with treatment-naive RS mCRC at MD Anderson Cancer Center between January/2011 to December/2018 were selected. We compared the progression-free survival (PFS) and OS of mCRC pts treated with FOLFOXIRI versus DR. Pts treated with anti-EGFR therapy were excluded. Results: A total of 37 pts were treated with FOLFOXIRI and 111 pts with DR. There were no statistical difference between groups regarding gender, KRAS and BRAF mutations, peritoneal metastasis and bevacizumab use. There were statistical difference in age (median: 46y vs 59y) and metastasectomy rates (14% vs 32%) (p < 0.001). KRAS mutation was found in 65% of the population. Median follow-up was 55.3m. Median PFS was 6.5m vs 11.2m (HR: 1.30 95% CI 0.85 – 1.99) and median OS was 17.0m vs 26.3m (HR: 1.01 95% CI 0.60 – 1.68). By univariate analysis, pts who have undergone metastasectomy had superior PFS (14.9m vs 9.2m; p<0.001) and OS (32.4m vs 22.9m; p=0.003). By multivariate analysis adjusted for age, BRAF mutation, metastasectomy, bevacizumab use and, treatment regimen, only age and metastasectomy had prognostic influence for PFS (p=0.039 and p=0.026, respectively). Conclusions: Despite RS having a poor prognosis for OS, our study does not suggest that RS mCRC pts benefit from intensive treatment. Randomized clinical trials may suggest more individualized therapies.

A systematic review of surrogate endpoints (SEPs) for overall survival (OS) in metastatic colorectal cancer (mCRC)

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Background: Although progression free survival (PFS) and overall response rate (ORR) are common endpoints in mCRC trials, validation of these as SEPs for OS across the evolving landscape of systemic treatment in mCRC, with novel therapeutics and expanding lines of treatment, is limited. We aimed to evaluate the potential surrogacy of PFS and RR for OS and explore variations across trial factors. Methods: We identified phase 3 randomized trials of systemic therapy in mCRC between 1986 - 2016 from 4 electronic databases. Data regarding endpoints and trial variables were extracted from published reports. Spearman’s coefficient (r) and linear regression were used to evaluate rank correlations between A) PFS and ORR with OS of both treatment and control arms (arm level analysis); B) net improvement in outcomes using hazard ratio (HR) for PFS and relative risk (RR) for ORR with HR for OS (trial level analysis). Results: A total of 128 trials containing 233 and 230 arms reporting on PFS and ORR, respectively, were identified. Arm level analysis revealed that correlation of PFS and ORR with OS was 0.69 (95%CI: 0.6 – 0.7) and 0.79 (95%CI: 0.7 – 0.8), respectively ( P < 0.001). Of 86 trials with reported HR for OS, PFS and ORR ratios were obtained for 84 and 74 trials, respectively. Trial level analysis revealed that correlation of PFS and ORR treatment effect with OS was 0.71 (95%CI: 0.6 – 0.8) and 0.58 (95%CI: 0.4 – 0.7), respectively ( P < 0.001). Level of correlation for PFS and ORR varied with line of therapy, type of therapy and trial size (Spearman r shown in table). Conclusions: Both ORR and PFS are appropriate SEPs for OS for systemic therapy in mCRC but their relative value varies notably with line/type of therapy and study size. Judicious use of these SEPs in clinical trials accordingly to supplant OS may help improve trial designs and performance.[Table: see text]

A pilot study of oncology massage to treat chemotherapy-induced peripheral neuropathy (CIPN)

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Background: Short- and long-term toxicity of platinum compounds and taxanes includes development of CIPN. Although anti-neuropathic medications are available, there is increased interest by health care providers and patients (pts) regarding the role of complementary approaches for symptom control. Therefore, we explored the role of massage therapy for symptomatic relief of chronic CIPN. Methods: This pilot study evaluated the optimum treatment schedule and initial efficacy of two treatment schedules of a standardized Swedish massage technique to treat lower extremity (LE) CIPN. Inclusion criteria: LE neuropathy attributed to oxaliplatin, paclitaxel, or docetaxel, no other history of attributable causes (concurrent upper extremity neuropathy allowed); self-reported neuropathy score ≥3, 0-10 scale; ≥ 6 months since last chemotherapy treatment; age ≥ 18. Pts were randomized to one of four groups: 1) LE massage 3 times (3X) week for 4 weeks; LE massage 2X week for 6 weeks; 3) head/neck/shoulder (control) massage 3X week for 4 weeks; or 4) control massage 2X week for 6 weeks. Massage completion rate was examined and symptoms of CIPN measured with the Pain Quality Assessment Scale [PQAS (Range: 0-10); subscales of PQAS-SP (surface pain), PQAS-DP (deep pain), and PQAS-PP (paroxysmal pain)] at baseline and at 10 weeks. Results: 71 pts fulfilled inclusion criteria: 77.5% women; 57.7% (breast cancer), and 42.3% (GI cancer); mean age 60.3 y/o (range: 40-77). Average length of time since the end of chemotherapy was > 3 yrs. Mean massage completion rates (max = 12) were 8.9 (SD 4.2) for 3X week and 9.8 (4.0) for 2X week with no statistical differences. There were no statistically significant differences in PQAS scores at follow-up between site-specific massage groups (lower extremity vs controls). Pts who had massage 3X week reported statistically and clinically significantly improved PQAS scores versus those who had massage 2X week (change scores: PQAS-SP: -2.3 vs. -0.6, p = 0.001; PQAS-DP: -2.1 vs. -0.9, p = 0.008; PQAS-PP: -2.3 vs. -1.0, p = 0.025), with sustained improvement maintained in the 3X week group, but minimal change in the 2X week group. Conclusions: We observed sustained reduction in pts with long-term CIPN up to 6 weeks after treatment completion for the more intensive 3X week massage group, regardless of massage treatment site. A large-scale efficacy trial is warranted to validate the role of oncology massage therapy for CIPN. Clinical trial information: NCT02221700.

Phase I study of DFP-11207, a novel oral 5-FU with enhanced PK and improved tolerability, in patients with solid tumors

3034

Background: DFP-11207 combines a 5-fluorouracil (5-FU) pro-drug with a reversible dihydropyrimidine dehydrogenase inhibitor and a potent inhibitor of orotate phosphoribosyl transferase resulting in enhanced pharmacological activity of 5-FU with decreased gastrointestinal and myelosuppressive toxicity. Methods: Patients with advanced solid tumors were treated in this single arm, dose escalation study. Accelerated dose escalation using single pt cohorts was followed until drug-related Gr2 adverse events occurred; then a 3+3 design was followed to determine maximum tolerated dose (MTD). Pts were dosed daily in 28-day cycles until intolerable toxicity or disease progression. PK sampling was performed for DFP-11207 metabolites on all pts and a 6 pt cohort received DFP-11207 in fed and fasted states to determine drug bioavailability. Results: Primary tumors among the 23 enrolled pts included esophageal, colorectal, gastric, pancreatic and gallbladder. Seventeen pts were treated at 8 dose levels of oral DFP-11207 administered daily, ranging from 40 to 440 mg/m2/d. At 440 mg/m2/d one pt experienced drug-related Gr3 dehydration and mucosal inflammation, and Gr4 febrile neutropenia; a second pt experienced Gr4 febrile neutropenia. One DLT of Gr3 vomiting occurred among 6 pts treated at 330 mg/m2/d dosed q12hrs confirming the MTD. Six pts were administered 300 mg DFP-11207 q12 hrs in a fed or fasted state to determine drug bioavailability. Among all pts, the most frequently reported drug-related TEAEs were fatigue (47.8%), nausea (47.8%), decreased appetite (39.1%), diarrhea (26.1%), vomiting (21.7%), anemia (13.0%), dysgeusia (13.0%), mucosal inflammation (13.0%) and palmar-plantar erythrodysaesthesia syndrome (13.0%). PK analyses of pts treated at 330 and 440 mg/m2/d indicate 5-FU concentrations of ~20 ng/mL throughout the dose cycle. There was no substantial difference in DFP-11207 bioavailability among pts in a fed or fasted state. Out of 21 efficacy evaluable pts, 7 pts had stable disease (33.3%), of which 2 had prolonged stable disease of > 6 months. No pts achieved CR or PR. Conclusions: DFP-11207 at the dose of 330 mg/m2/d q12hrs is well-tolerated in pts with solid tumors with mild myelosuppressive and gastrointestinal side effects, and results in circulating 5-FU levels conducive to an anti-tumor effect. DFP-11207 can be explored as monotherapy or substitute for 5-FU, capecitabine or S-1 in combination treatment regimens. Clinical trial information: NCT02171221.

Meat consumption and BRAF mutation status in colorectal cancer

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Background: Consumption of red and processed meat has been associated with increased risk of developing colorectal cancers, but less is known about the association of meat consumption with tumor molecular features. In this study, we tested the association of total meat consumption with molecular features of colorectal cancer and overall survival in a local cohort of patients. Methods: Data on meat consumption were collected using self-directed environmental surveys from patients with stage IV/locally advanced, treatment refractory colorectal cancer who were enrolled on the Assessment of Targeted Therapies Against Colorectal Cancer clinical protocol. Data on tumor molecular features were collected through medical record review. Patients were categorized into low, medium or high meat consumption groups based on servings per day tertile. Associations between tumor molecular features and meat intake were evaluated by Chi-square and logistic regression. Potential effects of meat consumption on overall survival were assessed using Cox Proportional Hazards models. Analyses were conducted with IBM SPSS v25. Results: Patients consumed an average of 0.74, 1.57 and 3.32 servings of meat per day in the low, medium and high categories, respectively. Out of 593 patients with evaluable data, 27 were found to have a BRAF V600E mutation. Total meat consumption differed significantly by BRAF V600E mutation status (p value 0.02) and by sex (p value < .01), but did not differ by tumor location, microsatellite instability, or RAS mutation status. Using logistic regression, we found that compared to patients with the highest level of meat consumption, those in the medium consumption group may be less likely to have a BRAF V600E mutation (OR 0.24; p value 0.08). Although meat consumption may be associated with BRAF mutation status, it was not predictive of overall survival in our analyses. Conclusions: Among patients in our study, meat consumption may be associated with tumor BRAF V600E mutation status but is not directly associated with survival. Additional work is needed to test this association in cohorts including more BRAF mutant cases. If confirmed, this finding may add further insight into the etiology and biology of these tumors.

Reporting of patient (pt) characteristics (c) and use of stratification factors (SF) in phase III trials for metastatic colorectal cancer (mCRC): Urgent need for standardization

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Background: An increasing number of pt and tumor c have predictive and prognostic implications in mCRC. However, there is no consensus on their reporting in trial results. Methods: Pt c and SF from 136 phase III trials of systemic therapies (Rx) in mCRC published between 1988 and 2018 (68,326 pts) were collected. Trials were also grouped per publication date (G1: 1988-97; G2: 98 – 2007; G3: 08-18). Patterns of reporting and trends across G were evaluated. Results: Pt c consistently reported were performance status, PS (98.5%), age (92.6%) and gender (90.4%); race (20.6%) & weight/BMI/BSA were not (13.2%). Tumor c frequently reported were metastatic (met) spread (70.6%) while time intervals related to disease course (25%) and synchronous met vs not (19.1%) were omitted. Of note, primary site was largely reported as colon vs rectum (69%) and sidedness or anatomical location was discernable only in 10.3%. Prior Rx reporting focused on chemo (58.5%) with radiation and surgery and reported in 34% & 28.7%. Reporting of prognostic factors was variable and limited: histology grade CEA, alk phos, LDH (range 10.3-15.4%). Only 11.8% of trials reported genomic factors - KRAS MT was included in all with BRAF MT in 4.4%. Of 140 trials used for SF analysis, 115 had ≥ 1 (range 1-7). Common SF were PS (60%), geography /institution (55.7%). Prior Rx (27%), met spread (24.3%) were sometimes used while primary site (7.8%), genomic factors (6.1%) rarely were. Trends across G are per Table. Conclusions: There is marked inconsistency in pt c & SF reporting in mCRC trials. Consensus guidelines will aid in standardization of trial interpretation and future meta-analyses; and will need to be updated based on emerging data. [Table: see text]

The association between female hormonal supplementation and molecular types in colorectal cancer

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Background: In the US, colorectal cancer is the third most common malignancy in women. Postmenopausal hormone use has been associated with decrease in incidence of colorectal cancer however few studies have evaluated the relationship between hormone use and molecular profiles of advanced colorectal cancer. The aim of this study is to evaluate correlations between female hormonal supplementation use and colorectal cancer molecular, clinical, and pathologic features. Methods: We conducted a retrospective case-case study of female patients with metastatic or unresectable, locally advanced colorectal cancer on the Assessment of Targeted Therapies Against Colorectal Cancer (ATTACC) protocol from 2010 to 2017. Post-menopausal hormone use was self-reported in an environmental survey as part of the ATTACC protocol. Molecular, clinical, and pathologic features were obtained through medical record review. Results: Among 258 female patients, 163 (63%) patients reported ever use of female hormonal supplementation. Ever use was significantly associated with BRAF V600E mutant tumors (OR 2.63, p-value 0.04). There was no association with KRAS, NRAS, PIK3CA mutations, microsatellite instability, or CpG island methylation. The mean age at diagnosis of ever users was 54.4 and mean of no supplement was 56.5 (p-value 0.07), indicating no age difference between ever and never users. Conclusions: Despite the overall protective effects of postmenopausal hormone use on colorectal cancer incidence, among those who develop colorectal cancer, our data suggest an association between female hormonal supplementation and BRAF mutation. Further studies are needed to evaluate this relationship in additional cohorts, interrogate the biological basis, and identify whether there is an association with survival of patients with metastatic or locally advanced colorectal cancer with estrogen or progestin supplement use.

Retrospective analysis of overall survival (OS) by subsequent therapy in patients (pts) with RAS wild-type (wt) metastatic colorectal cancer (mCRC) receiving irinotecan ± cetuximab in the EPIC study

3580

Background: The multicenter, open-label, randomized, phase 3 EPIC study (EMR 062202-025) investigated cetuximab + irinotecan vs irinotecan as a second-line (2L) therapy in pts with EGFR-detectable mCRC. A retrospective analysis in the EPIC RAS wt population showed improved overall response rate (29.4% vs 5.0%) and progression-free survival (5.4 vs 2.6 mo) upon the addition of cetuximab to irinotecan. Median OS (mOS) was similar in both treatment arms, possibly due to differences in subsequent therapies. We present OS by post-study therapy in the RAS wt population. Methods: 1298 RAS-unselected pts were enrolled from May 2003 to February 2006. The primary endpoint was OS. RAS status was determined retrospectively in 2018 from existing DNA samples using BEAMing technology; wt status was defined as having a sum of mutated RAS allele frequencies of ≤5%, with all relevant alleles being analyzable. Results: Among the 452 pts with RAS wt mCRC, 231 received cetuximab + irinotecan and 221 received irinotecan. Baseline characteristics were similar in both arms. OS data by post-study therapy are summarized in the Table. No new or unexpected safety signals were observed. Conclusions: Post-study cetuximab was associated with improved OS in both treatment arms compared with post-study therapy without cetuximab and no subsequent therapy, suggesting that cetuximab-based therapy may be suitable as a standard treatment for pts with RAS wt mCRC in the rechallenge setting. Study limitations include a potential bias due to the differences in proportion of subsequent therapies with and without cetuximab between arms (almost 50% of pts in the irinotecan arm received post-study cetuximab) as well as the likelihood for pts who live longer to receive cetuximab in any subsequent therapy line. [Table: see text]

Deleterious Effect of RAS and Evolutionary High-risk TP53 Double Mutation in Colorectal Liver Metastases

OBJECTIVE

To assess the impact of somatic gene mutations on survival among patients undergoing resection of colorectal liver metastases (CLM).

BACKGROUND

Patients undergoing CLM resection have heterogeneous outcomes, and accurate risk stratification is necessary to optimize patient selection for surgery.

METHODS

Next-generation sequencing of 50 cancer-related genes was performed from primary tumors and/or liver metastases in 401 patients undergoing CLM resection. Missense TP53 mutations were classified by the evolutionary action score (EAp53)-a novel approach that dichotomizes mutations as low or high risk.

RESULTS

The most frequent somatic gene mutations were TP53 (65.6%), followed by KRAS (48.1%) and APC (47.4%). Double mutation in RAS/TP53, identified in 31.4% of patients, was correlated with primary tumor location in the right colon (P = 0.006). On multivariable analysis, RAS/TP53 double mutation was an independent predictor of shorter overall survival (hazard ratio 2.62, 95% confidence interval 1.41-4.87, P = 0.002). In patients with co-mutated RAS, EAp53 high-risk mutations were associated with shorter 5-year overall survival of 12.2%, compared with 55.7% for TP53 wild type (P < 0.001). The negative prognostic effects of RAS and TP53 mutations were limited to tumors harboring mutations in both genes.

CONCLUSIONS

Concomitant RAS and TP53 mutations are associated with decreased survival after CLM resection. A high EAp53 predicts a subset of patients with worse prognosis. These preliminary analyses suggest that surgical resection of liver metastases should be carefully considered in this subset of patients.

Atezolizumab with or without cobimetinib versus regorafenib in previously treated metastatic colorectal cancer (IMblaze370): a multicentre, open-label, phase 3, randomised, controlled trial

BACKGROUND

Microsatellite-stable metastatic colorectal cancer is typically unresponsive to immunotherapy. This phase 3 study was designed to assess atezolizumab plus cobimetinib in metastatic colorectal cancer. Here, we report the comparison of atezolizumab plus cobimetinib or atezolizumab monotherapy versus regorafenib in the third-line setting.

METHODS

IMblaze 370 is a multicentre, open-label, phase 3, randomised, controlled trial, done at 73 academic medical centres and community oncology practices in 11 countries. Patients aged at least 18 years with unresectable locally advanced or metastatic colorectal cancer, baseline Eastern Cooperative Oncology Group performance status of 0-1, and disease progression on or intolerance to at least two previous systemic chemotherapy regimens were enrolled. We used permuted-block randomisation (block size four) to assign patients (2:1:1) via an interactive voice and web response system to atezolizumab (840 mg intravenously every 2 weeks) plus cobimetinib (60 mg orally once daily for days 1-21 of a 28-day cycle), atezolizumab monotherapy (1200 mg intravenously every 3 weeks), or regorafenib (160 mg orally once daily for days 1-21 of a 28-day cycle). Stratification factors were extended RAS status (wild-type vs mutant) and time since diagnosis of first metastasis (<18 months vs ≥18 months). Recruitment of patients with high microsatellite instability was capped at 5%. The primary endpoint was overall survival in the intention-to-treat population. Safety was assessed in the population of patients who received at least one dose of their assigned treatment. IMblaze370 is ongoing and is registered with ClinicalTrials.gov, number NCT02788279.

FINDINGS

Between July 27, 2016, and Jan 19, 2017, 363 patients were enrolled (183 patients in the atezolizumab plus cobimetinib group, 90 in the atezolizumab group, and 90 in the regorafenib group). At data cutoff (March 9, 2018), median follow-up was 7·3 months (IQR 3·7-13·6). Median overall survival was 8·87 months (95% CI 7·00-10·61) with atezolizumab plus cobimetinib, 7·10 months (6·05-10·05) with atezolizumab, and 8·51 months (6·41-10·71) with regorafenib; the hazard ratio was 1·00 (95% CI 0·73-1·38; p=0·99) for the combination versus regorafenib and 1·19 (0·83-1·71; p=0·34) for atezolizumab versus regorafenib. Grade 3-4 adverse events were reported in 109 (61%) of 179 patients in the atezolizumab plus cobimetinib group, 28 (31%) of 90 in the atezolizumab group, and 46 (58%) of 80 in the regorafenib group. The most common all-cause grade 3-4 adverse events in the combination group were diarrhoea (20 [11%] of 179), anaemia (ten [6%]), increased blood creatine phosphokinase (12 [7%]), and fatigue (eight [4%]). Serious adverse events were reported in 71 (40%) of 179 patients in the combination group, 15 (17%) of 90 in the atezolizumab group, and 18 (23%) of 80 in the regorafenib group. Two treatment-related deaths occurred in the combination group (sepsis) and one in the regorafenib group (intestinal perforation).

INTERPRETATION

IMblaze370 did not meet its primary endpoint of improved overall survival with atezolizumab plus cobimetinib or atezolizumab versus regorafenib. The safety of atezolizumab plus cobimetinib was consistent with those of the individual drugs. These results underscore the challenge of expanding the benefit of immunotherapy to patients whose tumours have lower baseline levels of immune inflammation, such as those with microsatellite-stable metastatic colorectal cancer.

FUNDING

F Hoffmann-La Roche Ltd/Genentech Inc.

Pharmacotherapy of Anal Cancer

Anal squamous cell carcinoma (SCCA), among other malignancies, is associated with the human papillomavirus (HPV) and its incidence continues to rise. Anal SCCA will likely remain an existing healthcare concern given compliance issues with the HPV vaccination seen in the US. Localized disease is predominantly treated with standard of care (SOC) definitive chemoradiation that has remained unchanged for decades. Clinical and molecular prognostic factors have emerged to characterize patients unresponsive to SOC, revealing the need for an alternate approach. Metastatic disease is an extremely small subset and understudied population due to its rarity. Recent prospective trials and mutational analysis have opened treatment options for this subset in need. Our review details the pharmacotherapeutic treatment in localized and metastatic anal SCCA chronologically, while also describing future outlooks.

Phase II study of nab-paclitaxel in refractory small bowel adenocarcinoma and CpG island methylator phenotype (CIMP)-high colorectal cancer

Background

Hypermethylation of promoter CpG islands [CpG island methylator phenotype (CIMP)] represents a unique pathway for the development of colorectal cancer (CRC), characterized by lack of chromosomal instability and a low rate of adenomatous polyposis coli (APC) mutations, which have both been correlated with taxane resistance. Similarly, small bowel adenocarcinoma (SBA), a rare tumor, also has a low rate of APC mutations. This phase II study evaluated taxane sensitivity in SBA and CIMP-high CRC.

Patients and methods

The primary objective was Response Evaluation Criteria in Solid Tumors version 1.1 response rate. Eligibility included Eastern Cooperative Oncology Group performance status 0/1, refractory disease, and SBA or CIMP-high metastatic CRC. Nab-paclitaxel was initially administered at a dose of 260 mg/m2 every 3 weeks but was reduced to 220 mg/m2 owing to toxicity.

Results

A total of 21 patients with CIMP-high CRC and 13 with SBA were enrolled from November 2012 to October 2014. The efficacy-assessable population (patients who received at least three doses of the treatment) comprised 15 CIMP-high CRC patients and 10 SBA patients. Common grade 3 or 4 toxicities were fatigue (12%), neutropenia (9%), febrile neutropenia (9%), dehydration (6%), and thrombocytopenia (6%). No responses were seen in the CIMP-high CRC cohort and two partial responses were seen in the SBA cohort. Median progression-free survival was significantly greater in the SBA cohort than in the CIMP-high CRC cohort (3.2 months compared with 2.1 months, P = 0.03). Neither APC mutation status nor CHFR methylation status correlated with efficacy in the CIMP-high CRC cohort. In vivo testing of paclitaxel in an SBA patient-derived xenograft validated the activity of taxanes in this disease type.

Conclusion

Although preclinical studies suggested taxane sensitivity was associated with chromosomal stability and wild-type APC, we found that nab-paclitaxel was inactive in CIMP-high metastatic CRC. Nab-paclitaxel may represent a novel therapeutic option for SBA.

Abstract P1-10-01: Defining the spectrum of germline variants among African American patients with triple negative breast cancer

Background: African American (AA) women are more likely to have breast cancer at a younger age and be diagnosed with triple negative breast cancer (TNBC), which is as yet unexplained. We examined results of multi-gene panel testing in AA women with TNBC tested at a large commercial laboratory to assess the utility of gene panels and findings in this group.

Methods: We assessed individuals who had clinical hereditary cancer testing with a multi-gene panel between September 2013 and May 2018. Women were included for analysis if they had a personal history of TNBC and self-identified as having any AA ancestry (n=3,268) or only Caucasian (CA) ancestry (n=8,953). Clinical data was collected from provider-completed test request forms. Comparisons were performed using descriptive statistics, t-tests (continuous variables), and chi-square tests (categorical variables) adjusting for multiple testing when necessary.

Results: In this cohort, AA women were significantly more likely than CA women to meet NCCN guidelines (97.5% vs. 96.6%, p=0.010) and significantly less likely to have an additional personal (16.2% vs. 21.8%, p&lt;0.001) or family (79.3% vs. 86.3%, p&lt;0.001) history of cancer. Overall, 11.5% of AA women were found to carry a pathogenic variant (PV) compared to 13.4% of CA women (p=0.004; Table 1). Compared to CA women, AA women with a PV were significantly younger at diagnosis (46.7 vs. 49.5 years of age; p&lt;0.001). The prevalence of PVs in BRCA1, CHEK2 and the Lynch syndrome genes was higher in CA women, whereas the prevalence of BRCA2 PVs was higher in AA women. While the prevalence of PVs in individual genes was not significantly different according to ancestry after adjusting for multiple comparisons, AA women were significantly less likely to have a PV in any breast cancer-related gene compared to CA women (p=0.048). AA women were significantly more likely to have a Variant of Uncertain Significance (VUS; 35.6% vs. 20.9%; p&lt;0.001) and to have &gt;1 VUS (8.6% vs. 2.6%, p&lt;0.001). Regardless of ancestry, patients diagnosed before age 40 were more likely to carry a PV (19.7% AA, 22.2% CA). However, the prevalence of PVs among patients diagnosed after age 60 was still striking (8.9% AA, 10.9% CA) and was similar to the PV prevalence among patients diagnosed between 40-60 (10.1% AA, 12.3% CA).

Conclusions: In the era of multi-gene panel testing, this large cohort of patients with TNBC supports the use of panel testing in AA women with TNBC regardless of age or additional personal/family history of cancer. While additional research to the rate and pathogenicity of VUS in AA women is needed, genetic counseling is necessary to explain the possibility and meaning of a VUS in this group.

Table 1.Distribution of PVs in BC-related genes according to ancestry AA WomenCA WomenGeneN (%)N (%)Any Breast Cancer-Related Gene347 (10.6)1104 (12.3)BRCA1132 (4.0)496 (5.5)BRCA297 (3.0)236 (2.6)ATM6 (0.2)25 (0.3)BARD119 (0.6)67 (0.7)BRIP120 (0.6)46 (0.5)CDH11 (&lt;0.1)1 (&lt;0.1)CHEK22 (0.1)33 (0.4)NBN2 (0.1)10 (0.1)PALB244 (1.3)138 (1.5)PTEN2 (0.1)4 (&lt;0.1)RAD51C20 (0.6)41 (0.5)STK1101 (&lt;0.1)TP532 (0.1)6 (0.1)Lynch Syndrome Genes10 (0.3)46 (0.5)Other Genes12 (0.4)24 (0.3)Multiple PVs6 (0.2)28 (0.3)Total (Any Gene)375 (11.5)1202 (13.4)

Citation Format: Pederson HJ, Heald B, Budd GT, Bernhisel R, Cummings S, Saam JR, Lancaster JM, Grobmyer SR, Eng C. Defining the spectrum of germline variants among African American patients with triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-10-01.

CO.28: Neoadjuvant Chemotherapy, Excision and Observation (NEO) for early rectal cancer

TPS724

Background: CO.28 is a phase II study which aims to determine if patients with stage I/II rectal cancer can be treated with induction chemotherapy (FOLFOX/CAPOX) and organ-preserving transanal microsurgery. Prior studies have explored the use of pelvic chemoradiation followed by transanal microsurgery as a means to increase organ preservation. However, pre-operative radiation may have acute and prolonged impacts such as wound complications and adverse on sphincter, sexual and urinary function. Moreover, patients who develop recurrence following this strategy are difficult to salvage as re-irradiation is not usually an option. There is virtually no prospective experience of neoadjuvant FOLFOX/CAPOX chemotherapy and excision for early rectal tumors. Methods: The primary objective is to determine the rate of organ preservation and the trial will be successful if more than 65% of patients avoid a formal rectal resection. In this two-staged phase II trial, patients are eligible if they have clinical N0 and T1-T3a/bN0M0 rectal tumors and no pathologic high risk features. After 6 cycles of q2weekly FOLFOX or 4 cycles of CAPOX, rectal endoscopy and pelvic MRI are repeated and if there is evidence of tumor response, patients proceed to tumor excision by Transanal Endoscopic Microsurgery (TEMS) or Transanal Minimally Invasive Surgery (TAMIS). It is required that participating surgeons have a minimum experience of 20 TEMS/TAMIS procedures and they are asked to submit an unedited video for central review. Pathologic ypT0 or ypT1N0 tumors are assigned to observation while ypT2+ or any ypN+ tumors are treated with radical surgery and total mesorectal excision (TME). Pre-operative pelvic radiation is suggested only for ypT3+ or node positive tumors. Endoscopic and cross-sectional imaging is repeated every 4-6 months for 36 months. Circulating tumor DNA (ctDNA) will be correlated with tumor response and relapse. A total of 58 patients will be accrued. Study Progress: The study was activated in Canada in late 2017 and at select US Cancer Centers in 2018, with total accrual to date of 4 patients. (NCT03259035) Clinical trial information: NCT03259035.

Systematic review of three decades of clinical trials in metastatic colorectal cancer: Making lemonade out of lemons?

656

Background: Despite multiple trials of new agents in metastatic colorectal cancer (mCRC), long term outcomes remain poor. This study explores the changing trends in the design, interpretation and outcomes of phase III randomized controlled trials (RCT) in mCRC over time. Methods: Phase III RCTs of systemic therapy for mCRC with enrollment between 1986 and 2016 were identified through 4 electronic databases and grouped into 3 time periods (1986-1996 – T1; 1997-2006 – T2 & 2007-2016 – T3). Study selection, quality appraisal and data collection were performed by 2 independent investigators. Study characteristics, primary and secondary endpoints, and authors’ interpretation of results and conclusions were analyzed. Improvement in overall survival (OS) was the difference between experimental and control arms. A study was deemed positive if it met its end point, was recommended for further study or for adoption for clinical use (p ≤ 0.05 significant for all analyses). Results: One hundred fifty trials (T1=36, T2=62, T3=52) with 77494 patients (T1=12406, T2=39158, T3=25930) were included. Although 1st line therapy trials continued to be the most common across all T, the percentage (%) of trials evaluating 3rd line and beyond (T1=0, T2=3, T3=27) have increased significantly over time as have trials with targeted agents (T1=11, T2=34, T3=79). Although OS remains the most common primary end point, more trials in T2 & T3 have used progression-free survival instead (14 vs 47 & 44). The % of trials with negative results but interpreted as positive increased over time (T1=18; T2=42; T3=35). Across all T, the median improvement in OS (months, m) of these trials was significantly lower compared to the trials that met primary end point across all T (T1 = 0 vs 1.8 m, T2 = -0.1 vs 3.25, T3 = -0.25 vs 2.55). Conclusions: A significant shift has occurred over the past three decades in the design and interpretation of phase III trials in advanced CRC. Any interpretations of potential survival benefits from trials that have not met primary end point must be made with significant caution.

Prognostic value of genomic alterations (GA) on overall survival in appendiceal adenocarcinoma (AA)

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Background: AA are extremely rare tumors, with potentially aggressive clinical behavior. The characterization of the molecular alterations of the disease is poorly described, as well as its association with clinical outcomes. The present study aims to evaluate the prognostic influence of GA on overall survival (OS) of AA patients (pts). Methods: We performed a retrospective study involving AA pts at MD Anderson Cancer Center between October 2012 and April 2017 who underwent next-generation sequencing (NGS) (at least 45 genes), using either tumor tissue specimens or peripheral blood for cell-free DNA (cfDNA). GA identified by NGS and clinicopathological variables were correlated with OS. Survival curves were performed by the Kaplan-Meier method and compared with log-rank test. Multivariate analysis of prognostic factors was performed by the Cox model. Results: A total of 78 pts were identified, of which 35 had died (45%) in a median follow-up time of 4.8 y. The majority of pts presented with stage IV disease (72%); 46% underwent cytoreductive surgery (CRS) + HIPEC. Tissue-based and cfDNA-based sequencing were performed on 73% and 23% of the pts, respectively, and 4% had both. The most frequent GA were KRAS (62%), TP53 (36%), GNAS (28%), SMAD4 (18%), PIK3CA (16%), and APC (15%). By univariate analysis, stage, tumor grade, and CRS + HIPEC demonstrated prognostic value (p < 0.05). Multivariate subset analysis of stage IV pts adjusting for age, tumor grade (TG), CRS + HIPEC, KRAS, GNAS, and p53, demonstrated that poorly differentiated tumors and a KRAS mutated tumor resulted in worse OS (HR: 12.1 and HR: 3.9, respectively, both with p < 0.05) and CRS + HIPEC resulted in an improved OS (HR: 0.32, p < 0.05). Conclusions: Our analysis indicates that TG and the presence of the KRAS mutation are poor prognostic factors in the OS of pts with AA. CRS + HIPEC offers survival advantage . Molecular characterization and prognostication of these rare tumors may help guide therapy. These findings need validation, thereby continued evaluation in a larger population and utilizing a wider molecular platform is ongoing.

The Management and Prevention of Anal Squamous Cell Carcinoma

Our aim is to discuss the current established management of care and associated prevention strategies of anal squamous cell carcinoma (SCCA). In general, the development of SCCA is commonly linked to a prior history of HPV. Unfortunately, HPV vaccination continues to be underutilized in the United States versus other countries. Increased acknowledgment of the importance of HPV vaccination as an anticancer vaccine should be encouraged. The present standard of care is primary chemoradiotherapy (CRT), which results in a high level of disease control for small, early-stage SCCA. More advanced cancers still fare poorly with this treatment, and the disease relapses locoregionally in the majority of cases (30%-50% of patients), resulting in an abdominoperineal resection. Current treatment recommendations are associated with substantial morbidity; alternative radiation doses and/or novel combinations of agents with CRT are needed to improve quality of life and oncologic outcomes. Cytotoxic chemotherapy remains the standard of care for treatment-naïve patients with metastatic disease, with a possible new treatment paradigm of carboplatin/weekly paclitaxel. In addition, immune checkpoint inhibition appears to have a promising role in the setting of patients with refractory disease. Several clinical trials with immunotherapeutic and vaccine approaches for locally advanced and metastatic anal cancer are ongoing, as are HPV-agnostic umbrella trials. Whenever possible, clinical trial enrollment is always encouraged for further therapeutic development in the setting of a rare cancer, given the potentially substantial global impact for other HPV-associated malignancies.

Minimally invasive management of the entire treatment sequence in patients with stage IV colorectal cancer: a propensity-score weighting analysis

BACKGROUND

In patients with stage IV colorectal cancer (CRC), minimally invasive surgery (MIS) may offer optimal oncologic outcome with low morbidity. However, the relative benefit of MIS compared to open surgery in patients requiring multistage resections has not been evaluated.

METHODS

Patients who underwent totally minimally invasive (TMI) or totally open (TO) resections of CRC primary and liver metastases (CLM) in 2009-2016 were analyzed. Inverse probability of weighted adjustment by propensity score was performed before analyzing risk factors for complications and survival.

RESULTS

The study included 43 TMI and 121 TO patients. Before and after adjustment, TMI patients had significantly less cumulated postoperative complications (41% vs. 59%, p = 0.001), blood loss (median 100 vs. 200 ml, p = 0.001) and shorter length of hospital stay (median 4.5 vs. 6.0 days, p < 0.001). Multivariate analysis identified TO approach vs. MIS (OR = 2.4, p < 0.001), major liver resection (OR = 4.4, p < 0.001), and multiple CLM (OR = 2.3, p = 0.001) as independent risk factors for complications. 5-year overall survival was comparable (81% vs 68%, p = 0.59).

CONCLUSION

In patients with CRC undergoing multistage surgical treatment, MIS resection contributes to optimal perioperative outcomes without compromise in oncologic outcomes.

Evolving indications and long-term oncological outcomes of risk-reducing bilateral nipple-sparing mastectomy

Background

Bilateral nipple‐sparing mastectomy (NSM) is a technically feasible operation and is associated with excellent cosmetic outcomes. The aim of this study was to evaluate trends in patient characteristics, indications for surgery and long‐term outcomes of bilateral NSM for breast cancer risk reduction over time.

Methods

A review of a single‐centre experience with bilateral NSM performed between 2001 and 2017 for breast cancer risk reduction in patients without breast cancer was performed. Trends in patient characteristics and indications for surgery were evaluated over four time intervals: 2001–2005, 2006–2009, 2010–2013 and 2014–2017. Statistical analysis was performed using χ² tests.

Results

Over the study period, 272 NSMs were performed in 136 patients; their median age was 41 years. The number of bilateral NSMs performed increased over time. The most common indication was a mutation in breast cancer‐associated genes (104 patients, 76·5 per cent), which included BRCA1 (62 patients), BRCA2 (35), PTEN (2), TP53 (3) and ATM (2). Other indications were family history of breast cancer (19 patients, 14·0 per cent), lobular carcinoma in situ (10, 7·4 per cent) and a history of mantle irradiation (3, 2·2 per cent). The proportion of patients having a bilateral NSM for mutation in a breast cancer‐associated gene increased over time (2001–2005: 2 of 12; 2006–2009: 9 of 17; 2010–2013: 34 of 41; 2014–2017: 61 of 66; P < 0·001). Mean follow‐up was 53 months; no breast cancers were found during follow‐up.

Conclusion

The use of bilateral NSM for breast cancer risk reduction is increasing and the indications have evolved over the past 16 years. These excellent long‐term oncological results suggest that bilateral NSM is a good option for surgical breast cancer risk reduction.

Experimental and investigational drugs for the treatment of anal cancer

INTRODUCTION

Squamous cell carcinoma of the anal canal (SCCA) is a rare malignancy, but its incidence rates have been increasing in the last decade. Studies have demonstrated that up to 47% of patients with locally advanced disease have high-risk features for treatment failure. The potential high rates of recurrence after standard chemoradiotherapy for locally advanced disease and the lack of established care for metastatic disease have created an urgent need for the evaluation of new drugs that will ultimately improve the efficacy of treatment.

AREAS COVERED

This review presents results of recent phase-I and -II clinical trials which evaluate novel therapeutic modalities. The review also describes the findings of comprehensive genomic profiling studies which provide insights for promising therapeutics.

EXPERT OPINION

HPV vaccination is underutilized in the United States and as a result, HPV-associated malignancies are likely to continue for several decades; however, pivotal breakthroughs may create a foundation for distinctive treatment approaches for other HPV-associated malignancies for which no other standard of care exists.

Consensus statement on essential patient characteristics in systemic treatment trials for metastatic colorectal cancer: Supported by the ARCAD Group

BACKGROUND

Patient characteristics and stratification factors are key features influencing trial outcomes. However, there is substantial heterogeneity in reporting of patient characteristics and use of stratification factors in phase 3 trials investigating systemic treatment of metastatic colorectal cancer (mCRC). We aimed to develop a minimum set of essential baseline characteristics and stratification factors to include in such trials.

METHODS

We performed a modified, two-round Delphi survey among international experts with wide experience in the conduct and methodology of phase 3 trials of systemic treatment of mCRC.

RESULTS

Thirty mCRC experts from 15 different countries completed both consensus rounds. A total of 14 patient characteristics were included in the recommended set: age, performance status, primary tumour location, primary tumour resection, prior chemotherapy, number of metastatic sites, liver-only disease, liver involvement, surgical resection of metastases, synchronous versus metachronous metastases, (K)RAS and BRAF mutation status, microsatellite instability/mismatch repair status and number of prior treatment lines. A total of five patient characteristics were considered the most relevant stratification factors: RAS/BRAF mutation status, performance status, primary tumour sidedness and liver-only disease.

CONCLUSIONS

This survey provides a minimum set of essential baseline patient characteristics and stratification factors to include in phase 3 trials of systemic treatment of mCRC. Inclusion of these patient characteristics and strata in study protocols and final study reports will improve interpretation of trial results and facilitate cross-study comparisons.

Treatment of primary rectal adenocarcinoma after prior pelvic radiation: The role of hyperfractionated accelerated reirradiation

Purpose

Previous studies have reported that hyperfractionated accelerated reirradiation can be used as part of multimodality treatment of locally recurrent rectal cancer with acceptable toxicity and promising outcomes. The purpose of this study was to evaluate the outcomes and toxicity of hyperfractionated accelerated reirradiation for patients with primary rectal adenocarcinoma and a history of prior pelvic radiation for other primary malignancies.

Methods and materials

We identified 10 patients with a prior history of pelvic radiation for other primary malignancies who were treated with hyperfractionated accelerated reirradiation for primary rectal adenocarcinoma. Radiation therapy was administered with 1.5 Gy twice daily fractions to a total dose of 39 Gy to 45Gy.

Results

The median follow-up time was 3.2 years (range, 0.6-9.0 years). Seven of 10 patients received surgery after reirradiation. The 3-year freedom-from-local-progression rate was 62% for all patients and 80% for patients who underwent surgery. The 3-year overall survival rate was 100%, with 3 deaths occurring at 4.7, 6.5, and 9.0 years after reirradiation. One patient had an acute Grade 3 toxicity of diarrhea, and 1 patient experienced a late Grade 3 toxicity of sacral insufficiency fracture.

Conclusions

Hyperfractionated accelerated reirradiation was well tolerated with promising rates of freedom from local progression and overall survival in patients with primary rectal cancer with a history of prior pelvic radiation therapy. This approach, along with concurrent chemotherapy and surgery, appears to be a viable treatment strategy for this patient population.

FBXW7 missense mutation: a novel negative prognostic factor in metastatic colorectal adenocarcinoma

Background

FBXW7 functions as a ubiquitin ligase tagging multiple dominant oncogenic proteins and commonly mutates in colorectal cancer. Data suggest missense mutations lead to greater loss of FBXW7 function than other gene aberrations do. However, the clinicopathologic factors and outcomes associated with FBXW7 missense mutations in metastatic colorectal cancer (mCRC) have not been described.

Methods

Data were obtained from mCRC patients whose tumors were evaluated by next-generation sequencing for hotspot mutations at The University of Texas MD Anderson Cancer Center. Alterations in FBXW7 were identified, and their associations with clinicopathologic features and overall survival (OS) were evaluated.

Results

Of 855 mCRC patients, 571 had data on FBXW7 status; 43 (7.5%) had FBXW7 mutations, including 37 with missense mutations. R465C mutations in exon 9 were the most common missense mutations (18.6%). PIK3CA mutations were associated with FBXW7 missense mutations (p=0.012). On univariate analysis, patients with FBXW7 missense mutations had significantly worse OS (median 28.7 mo) than those with wild-type FBXW7 (median 46.6 mo; p=0.003). On multivariate analysis including other known prognostic factors such as BRAF mutations, FBXW7 missense mutations were the strongest negative prognostic factor for OS (hazard ratio 2.0; p=0.003).

Conclusions

In the largest clinical dataset of mCRC to date, FBXW7 missense mutations showed a strong negative prognostic association.

Comparison of early radiological predictors of outcome in patients with colorectal cancer with unresectable hepatic metastases treated with bevacizumab

OBJECTIVE

The purpose was to validate the prognostic value of an early optimal morphological response on CT in patients treated with bevacizumab-containing chemotherapy for unresectable colorectal cancer liver metastases (CLM). It also evaluated the prognostic value of size-based criteria and the association of optimal morphological response with the receipt of bevacizumab.

DESIGN

141 patients treated first using bevacizumab and 142 patients from a randomised study evaluating the addition of bevacizumab to oxaliplatin-based chemotherapy were retrospectively analysed. Radiologists evaluated pretreatment and restaging CT scans using morphological response criteria. Responses were also assessed with size-based criteria: Response Evaluation Criteria in Solid Tumors (RECIST), early tumour shrinkage (ETS) and deepness of response (DpR). The ability of each criterion to predict progression-free survival (PFS), overall survival (OS) and postprogression survival (PPS) was determined using a univariate Cox proportional hazards model.

RESULTS

In both populations, median PFS was significantly longer for patients achieving an optimal morphological response (10.4 vs 6.8 months, p=0.03; and 8.3 vs 4.9 months, p<00001, respectively). Neither RECIST nor ETS responses were associated with a prolonged PFS. Median OS was longer for those with an optimal morphological response but only at second restaging in the first population (n=141, 20.8 vs 12.3 months, p=0.002). DpR but not optimal morphological response was associated with PPS. In the randomised study, an optimal morphological response was 6.2 times more likely among patients receiving bevacizumab (p<0.0001).

CONCLUSION

In patients with unresectable CLM, early morphological response may be a better predictor of PFS than size-based response. The addition of bevacizumab improves morphological response rate.