George, Thomas J.

Abstract Background: Cetuximab, an EGFR inhibitor used to treat multiple cancer types, including colon cancer, causes severe skin toxicity in 5%–20% of patients, leading to decreased quality of life and treatment delays. Our understanding of which patients have an increased risk of severe toxicities is limited. We conducted a genome-wide association study to identify germline variants predictive of cetuximab-induced severe skin toxicity. Methods: Our study included 1,209 patients with stage III colon cancer randomized to receive cetuximab plus 5-fluorouracil and oxaliplatin as part of the NCCTG N0147 (Alliance) clinical trial. Skin toxicity outcomes were collected using the Common Toxicity Criteria for Adverse Events version 3.0. We performed genotyping, evaluating approximately 10 million genetic variants. We used logistic regression to evaluate the association of each genetic variant and severe (grade ≥ 3) skin toxicity, adjusting for age, sex, and genetic ancestry. Genome-wide significance was defined as P < 5 × 10−8. Results: Participants were predominantly middle-aged white men; 20% (n = 243) experienced severe skin toxicity. Two genetic variants in the retinoic acid receptor alpha (RARA) gene were significantly associated with severe skin toxicity [OR, 3.93; 95% confidence interval (CI), 2.47–6.25; P < 7.8 × 10−9]. Functional annotations indicate these variants are in the RARA promoter. Additional significantly associated variants were identified in chromosome 2 intergenic regions. Conclusions: Identified variants could represent a potential target for risk stratification of patients with colon cancer receiving cetuximab. Impact: Retinoids have shown promise in the treatment of cetuximab-induced skin toxicity, so follow-up work could evaluate whether individuals with the RARA variant would benefit from retinoid therapy.

Abstract Background Adjuvant chemotherapy is a standard treatment option for patients with stage III and high-risk stage II colon cancer. Sex is one of several factors responsible for the wide inter-patient variability in drug responses. Amalgamated data on the effect of sex on the toxicity of current standard adjuvant treatment for colorectal cancer are missing. Methods The objective of our study was to compare incidence and severity of major toxicities of fluoropyrimidine- (5FU or capecitabine) based adjuvant chemotherapy, with or without oxaliplatin, between male and female patients after curative surgery for colon cancer. Adult patients enrolled in 27 relevant randomized trials included in the ACCENT (Adjuvant Colon Cancer End Points) database, a large, multi-group, international data repository containing individual patient data, were included. Comparisons were conducted using logistic regression models (stratified by study and treatment arm) within each type of adjuvant chemotherapy (5FU, FOLFOX, capecitabine, CAPOX, and FOLFIRI). The following major toxicities were compared (grade III or IV and grade I-IV, according to National Cancer Institute Common Terminology Criteria [NCI-CTC] criteria, regardless of attribution): nausea, vomiting, nausea or vomiting, stomatitis, diarrhea, leukopenia, neutropenia, thrombocytopenia, anemia, and neuropathy (in patients treated with oxaliplatin). Results Data from 34 640 patients were analyzed. Statistically significant and clinically relevant differences in the occurrence of grade III or IV nonhematological {especially nausea (5FU: odds ratio [OR] = 2.33, 95% confidence interval [CI] = 1.90 to 2.87, P < .001; FOLFOX: OR = 2.34, 95% CI = 1.76 to 3.11, P < .001), vomiting (5FU: OR = 2.38, 95% CI = 1.86 to 3.04, P < .001; FOLFOX: OR = 2.00, 95% CI = 1.50 to 2.66, P < .001; CAPOX: OR = 2.32, 95% CI = 1.55 to 3.46, P < .001), and diarrhea (5FU: OR = 1.35, 95% CI = 1.21 to 1.51, P < .001; FOLFOX: OR = 1.60, 95% CI = 1.35 to 1.90, P < .001; FOLFIRI: OR = 1.57, 95% CI = 1.25 to 1.97, P < .001)} as well as hematological toxicities (neutropenia [5FU: OR = 1.55, 95% CI = 1.37 to 1.76, P < .001; FOLFOX: OR = 1.96, 95% CI = 1.71 to 2.25, P < .001; FOLFIRI: OR = 2.01, 95% CI = 1.66 to 2.43, P < .001; capecitabine: OR = 4.07, 95% CI = 1.84 to 8.99, P < .001] and leukopenia [5FU: OR = 1.74, 95% CI = 1.40 to 2.17, P < .001; FOLFIRI: OR = 1.75, 95% CI = 1.28 to 2.40, P < .001]) were observed, with women being consistently at increased risk. Conclusions Our analysis confirms that women with colon cancer receiving adjuvant fluoropyrimidine-based chemotherapy are at increased risk of toxicity. Given the known sex differences in fluoropyrimidine pharmacokinetics, sex-specific dosing of fluoropyrimidines warrants further investigation.

e24011 Background: Advanced care planning and living wills are critical components of caring for patients at the end of their lives. Advance directives are designed to be implemented when a patient meets the legal definition of terminal and is deemed incapacitated. By reviewing the electronic health record (EHR) in patients with terminal cancer, we sought to evaluate whether advance directives were appropriately implemented. Methods: A retrospective analysis of the EHR of 500 cancer patients from 1/1/2013 to 12/31/2016 was performed. Data points were manually collected and entered in a central database, and data analysis was completed using SAS. Results: Of the 500 patients, 160 (32%) had an advance directive (AD). The most common clinical terminology used by physicians indicating a terminal diagnosis was “progressive” (36.6%) and “palliative” (31%). The most common clinical terminology indicating incapacity was “altered mental status” (25.6%), and “not oriented” (14%). 34 patients (6.8%) met all criteria of having a terminal diagnosis, a documented AD, and deemed incapacitated. Of these patients who met all of these data points, their ADs were implemented on average 1.7 days (SD: 4.4 days) after which they should have been. This resulted in a total of 58 days of additional care provided to these patients. Conclusions: End-of-life care is a challenging albeit vital part of the practice of medicine. This study provided insight on to how ADs are managed in day to day practice in a hospital. From our analysis, it is clear that physicians are able to identify when a patient is terminal; however, it is typically later than it should have been recognized (and thereby, leading to delays in the implementation of the patient’s AD). Further studies should be performed focusing on harnessing the power of the EHR and providing physicians formative and evaluative feedback of practice patterns to ensure that ADs are honored when appropriate.

4099 Background: Colorectal cancer (CRC) incidence and mortality has decreased since the 1970s but the incidence is increasing in young adults (age 20-49). The incidence of early onset CRC (eoCRC) will keep increasing significantly based on the trends of the SEER CRC registry data. There is limited data suggesting eoCRC may have different behaviors compared to traditional CRC (tCRC, age ≥ 50). Methods: Individual pt data of 47184 stage II/III CRC pts from 25 randomized studies in the ACCENT database were pooled. The distributions of demographics, clinicopathological features, biomarker status, and treatment-related data were summarized by age group. Overall survival (OS), disease-free survival (DFS), recurrence-free rate (RFR), and survival after recurrence (SAR) were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for stage, performance status (PS), BMI and grade. Results: Using 5% difference between age groups as clinically meaningful cutoff, eoCRC had similar gender, race, ethnicity, PS, risk group, disease sidedness and T stage as tCRC. eoCRC were less likely overweight (30 vs 36%) and more pts had ≥ 12 lymph nodes resected (63 vs 51%). eoCRC had more frequent dMMR status (18 vs 12%), less BRAF mutations (5 vs 13%), and more dMMR/BRAF wild type (WT) status (17 vs 7%). Overall, eoCRC had better OS, DFS, and SAR, with the most significant differences between the < 30 and > = 70 age groups. Similar results were observed within pMMR pts. eoCRC experienced less hematological side effects, diarrhea, and stomatitis, but had more nausea and/or vomiting. Conclusions: eoCRC have unique characteristics; although statistically significant, the clinical differences in outcomes between eoCRC and tCRC are potentially due to the difference seen in extremely young and old pts. eoCRC have a different adverse events panel compared to tCRC. [Table: see text]

PURPOSE: ASCO is the premier and largest global professional society for oncology care professionals. In 2015, ASCO launched a longitudinal Learning Cohort Pilot Project to catalog and better understand the learning behaviors and preferences of oncology health care providers. A secondary goal was to assess learner preferences and utilization related to ASCO’s portfolio of educational resources. METHODS: The Learning Cohort Pilot Project was conducted between November 2015 and August 2016 with 49 ASCO members. Participants were selected via convenience sampling and stratified random sampling to generate a cohort that mirrored the demographic distribution of overall ASCO membership. Participants completed a different ASCO resource-specific feedback activity each month, which measured professional educational needs, sources sought, and preferences for educational resources. Responses were organized by demographic variables in our participant pool to identify trends in provider learning preferences. Fisher’s exact test was used to assess the association between participant demographics and practice setting and responses. Holm’s procedure was used to adjust for multiple testing. RESULTS: The Learning Cohort Pilot Project revealed statistically significant relationships between participant demographic variables and learning preferences. Age and practice setting were the demographic variables most consistently associated with the different preferences explored throughout the targeted activities. CONCLUSION: The results of this pilot cohort reinforced the hypothesis that oncology care providers have different professional educational needs and preferences that can be potentially anticipated and met with tailored resources. Delivering solutions to meet these needs represents an opportunity for further research and resource development.

326 Background: Review initial outcomes for patients enrolled on the University of Florida Proton Therapy Institute PC01 protocol for patients with unresectable pancreatic cancer. Methods: The protocol received Institutional Review Board (IRB) approval in 7/2007. The first patient was enrolled in 4/2010. The accrual target was 66 patients to test if the Serious Adverse Event (SAE) ratecould be reduced from 15% (expected) to less than 5%. Protocol therapy consisted of proton therapy to a planning target volume (PTV) dose of 59.4 Cobalt Gray Equivalent (CGE) at 1.8CGE per fraction with concomitant oral Capecitabine (1000mg PO BID 5 days/week on radiation treatment days). Only gross disease was targeted. Results: 12 patients were enrolled. 1 patient died of a gunshot wound 5 days after starting treatment so only 11 patients are reported. Median follow up from start of treatment: 13 months (range 2 to 21 months). Median age: 68 (range 51 to 86) years. Gender: Males 5, Females 6. Race/Ethnicity: 9 White, 2 Hispanic. Overall survival: 90% at 6 months and 60% at 12 months. Freedom from progression: 80% at 6 months and 53% at one year. Local control: 100% at 6 months and 86% at 12 months. Freedom from metastasis: 80% at 6 months and 67% at 12 months.No patient experienced any grade 3 or greater toxicity during treatment or the follow up period. Grade 2 toxicity was limited to a single patient experiencing grade 2 fatigue. Median weight loss over the course of treatment was 1.7 (range: loss of 5.7 to gain of 4.9) Kg. 4 patients were deemed to have had an adequate radiographic response to radiotherapy so as to justify surgical exploration. Conclusions: Proton therapy to 59.4 CGE with concomitant Capecitabine was well tolerated with no grade 2 or greater gastrointestinal toxicities. 4 of 11 patients achieved a radiographic response allowing for attempted surgical resection. The study was closed to accrual on 9/1/2013 due to recognition that slow accrual made achievement of the primary study endpoint unlikely. At the same time, the lack of any meaningful gastrointestinal toxicity suggests significant opportunities for treatment intensification when proton therapy is used in this setting. Clinical trial information: NCT00685763.