An interim analysis of a phase II study using an epigenetic biomarker (CHFR methylation status) to personalize chemotherapy in patients with operable esophageal cancer.

Abstract

76 Background: Preoperative chemoradiotherapy using a platinum plus either a taxane or 5FU results in a pathological complete response rate (pCR) of approximately 25% to 30% in patients with operable esophageal cancer. A predictive biomarker to personalize chemotherapy in an effort to increase pCR would be a significant advance. Checkpoint with forkhead and ring finger domains (CHFR) is an E3 ligase which plays a role in response to mitotic stress. In our retrospective data, hypermethylation and silencing of CHFR, correlates with improved response and prolonged survival following therapy with taxanes. The primary endpoint of this study is to determine if there is a higher pCR rate when CHFR methylation status (MS) is used to decide if patients receive a taxane or 5FU. Methods: All patients presenting to Johns Hopkins with operable T2-T4/N0-N3 esophageal cancer are eligibile. A methylation-specific PCR which demonstrates CHFR MS has been developed by our lab. Methylated (M) patients receive weekly cisplatin (30mg/m2)/paclitaxel (50mg/m2) and unmethylated (U) patients receive previously described regimens of folfox or cisplatin/5FU. All patients receive concurrent radiation. Results: From July 2011 to September 2013, 35 patients have been assessed, 18 U (51%), 14 M (40%) and 3 unknown (9%). Twenty-four patients (22 males and 2 females) have been treated on study (age 48 – 74 years old, median 63.8) with 14 tumors U (58%) and 10 tumors M (42%) respectively. To date, 2/13 U patients (15%) have had a pCR and 3/8 M patients (38%) have had a pCR (p=0.32). Toxicities of each regimen are consistent with previous reports. Conclusions: Trimodality therapy is standard of care for operable esophageal cancer in the United States. Different chemotherapies have been combined with radiation prior to surgery to improve pCR rates but no biomarkers to personalize chemotherapy exist at present. Epigenetic biomarkers such as CHFR MS potentially may be used to decide which patients are more sensitive to taxane based regimens. Accrual to this study is ongoing. Clinical trial information: NCT01372202.