Significance of Co-expression of Epidermal Growth Factor Receptor and Ki67 on Clinical Outcome in Patients With Anal Cancer Treated With Chemoradiotherapy: An Analysis of NRG Oncology RTOG 9811.

PURPOSE: To measure co-expression of EGFR and Ki67 proteins in pretreatment tumor biopsies of anal cancer patients enrolled on NRG Oncology RTOG 9811, a phase III trial comparing 5-fluorouracil/mitomycin-C/radiation therapy (Arm A) versus 5-fluorouracil/cisplatin/radiation therapy (Arm B), and to correlate expression with clinical outcome. METHODS AND MATERIALS: EGFR and Ki67 co-expression was measured after constructing a tissue microarray using fluorescence immunohistochemistry and automated quantitative image analysis. The Ki67 score within EGFR high versus low areas (Ki67ratio in EGFRhigh:low) in each tumor core was analyzed at the median, quartiles, and as a continuous variable. Associations between the tumor markers and clinical endpoints (overall and disease-free survival, locoregional and colostomy failure, and distant metastases) were explored. RESULTS: A total of 282 pretreatment tumors were analyzed from NRG Oncology RTOG 9811. Of evaluated specimens, 183 (65%, n=89, Arm A; n=94, Arm B) were eligible and analyzable. There were no significant differences in baseline characteristics or outcomes between analyzable and unanalyzable patient cases. Median follow-up was 6.0 years. On multivariate analysis, after adjusting for gender, patients with Ki67ratio in EGFRhigh:low ≥median had worse overall survival (hazard ratio 2.41, 95% confidence interval 1.38-4.19, P=.0019). After adjusting for N stage and largest tumor dimension, patients with Ki67ratio in EGFRhigh:low ≥ median had a higher risk of a disease-free failure (hazard ratio 1.85, 95% confidence interval 1.18-2.92, P=.0078). Technical validation with an independent anal cancer patient cohort was performed and shows a very similar biomarker score distribution. CONCLUSIONS: High Ki67ratio in EGFRhigh:low is associated with worse clinical outcome in this subset of patients with anal cancer treated with chemoradiation on NRG Oncology RTOG 9811. Evaluation within a clinical trial will be required to determine whether patients with these tumor characteristics may specifically benefit from an EGFR-targeted therapeutic agent.

Neoadjuvant therapy may lead to successful surgical resection and improved survival in patients with borderline resectable pancreatic cancer.

BACKGROUND: Borderline resectable pancreatic cancers are technically amenable to surgical resection, but are associated with increased risk of locoregional recurrence. Patients with these tumours may be treated with neoadjuvant therapy in an attempt to improve margin-negative resection rates. METHODS: The University of Cincinnati Pancreatic Cancer Database was retrospectively reviewed. Borderline resectable disease was defined by the following radiographic criteria: (i) short segment occlusion of the superior mesenteric vein (SMV), portal vein (PV) or SMV/PV confluence; (ii) short segment hepatic artery encasement, or (iii) superior mesenteric artery/coeliac artery abutment of <180 degrees. Patients with resectable disease who had questionable metastatic disease or poor performance status were also included. RESULTS: Twenty-nine patients met the criteria. Of these, 26 underwent a full course of neoadjuvant therapy. Twelve (46%) underwent surgical resection and 14 had tumour progression or were deemed unresectable at laparotomy. The most common neoadjuvant therapy regimen was gemcitabine-based chemotherapy alone (58%). Of those undergoing surgery, 67% had margin-negative (R0) resections and 42% required venous resection. Median survival was 15.5 months for unresected patients and 23.3 months for resected patients. DISCUSSION: Borderline resectable pancreatic tumours can be treated neoadjuvantly, resulting in margin-negative resection and survival rates similar to those in initially resectable disease.