Moore, Dominic T.

8008 Background: Morphology remains the best biomarker for chemotherapy selection in NSCLC. Both bevacizumab and pemetrexed (in first line) are FDA indicated for non-SC histology only, making precise diagnosis key, although data are few on the reproducibility of their categorization. The standard of care, consensus-based World Health Organization diagnostic classification system, Ed. 4 (WHOC) includes 44 diagnostic categories (DC), does not include immunohistochemical (IHC) data, and is not independently validated. In this study, we estimate the reproducibility of SC versus non-SC classification to be only moderately precise. Methods: Pathologists (P) assigned WHOC diagnoses to virtual H&E slides from an incident surgical cohort of 96 primary lung tumors. At a power of 80% we estimated 24 P reviewing 48 slides each would allow for a reproducibility measure in the clinically useful range kappa=0.7, standard error=0.09. In addition to the 44 DC, we also considered the reproducibility of a simplified 10 category system and a chemotherapy-directed 2 class system. Results: 12 self-identified “lung experts” (E) and 12 community (C) P scored slides based on the 44 possible WHOC DC totaling 222 pathologist-pairs and 7130 slides-pairs. P rated confidence in their choices as: high 53%, somewhat 38%, and not confident 8%. 92% of slides were rated as having sufficient quality. Distribution of DC included SC 30% and adenocarcinoma 36%. Conclusions: To our knowledge this is the largest study ever performed of the WHOC, the only one to consider all 44 DC and to distinguish E vs C P. Although this model tests the reproducibility of the WHOC, not clinical lung cancer diagnoses, it shows that reproducible diagnosis of SC based on H&E morphology alone is inadequate. In the era of histology guided therapy, it highlights the need for strict diagnostic criteria and confirmatory IHC stains in the diagnosis of SC. [Table: see text] No significant financial relationships to disclose.

BACKGROUND Regorafenib, a multikinase inhibitor that inhibits angiogenesis, growth, and proliferation, prolongs survival as monotherapy in patients with refractory colorectal cancer. This international, double‐blind, placebo‐controlled, multicenter trial assessed the efficacy of regorafenib with folinic acid, fluorouracil, and irinotecan (FOLFIRI) as a second‐line treatment for metastatic colorectal cancer. METHODS Patients with metastatic colorectal cancer who progressed on first‐line oxaliplatin and fluoropyrimidine enrolled at 45 sites in the United States and Ireland. Patients, stratified by prior bevacizumab use, were randomized 2:1 to regorafenib or placebo. The treatment consisted of FOLFIRI on days 1 and 2 and days 15 and 16 with 160 mg of regorafenib or placebo on days 4 to 10 and days 18 to 24 of every 28‐day cycle. Crossover was not allowed. The primary endpoint was progression‐free survival (PFS). Under the assumption of a 75% event rate, 180 patients were required for 135 events to achieve 90% power to detect a hazard ratio (HR) of 0.65 with a 1‐sided α value of .1. RESULTS One hundred eighty‐one patients were randomized (120 to regorafenib‐FOLFIRI and 61 to placebo‐FOLFIRI) with a median age of 62 years. Among these, 117 (65%) received prior bevacizumab or aflibercept. PFS was longer with regorafenib‐FOLFIRI than placebo‐FOLFIRI (median, 6.1 vs 5.3 months; HR, 0.73; 95% confidence interval [CI], 0.53‐1.01; log‐rank P = .056). The median overall survival was not longer (HR, 1.01; 95% CI, 0.71‐1.44). The response rate was higher with regorafenib‐FOLFIRI (34%; 95% CI, 25%‐44%) than placebo‐FOLFIRI (21%; 95% CI, 11%‐33%; P = .07). Grade 3/4 adverse events with a >5% absolute increase from regorafenib included diarrhea, neutropenia, febrile neutropenia, hypophosphatemia, and hypertension. CONCLUSIONS The addition of regorafenib to FOLFIRI as second‐line therapy for metastatic colorectal cancer only modestly prolonged PFS over FOLFIRI alone. Cancer 2018. © 2018 American Cancer Society .