Quantitating pathologic response to neoadjuvant chemotherapy in KRAS-mutated versus nonmutated lung cancers.

7014 Background: Trials of neoadjuvant chemotherapy in non-small cell lung cancers (NSCLC) have demonstrated that pathologic response correlates with downstaging and survival. There is controversy as to whether KRAS mutated patients (pts) have the same benefit with adjuvant chemotherapy as non-mutated pts however the impact of KRAS mutations on response to neoadjuvant therapy has not been reported. Methods: Pts with resectable stage I-III non-squamous NSCLCs were treated with 4 cycles of cisplatin, docetaxel, and bevacizumab, followed by surgical resection. Tumors were tested for KRAS mutations. Percent treatment effect (necrosis, inflammation, fibrosis) was quantified histologically. Pts were followed until disease recurrence and/or death. Binary variables were compared using the Fisher’s Exact Test. Survival was assessed by pathological response based on the literature (≥90 vs <90%) using the Kaplan-Meier method, stratified by stage (IB-IIB vs. III) and by KRAS mutation. Results: We accrued 51 pts. 34/5...