Induction Therapy Is Not Associated With Improved Survival in Large cT4 N0 Non-Small Cell Lung Cancers

Abstract

Background: The eighth edition of the staging manual for non-small cell lung cancer reclassified tumors >7 cm as stage IIIA (T4 N0); previously, such tumors without nodal disease were considered stage IIB (T3 N0). This study tested the hypothesis that induction chemotherapy for these stage IIIA patients does not improve survival compared with primary surgery.

Methods: The National Cancer Database was queried for patients with non-small cell lung cancer with tumor size >7 cm who underwent surgical resection from 2010 to 2015. Patients with clinically node-positive disease or tumor invasion of major structures were excluded. Patients undergoing induction chemotherapy followed by surgical resection (IC group) were compared with patients undergoing primary surgery (PS group). Propensity score matching was performed.

Results: In total, 1610 patients with cT4 N0 disease on the basis of tumor size >7 cm and no tumor invasion underwent surgical resection: 1346 (83.6%) comprised the PS group and 264 (16.4%) the IC group. After propensity score matching, the IC group had a higher rate of pN0 (78.4% vs 66.0%; P < .001) and less lymphovascular invasion (13.9% vs 26.3%; P < .001), but longer postoperative stays (6 days vs 5 days; P < .001) and higher 30-day mortality (3.5% vs 0%; P = .002). Median 5-year survival was similar between the IC and PS groups (53.5% vs 62.2%; P = .075), and IC was not independently associated with survival (hazard ratio, 1.45; P = .146).

Conclusions: Patients with cT4 N0 non-small cell lung cancer on the basis of tumor size >7 cm and no tumor invasion of major structures have similar overall survival with either induction chemotherapy or primary surgery. Induction chemotherapy should not be routinely given for this subset of stage IIIA patients.