National cooperative group trials of "high-risk" patients with lung cancer: are they truly "high-risk"?

Abstract

The American College of Surgery Oncology Group (ACOSOG) trials z4032 and z4033 prospectively characterized lung cancer patients as "high-risk" for surgical intervention, and these results have appeared frequently in the literature. We hypothesized that many patients who meet the objective enrollment criteria for these trials ("high-risk") have similar perioperative outcomes as "normal-risk" patients. We reviewed a prospective institutional database and classified patients undergoing resection for clinical stage I lung cancer as "high-risk" and "normal-risk" by ACOSOG major criteria. From 2000 to 2010, 1,066 patients underwent resection for clinical stage I lung cancer. Of these, 194 (18%) met ACOSOG major criteria for risk (preoperative forced expiratory volume in 1 second or diffusion capacity of the lung for carbon monoxide≤50% predicted). "High-risk" patients were older (66.4 vs 64.6 years, p=0.02) but similar to controls in sex, prevalence of hypertension, diabetes, and coronary artery disease. "High-risk" patients were less likely than "normal-risk" patients to undergo a lobectomy (117 of 194 [60%] vs 665 of 872 [76%], p<0.001). "High-risk" and control patients experienced similar morbidity (any complication: 55 of 194 [28%] vs 230 of 872 [26%], p=0.59) and 30-day mortality (2 of 194 [1%] vs 14 of 872 [ 2%], p=0.75). A regression analysis showed age (hazard risk, 1.04; 95% confidence interval, 1.02 to 1.06) and coronary artery disease (hazard risk, 1.58; 95% confidence interval, 1.05 to 2.40) were associated with an elevated risk of complications in those undergoing lobectomy, whereas female sex (hazard ratio, 0.63; 95% confidence interval, 0.44 to 0.91) was protective. ACOSOG "high-risk" status was not associated with perioperative morbidity. There are no important differences in early postsurgical outcomes between lung cancer patients characterized as "high-risk" and "normal-risk" by ACOSOG trial enrollment criteria, despite a significant proportion of "high-risk" patients undergoing lobectomy.