Sublobar versus lobar resection for stage I non-small cell lung cancer: Alice's evidence.

To the Editor: N arsule et al 1 reviewed the status of sublobar resection for early stage lung cancer and concluded that sublobar resection seemed to provide outcomes comparable to lobectomy. The difference in the survival after lobectomy and sublobar resection, however, has been debated even after 1 randomized trial. A meta-analysis, published in 2005, of 1 randomized trial and 13 nonrandomized studies indicated that survival after sublobar resection for stage I lung cancer was comparable to that after lobectomy. Herein, we would like to perform a meta-analysis of sublobar resection versus lobectomy for prevention of all-cause mortality in stage I non-small cell lung cancer (NSCLC), combining not unadjusted (as combined in the previous meta-analysis) but adjusted risk estimates in nonrandomized studies. The MEDLINE and EMBASE databases and the Cochrane Library and Central Register of Controlled Trials were searched using PubMed and OVID. Text keywords included lung cancer; conservative resection, limited resection, segmentectomy, sublobar resection, or wedge resection; lobectomy or lobar resection; randomized, randomly, or randomization; and adjusted, adjustment, multivariate, multivariable, multiple, Cox, hazard, logistic, regression, or propensity. Studies considered for inclusion met the following criteria: the design was a study comparing outcomes of sublobar resection versus lobectomy; acceptable risk adjustment methods included propensity sore analyses, multivariate Cox proportional hazards regression models, and multivariate logistic regression models; the study population was patients with stage I NSCLC; and main outcomes included all-cause mortality (only adjusted risk estimates in nonrandomized studies). From each individual study, hazard ratios (HRs), or risk ratios (RRs) instead when HRs were unavailable, for follow-up all-cause death and 95% confidence intervals (CIs) were abstracted. Study-specific estimates were combined using inverse variance-weighted averages of logarithmic HRs and RRs in a randomeffects model. Our search through April 2011 identified 1 randomized trial and 9 nonrandomized studies. We abstracted 1 unadjusted RR from the randomized trial and adjusted (using propensity score analysis and/or multivariate Cox proportional hazards regression model) 10 HRs and 2 RRs from the nonrandomized studies. Pooled analysis (representing 5982 patients) demonstrated a statistically significant 50% increase in all-cause mortality with sublobar resection relative to lobectomy (HR, 1.50; 95%CI, 1.24Y1.82; P G 0.0001; P for heterogeneity = 0.002; Fig. 1). Exclusion of any single study from the analysis did not substantively alter the overall result of our analysis. Despite the conclusion by Narsule et al, we found that, based on a metaanalysis combining adjusted risk estimates, sublobar resection might be associated with a 50% increase in all-cause mortality relative to lobectomy in patients with stage I NSCLC, which was robust in sensitivity analyses. ‘‘That’s the most important piece of evidence we’ve heard yet,’’ said the King, rubbing his hands; ‘‘so now let the juryVV. ’’ Hisato Takagi, MD, PhD Department of Cardiothoracic Surgery Shizuoka Medical Centre Shizuoka, Japan kfgth973@ybb.ne. jp