Sins of omission: A meta-research study evaluating the omission of operability in published retrospective comparisons of surgery with stereotactic body radiotherapy in patients with early-stage non-small cell lung cancer.

INTRODUCTION: Patients receiving stereotactic body radiotherapy (SBRT) for early-stage non-small cell lung cancer (NSCLC) are typically inoperable, in concordance with guidelines that advocate surgical resection as preferred treatment for operable patients. This differential treatment allocation complicates retrospective comparisons of surgery with SBRT by introducing the potential for confounding by operability. METHODS: PubMed was queried for manuscripts reporting primary data from retrospective comparisons of overall survival (OS) between patients undergoing surgery versus SBRT for early-stage NSCLC. Each manuscript was categorized for two outcomes: (1) whether treatment allocation was based on a determination of patient operability, and (2) whether a direct OS comparison between operable SBRT patients and surgically treated patients was included. Associations with variables of interest were measured with statistical significance prespecified at p < 0.10. RESULTS: From 3,072 manuscripts identified in our query, sixty-one analyses met screening criteria. Twenty-one (34 %) reported operability status influencing treatment allocation. These were more likely to be published in journals with a surgical focus (52 vs 20 %) and impact factor < 5 (81 vs 58 %), and to contain cohorts from institutional datasets (81 vs 55 %), and to have a radiation oncologist as first (43 vs 25 %) or senior (43 vs 28 %) author. Seven (11 %) manuscripts featured a direct OS comparison between SBRT and surgery. CONCLUSION: Nearly-two-thirds of peer-reviewed retrospective studies that have compared OS between surgery and SBRT for early-stage NSCLC lack information on patient operability status, and nearly 90% lack a direct comparison between operable SBRT patients and those receiving surgery.

The impact of postmastectomy and regional nodal radiation after neoadjuvant chemotherapy for clinically lymph node-positive breast cancer: a National Cancer Database (NCDB) analysis.

BACKGROUND: Following neoadjuvant chemotherapy (NAC), the optimal strategies for postmastectomy radiotherapy (PMRT) and regional nodal irradiation (RNI) after breast-conserving surgery (BCS) are controversial. In this analysis, we evaluate the impact of these radiotherapy (RT) approaches for women with clinically node-positive breast cancer treated with NAC in the National Cancer Database (NCDB). PATIENTS AND METHODS: Women with cT1-3 cN1 M0 breast cancer treated with NAC were divided into four cohorts by surgery [Mastectomy (Mast) versus BCS] and post-chemotherapy pathologic nodal status (ypN0 versus ypN+). Overall survival (OS) was estimated using the Kaplan-Meier method and RT approaches were analyzed using the log-rank test, multivariate Cox models, and propensity score-matched analyses. RESULTS: From 2003 to 2011, 15 315 cases were identified including 3040 Mast-ypN0, 7243 Mast-ypN+, 2070 BCS-ypN0, and 2962 BCS-ypN+ patients. On univariate analysis, PMRT was associated with improved OS for both Mast-ypN0 (P = 0.019) and Mast-ypN+ (P < 0.001) patients. On multivariate analyses adjusted for factors including age, comorbidity score, cT stage, in-breast pathologic complete response, axillary surgery, ypN stage, estrogen receptor status and hormone therapy, PMRT remained independently associated with improved OS among Mast-ypN0 [hazard ratio (HR) = 0.729, 95% confidence interval (CI) 0.566-0.939, P = 0.015] and Mast-ypN+ patients (HR = 0.772, 95% CI 0.689-0.866, P < 0.001). No differences in OS were observed with the addition of RNI to breast RT for BCS-ypN0 or BCS-ypN+ patients. Propensity score-matched analyses demonstrated identical patterns of significance. On subset analysis, OS was improved with PMRT in each pathologic nodal subgroup (ypN0, ypN1, and ypN2-3) (all P < 0.05). CONCLUSIONS: In the largest reported analysis of RT for cN1 patients treated with NAC, PMRT was associated with improved OS for all pathologic nodal subgroups. No OS differences were observed with the addition of RNI to breast RT.