Gender Differences in the Recurrence Timing of Patients Undergoing Resection for Non-Small Cell Lung Cancer

Objective: This study was designed to visually represent postoperative recurrence patterns using event dynamicsand to assess sex-based differences in the timing of recurrence for non-small cell lung cancer. Methods: We studied829 patients (538 men, 291 women) with NSCLC who underwent complete pulmonary resection in 9 hospitals. Eventdynamics with the use of life-table methods were evaluated, and only first events (distant metastases or local recurrence)were considered. The effects of sex, histological type, pathological stage, and smoking history were studied. Result:The resulting smoothed hazard rate curves indicated that the recurrence risk pattern definitely correlated with sex, witha sharp peak in the first year in men and a broad peak during the first 2 to 3 years in women. These findings were alsoconfirmed by analyses according to pathological stage, histological type, and smoking history. Conclusion: The peaktimes of recurrence differed considerably between men and women. The delayed time of peak recurrence in women,associated with a longer disease-free interval within subsets of patients with similar disease stage, histological type,and smoking status, might account for the better survival in women.