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 dynamics and to assess sex-based differences in the timing of recurrence for non-small cell lung cancer. METHODS: We studied 829 patients (538 men, 291 women) with NSCLC who underwent complete pulmonary resection in 9 hospitals. Event dynamics 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, with a sharp peak in the first year in men and a broad peak during the first 2 to 3 years in women. These findings were also confirmed by analyses according to pathological stage, histological type, and smoking history. CONCLUSION: The peak times 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.