RESUMO
OBJECTIVE: This study assessed the relation of stressful life events with survival after breast cancer. METHODS: This study was based on women with histologically confirmed, newly diagnosed, localized or regional stage breast cancer first treated in 1 of 11 Quebec City (Canada) hospitals from 1982 through 1984. Among 765 eligible patients, 673 (88%) were interviewed 3 to 6 months after diagnosis about the number and perceived impact of stressful events in the 5 years before diagnosis. Three scores were calculated: number of events; number weighted by reported impact; and for almost 80% of events, number weighted by community-derived values reflecting adjustment required by the event. Scores were divided into quartiles to assess possible dose-response relationships. Survival was assessed in 1993. Hazard ratios and 95% confidence intervals (CIs) comparing all-cause and breast cancer-specific mortality were calculated with adjustment for age, presence of invaded axillary nodes, adjuvant radiotherapy, and systemic therapy (ie, chemotherapy and hormone therapy). RESULTS: When quartiles 2, 3, and 4 were compared with the appropriate lowest quartile, adjusted hazard ratios for all-cause mortality were 0.99 (CI = 0.70-1.38), 0.97 (CI = 0.73-1.31), and 1.04 (CI = 0.78-1.40) for number, number weighted by impact, and number weighted by community-derived values, respectively. Results were essentially similar for the relation between stressful life events limited to those occurring within the 12 months before diagnosis and overall mortality and between stressful life events in the 5 years before diagnosis and breast cancer-specific mortality. CONCLUSIONS: Stress was conceptualized as life events presumed to be negative, undesirable, or to require adjustment by the person confronting them. We found no evidence indicating that this kind of stress during the 5 years before diagnosis negatively affected survival among women with nonmetastatic breast cancer. Evidence from this study and others on the lack of effect of this type of stress on survival may be reassuring for women living with breast cancer.