Stressful life events and survival after breast cancer

Objective: This study assessed the relation of stressful life events with s urvival after breast cancer. Methods: This study was based on women with hi stologically confirmed, newly diagnosed, localized or regional stage breast cancer first treated in 1 of 11 Quebec City (Canada) hospitals from 1982 t hrough 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: numbe r of events; number weighted by reported impact; and for almost 80% of even ts, number weighted by community-derived values reflecting adjustment requi red by the event. Scores were divided into quartiles to assess possible dos e-response relationships. Survival was assessed in 1993, Hazard ratios and 95% confidence intervals (CIs) comparing all-cause and breast cancer-specif ic mortality were calculated with adjustment for age, presence of invaded a xillary nodes, adjuvant radiotherapy, and systemic therapy tie, chemotherap y and hormone therapy). Results: When quartiles 2, 3, and 4 were compared w ith the appropriate lowest quartile, adjusted hazard ratios for all-cause m ortality 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 co mmunity-derived values, respectively. Results were essentially similar for the relation between stressful life events limited to those occurring withi n the 12 months before diagnosis and overall mortality and between stressfu l life events in the 5 years before diagnosis and breast cancer-specific mo rtality. Conclusions: Stress was conceptualized as life events presumed to be negative, undesirable, or to require adjustment by the person confrontin g them. We found no evidence indicating that this kind of stress during the 5 years before diagnosis negatively affected survival among women with non metastatic breast cancer. Evidence from this study and others on the lack o f effect of this type of stress on survival may be reassuring for women liv ing with breast cancer.