Breast-conserving surgery with whole breast radiation therapy has a subsequent lower mood disorder incidence rate than total mastectomy in early-stage breast cancer patients: a nationwide population-based longitudinal study.

ABSTRACT

PURPOSE: Breast-conserving surgery (BCS) followed by whole breast radiation therapy (BCS-WBRT) or total mastectomy without WBRT (TM-no-WBRT) is the primary treatment for early stage breast cancer patients. Our study aimed to identify which early stage breast cancer treatment strategies had a subsequent lower incidence rate of mood disorder over a period of 10 years after the primary treatment. METHODS: This retrospective cohort study consisted of newly diagnosed early stage breast cancer patients in Taiwan from 2000 to 2013 using the National Health Insurance Research Database in Taiwan. We used a 11 propensity score matching by age to enrol patients into the BCS-WBRT and TM-no-WBRT groups. Statistical analyses were performed to calculate the hazard ratio and cumulative incidence rate. RESULTS: Our study consisted of 876 BCS-WBRT patients and 1949 TM-no-WBRT patients. After propensity score matching, each study group included 876 patients. The results showed that the mood disorder incidence rate was lower in the BCS-WBRT group than in the TM-no-WBRT group. Multivariate Cox regression analysis revealed that the BCS-WBRT group had a decreased risk of developing mood disorder (adjusted hazard ratio 0.69, 95% CI 0.53-0.90, p < 0.01). Furthermore, the Kaplan-Meier analysis showed that the BCS-WBRT group had a lower cumulative incidence rate of mood disorder, especially depression, after undergoing 10 years of primary treatment (p = 0.004). CONCLUSION: Our results indicated that BCS-WBRT was associated with a lower risk of development of mood disorder over a 10-year period compared to TM-no-WBRT in early stage breast cancer patients. Our findings may provide helpful information, along with other clinical data, for breast cancer patients as they choose the type of appropriate surgery for treatment.