Depression in breast cancer patients who have undergone mastectomy: A national cohort study

Objective The objective of this study was to compare the incidence of post-operative depression in breast cancer patients who have undergone mastectomy with the incidence of post-operative depression in non-breast cancer participants (controls). Methods Using data from the Korean Health Insurance Review and Assessment Service (HIRA), we selected 2,130 patients with breast cancer who have undergone mastectomy for this national cohort study and matched these patients 1:4 with 8,520 control participants according to age, sex, income, region, and pre-operative depression. The incidence of post-operative depression was measured from mastectomy year to post-op year 10. The Mann-Whitney U test was used for data analysis, and the false-discovery rate was applied to determine statistical significance (P < 0.05).Results The incidence of depression was higher in the breast cancer with mastectomy group than in the control group up to 3 years after mastectomy). However, there was no difference in the incidence of depression between the breast cancer with mastectomy group and the control group after post-op 4 years. The incidence of depression was higher in the breast cancer with mastectomy group than in the control group up to 2 years after mastectomy, and there was no difference in the incidence of depression between the two groups after post-op 3 years in middle-aged and older adults (≥ 40 years old). In young adults (≤ 39 years old), the incidence of depression was significantly higher in the breast cancer with mastectomy group than in the control group in mastectomy year. Conclusion Patients undergoing mastectomy for breast cancer experience depression more frequently than healthy people. However, patients overcome their depressive mood symptoms during the postoperative period. Young adults overcome their symptoms more quickly than middleaged and older adults.