Background: Breast cancer and chemotherapy can cause substantial psychological distress. Maladaptive coping strategies may interfere with psychological adjustment during treatment. This study examined sociodemographic and clinical correlates of maladaptive coping among Iranian women with breast cancer undergoing chemotherapy.

Methods: This cross-sectional analytical study enrolled 200 women with stage I–III non-metastatic breast cancer receiving outpatient chemotherapy at three tertiary oncology centers in Kerman, Iran. Data were collected using a researcher-developed sociodemographic and clinical questionnaire and six Persian Brief COPE subscales: self-blame, denial, mental distraction, substance use, emotional venting, and behavioral disengagement. Independent-samples t tests and one-way ANOVA with Fisher’s least significant difference post-hoc tests assessed subgroup differences.

Results: Participants’ mean age was 46.91±6.08 years. Self-blame was associated with education level, perceived income adequacy, primary source of emotional support, and chemotherapy duration (all p<0.05). Women whose primary support came from their spouses reported lower self-blame than those supported by their children or parents; self-blame was highest in the third month of chemotherapy. Denial was higher among unmarried women and participants covered by Social Security insurance (both p<0.05). Substance-use coping differed by marital status, insurance type, source of support, and chemotherapy duration (all p<0.05), with the highest scores among divorced or widowed women. Self-distraction was higher among women with lobular versus ductal carcinoma, right-sided breast involvement, and primary support from children or spouses (all p<0.05). Venting and behavioral disengagement did not differ significantly across subgroups.

Conclusion: Several sociodemographic and clinical factors were associated with maladaptive coping strategies during chemotherapy. Targeted psychosocial screening and supportive interventions may be particularly beneficial for women without spousal support and during vulnerable stages of treatment.