Background and purpose: Breast cancer is the most common cause of cancer-specific mortality among women worldwide. This study aimed at investigating the epidemiological, clinical, and pathological characteristics of breast cancer among patients attending Baghban Clinic in Sari.

Materials and methods: The patients’ records (2008-2014) were used and data including age, gender, marital status, menopausal status, pregnancy and breast feeding, tumor size, type of tumor, number of involved lymph nodes, and metastasis were collected using a researcher-made checklist.

Results: The study population included 1019 patients (mean age: 50.1± 11.5 years) with breast cancer. The menarche age was 12-16 years in 77.8% of the patients. About 61.5% of patients had been diagnosed with breast cancer before menopausal age. The first pregnancy of 6.6% of the patients occurred after 30 years of age. Familial history of cancer was reported in 237 patients, 65.4% of which were breast cancer. The most common type of breast cancer was ductal carcinoma (90.7%) with moderate differentiation among 61% of the patients. The mean tumor size was significantly higher among patients that underwent total mastectomy compared to those with history of partial mastectomy (7.7±1.4 vs. 7.4±1.6, P=0.008).

Conclusion: Our study showed ductal carcinoma as the most common type of breast cancer among studied women and tumor size was found to be one of the main factors associated with total mastectomy.