Objectives To investigate the prevalence of high cancer risk and its influencing factors among women aged 35 – 64 years in the agricultural and herding areas of Hinggan League, Inner Mongolia Autonomous Region, and to provide evidence for local breast cancer prevention and control in the population.

Methods Face-to-face interview with a self-designed questionnaire, clinical examination, and breast cancer screening were conducted from January to December 2022 among 5 000 women aged 35 – 64 years recruited by random sampling in the agricultural and herding areas of six prefectures/counties/banners of Hinggan League, Inner Mongolia Autonomous Region. High risk for breast cancer was assessed using the Gail model according to the determinants listed in the Guidelines and Specifications for Breast Cancer Diagnosis and Treatment of China Anti Cancer Association – 2021. Multivariate non-conditional logistic regression model was used to analyze the main factors influencing the high risk of breast cancer among the participants.

Results Of the 49 831 valid participants, 13 334 (26.76%) were classified as being at high risk for breast cancer. The multivariate non-conditional logistic regression analysis showed that the participants with the following characteristics were more likely to be at high risk for breast cancer: age 45 – 64 years, Mongolian ethnicity, education of middle school and above, menopausal status, family history of breast cancer, history of breast surgery or biopsy, and breast skin changes on palpation; whereas belonging to other ethnic minorities, living with family members, and previous breast examination were protective factors against being at high risk for breast cancer.

Conclusion The proportion of individuals at high risk of breast cancer was relatively low among women aged 35 – 64 years in the agricultural and herding areas of Hinggan League, Inner Mongolia Autonomous Region. Age, ethnicity, education level, whether living with family members, menopausal status, family history of breast cancer, ever having had a breast examination, history of breast surgery or biopsy, and breast skin changes on palpation are the main influencing factors for having a high risk of breast cancer among women.