Association between body mass index combined with high-sensitivity C-reactive protein and the risk of postmenopausal breast cancer: A prospective cohort study.

The present study aimed to assess the risk of postmenopausal breast cancer in women based on a combination of body mass index (BMI) and high-sensitivity C-reactive protein (hs-CRP) levels. A total of 20,400 participants were investigated as part of the 'Kailuan Study' clinical trial. Participants were classified into four groups based on BMI (BMI ≥24 or <24 kg/m) and hs-CRP level (hs-CRP ≥3 or <3 mg/l). Cox proportional hazards models were used to evaluate the association between the combination of BMI and hs-CRP and the risk of postmenopausal breast cancer. A total of 19,540 participants met the inclusion criteria. The median follow-up time was 14.97 years, with a cumulative follow-up period of 283,599.43 person-years. Among the participants, 269 individuals were diagnosed with postmenopausal breast cancer. Individuals with a high BMI (BMI ≥24 kg/m) and a high hs-CRP level (hs-CRP ≥3 mg/) had a greater risk of postmenopausal breast cancer compared with individuals with a low BMI (BMI <24 kg/m) and a low hs-CRP level (<3 mg/l) (hazard ratio, 1.75; 95% confidence interval, 1.25-2.47). The sensitivity analysis showed findings consistent with the primary results. In conclusion, the combination of high BMI and high hs-CRP level is associated with an increased risk of postmenopausal breast cancer. The present study is part of the Kailuan Study. Trial registration number: ChiCTRTNCR11001489 (Chinese Clinical Trial Registry, https://www.chictr.org.cn/showproj.html?proj=8050). Date of registration: 19/07/2015.