Bisphosphonate Use and Breast Cancer Risk among Women with Ductal Carcinoma In Situ
Menée auprès de 587 témoins et 301 patientes ayant des antécédents de carcinome canalaire in situ, cette étude analyse l'association entre une utilisation de bisphosphonates et le risque de cancer invasif
Women with a history of ductal carcinoma in situ (DCIS) have an elevated risk of a subsequent invasive breast cancer, but there are few established potentially modifiable factors known to lower this risk. Bisphosphonates are a commonly used treatment for patients with osteoporosis and have been shown to lower risks of recurrence and mortality in patients with invasive breast cancer; however, their use has not previously been investigated within the context of DCIS. Utilizing a population-based nested case-control design, we compared 301 cases of women diagnosed with DCIS and a subsequent breast cancer and 587 individually matched controls (on age, DCIS diagnosis year, primary treatment, histology, grade, and disease-free survival time) who were diagnosed with DCIS but never a subsequent breast cancer. Information on recency and duration of bisphosphonate use was ascertained from patient interviews and medical record reviews. Current users of bisphosphonates had a reduced risk of developing an invasive breast cancer compared to never users (OR=0.50, 95% CI: 0.26-0.99). Users of bisphosphonates for {greater than or equal to}48 months had a similar reduction in risk (OR=0.45, 95% CI: 0.24-1.06). This is the first study to document that bisphosphonate use is associated with a lower risk of subsequent invasive breast cancer among women with a history of DCIS. This finding is consistent with the protective effect of bisphosphonates observed in other breast cancer settings. If validated by others, bisphosphonates may be an effective risk-reducing approach with the potential added benefits of its positive impacts on bone health and fracture risk.
Cancer Research 2021