The incidence of bone metastasis after early-stage breast cancer in Canada

Abstract

Current information on the incidence and prevalence of bone metastases in women with breast cancer is scarce. This study examined the occurrence and predictors of bone metastases, as well as post-metastasis survival in a prospective cohort of Canadian women with breast cancer. We included women treated for early-stage (stage I, II, or III) breast cancer at the Henrietta Banting Breast Centre (HBBC) in Toronto, Canada between 1987 and 2000. Data were abstracted from medical records and pathology reports in the HBBC database; follow-up extended to end of data availability or August 31, 2015. Actuarial survival analyses provided cumulative incidence of bone metastases at 5, 10, and 15 years after breast cancer diagnosis. Kaplan-Meier curves describe breast cancer mortality. Regression models assessed patient, tumor, and treatment characteristics as predictors of bone metastases with all-cause mortality as a competing risk. Among 2097 women studied, the 5-, 10-, and 15-year probability of bone metastasis was 6.5, 10.3, and 11.3 % for the first recurrence, and 8.4, 12.5, and 13.6 % for any bone recurrence. At median follow-up (12.5 years), 13.2 % of patients had bone metastases. Median survival was 1.6 years following bone metastasis, and shorter if both bone and visceral metastases occurred. Advanced age and adjuvant treatment with tamoxifen were protective against bone metastasis. In this representative cohort of women diagnosed with early-stage breast cancer in Ontario, Canada, with long follow-up, the incidence of bone metastases was consistent with longitudinal studies from the United Kingdom, Denmark, and the US.

Incidence proportions and prognosis of breast cancer patients with bone metastases at initial diagnosis

“…The median OS was 30 and 68.2 months from initial diagnosis in the SEER cohort and FUSCC cohort, respectively, which is similar with the survival reported by previous authors 20, 29, 30, 33. We assume that the longer survival in the FUSCC cohort was because the patients in this cohort were much younger and had less extraosseous metastatic sites.…”

“…We also validated the results of survival analysis in another independent cohort from FUSCC. Some studies have evaluated the epidemiology and prognosis of breast cancer patients with bone metastases at the population level, but most of the patients in these studies presented bone metastases after a diagnosis of early‐stage breast cancer 2, 20, 29, 30, 31, 32, 33. However, limited data have been reported in the specific group of patients with bone metastases upon their initial diagnosis of breast cancer 34.…”

“…Patients with HR‐positive breast cancer are at increased risk for the development of bone metastases, whereas bone metastases are less frequent in cases of triple‐negative tumors 15, 16, 17, 18, 19, 20, 21. Previous studies also indicated that tumor subtype is an important prognostic factor for the survival of patients with bone metastases, where worse survival was seen in patients with triple‐negative breast cancer 22, 23…”

A Rare Sternal Lesion on Magnetic Resonance Mammography Mimicking a Metastasis in a Patient With a History of Mamma Carcinoma: A Case Report

“…These imaging characteristics are also seen in metastases of breast carcinoma. The incidence of bone metastases is reported to be 6-6.5% [10,11]. In sixty-nine percent of diagnosed bone metastases, the chest cage is one of the locations where metastases are found [12].…”

Identification of the Risk Factors of Bone Metastatic among Breast Cancer Women in Al-Bashir Hospital

“…In our study, we notice that about 59% of breast cancer cases diagnosed as bone metastasis cases after treatment (surgery, chemotherapy and radiotherapy) and 41% of cases diagnosed as bone metastasis at first presentation. In Ontario, Canada (2016); the probability of bone metastasis was 6.5%, 10.3%, and 11.3% for the first recurrence among 2097 breast cancer women after 5, 10 and 15 years from diagnosis respectively, and 8.4%, 12.5%, and 13.6% for any bone recurrence [8], the results of our study were the inverse of the Canadian, the incidence of bone metastases at 5, 10, and more than 10 years after breast cancer diagnosis decreased with time proceeding after diagnosis and it were 69.8%, 22.3% and 7.9% respectively, the difference in the results may be related to the difference in the sample size or variability of nature of the disease between the countries.…”