Bone metastasis pattern in initial metastatic breast cancer: a population-based study

Area of Science:

• Oncology
• Epidemiology
• Cancer Metastasis

Background:

• Bone is a frequent site for breast cancer metastasis.
• Population-based studies on patients with initial bone metastasis in metastatic breast cancer (MBC) are limited.

Purpose of the Study:

• To provide population-based estimates of the epidemiologic characteristics of breast cancer patients with initial bone metastasis.
• To identify factors predicting bone metastasis and prognosis in these patients.
• To analyze survival outcomes for initial bone metastasis compared to other metastatic sites.

Main Methods:

• Utilized the National Cancer Institute's Surveillance, Epidemiology, and End Results database (2010-2013).
• Included 245,707 breast cancer patients, identifying 8,901 with initial bone metastasis.
• Employed multivariate logistic and Cox regression for predictive and prognostic factor identification; Kaplan-Meier and log-rank tests for survival analysis.

Main Results:

• Initial bone metastasis occurred in 3.6% of the entire cohort and 62.5% of initial MBC patients.
• 70.5% of patients with bone metastasis were hormone receptor (HR) positive (HR+/HER2-: 57.6%; HR+/HER2+: 12.9%).
• Patients with initial bone metastasis had better 5-year survival than those with brain, liver, or lung metastasis. HR+/HER2- and HR+/HER2+ subtypes showed a propensity for bone metastasis and better prognosis. Local surgery improved overall survival.

Conclusions:

• This study offers population-based data on the epidemiology and prognosis of initial bone metastasis in breast cancer.
• Findings support enhanced surveillance and optimized treatment strategies for bone metastasis in breast cancer patients.