Clinicopathological features in bilateral breast cancer

Area of Science:

• Oncology
• Breast Cancer Research
• Clinical Epidemiology

Background:

• Bilateral breast cancer (BBC) occurs in 1.4-11.0% of all breast cancer cases.
• BBC can manifest as synchronous (SC) or metachronous (MC) diagnoses.
• Limited data exist on the clinical course and distinct characteristics of SC versus MC breast cancer.

Purpose of the Study:

• To evaluate demographic, pathological, and clinical characteristics of BBC.
• To compare treatments and responses between metachronous and synchronous breast cancer.
• To contrast BBC findings with historical unilateral breast cancer data.

Main Methods:

• Retrospective analysis of 150 BBC cases from 10 centers (2000-2011).
• Examination of age, family history, menopausal status, and pathological features.
• Assessment of neoadjuvant, surgery, adjuvant, and palliative therapies, including chemotherapy and radiotherapy.

Main Results:

• MC and SC groups had similar age, menopausal status, tumor type, and HER2/neu expression.
• Significant differences observed in family history, tumor grade, tumor stage, ER-negativity, and metastasis rates.
• MC group showed a higher response rate to palliative chemotherapy; median PFS did not differ.

Conclusions:

• Metachronous breast cancer is distinct from synchronous breast cancer.
• MC breast cancer is characterized by more advanced grade and stage, less ER expression, and higher rates of local relapse and distant metastasis.
• Patients with MC breast cancer demonstrated a better response to chemotherapy in cases of relapse or metastasis.