Breast cancer treatment in patients with tuberculosis: Challenges and therapeutic considerations.

Breast cancer (BC) and tuberculosis (TB) remain two major global health problems, representing the leading causes of cancer- and infection-related deaths worldwide. BC and TB have distinct global distributions but may coexist in individuals, particularly in settings where persistent TB burden coincides with increasing demand for BC diagnosis and treatment. The co-occurrence of BC and TB poses diagnostic and therapeutic challenges for multidisciplinary specialists, including drug-drug interactions (DDIs) and potentially overlapping toxicities. Misdiagnosis of concomitant TB with BC can result from overlapping clinical and radiologic features, and clinicians must differentiate between pulmonary metastatic disease, pulmonary TB, axillary metastases, axillary TB, primary BC lesions, and mammary TB. Rifampicin is the cornerstone of TB treatment and a potent inducer of cytochrome P450 enzymes, most importantly CYP3A4, increasing the risk of DDIs with many anti-cancer drugs. Thus, reviewing each agent's pharmacokinetics is essential to avoid loss of antitumor efficacy and to prevent increased toxicities. The main aim of this narrative review is to summarize the available evidence on the diagnostic and therapeutic considerations for patients with coexistent TB and BC.