What is the primary indication for a mastectomy or breast conservation therapy (BCT) followed by chemotherapy in breast cancer patients?

The primary indication for a mastectomy or breast conservation therapy (BCT) followed by chemotherapy in breast cancer patients relates to negative sentinel lymph node involvement and the estrogen receptor (ER) status. In this context, patients with negative sentinel lymph nodes and ER-negative tumors are typically considered for aggressive treatment options, including surgery and chemotherapy.

Negative sentinel lymph nodes indicate that there is no evidence of cancer spread to the lymphatic system, which generally allows for less extensive surgical intervention and the potential for breast conservation as part of treatment. The absence of estrogen receptor positivity suggests that hormonal therapies may not be effective, making chemotherapy a crucial component of the treatment plan to address the aggressive nature of ER-negative breast cancers.

In contrast, cases involving positive sentinel lymph nodes or those with advanced disease, such as stage IV, typically necessitate different treatment approaches, often involving systemic therapy as the first line rather than upfront surgical management. Additionally, HER2 positivity indicates a different treatment pathway, usually involving targeted therapies such as trastuzumab, rather than solely emphasizing surgical intervention.