Final answer:
The definitive surgery for breast cancer during pregnancy without metastatic disease can vary but often involves either a lumpectomy or a simple mastectomy. The choice of surgery depends on multiple factors and requires a multi-disciplinary team to ensure the safety and best outcome for the mother and fetus.
Step-by-step explanation:
The definitive surgery for breast cancer during pregnancy without metastatic disease is not universally agreed upon and can depend on multiple factors including the size and location of the tumor, the stage of the cancer, the trimester of pregnancy, patient preferences, and the recommendations of the oncology team. However, in many cases, a lumpectomy or a simple mastectomy can be considered as surgical options. A lumpectomy involves removing the breast tumor (the 'lump') and a small margin of surrounding healthy tissue, often followed by radiation therapy, which may be delayed until after delivery. A simple mastectomy involves removing the entire breast without the removal of axillary lymph nodes or muscle tissue from beneath the breast.
Once the cancer is diagnosed, a thorough evaluation by a multi-disciplinary team that includes oncologists, surgeons, obstetricians, and potentially other specialists is essential to determine the best course of treatment tailored to the individual patient's needs. The team would consider the safety of both the mother and the fetus when planning the timing and type of surgery.