KCMC-FCCT Tumor Board September 2023

A single case of breast cancer was discussed at the September tumor board. A 52 year-old nulliparous woman with no family history of breast cancer presented with bloody nipple discharge, a palpable left breast mass and axillary adenopathy. A staging CT scan of the abdomen and pelvis identified an ovarian cyst that was evaluated laparoscopically and found to be benign. The patient underwent a left lumpectomy and left axillary lymph node dissection. The pathology of the breast specimen revealed grade 2 ductal carcinoma in situ (DCIS) without an obvious invasive component. However, the axillary lymph nodes contained invasive ductal carcinoma that was estrogen and progesterone negative but Her2/neu positive by immunohistochemistry. The patient had already initiated post-operative adjuvant chemotherapy with cyclophosphamide and doxorubicin with the plan to then receive paclitaxel and trastuzumab. The plan was to either refer her to Dar Es Salaam for radiation after completion of chemotherapy or offer her a mastectomy that could be performed at KCMC.

Part of the discussion surrounding this case involved the fact that in the USA, DCIS only rarely presents as a palpable mass but more commonly as abnormal micro-calcifications on a screening mammogram. DCIS does not spread to regional lymph nodes but can be a precursor to invasive cancer that can metastasize. In the USA, more extensive pathologic evaluation is available to rule out areas of focal micro-invasion of DCIS that may not be readily evident on routine pathologic evaluation. In the USA, breast MRI would also have been used to rule out a separate invasive focus of breast cancer elsewhere in the breast that could have been responsible for the axillary metastases. Dual her2/neu directed therapy with a combination of trastuzumab and pertuzumab is often offered along with chemotherapy. The role of post mastectomy chest wall radiation therapy (if the patient chose mastectomy) was also debated.