Personalized Treatment of Rare Cancers Based on Comprehensive Diagnostics: Case Reports of Two Neuroendocrine Breast Cancers

The present case study illustrates the diagnostic and therapeutic challenges presenting the epicrisis of two patients diagnosed with NEBC in these above-mentioned situations. Neuroendocrine breast cancer (NEBC) is an uncommon disease that accounts for 0.1 % of all breast carcinomas and 1% of all neuroendocrine tumours [6]. In the absence of prospective trial data on NEBC cohorts, herein, we present two case reports diagnosed with large cell and small cell NEBC. After initial therapies failed, comprehensive tumour profiling was applied, leading to individualized treatment options for both patients. In both patients, targetable alterations of the PI3K/AKT/mTOR pathway were found, including a PIK3CA mutation itself and a STK11 mutation that negatively regulates the mTOR complex. The epicrisis of the two patients exemplifies how to manage rare and difficult to treat cancers and how new diagnostic tools contribute to medical management. We should think about using tailored therapies based on comprehensive tumour characteristics earlier, because only then can we know whether this approach will provide a benefit. Trials based on several rare cancer types and extensive profiling could hold the key for a successful treatment.