Abstract
A small percentage of patients have multiple synchronous primary cancers at presentation. In the last five years, many regimens associated with immunotherapy and chemotherapy were approved for first-line metastatic non-small-cell lung cancer (NSCLC) and other solid tumors, but the study of immunotherapy when multiple cancers are present in one patient remains incomplete. Next-generation sequencing biomarkers and immunotherapy markers including PD-L1 can be effectively utilized in the diagnosis and treatment plan for multiple synchronous primary cancers. Immune biomarkers and PD-L1 expression warrant individualized treatments in synchronous primary adenocarcinoma and pulmonary sarcomatoid carcinoma. We describe the case of a patient with pulmonary sarcomatoid carcinoma and lung adenocarcinoma, metastatic to brain de novo. The patient achieved a complete response after only three cycles of carboplatin, paclitaxel, bevacizumab, and atezolizumab and remains free of any evidence of disease after 18 mo of maintenance therapy.