Management of multiple primary cancers, a not so infrequent event in oncology practice, is a critical issue due to the lack of literature . In this study, we reported the case of a patient with metachronous double metastatic non small cell lung cancer (NSCLC) and pancreatic ductal adenocarcinoma (PDAC) who received gefitinib in combination with gemcitabine plus nab-paclitaxel and with mFOLFOX6 in first and second line, respectively. She achieved a progression free survival and an overall survival (OS) of 28 months for NSCLC and PFS-1 and OS of 20 and 13 months, respectively for PDAC. Moreover, the combination of gefitinib and chemotherapies treatments displayed a good safety profile. Given the insignificant frequency of this case, we performed a molecular characterization of both neoplasms with the aim to investigate the existence of particular activated pathways and/or similar immunological mutations. it is interesting to note that two neoplasms shared a commune mutation of B7-H3 gene, with the consecutive impairment of its expressed protein. In both PDAC and NSCLC, the expression of this protein was associated with a worse survival. Since B7-H3 is an anti-apoptotic protein, the reduction of its expression or function should justify a pro-apoptotic activity with a putative justification of the long survival of the patient considered in this report.