ALK Traslocated Pulmonary Sarcomatoid Carcinoma

Abstract Introduction: Pulmonary sarcomatoid carcinoma (PSC) is a heterogeneous group of primitive lung cancer representing from 0.3% to 3% of all primary lung malignancies. Most patients with PSC consist of elderly, smoking men with a large, peripheral mass with welldefined margins. Case Report: We report a case of carcinosarcoma with ALK translocation in a 43 years old woman with a good response to therapy with Alectinib and a Progression Free survival (PFS) of 15 months. She underwent Total body CT scan that showed bone, liver and spleen metastasis. Histological sample was obtained with bronchoscopy, showing carcinosarcoma. Molecular analysis performed on tumor tissue showed an 80% immunochemistry ALK positivity and a negativity for EGFR, ROS 1 with a tumor proportion score (TPS) of programmed death ligand (PDL-1) of 20%. After one cycle of platinum-based doublet chemotherapy, interrupted for hematological toxicity, she was treated with Alectinib. We obtained a complete radiological response (CR) in extrapulmonary sites of disease but a SUV increased level was present in right upper lobe lesion (RUL). After few months she received Stereotactic Body Radiation Therapy (SBRT) in RUL showing a partial response. Discussion: PSC are a mixture of carcinoma and sarcoma containing differentiated sarcomatous elements. Generally, they are considered chemo resistant. In the last years, there has been development of targeted and immunotherapy in lung cancer but the role of these drugs in PCS is still unknown. Lots of studies are evaluating the role of MET amplification, PDL1 overexpression, EGFR mutation, ALK translocation. Conclusion: ALK rearrangement is a rare finding in PSC. This article shows the importance to test patients in order to find driver mutation even in rare and poor prognosis histological features of lung cancer. Keywords: Sarcomatoid carcinoma (SC); lung; ALK, ALectinib