5. Eng C, Chang GJ, You YN, Das P, Rodriguez-Bigas M, Xing Y, Vauthey JN, Rogers JE, Ohinata A, Pathak P et al : The role of systemic chemotherapy and multidisciplinary management in improving the overall survival of patients with metastatic squamous cell carcinoma of the anal canal . Oncotarget 2014, 5(22):11133-11142.