affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, Complejo Asistencial de Zamora, Hospital Clinico San Carlos, affiliation not provided to SSRN, Hospital Universitario Fundación Alcorcón - Medical Oncology Department, Hospital Universitario Virgen Macarena, Hospital Clínico de Valladolid, Hospital Regional Universitario de Málaga, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, Hospital General Universitario de Elche, affiliation not provided to SSRN, University of Las Palmas de Gran Canaria - Hospital Universitario Insular de Gran Canaria, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, Althaia, Xarxa Assistencial Universitària de Manresa - Medical Oncology Department, Hospital Clinico San Carlos, affiliation not provided to SSRN, affiliation not provided to SSRN, Universidad Autónoma de Madrid - Medical Oncology Department, affiliation not provided to SSRN and Universidad Autónoma de Madrid - Medical Oncology Department