Coca-Pelaz A, Rodrigo JP, Suárez S, et al. - Given the correlation of second primary tumors (SPTs) with reduced life expectancy in patients treated for head and neck cancer (HNC), researchers sought to determine the incidence of SPTs, synchronous, and metachronous, in HNC population. They conducted a systematic review of literature following PRISMA guidelines, from 1979 to 2019, and included data of 456,130 patients from 61 articles. Outcomes revealed the mean incidence of 13.2% for SPTs during a minimum follow-up of 22 months: 5.3% for synchronous SPTs and 9.4% for metachronous SPTs. The head and neck area is the most frequent site for SPTs, followed by the lungs and esophagus. In view of the impact in the prognosis, they emphasize developing strategies for the early diagnosis of SPTs.