The role of HPV on the risk of second primary neoplasia in patients with oropharyngeal carcinoma.

OBJECTIVES: It has been reported that patients with HPV-positive oropharyngeal cancer (OPC) have a lower risk of appearance of second primary neoplasm (SPN) than HPV-negative OPC patients. The aim of our study was to analyze the risk of developing SPN in a large group of patients with OPC according to HPV status in the primary tumor.

MATERIALS AND METHODS: We included 412 OPC patients treated at our center from 1991 to 2014 for which the HPV DNA positivity was evaluated by PCR in available tumor specimens. HPV DNA positive samples were further tested for HPV E6∗I mRNA detection and/or p16INK4a immunohistochemistry. We estimated the incidence of SPN in all cancer sites and in cancer sites related to tobacco and alcohol consumption according to the HPV status in the primary tumor.

RESULTS: Fifty-one (12.4%) out of 412 OPCs included in the study were HPV-related. Five-year SPN-free survival for HPV-negative versus HPV-positive OPC patients was 57.0% and 89.0% (P<0.001), respectively. Corresponding estimates for 10-year SPN-free survival were 35.2% versus 78.5% (P<0.001). When restricting the analyses to tobacco/alcohol-related SPNs, the corresponding survival rates where 62.0% versus 97.6% (P<0.001) and 42.2% versus 97.6%, (P<0.001), for 5-year and 10-year survival rates, respectively. HPV status and previous toxic habits might allow classifying patients regarding the risk of tobacco/alcohol-related SPNs.

CONCLUSION: HPV-related OPC patients have a significant lower risk of SPN development, particularly in those locations related to tobacco use or alcohol consumption.