Persistência do Papilomavírus humano (HPV) após tratamento do câncer do colo uterino no norte do Brasil

Abstract

The cervical cancer is, after breast cancer, the leading oncologic cause of death among women living in developing countries. The cervical cancer is the third most incident cancer in Brazil and without considering non-melanoma skin tumors is the most incident in the northern region of Brazil. Human papillomavirus-HPV is considered the causal agent of cervical cancer and associated with different risk factors inherent to each woman (behavioral, reproductive and socioeconomic), determines the development of this disease. The HPV infection is most often asymptomatic and transient; however, 10-20% of infections caused mainly by genotypes of high oncogenic risk of the virus may persist and lead to invasive cervical cancer. The objective of this study was to investigate the persistence of HPV in cervical specimens in women with invasive cervical cancer after being treated with radiotherapy and / or concomitant chemotherapy in order to determine if the infection with the virus may be a risk factor for recurrence of disease or be associated with a worse prognosis. Forty four patients were selected, from July 2015 to July 2018, with a mean age of 47 years, with cervical cancer (at stages IB1-IVB of disease), attended at Ophir Loyola Hospital, an oncological reference center in the state of Pará. Clinical-epidemiological data and two cervical smear samples (one prior and one post-treatment) were collected, totaling 88 samples for the diagnosis of HPV. Samples were analyzed by Polymerase Chain Reaction (Nested PCR) to detect the presence of HPV DNA; and were genotyped for 9 viral types (two low risk: 6 and 11, and seven high oncogenic risk: 16, 18, 31, 33, 35, 52, 58) by real-time PCR. It was verified that the majority of the patients were treated by epidermoid cancer in stage IIB of the disease; and that prior to treatment HPV was present in 93% (41/44) of the patients, persisting in 75% (33/44) of them, at the end of treatment. Seven viral genotypes were detected (HPV 6, 16, 18, 33, 35, 52 and 58) causing both single and multiple infections, with HPV 16 being the most prevalent genotype. It has been shown that treatment with concomitant radiotherapy / chemotherapy is effective to eliminate the virus, but more studies are needed to determine if the presence of the virus influences the final response to treatment. Making evident the need to implement strategies of prevention and control of this type of cancer, based on the detection of HPV DNA.