Dados do Trabalho

Título

DETECTION OF HPV 16 AND 18 CELL FREE DNA IN THE PLASMA OF WOMEN FOLLOWING TREATMENT FOR CERVICAL CANCER IN A REFERENCE CENTER FOR CANCER TREATMENT IN AMAZON

Introdução

Cervical cancer is the fourth most common cancer in terms of incidence and mortality in the female population worldwide, resulting from persistent infection by oncogenic Human Papillomaviruses (HPV). Detection of HPV cell free DNA can help monitor treatment response and detect residual disease or relapse.

Objetivo

This study aimed to evaluate the presence of HPV cell free DNA in the plasma of women with cervical cancer before and after treatment, in addition to characterizing the clinical and therapeutic conditions of these patients after treatment.

Métodos

Prospective study carried out with women assisted at the Fundação Centro de Controle de Oncologia do Estado do Amazonas (FCECON), with diagnosis of cervical cancer (CC). Sample size was calculated based on the total number of women diagnosed with CC in 2019 (330 cases), prevalence of 58.8%, precision of 5%, confidence level of 95%, loss of follow-up of 30%, reaching the sample of 50 patients. Plasma collections were performed at the following times: before treatment, 6, 9 and 18 months after the start of treatment. Circulating cell free DNA was manually extracted from plasma using the Promega RealiaPrep TM BloodgDNA Kit. The material was subjected to β-actin gene detection as an internal control. For the identification of HPV genotypes 16 and 18, the samples, in duplicate, were submitted to the type-specific real-time PCR (qPCR) assay, with the E7 protein as a target, following the protocols according to VEO et al (2015). DNA from SiHa cells and RNase and Dnase-free water were used as positive and negative controls, respectively. The study was approved by the Institutional Review Board (IRB) of FCECON (N. 3,997,504).

Resultados

57 women were included in the study, of which 84.22% (48/57) were included in the age groups between 26-45 and 46-64 years old; 43 (75.44%) reported having an income less than or equal to U$ 270.00; 77.19% (44/57) declared themselves to be from Amazonas, of which 50.88% (29/57) are from the interior of the state. At the time of diagnosis, 31.58% (18/57) of participants had HPV-16 detected in their blood plasma. The presence of HPV-18 was not detected in any sample. After 6 months of starting treatment, 5.56% (1/18) of the samples had detectable HPV-16; 38.89% (7/18) and 22.22% (4/18) had undetectable viral DNA in plasma after 9 and 18 months, respectively. A total of 89.47% (51/57) had histopathological results of squamous cell carcinoma. More than 67.00% were classified as III or more FIGO stage at diagnosis.

Conclusões

Detection of cell free HPV 16 DNA in plasma is feasible and may play an important role in monitoring response to cervical cancer treatment. However, there should be other studies with a longer follow-up period so that it is possible to correlate the presence of viral DNA in the plasma with disease recurrence.

Palavras-chave

Cell free DNA; Cervical Cancer; HPV; Relapse.

Financiador do resumo

Fundação de Amparo a Pesquisa do Estado do Amazonas - FAPEAM