Published online Nov 10, 2018. doi: 10.5306/wjco.v9.i7.123
Peer-review started: May 28, 2018
First decision: July 9, 2018
Revised: August 26, 2018
Accepted: October 24, 2018
Article in press: October 24, 2018
Published online: November 10, 2018
Processing time: 165 Days and 5.1 Hours
Breast cancer is the leading cause of death among women, classified in molecular subtypes according to a genetic profile. Approximately 18% of human cancers are caused by infectious factors, and it is recognized that breast cancer is strongly related to environmental factors, such as viruses, diet, radiation, among others. Human papilloma virus (HPV) has been detected in 0% to 86% of breast cancer tumors, and it represents a possible risk factor. The host immune response might influence the prognosis of cancer patients after standard treatment.
It was recently suggested that HPV presence may act as a risk factor in breast cancer development, but it has not been correlated with molecular subtypes. In addition, it is important to evaluate the immune response of breast cancer patients and to be able to suggest some prognostic values that make it possible to offer better patients treatment.
The main objective is to detect HPV presence and to characterize the cellular immune response in breast cancer patients based on the molecular subtypes.
The patients inclusion was done prospectively, and the breast cancer molecular classification was made according to the St. Gallen International Breast Cancer Conference. HPV detection and genotyping were performed using HPV INNO-LIPA Genotyping Extra test, and lymphocyte subsets were measured by flow cytometry.
Luminal A was the most frequent breast cancer molecular subtype (33.33%), and HPV was detected in 25% of the breast cancer patients, with genotype 18 as the most frequent in the studied population. The means of CD3+, CD4+ and CD8+ subsets were decreased in patients with breast cancer, respective to benign pathology, with a statistically significant difference between CD8+ values (P = 0.048). The mean of NK+ cells was increased in the benign pathology group. HER2+ and Luminal B HER2+ tumors had the lowest counts of cell subsets. The HPV breast cancer patients had elevated counts of cellular subsets.
It can be observed that HPV positive breast cancer tumors have a better prognosis, correlated with Luminal A subtypes, and show a better cellular immune response, specifically in relation with TCD8+ cells counts, suggesting a better response to chemotherapy and radiant treatment, as in the case of HPV positive oropharynx tumors.
Future effforts should focus on evaluating patients disease-free survival, based on HPV positivity in the tumor tissue. In addition, viral load and HPV genome integration, the identification of HPV variants by sequencing, and the infiltrating lymphocytes in the tumor bed should also be studied. As a final consideration, the experience of working with fresh samples is complex and involves a process of sample collection in the operating room, in addition to the management of bioethical parameters, and our experience will allow for the possibility of obtaining more accurate results.