Human papillomavirus (HPV) in breast tumors: prevalence in a group of Mexican patients

Abstract

Background: Breast cancer is one of the main health problems in developed countries, occupying first place in mortality in women. It is well-known that there are risk factors associated with breast cancer development. Nonetheless, in 50-80% of cases known risk factors have not been identified, this has generated the attempt to identify new factors related with this neoplasia as viral infections. The aim of this work is investigate the prevalence of HPV DNA in patients with breast lesions at the Instituto Nacional de Cancerologia de Mexico.

Methods: Fifty-one cases of breast cancer were selected from the files of the institute and compared by age and tumor size with 43 cases of non malignant breast lesions (fibroadenoma, fibrocystic disease and phyllodes tumor). Paraffin embedded specimens were selected, HPV DNA was analyzed by polymerase chain reaction (PCR) and sequenced for different types of HPV in case of positivity for HPV-DNA. Descriptive analysis of clinical and pathological variables was performed and comparisons between positive and negative cases was done.

Results: All patients were mexican, mean age was 53.3, median age of menarche was 13 and median tumor size 9 cms. Cervicovaginal cytology was performed to all patients, 1 patient (1.9%) of cancer group had HPV and none in the other group, no cases were diagnosed with cervical dysplasia. In the group of carcinomas 36 (70.5%) were negative and 15 (29.4%) were positive to HPV-DNA, 10(66.6%) were positive for HPV 16, 3(20%) for HPV 18, two cases (13.4%) were positive for both. In the group of benign conditions all were negative to HPV-DNA.

Conclusion: Presence of HPV in breast cancer in our group of cases is high in comparison to other authors; larger numbers of cases need to be analyzed in order to establish the exact role of this virus in the pathogenesis of breast cancer.

Figure 1

Electroforetical analysis of nested PCR products. In left line – MW marker, lines marked 34 – 49 are negative and positive samples, PCR product size 150 bp, + – positive control (described in protocol), 0,0 – double negative control (PCR premix with no DNA).