High-risk human papillomavirus in mammary gland carcinomas and non-neoplastic tissues of Mexican women: no evidence supporting a cause and effect relationship.

Human papillomavirus (HPV) has been implicated in breast carcinogenesis. Consecutive and non-selected mastectomy specimens from Mexican patients harboring breast carcinomas were sampled in order to look for the presence of HPV DNA. HPV-16 was detected in 6 (10%) of 60 breast carcinomas. Two of these also had HPV genome in adjacent non-neoplastic mammary-tissues. Seven cases had HPV DNA only in non-neoplastic tissue specimens. HPV DNA was also detected in 4 (25%) of 10 tumor-bed specimens without residual neoplastic lesions that were obtained from patients who underwent neoadjuvant chemotherapy or neoadjuvant chemotherapy/radiotherapy. HPV-positive tumors tended to be smaller in size, than HPV-negative tumors (p=0.047). Histological distributions of HPV-positive and -negative cases showed no significant difference. Although all the HPV-16 DNA were found integrated, its low viral load rendered it difficult to incriminate this virus in breast carcinogenesis. However, the possibility that HPV infection occurred during carcinoma development cannot be ruled out.