Human papillomavirus is not associated with breast carcinoma

Abstract

Breast cancer is the most common cancer in women, accounting for 23% of all female cancers around the world. Research on its etiology has focused primarily on genetic and environmental factors [1]. Infectious etiology in carcinogenesis has long been suggested by epidemiological and experimental studies. Current estimates suggest that approximately 15–20% of all cancers worldwide appear to be associated with viral infections, and several human DNA viruses are now accepted as causative agent of specific malignancies [2]. Human papillomavirus (HPV) is one of the viruses and is responsible for causing virtually all cases of cervical cancer in women [2]. A number of studies have reported HPV DNA detection in extragenital cancers, although the etiological involvement of HPV in those malignancies is still controversial [3]. The aim of the present study was to investigate a possible presence of HPV DNA in breast cancer tissue in a population of Turkish women and discuss the results in the light of literature. In this study, 84 patients with invasive breast carcinoma as a study group and 49 patients with invasive cervical carcinoma and CIN lesions as a control group were selected from our pathology department’s archives. All of the cases were screened by nested MY/GP polymerase chain reaction (PCR) for HPV DNA in paraffin-embedded archival tissue samples. In the study group, all tested samples (84 breast carcinoma) were negative for HPV DNA (Fig. 1). In the control group (21 with invasive cervical carcinoma, 12 with CIN III, 7 with CIN II, and 9 with CIN I) 34 out of 49 (69.4%) cervical tissues were positive for the HPV DNA. Di Lonardo et al. were first to report the relationship between HPV and breast cancer in 1992. They investigated the presence of HPV DNA on paraffin-embedded tissue sections using PCR and in situ hybridization techniques. By PCR, they detected HPV 16 DNA in breast carcinomas, with a frequency of 29.4% positive cases. However, they were unable to identify any HPV DNA sequences by in situ hybridization [4]. Since then, some other studies which looked for HPV DNA in breast carcinoma by PCR were published and the prevalence of HPV DNA in breast carcinomas was found to be varied between 4 and 86% [5–7]. To date, the mechanism by which the virus reaches the breast has not been clearly identified. However, there are two proposed mechanisms that HPVs are transmitted to the breast, mechanical and systemic pathways [5, 7]. de Villiers et al. detected the viruses in both the nipple and the areolar tissue in patients with breast carcinoma. Their study is consistent with the mechanical pathway involving transfer of the virus in a retrograde fashion via the nipple, areola, lactiferous ducts, and sinuses [6]. On the other hand, Widschwendter et al. found the same type of HPV DNA positivity in breast carcinomas, as well as in regional lymph node metastases of the patients with invasive cervical cancer, and they suggested oncogenic HPV DNA might be transported from an original site of infection to the breast tissue by the blood or lymphatic system in a systemic pathway [8]. However, some other studies from different countries were failed to demonstrate the presence of HPV DNA in D. Yavuzer (&) N. Karadayi Department of Pathology, Dr. Lutfi Kirdar Kartal Training and Research Hospital, Cevizli, 34865 Istanbul, Turkey e-mail: dilekyavuzer@yahoo.com