Breast cancer and human papillomavirus infection: No evidence of HPV etiology of breast cancer in Indian women

Suresh Hedau,Alok C Bharti,Y Mohan Singh,Trivikram Deshpande,Showket Hussain,Sekhar Chakraborty,Umesh Kumar,Mohammad Muzaffar Mir,Rakesh Kumar,Neeraj Jain,Abhishek Tyagi,Shailja Pande,Kumaravel Somasundaram,Bhudev C Das,Shirish Shukla,Dilafroze Bhat

doi:10.1186/1471-2407-11-27

Abstract

BackgroundTwo clinically relevant high-risk HPV (HR-HPV) types 16 and 18 are etiologically associated with the development of cervical carcinoma and are also reported to be present in many other carcinomas in extra-genital organ sites. Presence of HPV has been reported in breast carcinoma which is the second most common cancer in India and is showing a fast rising trend in urban population. The two early genes E6 and E7 of HPV type 16 have been shown to immortalize breast epithelial cells in vitro, but the role of HPV infection in breast carcinogenesis is highly controversial. Present study has therefore been undertaken to analyze the prevalence of HPV infection in both breast cancer tissues and blood samples from a large number of Indian women with breast cancer from different geographic regions.MethodsThe presence of all mucosal HPVs and the most common high-risk HPV types 16 and 18 DNA was detected by two different PCR methods - (i) conventional PCR assays using consensus primers (MY09/11, or GP5+/GP6+) or HPV16 E6/E7 primers and (ii) highly sensitive Real-Time PCR. A total of 228 biopsies and corresponding 142 blood samples collected prospectively from 252 patients from four different regions of India with significant socio-cultural, ethnic and demographic variations were tested.ResultsAll biopsies and blood samples of breast cancer patients tested by PCR methods did not show positivity for HPV DNA sequences in conventional PCRs either by MY09/11 or by GP5+/GP6+/HPV16 E6/E7 primers. Further testing of these samples by real time PCR also failed to detect HPV DNA sequences.ConclusionsLack of detection of HPV DNA either in the tumor or in the blood DNA of breast cancer patients by both conventional and real time PCR does not support a role of genital HPV in the pathogenesis of breast cancer in Indian women.

Highlights

Two clinically relevant high-risk human papilloma virus (HPV) (HR-HPV) types 16 and 18 are etiologically associated with the development of cervical carcinoma and are reported to be present in many other carcinomas in extra-genital organ sites
High-risk human papillomaviruses (HR-HPVs) are carcinogenic viruses which are primarily associated with cervical cancer but are linked with other anogenital cancers and cancers of other organ sites [5] such as oral cavity [6,7,8], esophagus [9,10,11], nasopharyngeal and laryngeal carcinoma [5,12,13,14,15] and possibly in retinoblastoma [16,17,18]
Several other viruses have been implicated in the etiology of human breast cancer [23,24] but these are not confirmed by other authors [25,26]

Summary

Introduction

Two clinically relevant high-risk HPV (HR-HPV) types 16 and 18 are etiologically associated with the development of cervical carcinoma and are reported to be present in many other carcinomas in extra-genital organ sites. Presence of HPV has been reported in breast carcinoma which is the second most common cancer in India and is showing a fast rising trend in urban population. High-risk human papillomaviruses (HR-HPVs) are carcinogenic viruses which are primarily associated with cervical cancer but are linked with other anogenital cancers and cancers of other organ sites [5] such as oral cavity [6,7,8], esophagus [9,10,11], nasopharyngeal and laryngeal carcinoma [5,12,13,14,15] and possibly in retinoblastoma [16,17,18]. Several other viruses have been implicated in the etiology of human breast cancer [23,24] but these are not confirmed by other authors [25,26]

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Conclusion