We have analyzed the possible relevance of HPV infection for breast cancer risk among Iranian women from north part of Iran. Among women with breast cancer, 25.9% had positive test results for HPV DNA in breast tumor samples in contrast to 2.4% of women with noncancer status (P=0.002). The infection of HPV has increased the risk of breast cancer (OR 14.247; 95% CI 1.558–130.284,P=0.019). The high-risk HPV genotypes (types 16 and 18) in samples of breast cancer patients were the predominant types (53.34%). Other genotypes detected in breast cancer were HPV-6, HPV-11, HPV-15, HPV-23, and HPV-124, and one isolate could not be genotyped compared to HPV reference sequences. While the sole detected HPV in control specimens was HPV-124. Our study reveals that HPV infection and age are the risk factors in breast cancer development in the north part of Iran.

28 Background: Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer deaths among women worldwide. Human papillomaviruses have been related to the pathogenesis of breast cancer. In this study, we have analyzed the possible relevance of HPV infection for breast cancer risk among Iranian women from north part of Iran, Mazandaran province. Methods: Polymerase chain reaction method with three different primer sets was applied for detection of HPVs in formalin-fixed paraffin-embedded breast cancer and breast fibroadema as case and control tissues, respectively. HPV genotypes were determined by phylogenetic analysis of viral genome sequences. Results: Of the 58 women with breast cancer, 25.9% (15 isolates) had positive test results for HPV DNA in breast tumor samples in contrast to 2.4% of women (1 out of 41) with non cancer status (P + 0.002). The infection of HPV had an OR of 14.247 (95% CI 1.558-130.284; P + 0.019). The HPV genotypes in samples of breast cancer patients were 26.67% for HPV-16 (4 isolates) and HPV-18 (4 isolates), 13.3% for HPV-23 (2 isolates) and HPV-6 (2 isolates), 6.67% for HPV-11 (1 isolate), HPV-15 (1 isolate) and HPV-124 (1 isolate) and one isolate could not be genotyped compared to HPV reference sequences, while the sole detected HPV in control specimens was HPV-124. Conclusions: Our study reveals that HPV infection and age are the risk factors in breast cancer development in the north part of Iran, Mazandaran province. The association between risk of breast cancer development and viral infection is open and deserves further investigation.