Abstracto

Human mammary tumor virus (HMTV) infection and breast cancer risk in humans: an adaptive meta-analysis for case-control studies

Bae Jong Myon and Kim Eun Hee

Objective: There is an ongoing debate about the association between human mammary tumor virus (HMTV) infection and breast cancer. A systematic review (SR) published in 2014 revealed that there was a statistically significant association. However, duplication of the studies selected in that SR was suspected, and it also presented the need for a more detailed subgroup analysis by region. Therefore, the present study repeated the meta-analysis with the addition of relevant articles published before October 2015. Methods: Using the articles selected for the previous SR, a list of the references and the “cited articles” and “similar articles” provided by PubMed was made. From these, we only selected case-control studies that used PCR to detect the HMTV gene in tissue. The criterion for duplication was articles that showed names of identical investigators or affiliated institutions. Among the duplicated articles, the one with the highest number of samples was chosen. Meta-analysis was used to obtain the summary odds ratio (SOR) and 95% confidence interval (CI). Results: Thirteen case-control studies were selected. The total number of case and control groups was 1878 and 1204 people, respectively. The results of meta-analysis of these 13 articles showed that HMTV infection increased the risk of breast cancer (SOR=8.37, 95% CI: 2.29-23.39; I-squared=98.4%). Conclusion: In subgroup analysis, there was statistical significance for North America, the Mediterranean, and Australia. The results of this study support the claim that HMTV infection increases the risk of breast cancer in humans.