MMTV Prevalence in Breast Cancer Samples in Romania - Do Major Geographical Differences Exist in The World Population?

Abstract Background Breast cancer, although the most frequently diagnosed malignant tumor in humans, has a less clear etiology compared to other frequent cancer types. Mouse-mammary tumor virus (MMTV) is involved in breast cancer in mice and dogs and might play a role in the etiology of some breast cancers in humans, since it has been identified in 20-40% of breast cancer samples in Western Europe, USA, Australia and some other parts of the world’s population. The purpose of our study was to identify MMTV DNA sequences in breast tissue samples from breast cancer patients who underwent curative surgery in our regional center in Romania, EU. MethodsWe selected 75 patients with non-metastatic breast cancer treated surgically with curative intent, which did not undergo any neoadjuvant treatment. Out of these patients, 50 underwent radical lumpectomy and 25 modified radical mastectomy. We searched using PCR the MMTV-like DNA env sequence in the breast cancer tissue and normal breast tissue obtained from the same patients. ResultsNone of the examined samples was positive for MMTV-like target sequences on PCR.ConclusionsWe could not prove that MMTV plays a role in the etiology of breast cancer in our patient group. This finding is similar to publications of other geographically related research groups and might be due to the fact that only the Mus musculus domesticus mouse species was proven to carry infectious MMTV, but not the Mus musculus musculus species, which is specific to South-Eastern Europe (including Romania) and some parts of Asia.