Low frequency of human papillomavirus DNA in breast cancer by Mendizabal-Ruiz et al 2009 - Research Paper Example

& No Critical Review Paper (HPV-DNA) 13 March Introduction This brief paper is a review of the study conducted by A. P. Mendizabal-Ruiz and five other colleagues (all of them from Mexico) regarding the probability of a relationship between the human papilloma virus (HPV) and some breast cancer cases. Their joint study conducted a total 107 paraffin-embedded tissue samples taken from their pathology department. It is well known or well established in medical science that the HPV is an etiological agent for cervical uterine cancers (Mendizabal-Ruiz et al.

, 2009:189). All the samples were taken from patients who have no prior history of breast cancers. This means those who had a family history of breast cancer were intentionally excluded from the group sampling in order to isolate the probable cause of the breast cancer to the presence of the HPV only. Out of the 107 samples taken from the pathology department, 67 of them are diagnosed to have breast cancer present while the remaining 40 samples were non-malignant. The purported rationale for this study was to investigate the possible connection that HPV has to certain types of breast cancers, since HPV is already well known to be a causative agent of most cervical uterine cancers.

Since some breast cancers were found to have the HPV variants present in some of these cases, it was worth investigating if there is more to presence of the HPV's DNA in these breast cancer cases to link the two together. The HPV has several variants and types 16, 18 and 33 are quite common among certain populations. The authors of this study used the polymerase chain reaction method to try to detect the DNA of these HPVs. The aims of their study were to detect a presence of this DNA in breast cancer tissue samples and establish a possible role or link of this virus in the genesis of breast cancer.

Discussion Limitations of the study – the sample group can be considered small when considering the gravity of the disease being studied. Breast cancer is a leading cause of preventable deaths among women (second only to lung cancer resulting from smoking) and a larger sample base is certainly justified. It can be admitted this study is part of an initial group of studies only; it was sort of a follow up study to confirm the earlier findings by Di Leonardo et al. which had reported first about the possible links between HPV and breast cancer (that study found HPV type-16 in five out of 17 cases of breast carcinoma but all were just tentative).

The small sampling group resulted in the authors Mendizabal-Ruiz to conclude that a presence of the HPV DNA does not play an important role in breast cancer (that study found only 3 cases of HPV out of the 67 positive breast cancer cases studied or a low of 4.4%). This can give a misleading conclusion since a larger study conducted by another group of medical researchers (using meta-analysis that involved 10 case-control studies of 447 breast carcinoma cases and 275 control samples) concluded otherwise, that there is a significant increase in the breast carcinoma risk when associated with HPV positivity (Ni Ling et al., 2010:1). Strength of the study – the study by Mendizabal-Ruiz et al.

tried to isolate the probable cause of breast cancers due to the presence of HPV DNA only, by excluding samples which had prior family histories of breast cancers. This tries to narrow it down to HPV only. Conclusion Based on the results of the study done by Mendizabal-Ruiz et al., it is too inconclusive to make any meaningful conclusions. The sample size is simply too small to begin with and a finding of 3 positive cases where the DNA of the HPV was present does not justify any of the conclusions they made as it can lead to misleading ideas about the role of the HPV in breast cancer genesis.

At the very least, study should be repeated with a much larger sample. Reference List Mendizabal-Ruiz, et al. (2009) Epidemiology: Low frequency of human papilloma virus DNA in breast cancer tissue. Breast Cancer Research and Treatment, 114(1), pp. 189-194. Ni Ling, et al. (2010) Epidemiology: Human papilloma virus infection and sporadic breast carcinoma risk: a meta-analysis. Breast Cancer Research and Treatment, [e-version DOI: 10.1007/s10549-010-1128-0] available through Springer Link database [accessed 10 February 2011].