The Relation of HPV and Breast Cancer: the Definitive Effect of HPV - Coursework Example

Human papillomavirus types 16 and 18 have been implicated in the development of cervical cancers. To protect women from this disease, HPV vaccines have already been developed, and getting it is already being advised to women, especially to those at risk. With the growing number of women afflicted with breast cancer, there is great demand for determining a possible cure for such disease. HPV’s association with other cancers such as oral, esophageal nasopharyngeal and larngyeal, and with some researches claiming evidences of its HPV etiology, the possibility of using HPV vaccines against breast cancer looked promising. However, as studies on the matter are further being conducted, they begin to arrive at conflicting conclusions. Thus, there is still an ongoing debate as to whether HPV causes breast cancer, and whether HPV vaccines can be used against it as well. Let’s look at two journal articles, published in year 2011, to exemplify such issue. Different Findings In the study of Antonsson et al. (2011), the prevalence of HPV in breast cancer tissue was determined through polymerase chain reaction (PCR) analysis and sequencing. Briefly, tissue samples were obtained from each of the fifty-four different fresh frozen breast cancer tissues obtained from surgeries at Wesley Hospital, Brisbane, Queensland, Australia between 2003 and 2007. The median age of these patients were 57 years old, with the age range of 31-88 years. 59% were post-menopausal, 63% were node-negative, and their mean tumour size was 24.3mm. According to the authors, this meant that HPV infection of breast cancer or HPV as an etiological agent decrease the metastatic potential of the tumour. To detect HPV, each sample was mixed with HPV general and type 18-specific primer pairs FAP59/FAP 64. After PCR, amplified products were analyzed using 1.5% agarose gel electrophoresis. 50% of the samples were found to be HPV-positive, specifically of HPV type 18, although the strains were different. Upon analyzing further, HPV-positive breast cancer patients (mean age = 50 y. o.) were found to be younger than the whole group, and HPV positive tumours were also found to be smaller than the others. Histologically, HPV positive samples (96.3%) were more likely to be ductal than HPV negative ones (85.2%). Aside from PCR, an in situ hybridization was also performed using INFORM® HPV III Family 16 Probe (B) (Roche Ventana Medical System, Tucson, Arizona) that can detect 16 different cancer-causing HPV types (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68, 73, and 82). However, no HPV were found in the samples using this method. The authors attributed this to the lower sensitivity of in situ hybridization as compared to PCR. Despite the results, the authors however recognized that their findings failed to determine whether the virus actually caused the breast cancer or it was just a chance passage for all 27 cases. As well, the potential mechanism behind the presence of HPV in the breast was still unanswered. A similar study was also conducted in India by Hedau et al. (2011). Breast tissue and blood samples from two hundred fifty two (252) breast cancer patients were analyzed through PCR using the general MY09/11, GP5+/GP6+ and type 16 specific E6/E7 as primers. The age of the participants were 51.5 ± 16.7, with a range of 25-80 years. 38% were postmenopausal. However, unlike that of Antonnson, the results of Hedau’s experiments showed absence of HPV DNA in breast cancer tissues. Social Implications In comparing the results of other similar studies conducted in different countries, Hedau et al. (2011) found that the breast tissue samples of a portion of breast cancer patients from Italy, Sweden, China, Brazil, Austria, USA, Greece, Australia, Turkey, Japan, and Mexico were positive in HPV, with China and Mexico having more established results as more than one study have arrived at the same outcome of some breast cancer tissues being HPV-positive. On the other hand, studies in UK, India, Switzerland and France did not find HPV in breast cancer tissues, with results of India validated by Hedau et al (2011). Although it may be contended that the prevalence of HPV-caused breast cancer is population based, two studies each for USA and for Austria had conflicting findings. Thus, the relation of HPV and breast cancer being dependent on the population still needs verification, probably by repeating the studies on the said countries. If HPV causing breast cancer is dependent upon the population, then what about the population make it more or less susceptible it? Some suggests sexual practices as a possible reason for differences found among population, that possibly, sexual acts that involve contact of HPV-infected material, such as genitals and hands, with breasts may lead to infection via mechanical route (Hedau et al., 2011). To prove that, however, the mode of HPV infection of the breast must be elucidated. Currently, Antonnson et al. (2011) and other researchers believe HPV may be mechanically or hematogenously transferred to the breast tissue. In the mechanical route, it is suggested that indirectly (infected genital-hand-breast) or directly (infected genital-breast) the virus can penetrate the breast tissue through the skin. Hematogenous route on the other hand, uses the bloodstream to transport the HPV from one organ to the next. If the mechanical route, indeed, explains HPV infection of the breast, then it should be analyzed whether or not the countries found to have HPV-infected breast cancer tissue have sexual practices that have an increased manipulation of the breast as compared to other countries. If so, then countries with similar sexual practices must be studies as well to further concretize the relation. On the other hand, if the hematogenous route holds true, then patients with cervical cancer are at a higher risk to develop breast cancer, and as such must be advised to undergo screening for breast cancer. Despite differences in the resulting health policies, decreasing the prevalence of cervical cancer is vital in lowering the number of women acquiring and suffering from breast cancer. HPV vaccine is thus a leading candidate in preventing breast cancers as well, particularly those caused or worsen by HPV. Conclusion Despite the seemingly different outcomes of their experiments, both researches do not discount the possibility of HPV possibly causing breast cancer, although, as established by multiple studies already, not all breast cancers can be possibly caused by HPV. The differences among the results of studies implicate population-based variation, including but not limited to sexual practices. This thus demands more studies to be conducted on the possible mechanisms by which HPV reach breast tissue. Although both mechanical and hematogenous routes may have social implications, their impact on health policies will be different. Despite this, decreasing the prevalence of cervical cancer will be central to preventing breast cancer. Thus, despite the differences in the findings of several researches in terms of the presence of HPV in breast cancer tissues, HPV vaccines still remain to be a leading candidate for the prevention of breast cancer, especially those caused by or worsen HPV. Further study on the role of HPV in breast cancer will also need to look into the definitive effect of HPV. Does it really have a role in the development of tumor? Do cancerous breast tissues have an increased susceptibility to HPV infection? Are the findings of all the studies claiming presence of HPV in breast cancer tissues incidental? Indeed, this specific area of cancer study needs a lot of research still. However, with the technological advancements such as polymerase chain reaction and other immunologic techniques, answers to the pending questions are within reach. Works Cited Antonsson, Annika, Terrence P. Spurr, Alice C. Chen, Glenn D. Francis, Nigel A.J. McMillan, Nicholas A. Saunders, Michael Law, and Ian C. Bennett. “High Prevalence of Human Papillomaviruses in Fresh Frozen Breast Cancer Samples.” Journal of Medical Virology 83 (2011): 2157-2163 Hedau, Suresh, Umesh Kumar, Showket Hussain, Shirish Shukla, Shailja Pande1, Neeraj Jain, Abhishek Tyagi, Trivikram Deshpande3, Dilafroze Bhat, Mohammad Muzaffar Mir, Sekhar Chakraborty, Y Mohan Singh, Rakesh Kumar, Kumaravel Somasundaram, Alok C Bharti, Bhudev C Das. “Breast cancer and human papillomavirus infection: No evidence of HPV etiology of breast cancer in Indian women.” BMC Cancer 11 (2011) Read More