Breast Cancer in African-American Women - Literature review Example

Breast Cancer in African-American Women: Differences in Tumor Biology From European-American Women In a study by Amend, Hicks, and Ambrosone (2006) the authors explored the underlying reasons for the difference in mortality rates from breast cancer between black African-American and white European-American women. These differences have been previously explored and it has been suggested that the variation is due to socio-economic factors. This study sought to evaluate the difference in the biological nature of the tumor. The goal of the study was to compare the tumors in the two different races for variations in aggressiveness, and the increased incidence of key receptors. The study evaluated and rated tumors based on three different aspects. Tumor grade was designated in accordance with a typical histological scale with 1 being a low grade and 3 being a high grade tumor. Estrogen and progesterone receptors were measured for positive or negative and associated with the prognosis for recovery. In addition, the expression of the HER-2 gene was measured to see if there was a difference between African-American and Caucasian women and its association with a more rigorous clinical course and a lower survival rate. Sub-Saharan women were included in the study to compare the biology and risk factors to African-American women. The study offered suggestions that highlighted the importance of molecular biology when diagnosing and treating breast cancer tumors. The research was conducted by an extensive literature review. The review drew upon 31 previous studies that had been published in peer reviewed journals. The study found that African-American women were more prone to have a high grade tumor than American-European women. It further reported that women with estrogen receptor (ER) and progesterone receptor (PR) positive had a better prognosis that the negative receptor counterparts. African-American women had an increased prevalence of both ER and PR negative tumors which decreased their overall survival. The study did not find any difference in the HER-2 gene expression between the populations. The study identified the basal phenotype tumor as being particularly resistant to current treatments. The basal phenotype, with a triple negative receptor structure, was also more prevalent in African-American women. It was further found that there were similarities between Sub-Saharan women and African-Americans. This would reduce the influence of environmental and social factors. The study concluded that African-American women have a tumor phenotype that is more aggressive, more resistant to treatment, and has a reduced prognosis for recovery. This article was aimed at the medical community and primarily oncologists. Though the article is highly technical, its conclusions and findings are easily understood by the lay person. It would be of value to professionals prescribing treatment or to provide information to the general public. Researchers would find the article useful to point them into the direction that new molecular and genetic research needs to be done. The article clearly points out the increased difficulty that African-American women with breast cancer face. When viewing breast cancer victims, all races are not created equal. For me, this was the most enlightening part of the study. Breast Cancer Risk Estimates for Relatives of White and African American Women With Breast Cancer in the Women’s Contraceptive and Reproductive Experiences Study A study published in the Journal of Clinical Oncology of June 1, 2006 estimated the increased risk of being diagnosed with breast cancer when first degree relatives (FDRs) had previously contracted the disease. First degree relatives include mother, sisters, and daughters. The data was further disaggregated between white and African-American women. It has been generally accepted that there is a familial component to risk, yet little research has been done regarding African-American women. The purpose of the study was to update the existing estimates and to include African-Americans as a separate group. It was further used as a comparison between racial groups. The study, conducted by Simon et al. (2006), was carried out using the FDRs of participants in the Womens CARE study. The participants had previously contracted breast cancer and the population of FDRs was screened to eliminate cases with questionable history or had contracted another form of cancer. An analysis was conducted that evaluated the probability based on age of diagnosis of the participant, number of relatives with breast cancer, and race. The data showed that women with increased numbers of FDRs with breast cancer increased the risk of contracting the disease. In addition, it confirmed that the familial effect is more pronounced among the white population. In addition, a younger age of diagnosis translates into a higher risk for FDRs, and white women were placed at greater risk than African-Americans. The research was conducted through a population based study and the results were analyzed to present a cumulative degree of risk. Family history was gained through interviews with the participants though it was not verified with the FDRs. Risks were estimated using the Cox proportional hazards model and the results were presented as a percentage probability for 5 or 10 year reference groups. The distribution of race and number of FDRs with breast cancer was presented in a table. The cumulative risk was presented in a table that disaggregated age. It reported the risk and the standard error (SR). The tables were accompanied by graphs to give the reader a visual sense of the data. The data showed that the risk of breast cancer increases with the number of FDRs that also have breast cancer. In addition, it confirmed that white women were more adversely affected by family history. By age 79 , white women with more than one FDR had a cumulative risk of 25.2 percent. African-American women in this category had a 16.9 percent risk. In addition, the data showed that the FDRs of a participant that was diagnosed before age 45 were at more risk than a participant that contacted the cancer after age 45. Both races were affected by this factor. The FDRs of a white participant who was younger than 45 at diagnosis had a 41 percent risk by age 70, while for African-American women in this group the risk was 25.8 percent. The article was well written and easily understood by anyone with a minimal exposure to statistics or health care. It could benefit counselors who are seeking to accurately portray risk to the patient. It would also benefit the general public by providing an accurate assessment of risk and the need for regular screening. I found the article to be helpful to advising patients and understanding the need for other family members to be checked for breast cancer. Body Size and Breast Cancer Risk in Black Women and White Women A study by Hall, Newman, Milikan, and Moorman (2000) investigated the correlation between menopausal status, body size, body mass index, and waist/hip ratio to the risk of contracting breast cancer in black and white women. The purpose of the study was to increase the body of knowledge of the risk factors for breast cancer in black women. Previous research was limited and did not consider menopausal status as a factor. In addition, the existing research indicated that the factors for breast cancer in black women were contrary to the literature on white women. The goal of the study was to determine if these factors influenced the risk of breast cancer. The study used a population of women that had previously contracted invasive breast cancer. Data was collected that included family history, menstrual history, hormone use, alcohol use, and socio-demographic information. The physical characteristics of body mass and waist/hip ratio were measured. The data was then stratified by menopausal status and race. Odds ratios were calculated for post and pre-menopausal black and white women. The results indicated a correlation between the factors measured and the risk of breast cancer. The study was conducted using the population-based case-control method. There were 350 cases of black women in the population and 353 controls. The white population had 523 cases and 471 controls. Data was collected through a standardized questionnaire and height and weight were measured. Logical regression was used to control several confounders that included age at menarche, education, use of contraceptives, and smoking. The distribution of risk factors was presented in a table. A series of tables were used to present odds ratios for pre and post menopausal women. The data in the tables was broken down by physical characteristics and race. The odds ratios were stated as a 95 percent confidence interval. The data showed that among black women, cases were more likely to have a family member with breast cancer, have an earlier age of menarche, and a later age at menopause. White cases were more likely to have never breast-fed and had a later age of first full-term pregnancy. Body mass was shown to not be a factor in postmenopausal white women. However, in black women there was an inverse association between body mass and the risk of breast cancer. A higher waist/hip ratio translated into a higher risk in all postmenopausal women. The data indicated that though obesity was more prevalent among the black population, it did not account for the increase in breast cancer as measured by body mass index. Adult height was shown to increase risk in older white women, but had no effect on younger white or black women. The study concluded that while waist/hip ratio increases risk, body mass has an inverse relationship to young women of both races. This study was important in that it placed the problem of obesity in perspective to its association to the risk of breast cancer. In addition, it highlighted the impact that menopause has on breast cancer risk. The study was extensive and considered several factors that impact the risk of breast cancer. The article is important because it adds data to previously unexplored areas. The article, though aimed at a professional audience, is easily understandable by any health care worker. The article will be helpful to me in assessing the risk based on menopausal status and body size. Lifetime Recreational Exercise Activity and Breast Cancer Risk Among Black Women and White Women A study by Bernstein et al. (2005) examined the amount of exercise necessary to effectively reduce the risk of contracting breast cancer. The effect of exercise on reducing risk has previously been studied and the literature generally supports the hypothesis that regular exercise reduces the risk of breast cancer. The purpose of this study was to determine the amount of lifetime activity necessary to result in a benefit. It also was designed to examine the effect of age and race and determine if these subgroups are equally affected. Participants that had previously been diagnosed with breast cancer were compared to a control group identified by random sampling. Interviews were conducted to obtain the total lifetime exercise quotient. Activities included all types of sports, hiking, jogging, and dancing. This information was used to calculate a metabolic equivalents of energy expenditure (MET). Additional family history was gathered that included age at menarche, number of term pregnancies, family history of breast cancer, and race. The data was analyzed and indicated that higher levels of MET result in a reduced incidence of breast cancer. The study also evaluated the effect of exercise on the risk of estrogen receptor (ER) negative and estrogen receptor positive tumors. While previous research had shown a reduced ratio of ER negative tumors to ER positive, this study was unable to confirm those results. The research was a population based control-case study involving black and white women aged 35-64 years. The case subjects had newly diagnosed invasive breast cancer. The control subjects were contacted using random dialing in the four major cities where the case subjects came from. Data analysis was accomplished with unconditional logistic regression modeling that was used to calculate odds ratios at the 95 percent confidence interval. The data was adjusted for confounding variables such as family history, age of menarche, number of term pregnancies, and menopausal status. The data was presented in tables and was broken down into several subgroups. These subgroups included total population, by race, by family history of breast cancer, and ER status. The study found that the risk of breast cancer was reduced by 20% in the two highest of the five exercise categories when compared to inactive women. Black women in these categories experienced greater benefit than white women. The study reported that all categories of exercise were inversely associated the risk of breast cancer, with increasing levels resulting in a lower risk. The study further indicated that body mass index, menopausal status, use of hormone therapy, or use of oral contraceptives did not modify the effect of exercise on lowering the risk of breast cancer. However, among women with a first degree family member with breast cancer low levels of exercise had no effect. Increasing the level of exercise did lower the risk among this group. The study found no correlation between ER status and exercise. The study concluded that an average of 1.3 hours of exercise per week can reduce the risk of breast cancer by 20 percent. This study was an extensive project involving almost 5,000 cases from four major cities. The data was presented in a logical and easy to understand format. The study was important in that it pointed out the value of exercise in maintaining good health. This will be personally valuable to me as I assess my own level of physical activity. References Amend, K., Hicks, D., & Ambrosone, C. B. (2006). Breast cancer in African-American women: Differences in tumor biology from European-American women [Electronic version]. Cancer Research, 66(17), 8327-8330. Bernstein, L. et al. (2005). Lifetime recreational exercise activity and breast cancer risk among black women and white women [Electronic version]. Journal of the National Cancer Institute,, 97(22), 1671-1679. Hall, I. J., Newman, B., Millikan, R. C., & Moorman, P. G. (2000). Body size and breast cancer risk in black women and white women [Electronic version]. American Journal of Epidemiology, 151(8), 754-7634. Simon, M. S. et al. (2006). Breast cancer risk estimates for relatives of white and African American women with breast cancer in the Women’s Contraceptive and Reproductive Experiences study [Electronic version]. Journal of Clinical Oncology, 24(16), 2498-2504. Read More