Breast cancer case study

Florian, J. A., J. L. Eiseman, and R. S. Parker. Nonlinear Model Predictive Control for Dosing Daily Anticancer Agents A Tamoxifen Treatment of Breast Cancer Case Study, Comput. Biol. Med., 38, 339 (2008). 

Breast Cancer. Many studies have observed low incidences of hormone-dependent cancers, particularly breast cancer, in Asian countries compared with Western countries and it is becoming increasingly accepted that dietary factors play an important role. Although breast cancer can occur in either males or females, only about 1 % of all cases occur in men, and male breast cancer is a rare disease in all parts of the world." Although there appear to be some similar risk factors for breast cancer in males and females, there is no indication in the literature that diet is either a risk or a protective factor for male breast cancer. The development of breast cancer is known to be highly dependent on the hormones associated with female reproductive functions, while established genetic factors have been... 

Associations between breast cancer and total and specific fruit and vegetable group intakes were examined using standardized exposure definitions (Smith-Warner and others 2001). Data sources were eight prospective studies that had at least 200 incident breast cancer cases, included assessment of usual dietary intake, and had completed a validation study of the diet assessment method or a closely related instrument. 

Our study group consisted of 167 individuals, of whom 99 were healthy women controls and 68 breast cancer cases. The experimental group was comprised of women who had been diagnosed with breast cancer at the Department of Medical Oncology, Mersin University, Turkey. Controls were selected by taking age and sex variable into consideration. Genomic DNA from breast cancer patients and control subjects was analyzed by PCR-RFLP. 

Saez A, Andreu FJ, Segui MA, Bare ML, Fernandez S, Dinares C, et al. HER-2 gene amplification by chromogenic in situ hybridisation (CISH) compared with fluorescence in situ hybridisation (FISH) in breast cancer-A study of two hundred cases. Breast 2006 15(4) 519-27. 

Serum PCBs were measured in blood samples collected in 1974 or 1989 in a breast cancer case-control study nested within a prospective cohort study of Washington County, Maryland residents (Helzlsouer et al. 1999). A group of 346 women who were diagnosed with breast cancer by June, 1994 (i.e., after a follow-up period of up to 20 years) were matched to 346 cancer-tree controls by age, race, menopausal status, and date of blood donation. Mean and median concentrations of total PCBs in 1974 or 1989 were... 

Coal Tar Products. An excess of breast cancer cases in St. Louis Park, Minnesota, was tentatively associated with coal tar contamination of the water supply (Dean et al. 1988). However, in a subsequent analysis of these data, the Minnesota Department of Health (1985) concluded that this study did not provide adequate evidence to associate breast-cancer with coal tar creosote-contaminated water (for a detailed discussion of these data, see Section 3.2.2.7 Cancer). No adverse effects on sperm characteristics were reported in male workers exposed to coal tar pitch volatiles in an industrial setting (Ward 1988). In addition, no adverse reproductive outcomes were detected in a survey of inhabitants of a housing development built on an abandoned creosote factory site, which was known to be contaminated with creosote (Agency for Toxic Substances and Disease Registry 1994). A retrospective study of dermal exposure to coal tar found no increased risk of spontaneous abortion associated with exposure to coal tar during pregnancy, but this was a small study and was unlikely to have sufficient resolution to detect a modest increase in risk (Franssen et al. 1999). 

In a case-control study of the relation between occupational exposures to various suspected estrogenic chemicals and the occurrence of breast cancer, the breast cancer odds ratio (OR) was not elevated above unity (OR=0.8 95% 01=0.2-3.2) for occupational exposure to endosulfan compared to unexposed controls (Aschengrau et al. 1998) however, the sample sizes were very small (three exposed seven not exposed), and co-exposure to other unreported chemicals also reportedly occurred. Both of these factors may have contributed to the high degree of uncertainty in the OR indicated by the wide confidence interval. 

Carotenoids and breast cancer — Among seven case-control studies investigating the correlation between different carotenoid plasma levels or dietary intakes and breast cancer risk, five showed significant inverse associations with some carotenoids. - In most cases, this protective effect was due to 3-carotene and lutein. However, one (the Canadian National Breast Screening Study ) showed no association for all studied carotenoids including (I-carotene and lutein. More recently, another study even demonstrated a positive correlation between breast cancer risk and tissue and serum levels of P-carotenes and total carotenes. Nevertheless, these observational results must be confirmed by intervention studies to prove consistent. 

Zaroukian, S. et al., Correlation between nutritional biomarkers and breast cancer a case-control study, Breast, 14, 209, 2005. 

Black cohosh has been one of the most studied herbal remedies for vasomotor symptoms, and it has not demonstrated a substantial benefit over placebo. The mechanism of action, safety profile, drug-drug interactions, and adverse effects of black cohosh remain unknown. In non-placebo-controlled trials conducted for 6 months or less, black cohosh demonstrated a small reduction in vasomotor symptoms. It has not been shown to be effective for vasomotor symptoms in women with breast cancer.33 There have been case reports of hepatotoxicity with the use of black cohosh.36 Caution should be exercised when considering the use of this product, especially in patients with liver dysfunction. 

Cytotoxic chemotherapy is eventually required in most patients with metastatic breast cancer. Patients with hormone-receptor-negative tumors require chemotherapy as initial therapy of symptomatic metastases. Patients who respond initially to hormonal manipulations eventually cease to respond and go on to require chemotherapy. The median duration of response is 5 to 12 months, but some patients will have an excellent response to an initial course of chemotherapy and may live 5 to 10 years or longer without evidence of disease. In general, median survival of patients after treatment with commonly used drug combinations for metastatic breast cancer is 14 to 33 months. The median time to response has ranged from 2 to 3 months in most studies, but this period depends in large part on the site of measurable disease. The median time to appearance of response is between 3 and 6 weeks in patients whose disease is primarily in the skin and lymph nodes, 6 to 9 weeks in patients with metastatic lung involvement, 15 weeks in patients with hepatic involvement, and nearly 18 weeks in patients with bone involvement. Thus it is often the case that an immediate response to therapy is not... 

In 1990, Vatten et al.51 in Norway subsequently reviewed data on breast cancer risk from a cohort of 14,593 women with 152 cases of breast cancer during a follow up of 12 years on subjects who were between 35 and 51 years old at the beginning of the study and between 46 and 63 years at the end. They reported no overall statistically significant correlation between breast cancer and coffee consumption, but when body mass index was taken into account, lean women who consumed >5 cups per day had a lower risk than women who drank two cups or less. In obese women, however, there was a positive correlation between coffee intake and breast cancer. In a 1993 study, though, Folsom and associates52 failed to find an association between caffeine and postmenopausal breast cancer in 34,388 women in the Iowa Women s Health Study, with a median caffeine intake of 212 mg/day in women who developed breast cancer and 201 mg/day for women who did not and in Denmark, Ewertz53 studied... 

In 1981, Lawson et al.,87 for example, compared a group of 210 women hospitalized for fibrocystic disease with 241 women who had breast cancer and were drawn from two ongoing studies in different countries. They matched each case to three female control patients on age, current smoking habits, country, and study. Recent coffee and tea consumption in cases and controls were compared and were shown to have a modest positive association with hot beverage consumption for both fibrocystic disease and breast cancer, but there was no dose-response relationship. The risk of fibrocystic disease associated with heavy consumption of hot beverages (7+ cups per day) vs. none was elevated but not statistically significant. 

Katsouyanni, K., Trichopoulos, D., Boyle, P., Xirouchaki, E., Trichopoulou, A., Lisseos, B., Vasilaros, S., MacMahon, B., Diet and breast cancer A case-control study in Greece, Int J Cancer, 38, 815, 1986. 

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