Breast cancer, factors affecting

Grizzle, W. E., Myers, R. B., and Oelschlager, D. K. 1995. Prognostic biomarkers in breast cancer Factors affecting immunohistochemical evaluation. Breast 7 243-250. 

Breast cancer is one of the most common forms of cancer affecting women and, in Western countries, the incidence is rising. The risk of breast cancer increases markedly with age, although a decrease in the rate occurs after the menopause, suggesting that development is hormone-dependent. To date, a number of hormone-related risk factors have been identified (Bingham et al, 1998). Countries such as Japan have relatively low rates of breast cancer, which have been associated with consumption of a diet high in soy foods. Currently, however, the data from epidemiological studies is inconclusive. 

A major challenge in breast cancer is the need to identify and understand the factors that most affect a patient s prognosis. The best indicator of survival for... 

It is apparent from clinical and laboratory experiments and observation that the spread of breast cancer via the bloodstream occurs early in the course of the disease. This results in patients relapsing with systemic metastatic disease following local curative therapy. The likelihood of later development of metastatic disease is related to the size of the primary tumor, presence of lymph node involvement and number of nodes affected, and a number of additional pathologic prognostic factors, which include proliferative capacity, nuclear grade, hormone receptor status, and presence or absence of oncogenes and other protein products. Systemic adjuvant therapy is commonly... 

Genetic make-up is certainly a factor that predisposes an individual to cancer - a familial pattern of breast cancer is, for example, well-established. However, an additive and even predominant environmental effect is clearly evident when one studies migrant populations. In Japan, the incidence of stomach cancer is high, probably due to a high consumption of salted fish and pickled foods but the incidence of prostate cancer is low, perhaps because this has an association with the consumption of large amounts of red meat. However, in migrant Japanese communities in the USA, the incidence of these two cancers more closely mirrors that of the native US population, suggesting that the adopted US diet has affected their predisposition to the two cancers. In addition, black Americans have similar incidences of the main cancers to white Americans, but these differ markedly from those seen in black Africans. 

Other factors affecting the incidence of breast cancer are family history [25,... 

Clearly, the Information from these studies will have a profound Impact on medical practice, but when and In what form Is hard to predict. One Important point Is the extent to which the presence of a given marker Increases the probability of developing the disease for which It Is a risk factor. Does the risk of developing heart disease or breast cancer rise from 3% to 4%, or does It rise from 3% to 30% How does the number of markers associated with risk— three, four, or seven—affect the situation The answers to these questions are far from clear In their application to overall medical knowledge, and even less clear In making predictions for each person at Increased risk for a disease. 

Genetic, reproductive, and environmental factors have been identified to play a role in the development of ovarian cancer. The vast majority of ovarian cancers are sporadic in nature. Patients with a family history are at high risk, although an identifiable genetic predisposition for hereditary ovarian cancer is found only in approximately 5% of affected women. Families with three or more first-degree relatives with ovarian and/or ovarian and breast cancer carry a substantially (16%-60%) increased risk for developing ovarian cancer. 

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