• The newly discovered breast cancer genes BRCA1 and BRCA2 encode large proteins and women inheriting mutation in these genes are highly susceptible to develop breast cancer. Investigations suggest that these genes not only initiate cancer directly, but also may be involved in maintaining the integrity of the genome.

• Physical activity, during leisure-time and at work can substantially reduce the risk of breast cancer in both premenopausal and post- menopausal women.

• By measuring the level of certain cellular protein markers, a subgroup of breast cancer patients has been identified. For the patients in this group radiation therapy following breast-conserving surgery is important to prevent localized relapse.

• Inherited BRCA1 gene mutation can confer high risk for ovarian cancer in a family with a history of multiple breast and ovarian cancers. However, in the general population women who develop ovarian cancer before the age of 70 with inherited BRCA1 mutation constitute only about five percent of all cases.

• The ThinPrep Pap test, a novel, fluid-based, thin layer slide preparation is markedly more effective than the conventional Pap smear, significantly increasing the sensitivity of both low grade squamous intraepithelial lesions and higher diagnosis. In this method, the physician obtains an adequate sampling from the cervix using either a broom-like device or a plastic spatula. The cytobrush or spatula sample is rinsed into a special preservative solution, capturing virtually all of the cell sample. A special instrument called ThinPrepR 2000 Processor disperses and filters the contents to reduce blood, mucus, and inflammation. A thin, even layer is then automatically deposited onto a slide, resulting in a uniform preparation of well-preserved cells ready for microscopic examination.

• Since about 85 percent of uterine cancers are estrogen dependent, use of this hormone for patients with a history of uterine cancer to reduce menopausal symptoms or the risk of cardiovascular disease and osteoporosis is controversial. Estrogen replacement therapy (ERT) is commonly prescribed for women after menopause. To its controversy over the safety of estrogen therapy for survivors of uterine cancer, the National Cancer Institute will conduct the first large, nationwide study that will start enrolling patients this summer.

• The only effective treatment for psoriasis, the use of psoralen together with ultraviolet A radiation, may increase the risk of melanoma if continued for 15 years. The risk is even higher if the number of treatment is 250 or more.

• In radiotherapy, the source of ionizing radiation is some times placed on or very close to the surface of the body or short distance from the area being treated. This is called contact therapy or brachytherapy. Since 1955 several major changes have been introduced into brachytherapy. To avoid excessive radiation to the surrounding tissue, principles from physics and mathematics are employed to determine the exact dose that will have maximum effect on the tumor, but will spare the normal tissue. Computer technology has improved the dose distribution parameter needed to augment the accuracy of this technique.

• Mutations of tumor suppressor gene ptc are found in basal cell carcinoma, the most prevalent human skin cancer. Excessive secretion of a protein SHH, which binds with PTC protein mimicking the loss of ptc gene function, can lead to basal cell carcinoma.

• A simple way of assessing the risk of developing melanoma is to determine the number and type of abnormal moles, higher the number of these dysplastic nevi, greater is the risk. This method can identify subjects with higher risk so that they can be monitored and when necessary treated with proper intervention.

• Cytokines are potent regulators of many cellular functions involving directly or indirectly the immune (and probably other) systems. This makes them an attractive, but also elusive goal for inclusion into combined cancer treatment protocols. In animal tumor models as well as in clinical trials, some cytokines (such as the interleukins 1, 2, 4 and 6, the interferons alpha and gamma, the tumor necrosis factor and others) have clearly demonstrated anticancer activity by various mechanisms; their interplay is complex and not yet completely understood.

Glossary

• A glossary of unfamiliar words and jargons in Cancer Watch, May 1997.