Hereditary breast cancer and family cancer syndromes

Abstract

Hereditary breast cancer (HBC) shows extant clinical and genetic heterogeneity. Clinically one finds the onset of breast cancer at an early age, an excess of bilaterality, and patterns of multiple primary cancer such as combinations of breast and ovarian carcinoma in the hereditary breast-ovarian cancer (HBOC) syndrome. In addition to HBOC, one sees a variety of putative breast cancer-prone genotypes inclusive of hereditary site-specific breast cancer, and the Li-Fraumeni (SBLA) syndrome that is characterized by cancers involving all three germinal layers including sarcomas, brain tumors, leukemia, lymphoma, and adrenal cortical carcinoma in addition to often markedly early-onset breast cancer. Breast cancer is also associated with autosomal dominantly inherited Cowden's disease and autosomal recessively inherited ataxia-telangiectasia. Examples of pedigrees depicting clinical examples of these several HBC syndromes are presented in order to describe HBC's heterogeneity. The recent identification of the BRCA1 gene in early-onset hereditary site-specific breast cancer and the HBOC syndrome has led to new challenges for the genetic counselor. We review genetic counseling, which embraces surveillance and management recommendations that are responsive to the natural history of HBC and address the concept for future development of centers of expertise for HBC in the interest of improving cancer control.

Clinical impact of detection of loss of heterozygosity of BRCA1 and BRCA2 markers in sporadic breast cancer

“…The ratio obtained in tumour DNA divided by the allele peaks ratio of matched normal DNA has a mathematical range of 0.00-1.00. Theoretically, a complete allele loss in tumour tissue results in a value of 0.00, retention of both alleles in both tissues in a ratio of 1.00 (Sato et al, 1990;Lubin et al, 1991 (Lynch et al, 1994). In 1990 an autosomal dominant susceptibility gene for breast and ovarian cancer, BRCAI, was assigned to chromosome 17q21 by multipoint genetic linkage (Hall et al, 1990 Albertsen et al, 1994) and was later cloned and sequenced .…”

Seaweed Prevents Breast Cancer?

“…[1][2][3][4] Tamoxifen is accepted as a chemopreventive agent following the results of the National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1 study. 5) However, despite the increasing incidence of breast cancer in Japan, the use of chemopreventive agents is so far forbidden.…”

Treating pediatric liver tumors in India: A challenging proposition

“…Interestingly, in two patients of hepatoblastoma we found a maternal history of colon cancer. Association of hepatic tumors with inherited syndromes such as familial adenomatous polyposis is well known [4] and must be searched for. Treatment abandonment is a major hurdle in improving outcome of pediatric liver tumors.…”

“…The response rate reported in earlier studies from India is nearly half as compared to reported by Nair et al The difference is difficult to explain from better supportive care alone, as the patients dying from infections during first 3-months of therapy were excluded from analysis in earlier Indian studies [2][3][4][5]. Additional causes for the better response could be lower number of children with very severe aplastic anemia (VSAA) and a…”