Tumour markers(coned)

g) Genomic markers!! breast cancer in particular and rarely leukaemia, and are likely to represent about 1 percent of the population.

 In the case of breast and ovarian cancer as subset of affected individuals might be accounted for by dominantly inherited high penetrance susceptibility genes and two of these genes have been identified by positional cloning . BRCA 1, located on chromosome 17 , is capable when mutated of producing a high risk of breast cancer and also of ovarian cancer  Roughly  1 in 500  women carries a germline BRCA  1 mutation often giving rise to a  strong family history . Men with BRCA 1 mutations may have a modestly increased risk of prostate cancer. Mutations in BRCA 1 are  responsible for 50% of all inherited breast cancer cases. There is an array of mutational heterogeneity described for BRCA  1 as is often the case for genetic disorders. An exception is the Ashkenazi Jewish population . Mutation in another gene on chromosome 13, BRCA 2, also confer a high risk of breast cancer and men with BRCA 2 2 mutations are also prone to develop breast cancer . BRCA 2 accounts for 70% of those cases of breast cancer which are not caused by BRCA 1. The frequency of BRCA 2 mutations is estimated to be individuals without germline alterations in BRCA 1 or BRCA 2. Hereditary factors may still contribute to a significant fraction of these but those factors must be weaker and therefore more difficult to discern. One such factor may be the heterozygous state for mutations in the ataxia telangiectasia gene at 11q22. Such individuals have as much as a four to five fold increased risk of breast cancer and are likely to represent about 1 percent of the population.

CA 19.9

CA 27.29

CA 27.29 is an epitope on the protein core of the MUC-1 mucin glycoprotein  . CA 27.29 levels may be used in conjunction with other procedures for early detection of recurrence in women previously treated for stage II and stage III breast cancer and for therapeutic monitoring of patients with metastatic breast cancer. CA 27.29 levels can also be elevated in cancers of the colon stomach kidney lung ovary pancreas  uterus and liver . First trimester pregnancy endometriosis ovarian cysts benign breast disease , kidney disease and liver disease  are noncancerous conditions that can also elevate CA 27.29 levels.

CA 72.4

CA 125

This is a cell surface glycoprotein  present on 80 percent of nonmucinous  ovarian carcinomas. It is also useful for residual disease detection in patients with epithelial ovarian cancer. Serum studies have correlated increasing CA 125 levels with malignant disease and poor therapeutic response . Decreasing levels on the other hand are associated with a favorable therapeutic response . Overall CA125 levels correlate with disease in 87% of individuals. Elevated post treatment CA 125 levels  35 U/mL were found to be indicative of residual ovarian tumours possibly negating the need for a second look exploratory laparotomy. Low levels do not rule out the presence of residual  disease patients should still receive regular general physical and pelvic examination . CA 125 is also elevated in adenocarcinoma of cervix endometrium gastrointestinal tract pancreas lung breast colon in menstruation and pregnancy. It is also elevated in about 265 cases of benign ovarian tumours and 66% cases of non neoplastic conditions like endometriosis adenomyosis fibroids and acute salpingitis. CA 125 is useful to monitor  the response of treatment and if elevated suggests recurrence in women with ovarian cancer. Approximately half of women with metastatic ovarian cancer have an elevated CA 125 level.