best practices and rationalistic perspectives in causation-based
prevention, early detection and multidisciplinary treatment
of breast and gastric cancer
Gastric & Breast Cancer
cancer risks in BRCA mutation carriers
Inherited mutations that affect a single allele of either BRCA1
or BRCA2 are mainly linked with cancers of the breast, ovary,
and fallopian tube, whereas the risks of other cancers as colorectal,
pancreas and stomach are rather small. Male carriers have also
an increased risk of cancer in the breast, prostate and other
sites. BRCA1 is the most important gene for cancer susceptibility
in women and BRCA2 for men.
• Biallelic germline mutations in BRCA2 are also associated
with the very rare D1 complementation group of Fanconi anaemia
• Women who are born with mutations in BRCA1, BRCA2 genes
have a high lifetime risk of breast and ovarian cancer but the
magnitude of this risk is controversial.
• Table 1
summarizes the risks in the literature that vary widely among
BRCA mutation carriers depending mainly on family history.
• But a latest study on 1,008 New York-area Ashkenazi women
(NYBCS; Science 2003, Oct. 24) reverses this status. All the relatives
of a case, not only those from high-incidence (multiple-cases)
families but even those from low-incidence (single case or distant
relatives) families have a high lifetime breast-, ovarian cancer
risk if they carry a BRCA1 or BRCA2 mutation (breast cancer [82%,
for both BRCA1 and BRCA2] and ovarian cancer [BRCA1: 54%; BRCA2:
these findings are validated, clinically important implications
will emerge on genetic testing, involving even distant relatives
of a case and on risk-reducing prevention strategy, recommending
prophylactic surgery rather than surveillance.