Frequencies of BRCA1 and BRCA2 Mutations Among 1,342 Unselected Patients With Invasive Ovarian Cancer

Gynecol Oncol. 2011 May 1;121(2):353-7. doi: 10.1016/j.ygyno.2011.01.020. Epub 2011 Feb 15.

Abstract

Background: The heritable fraction of ovarian cancer exceeds that of any other common adult cancer. Most inherited cases of ovarian cancer are due to a germline mutation in BRCA1 or BRCA2. It is important to have an accurate estimate of the proportion of ovarian cancer patients who carry a mutation and the specific factors which predict the presence of a mutation.

Methods: We tested a population-based series of 1342 unselected patients diagnosed with invasive ovarian cancer between 1995-1999 and 2002-2004 in Ontario, Canada, for germline mutations in BRCA1 and BRCA2. The two genes were tested in their entirety, using a range of techniques, including multiplex ligation-dependent probe amplification (MLPA).

Results: Among the 1342 women, 176 women carried a mutation (107 in BRCA1, 67 in BRCA2, and two in both genes) for a combined mutation frequency of 13.3%. Seven deletions were identified using MLPA (3.9% of all detected mutations). The prevalence of mutations was particularly high among women diagnosed in their forties (24.0%), in women with serous ovarian cancer (18.0%) and women of Italian (43.5%), Jewish (30.0%) or Indo-Pakistani origin (29.4%). A mutation was seen in 33.9% of women with a first-degree relative with breast or ovarian cancer and in 7.9% of women with no first-degree relative with breast or ovarian cancer. No mutation was seen in women with mucinous carcinoma.

Conclusions: BRCA1 and BRCA2 mutations are common in women with invasive ovarian cancer. All women diagnosed with invasive non-mucinous ovarian cancer should be considered to be candidates for genetic testing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Female
  • Genes, BRCA1*
  • Genes, BRCA2*
  • Germ-Line Mutation*
  • Humans
  • Middle Aged
  • Neoplasm Invasiveness
  • Ontario / epidemiology
  • Ovarian Neoplasms / epidemiology
  • Ovarian Neoplasms / genetics*
  • Ovarian Neoplasms / pathology
  • Prevalence
  • Young Adult