Hereditary Cancer Genetics

Approximately 5 to 10 percent of cancers are due to an inherited predisposition. The Genetics Clinic at Lakeridge Health Oshawa evaluates individuals who have a strong personal and/or family history of cancer.

The Genetics clinic also provides assessment for eligibility for the High-Risk Ontario Breast Screening Program (OBSP), group information sessions followed by individual counselling appointments for unaffected women with a strong family history of breast and/or ovarian cancer, and information about research studies regarding hereditary cancer. 

Lakeridge Health Oshawa Clinical Genetics Hereditary Cancer Referral Criteria

Hereditary Breast and Ovarian Cancer (HBOC)

  • Multiple cases of breast cancer in family (three or more cases at any age or two cases under 50 years of age)
  • Breast cancer diagnosed under 35 years of age
  • Triple negative breast cancer diagnosed under 60 years of age
  • Bilateral breast cancer
  • Breast and ovarian cancer within the same family
  • Breast/Ovarian cancer in Ashkenazi Jewish women
  • Male breast cancer
  • Personal/family history of ovarian cancer
  • Other HBOC associated cancers in family: melanoma, pancreatic or prostate cancer diagnosed at a young age
  • Known BRCA1/2 mutation in the family
  • Anyone who had BRCA1/2 genetic testing prior to April 1, 2008
  • Please note: additional testing may be available to patients who have previously had negative BRCA1/2 genetic testing and have a strong family history (4 or more cases) of breast/ovarian/other cancers.

OBSP High-Risk Breast Screening Assessment

Refer to the OBSP Requisition for High Risk Screening for referral criteria

Hereditary Colorectal Cancer (Lynch syndrome and Polyposis)

  • Individual with colon or uterine cancer diagnosed under 60 years old
  • Individual with 10 or more colorectal polyps
  • Multiple cases of colorectal cancer in the family
  • Family history suggestive of Lynch Syndrome (colorectal, endometrial, pancreatic, ovarian, kidney, urinary tract, small bowel, gastric and brain cancers)
  • Family history suggestive of hereditary polyposis
  • Known Lynch (MLH1, MSH2, MSH6, PMS2, EPCAM) or polyposis (APC, MutYH) gene mutation in family

Other Hereditary Cancers (Exclusions: lung and cervical cancer)

  • A family history of a known hereditary cancer syndrome. Please provide details on the referral form.
  • Individual diagnosed with more than one primary cancer
  • Multiple family members with the same cancer or rare cancers, especially if diagnosed under age 50
  • Hereditary Cancer Testing Eligibility Criteria

If you are uncertain whether an individual/family history will meet criteria, please refer. We will triage the referral and notify your office of the decision regarding eligibility. We suggest informing your patient that their family history will be evaluated to determine if there is a need for an appointment. Genetic testing is offered only to families that are suggestive of a hereditary cancer syndrome, and in most cases, will be offered to a family member affected with cancer first.


Clinical Genetics
2nd floor R.S. McLaughlin Central East Regional Cancer Centre
Lakeridge Health Oshawa
Phone  (905) 433-2733
Fax (905) 721-6122

Referring your patient

Clinical Genetics at Lakeridge Health Oshawa meets with individuals and families for evaluation and genetic counselling for Preconception/Prenatal Genetics, Hereditary Cancer Genetics, and General Pediatric and Adult Genetics.

We accept referrals from physicians, using our referral form.  Referrals can be faxed to (905) 721-6122.

Individuals residing in the Central East region can also be referred to the Genetics programs at Rouge Valley Centenary and Peterborough Regional Health Centre.