With a family history of cancer, when do you need genetic counselling? Who arranges genetic testing?
Colorectal cancer patients and their first-degree relatives can be referred for genetic counselling and testing, with common criteria including a strong family history, multiple cancers in the same person and early onset (Hong Kong Cancer Strategy 2019); genetic testing should be done at specialist cancer centres with expertise in genetic counselling, preceded by genetic counselling (Cancer Expert Working Group on Cancer Prevention and Screening, June 2020). Individual cases are decided by the treating doctor.
When are colorectal cancer patients and their families referred for genetic counselling?
Colorectal cancer patients and their first-degree relatives can be referred for genetic counselling and genetic testing; referral criteria vary between testing services, and common criteria include a strong family history, multiple cancers in the same person, early age at onset, a disease-causing mutation in a cancer susceptibility gene, or clinical suspicion of a hereditary cancer syndrome (Hong Kong Cancer Strategy 2019, Annex One, July 2019).
For colorectal cancer patients with an identifiable gene mutation, their family members can have two-tier screening: genetic testing first, then endoscopy arranged according to the result, to reduce unnecessary examinations and potential complications (Cancer Expert Working Group on Cancer Prevention and Screening colorectal cancer recommendations, June 2024).
For the Cancer Expert Working Group on Cancer Prevention and Screening's colorectal cancer screening recommendations by family history and hereditary condition, see How to choose a colorectal cancer doctor.
With a family history of breast cancer, what does the Working Group say about screening and genetic counselling?
The following women are at high risk of breast cancer: those confirmed by genetic testing to carry a disease-causing BRCA1 or BRCA2 mutation; those with certain family histories of breast or ovarian cancer, for example any first-degree female relative confirmed to carry a BRCA1 or BRCA2 mutation, or two first-degree female relatives with breast cancer, one of them diagnosed at or before age 50; or those with certain personal risk factors (Cancer Expert Working Group on Cancer Prevention and Screening breast cancer recommendations, June 2020). The breast cancer recommendations set out screening and genetic testing recommendations for high-risk women separately; see the table below (Cancer Expert Working Group on Cancer Prevention and Screening, June 2020).
| Who | Recommendation of the Cancer Expert Working Group on Cancer Prevention and Screening (2020) |
|---|---|
| Women with a first-degree female relative confirmed to carry a disease-causing BRCA1 or BRCA2 mutation | Should be offered genetic testing to confirm or rule out whether they carry the mutation |
| Women at high risk because of other family history who want to clarify their own or their family's genetic risk | Should consider referral to a specialist cancer clinic for advice, counselling and management |
| Screening for high-risk women | Seek a doctor's advice; have mammography every year, starting at 35 or 10 years before the age at diagnosis of the youngest diagnosed relative (whichever is earlier, but not before 30) |
Screening first or genetic counselling first: who decides?
The screening recommendations and the genetic testing recommendations for high-risk women are set out separately (Cancer Expert Working Group on Cancer Prevention and Screening breast cancer recommendations, June 2020); which one an individual woman has first, and whether she is referred for genetic counselling, is decided by the doctor according to her personal and family medical history.
The Department of Health's Breast Cancer Screening Pilot Programme Phase II was launched on 10 June 2025 and provides subsidised screening for female Hong Kong residents aged 35 to 74 who carry specified gene mutations or have a strong family history of breast or ovarian cancer (Cancer Online Resource Hub, April 2026); for eligibility, see How to choose a breast cancer doctor.
Who arranges genetic testing?
Genetic testing should be done at specialist cancer centres with expertise in genetic counselling, and genetic counselling should be provided before testing; healthcare professionals should explain in detail to the person tested the uncertainties and implications of the result (Cancer Expert Working Group on Cancer Prevention and Screening breast cancer recommendations, June 2020).
The providers of genetic counselling and testing for colorectal cancer patients and their first-degree relatives at the time included the University of Hong Kong's Hereditary Gastrointestinal Cancer Genetic Diagnosis Laboratory, the Department of Health's Clinical Genetic Service and the private sector; the Department of Health's Clinical Genetic Service also accepted referrals of patients with suspected hereditary breast and ovarian cancer syndrome and their families (Hong Kong Cancer Strategy 2019, Annex One, July 2019).
The Department of Health's Clinical Genetic Service (including the Genetic Counselling Clinic) was taken over by the Hospital Authority from 1 July 2023; patients previously followed up by the Department of Health were transferred to the Clinical Genetics Service Unit of Hong Kong Children's Hospital, and new referrals from public or private hospitals are also arranged directly to that unit for follow-up (Hospital Authority announcement through a Government press release, June 2023).
Individual cases are decided by the treating doctor according to the patient's condition.
Frequently asked questions
When do colorectal cancer patients need genetic counselling or family screening?
Colorectal cancer patients and their first-degree relatives can be referred for genetic counselling and testing, with common criteria including a strong family history, multiple cancers in the same person, early onset and a known disease-causing gene mutation (Hong Kong Cancer Strategy 2019, Annex One, July 2019); where the patient carries an identifiable gene mutation, family members can have genetic testing first and then endoscopy arranged according to the result (Cancer Expert Working Group on Cancer Prevention and Screening colorectal cancer recommendations, June 2024).
With a family history of breast cancer, should I have screening or genetic counselling first?
The screening recommendations for high-risk women (yearly mammography) and the genetic testing recommendations (women whose first-degree female relative carries a BRCA1 or BRCA2 mutation should be offered testing; with other family history, referral to a specialist cancer clinic can be considered) are set out separately (Cancer Expert Working Group on Cancer Prevention and Screening breast cancer recommendations, June 2020); how an individual woman's care is arranged is decided by the doctor according to her personal and family medical history.
Which doctors or genetic counselling services usually arrange genetic testing for breast cancer?
Genetic testing should be done at specialist cancer centres with expertise in genetic counselling, with genetic counselling before testing (Cancer Expert Working Group on Cancer Prevention and Screening breast cancer recommendations, June 2020); the public clinical genetic service was taken over by the Hospital Authority from 1 July 2023, and new referrals are arranged to the Clinical Genetics Service Unit of Hong Kong Children's Hospital (Hospital Authority announcement through a Government press release, June 2023).