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Bowel cancer - A family affair. Alice Christian Genetic Associate C&SRGS. Identification of a familial mutation may lead to the identification of many relatives at risk. Hereditary Cancers. How to spot an inherited cancer What to do about it Surveillance Referral pathways.
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Bowel cancer- A family affair Alice Christian Genetic Associate C&SRGS
Identification of a familial mutation may lead to the identification of many relatives at risk
Hereditary Cancers • How to spot an inherited cancer • What to do about it • Surveillance • Referral pathways
Family history is the key • 3 generation pedigree • All cancers noted • Ages at diagnosis
Features of Hereditary Cancer • More cancer than expected in the family • Types of cancer are consistent, or fit a known hereditary cancer pattern • Early age of onset (<55 with Fhx or very young with no Fhx) • Multiple primary tumours in an individual • Presence of unusual cancers or other features – eg. Skin lesions, CHRPES
? ? Colon - 56yrs Colon - 50 yrs
Endometrial - 50yrs Urinary tract - 60yrs Colon - 56yrs Endometrial - 60yrs Ovarian - 45yrs Colon - 50 yrs
Lynch syndrome (Hereditary Non-Polyposis Colorectal Cancer (HNPCC) ) Increased risk for: • Colon cancer ~ up to an 80% lifetime risk • Endometrial cancer ~30-60% lifetime risk • Ovarian cancer ~ 10% lifetime risk • Other cancers e.g. gastric, hepatobiliary, kidney, urinary tract, small bowel cancer • Sebaceous adenomas
Familial Adenomatous Polyposis (FAP) • Adenomatous polyps in colon and rectum • Colorectal cancer, usually by age 40 • Increased chance for some other malignancies: • duodenum, stomach, brain, papillary thyroid cancer in young women, ?hepatoblastoma in young children
Criteria: • Familial adenomatous polyposis (FAP) is diagnosed clinically in an individual with: • Greater than 100 colorectal adenomatous polyps OR • Fewer than 100 adenomatous polyps AND a relative with FAP
Adenomatous Polyps in Colon From http://www.gastrolab.net
Other Features • Benign desmoid tumors • Dental anomalies • Epidermoid cysts (esp. scalp) • Retinal lesions (CHRPE) • Osteomas of the mandible • Variable presentation, even within the same family
Congenital hypertrophy of the retinal pigment epithelium (CHRPE) - FAP
Mucocutaneous hyperpigmentation is associated with Peutz-Jegher syndrome. May be subtle and fade with age
www.nzgg.org.nz *Guidelines only – must be flexible! ** due for review
Risk may be up to 2x that of the general population • Most of this additional risk from 60 years of age • If considering one-off screening for reassurance • – 50yrs for men, 55 for women.
Surveillance for moderate risk group • Surveillance – 5 yearly, from 50 (or 10 years before youngest diagnosis) • Unlikely to be available through the public system • Available through private system • Other alternatives may be more accessible: • Faecal occult blood (evidence for popn risk) • CT colonography
Who should be referred for assessment of family history? • Known cancer syndrome in the family • Fit “high risk criteria” • Problematic “moderate risk”
Where to refer? • Genetic services • NZ familial GI registry
New Zealand Genetic Services Clinic Locations NRGS ` Central & Southern RGS
NZ Familial GI Cancer Registry • Provide assessment for familial gastrointestinal cancer syndromes • Facilitate ongoing surveillance for at-risk family members • Gatekeepers for colonoscopy • Funding recently extended to allow a national service
Registry locations • Auckland hospital • Christchurch hospital • Proposed Wellington site by 2011 - 2012
Registry pathway: • Refer families for assessment by the registry • All cancers confirmed where possible (30% concordance between family history given to GP, and confirmed history) • Surveillance guidelines provided based on family history. High risk families enrolled in registry for ongoing management.
Families identified as having a likely familial cancer syndrome are referred to genetic services. • Genetic services offer genetic testing. • Outcome shared with registry who establish appropriate management • Genetic services meet with extended family for predictive testing of identified mutations
Genetic Testing Limitations • Mutations detected in minority of families • Requires blood from living affected relative • Lengthy and expensive process • Predictive test gives no information on if, when or what type of cancer an individual will develop • Sporadic cancer occurs within cancer syndrome families.
Conclusion • Family history is the key • If looks familial refer to genetic services or Familial GI registry • In terminal patients store DNA if there is any chance it is familial (EDTA 20mls) • Ring if you have any queriesor not sure whether to refer or not.
Toll-free 0508 364 436 • (04) 3855310 or ext 5310 • Healthpoint