Epidemiology
Population prevalence
1:1500
Genetic inheritance
Autosomal dominant
Endometrial or colon cancer before age
50
Necessary screening
Colonoscopy
Endometrial biopsy, menstrual history
Recommended surgery
RRSO, hysterectomy
Most common associated cancers
Colon, uterine, ovarian
Function of genes
Mismatch repair. Inability to repair individual DNA base pair errors
No malignancy, but family history of lynch cancers should be tested, true or false
true
Colonoscopy
Age 20-25, every 1-2 years or 2-5 yrs before earliest diagnosis
Recommended age of surgery
40-45 yrs
Other associated cancers
Small bowel, gastric hepatobiliary, renal, pancreas, ureteric, brain and sebaceous skin
Associated genes
MLH1, MSH2, MSH6, PMS2
When should tumor testing be performed
All endometrial and colon cancers prior to age 60
Endometrial biopsy
Age 30-35, every 1-2 years
Progestin based contraception
Decrease risk of endometrial/ovarian cancer
OCPs, Depot, Less data on IUD
Risk of colon, uterine, ovarian cancers
60%, 60% and 10% by age 70
Risk of endometrial cancer depends on
which gene is mutated
MLH1: 40%, MSH2: 30%, MSH6 40% (later onset)
Types of testing
Germline testing or tumor testing (immunohistochemistry or MSI testing)
AUB
maintain menstrual diary, if AUB, perform EMB
Preoperative testing
EMB to rule out occult cancer
Colonoscopy
Associated with what percent of uterine and ovarian cancers
5%, 10%
Microsatellite instability
Insertion or deletion of single nucleotides
Microsatellite: noncoding single nucleotide or dinucleotide repeats
Affects entire genome, not just coding region
Tumor testing with loss of MLH1
Perform MLH1 promoter methylation testing
Screening for other cancers
none
Postoperative care
DEXA scan 2 yrs after RRSO
Calcium/vitamin D
HRT?