Management of Lynch Syndrome

Cancer Risk Assessment

Lynch syndrome is an autosomal dominantly inherited cancer syndrome caused by pathogenic variants in DNA mismatch repair (MMR) genes (MLH1, MSH2, MSH6, and PMS2) 4, 5
Lifetime risk of endometrial cancer varies by gene: 57% for MSH2, 43% for MLH1, and 46% for MSH6 carriers 6
Lifetime risk of ovarian cancer varies by gene: 17% for MSH2, 10% for MLH1, and 13% for MSH6 carriers 6
Cumulative risk of endometrial cancer at age 40 is 2% for MSH2, 3% for MLH1, and 0% for MSH6 carriers 6
Risk assessment should be individualized based on specific gene mutation to guide timing of interventions 6

Total hysterectomy and bilateral salpingo-oophorectomy is the most effective method to prevent gynecological cancers 2, 7
Timing recommendations based on gene type:
- MSH6 carriers: consider surgery after age 40 6
- MSH2 or MLH1 carriers: consider surgery around age 35 6
- PMS2 carriers: lower risk but should still be offered risk-reducing surgery 6
Preoperative counseling about risks, benefits, and long-term effects is essential 3
Preoperative endometrial biopsy and pelvic ultrasound recommended to identify occult cancer, particularly if symptomatic 3
Laparoscopic approach is preferred when possible due to less postoperative pain, quicker recovery, and improved short-term quality of life 2, 7
Surgery should be performed at a specialist surgical center, though women at low surgical risk may choose local care 7, 3
Entire endometrium should be sampled and pathological assessment performed at a specialist gynecological pathology center 3
Coordinate risk-reducing gynecological surgery with:
- Colorectal surveillance (colonoscopy at time of surgery if not up-to-date) 7, 3
- Risk-reducing colorectal surgery when indicated 1, 7
- Colorectal cancer surgery when applicable 1, 7

Estrogen-only hormone replacement therapy (preferably transdermal) strongly recommended until natural menopause age (51 years) for women undergoing risk-reducing oophorectomy 1, 2, 7
HRT prevents surgical menopause sequelae including vasomotor symptoms, urogenital dryness, sexual dysfunction, cognitive decline, osteoporosis, and cardiovascular disease 2, 7

Combined oral contraceptive pill recommended for women requiring contraception as it reduces endometrial and ovarian cancer risk 1, 7, 6
Specialist consultation for fertility and contraceptive needs 1, 3
Aspirin chemoprevention strongly recommended to reduce colorectal and other cancer risks 1, 7, 6
Maintain healthy body mass index 1, 6
Eat a healthy diet and exercise regularly 1, 6
Avoid smoking and limit alcohol consumption 1, 6
Avoid known carcinogens (e.g., tamoxifen) 1, 6

Delaying risk-reducing surgery beyond recommended age increases cancer risk 6
Failure to provide estrogen-only HRT after oophorectomy in premenopausal women can lead to significant quality of life issues and health risks 2, 7
Overlooking the need for coordinated care between gynecologic and colorectal specialists 1, 7
Underestimating the importance of aspirin chemoprevention as an adjunct to surgical prevention 1, 6