Subtotal colectomy reduces the chance of a second primary colon cancer but has not been shown to have a survival advantage.r People who are not having regular colonoscopies are most likely to benefit.
Since MSH6 and PMS2 pathogenic variant carriers have a lower risk of colorectal cancer (CRC) and the age at diagnosis is later than in patients with MLH1 and MSH2 pathogenic variants, start screening at 35 years in MSH6 and PMS2 carriers, unless an early-onset cancer exists in a given family.rr
A study of 114 Lynch syndrome families comparing outcomes of screening at intervals of <2 years with >2 years demonstrated CRCs were diagnosed at a higher stage with the longer interval surveillance. Evidence supports screening 1–2 yearly.r
Since 57% of the neoplasms in Lynch syndrome occur proximal to the splenic flexure,r visualisation to the caecum is essential.
Considerable evidence supports the effectiveness of aspirin as risk-reducing medication for CRC in high risk Lynch syndrome patients (35-40% reduction in CRC risk). The benefit appears five years after starting aspirin and persists for at least 20 years. While there is limited evidence about the optimal dose and starting age, regular daily low-dose aspirin could be considered.r
Hysterectomy is the only proven intervention which significantly reduces the risk of endometrial cancer.r
There is no evidence to support a survival benefit from transvaginal ultrasound (TVU) and aspiration biopsy.r If surveillance is offered, it should be done in the context of a clinical trial.r
Risk-reducing salpingo-oophorectomy (RRSO) reduces the risk of developing ovarian cancer in pathogenic variant carriers.r Disease-free survival for ovarian cancers in patients with Lynch syndrome appears higher than for BRCA-associated ovarian cancer. Most ovarian cancers are diagnosed in pre-menopausal women and prognosis is generally good.r However, pre-menopausal women experience greater adverse effects from this surgery.r The risk of ovarian cancer is highest in MLH1, MSH2 and MSH6 pathogenic variant carriers suggesting they would benefit more from surgery than PMS2 carriers. Individualised risk is therefore based on the pathogenic variant, personal preference and family history.
Data extrapolated from other high-risk groups demonstrates annual TVU and serum CA125 levels have low sensitivity and specificity for ovarian cancer, and do not reliably detect ovarian cancers at an early stage, nor do they affect outcomes. This is true of women in the general population and women at high risk of hereditary ovarian cancer.r
Ovarian cancer risk management relies on risk-reducing salpingo-oophorectomy (RRSO - removal of the ovaries and fallopian tubes). See Cancer Australia for further information.
There is no evidence supporting the role of gastroscopy in the surveillance for gastric cancer in Lynch syndrome patients.r However, gastroscopy should be considered in families at high risk of gastric cancer.r There is a suggestion that chronic immune gastritis may play a role in the development of gastric cancer in individuals with Lynch syndrome, so an evaluation for gastritis and Helicobacter pylori infection could be considered.r
Urothelial transitional cell carcinoma
There is no evidence for the role of urine cytology in the surveillance of urothelial carcinomas in MMR gene carriers. One study of individuals with confirmed or suspected Lynch syndrome demonstrated urine cytology had a sensitivity for malignancy of only 29%.r
In the general population, surveillance can be associated with over-diagnosis and over treatment with no evidence for improved short-term survival (ten year period). Surveillance for prostate cancer may be beneficial in situations where individuals have an increased risk of developing aggressive, early onset cancer. There is insufficient evidence regarding the characteristics of the prostate cancers seen in Lynch syndrome and therefore the role of prostate cancer surveillance in Lynch syndrome is unclear.