Bilateral risk-reducing mastectomy reduces absolute breast cancer risk to <2%.r
Statistically significant survival benefit associated with bilateral risk-reducing mastectomy compared with surveillance is yet to be demonstrated.
As for the general population and BRCA1 or BRCA2 mutation carriers,r pre-menopausal risk reducing salpingo-oophorectomy (RRBSO) would be expected to reduce the risk of breast cancer. No studies have been done in women with Cowden syndrome.
MRI + MMG is the preferred screening technique due to its high sensitivity. MRI detects tumours which are smaller and more likely to be node-negative than MMG. MRI has a recall rate (requiring further investigation and/or biopsy) of 15% for initial screening, which decreases with subsequent rounds of screening to <10%.
There is no evidence to date that early detection of breast cancer is associated with a better prognosis and survival in PTEN gene mutation carriers. However, for women who do not choose risk-reducing surgery, surveillance is strongly recommended.
No clinical benefit has been proven for endometrial surveillance and thus it is not recommended.
Surveillance is not recommended because there have been no studies demonstrating benefit of screening thyroid ultrasound.
Some groups suggest second yearly renal US from age 40 years.r However there is no evidence for or against this investigation.
Some patients develop adenomas and hyperplastic polyps in addition to colonic hamartomas. Whilst an increased risk of young onset colorectal cancer (9%) has been reported,r there is no evidence that all families with PTEN are at high risk of bowel cancer. Families with a history of colorectal cancer should follow screening guidelines based on their family history of colorectal cancer.
Evidence regarding other cancers
A recent summary of PTEN mutation carriers also reported an increased risk of melanoma,r although the risk was still small.