Screening by Young Age and Family History of Colon Cancer Misses the Majority of Endometrial Cancer Patients with Lynch Syndrome
A Bruegl, B Djordjevic, B Fellman, D Urbauer, R Luthra, R Broaddus. MD Anderson Cancer Center, Houston, TX; University of Ottawa, Ottawa, ON, Canada
Background: Current clinical screening guidelines to identify women with Lynch Syndrome rely heavily on young age at diagnosis of endometrial cancer (EC) or colorectal cancer and presence of family history of colon cancer. Such guidelines were codified by the Society of Gynecologic Oncologists (SGO) in 2007. These guidelines have not been tested in a population-based fashion.
Design: 408 consecutive, unselected EC cases were evaluated for immunohistochemical expression of DNA mismatch repair proteins. Tumors with loss of MSH2, MSH6 or PMS2 were designated as probable Lynch Syndrome (PLS). Tumors with loss of MLH1 and absence of MLH1 promoter methylation were also designated PLS. Clinical data were collected from the electronic medical record.
Results: 43/408 (10.5%) EC tested had PLS. 29/43 (67.4%) EC cases with PLS did not meet SGO criteria. Table 1 summarizes known Lynch Syndrome risk factors for the 43 PLS patients. Those who met SGO Criteria were younger, more frequently had tumor rising in lower uterine segment, and more frequently had a family history of colon cancer. Note that the majority of EC cases with PLS in both groups did not have these historical risk factors.
|Meets SGO Criteria (n=14)||Does Not Meet SGO Criteria (n=29)|
|Median age at Diagnosis||48.5||63.0|
|BMI less than 30||7/14 (50.0%)||10/29 (34.5%)|
|Family History Endometrial Cancer||2/14 (14.3%)||2/29 (6.9%)|
|Family History Colorectal Cancer||4/14 (28.6%)||4/29 (13.8%)|
|Lower Uterine Segment Tumor||3/14 (21.4%)||2/29 (6.9%)|