Cascade screening in HBOC and Lynch syndrome: guidelines and procedures in a UK centre

We present time trends (1990 –2020) of identification of index cases with germline CPG variants and numbers of subsequent cascade tests, forBRCA1,BRCA2, and the Lynch genes (MLH1,MSH2,MSH6 andPMS2). ForBRCA1/2 there was a definite increase in the proportion of index cases with ovarian cancer only and pre-symptomatic index tests both doubling from 16 to 32% and 3.2 to  >  8% respectively. A mean of 1.73–1.74 additional family tests were generated for eachBRCA1/2 index case within 2 years. Overall close to one positive cascade test was generated per index case resulting in  >  1000 risk reducing surgery operations. In Lynch syndrome slightly more cascade tests were performed in the first two years potentially reflecting the increased actionability in males with 42.2% of pre-symptomatic tests in males compared to 25.8% inBRCA1/2 (p <  0.0001).
Source: Familial Cancer - Category: Cancer & Oncology Source Type: research