A retrospective analysis revealed a higher risk of cancer-related mortality for individuals who had familial colorectal cancer type X (FCCTX) compared with those with Lynch syndrome (LS).1 The study results were published online October 30, 2018, in the Journal of the National Cancer Institute.

Families with FCCTX or LS were identified through the Colon Cancer Family Registry. The families had been recruited to the registry between 1997 and 2012; follow-up occurred after approximately 5 years following initial registry. In total, 168 families with FCCTX, which included 3486 individuals; and 780 families with LS, which included 11788 individuals; were recruited for the study. Risk estimates were compared for the first and second colorectal cancers (CRCs) between FCCTX and LS families. The risk of cancer-related death and the disease-free survival (DFS) rates were also compared between family groups.

LS families had a higher risk of first and second CRC occurrences compared with those who had FCCTX. The first CRC occurrence was seen at an earlier age in LS families compared with FCCTX families (49.4 years vs 59.4 years, P < .001). The second CRC occurrence was also seen at an earlier age in LS families compared with FCCTX families (56.1 years vs 60.4 years, P = .06).

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FCCTX families had a higher 10-year risk of cancer-related death than LS families (15.4% in men and 19.3% in women with FCCTX vs 8.9% in men and 8.7% in women with LS, respectively).

“Individuals with CRCs arising in the context of FCCTX do not experience the same improved DFS and overall survival of those with LS, and that difference may be relevant in management decisions,” the study authors concluded.


  1. Choi Y-H, Lakhal-Chaieb L, Kröl A, et al. Risks of colorectal cancer and cancer-related mortality in familial colorectal cancer type X and Lynch syndrome families [published online October 30, 2018]. J Natl Cancer Inst. doi: 10.1093/jnci/djy15.