M. Abbass1, L. Laguardia1, M. O’Malley1, D. Liska1, J. Church1, M. F. Kalady1 1Cleveland Clinic Foundation,Digestive Disease And Surgery Institute/ Department Of Colorectal Surgery,Cleveland, OHIO, USA
Introduction:
Approximately 25% of Lynch syndrome patients will develop rectal cancer, either as the index cancer, or after a total colectomy and ileorectal anastomosis. Few population based studies describe general characteristics of rectal cancer in Lynch syndrome, but there is minimal data about detailed treatment, management, and outcomes. Furthermore, there is sparse information about differences between rectal cancer in Lynch and HNPCC. Our Registry is a clinic-based registry with granular clinical information. The aim of this study is to report a detailed account of our experience with the treatment of rectal cancer in Lynch syndrome and HNPCC.
Methods:
A single institution hereditary colorectal cancer database was queried for patients with rectal cancer and either Lynch syndrome or Hereditary Nonpolyposis Colorectal Cancer (HNPCC) as defined by meeting Amsterdam criteria. Demographics, genotype, personal history of colon cancer, treatment of the disease, and outcomes were reviewed. The study included patients between the years 1998 and 2018.
Results:
78 patients with rectal cancer were included. The Lynch syndrome genotypes were as follows: 24 MSH2, 14 MLH1, 5 MSH6, and 1 PMS2. The data is summarized in the table below
Conclusion:
Rectal cancer in Lynch and HNPCC is relatively rare but often presents as the index colorectal cancer. Although the majority of cases are early stage, patients with Lynch syndrome are more likely to present at more advanced stage, receive neoadjuvant radiation therapy, and undergo a total proctocolectomy than patients with rectal cancer within HNPCC. The incidence of subsequent colon neoplasia is high in both Lynch and HNPCC if the colon is not removed at the time of rectal cancer surgery.
