ICARE Social Media Post March 2020

Colon Cancer and Polyp Risks

New colon cancer and polyposis genes recently identified include NTHL1, POLE, POLD1, MSH3, and RNF43. Previous studies suggest these genes raise the risk for colon cancer and polyposis; however, recent data suggest that environmental factors may also play an important role in risk. Ultimately, these genes account for a very small fraction of polyposis cases.

For more information check out https://www.ncbi.nlm.nih.gov/pubmed/31243857 and https://www.ncbi.nlm.nih.gov/pubmed/31227763

ICARE Newsletter Summer 2018

NTHL1: A New Gene for Inherited Colorectal Cancers

In a study of 51 individuals with multiple colon polyps drawn from 48 families, genetic testing through whole-exome sequencing identified 7 individuals (from 3 unrelated families) to have a mutation in both copies of their NTHL1 gene, and pedigree structure was consistent with autosomal recessive inheritance.1 All these individuals had colorectal cancer and a large number of adenomas (ranging from 8-50), and none of the 8 cancers or adenomas tested showed microsatellite instability. There were also individuals who developed endometrial and duodenal cancer. A subsequent study of over 2400 families confirmed the association between this gene and colorectal cancer risk.2

1Weren RD, et al. Nat Genet. 2015 Jun. PMID: 25938944.
2Broderick P, et al. Gastroenterology. 2017 Jan. PMID: 27713038.

ICARE Newsletter Summer 2018

Updates to NCCN Genetic/Familial High-Risk Assessment: Colorectal Guidelines

For Individuals with Lynch Syndrome:

  • Surveillance for gastric and small bowel cancer now indicates there is no clear data to support this, but surveillance can be performed every 3-5 years starting at age 40
  • Lack of evidence to make a recommendation for pancreatic or prostate cancer screening, beyond those already recommended through other NCCN Guideline panels
  • Increased breast cancer risk was acknowledged, however there is not enough evidence to support increased screening above what is recommended for the general population

In the multi-gene testing section:

  • New genes added for colorectal cancer risk included NTHL1 and MSH3 (‘biallelic’ mutations)
  • Indicated lack of data to determine screening recommendations among those with single (heterozygous) mutation in MUTYH and a second degree relative with colorectal cancer

For the complete updated versions of the NCCN Guidelines, please visit NCCN.org