Volume 8 Supplement 1

Proceedings of the 13th Annual Meeting of the Collaborative Group of the Americas on Inherited Colorectal Cancer

Open Access

Clinicopathologic and genetic features of young patients with colorectal cancer

  • Melyssa Aronson1Email author,
  • Steve Gallinger1,
  • Heidi Rothenmund1,
  • Kara Semotiuk1,
  • Spring Holter1,
  • Terri Berk1,
  • Aaron Pollett1,
  • Zane Cohen1,
  • Bharati Bapat1,
  • Hyeja Kim1 and
  • Robert Gryfe1
Hereditary Cancer in Clinical Practice20108(Suppl 1):P2

DOI: 10.1186/1897-4287-8-S1-P2

Published: 25 May 2010

Background

Colorectal cancer (CRC) is the 3rd most common cancer in Canada, often occurring at older ages. While early-onset CRC can be suggestive of an inherited syndrome, the underlying genetic cause remains unexplained in many of these young individuals.

Method

Clinicopathologic features along with genetic and family information were collected on individuals diagnosed with CRC ≤35 years old identified through the Familial Gastrointestinal Cancer Registry in Toronto, Canada.

Results

441 individuals from 353 families were identified, and to-date, medical records confirmed 254 diagnoses, which were included for analysis. Ninety patients (35.4%) had germline mutations in self or kin (31 MSH2, 36 MLHI, 1 MSH6, 3 PMS2, 24 APC, 2 MYH biallelic and 1 BRCA2). Individuals were classified into six categories; (a) 74 had Lynch syndrome (LS) confirmed by germline mutation or tumour deficiency (b) 4 had constitutional mismatch repair-deficiency (CMMR-D) (c) 61 had polyposis (mutation positive, >25 adenomas or hamartomatous polyps), (d) 6 met Family X criteria, (e) 7 had inflammatory bowel disease (IBD), and (f) 102 were unclassified (NOS), with 69 of these individuals having MSS and/or IHC intact tumours.

On average, patients with CMMR-D presented younger, with a mean age of 14 years old at diagnosis. 65.2% of patients with LS presented with a proximal tumour (65.2%) compared with the polyposis (10.2%) and NOS (34.4%) groups. In contrast, 83% of polyposis patients and 65.5% of NOS patients presented with distal colon or rectal cancers.

Family history was significant for the majority of LS patients with 54 of 73 (74%) meeting Amsterdam I or II criteria. Two of the 7 patients with IBD, and 15 of 98 NOS patients also met Amsterdam I/II criteria, as opposed to the CMMR-D families where none met these criteria. Six LS patients presented with sporadic CRC, as did approximately 25% of polyposis patients and 59.2% of the NOS patients.

Conclusions

Cancer site differs between individuals ≤35 years with LS, polyposis and NOS CRC. Greater than 1/3 of patients presented with no significant family history of CRC. While the majority of patients diagnosed with CRC ≤35 have a known hereditary CRC syndrome or risk predisposition, 69 of 221 (31.2%) of individuals appear to have no recognizable syndrome.

Authors’ Affiliations

(1)
Dr. Zane Cohen Digestive Disease Clinical Research Centre, Mt. Sinai Hospital

Copyright

© Aronson et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd.

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