Translational Oncology (Aug 2016)

Colorectal Cancer with Residual Polyp of Origin: A Model of Malignant Transformation

  • Brooke R. Druliner,
  • Shahrooz Rashtak,
  • Xiaoyang Ruan,
  • Taejeong Bae,
  • Nikolaos Vasmatzis,
  • Daniel O’Brien,
  • Ruth Johnson,
  • Donna Felmlee-Devine,
  • Jill Washechek-Aletto,
  • Nivedita Basu,
  • Hongfang Liu,
  • Thomas Smyrk,
  • Alexej Abyzov,
  • Lisa A. Boardman

DOI
https://doi.org/10.1016/j.tranon.2016.06.002
Journal volume & issue
Vol. 9, no. 4
pp. 280 – 286

Abstract

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The majority of colorectal cancers (CRCs) arise from adenomatous polyps. In this study, we sought to present the underrecognized CRC with the residual polyp of origin (CRC RPO+) as an entity to be utilized as a model to study colorectal carcinogenesis. We identified all subjects with biopsy-proven CRC RPO+ that were evaluated over 10 years at Mayo Clinic, Rochester, MN, and compared their clinical and pathologic characteristics to CRC without remnant polyps (CRC RPO−). Overall survival and disease-free survival overlap with an equivalent hazard ratio between CRC RPO+ and RPO− cases when age, stage, and grade are adjusted. The somatic genomic profile obtained by whole genome sequencing and the gene expression profiles by RNA-seq for CRC RPO+ tumors were compared with that of age -and gender-matched CRC RPO− evaluated by The Cancer Genome Atlas. CRC RPO+ cases were more commonly found with lower-grade, earlier-stage disease than CRC RPO−. However, within the same disease stage and grade, their clinical course is very similar to that of CRC RPO−. The mutation frequencies of commonly mutated genes in CRC are similar between CRC RPO+ and RPO− cases. Likewise, gene expression patterns are indistinguishable between the RPO+ and RPO− cases. We have confirmed that CRC RPO+ is clinically and biologically similar to CRC RPO− and may be utilized as a model of the adenoma to carcinoma transition.