STRAP is a strong predictive marker of adjuvant chemotherapy benefit in colorectal cancer

Neoplasia. Nov-Dec 2004;6(6):813-20. doi: 10.1593/neo.04307.

Abstract

Background: Molecular predictors for the effectiveness of adjuvant chemotherapy in colorectal cancer are of considerable clinical interest. To this aim, we analyzed the serine threonine receptor-associated protein (STRAP), an inhibitor of TGF-beta signaling, with regard to prognosis and prediction of adjuvant 5-FU chemotherapy benefit.

Methods: The gene copy status of STRAP was determined using quantitative real-time polymerase chain reaction in 166 colorectal tumor biopsies, which had been collected from a randomized multicenter trial of 5-fluorouracil (5-FU)/mitomycin C (MMC) adjuvant chemotherapy of the Swiss Group for Clinical Cancer Research (SAKK).

Results: Amplification of STRAP was found in 22.8% of the tumors. When left without adjuvant chemotherapy, patients bearing tumors with a STRAP amplification had a significantly better prognosis (hazard ratio for death: 0.26; P=.004). Interestingly, these patients, when receiving adjuvant treatment, had a worse survival (hazard ratio for death: 3.48; P=.019) than without chemotherapy, whereas patients carrying tumors with diploidy or deletion of STRAP benefited from the treatment (hazard ratio for death: 0.44; P=.052). This suggests the amplification of STRAP as a strong predictor of an unfavorable effect of 5-FU-based adjuvant chemotherapy.

Conclusion: If confirmed, the STRAP gene copy status might provide a parameter to decide about the use of 5-FU-based adjuvant chemotherapy.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antimetabolites, Antineoplastic / therapeutic use
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Biomarkers, Tumor / analysis*
  • Carrier Proteins / biosynthesis*
  • Carrier Proteins / genetics
  • Chemotherapy, Adjuvant
  • Colorectal Neoplasms / drug therapy*
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / mortality
  • Female
  • Fluorouracil / therapeutic use
  • Gene Dosage
  • Humans
  • Male
  • Middle Aged
  • Mitomycin / therapeutic use
  • Polymerase Chain Reaction
  • Prognosis

Substances

  • Antimetabolites, Antineoplastic
  • Biomarkers, Tumor
  • Carrier Proteins
  • Strap protein
  • Mitomycin
  • Fluorouracil