Radiat Oncol J.  2018 Sep;36(3):218-226. 10.3857/roj.2018.00094.

Single nucleotide polymorphism of GSTP1 and pathological complete response in locally advanced rectal cancer patients treated with neoadjuvant concomitant radiochemotherapy

Affiliations
  • 1Department of Radiation Oncology, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy. lucanicosia.rg@gmail.com
  • 2Department of Neuroscience, Mental Health and Sense Organs, Sapienza University of Rome, Rome, Italy.
  • 3Department of Neurological Sciences, IRCCS Neuromed, Pozzilli, Italy.
  • 4Department of Advanced Molecular Diagnostic, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy.

Abstract

PURPOSE
Standard treatment for locally advanced rectal cancer consists of neoadjuvant radiochemotherapy with concomitant fluoropyrimidine or oxaliplatin and surgery with curative intent. Pathological complete response has shown to be predictive for better outcome and survival; nevertheless there are no biological or genetic factors predictive for response to treatment. We explored the correlation between the single nucleotide polymorphisms (SNPs) GSTP1 (A313G) and XRCC1 (G28152A), and the pathological complete response and survival after neoadjuvant radiochemotherapy in locally advanced rectal cancer patients.
MATERIALS AND METHODS
Genotypes GSTP1 (A313G) and XRCC1 (G28152A) were determined by pyrosequencing technology in 80 patients affected by locally advanced rectal cancer.
RESULTS
The overall rate of pathological complete response in our study population was 18.75%. Patients homozygous AA for GSTP1 (A313G) presented a rate of pathological complete response of 26.6% as compared to 8.5% of the AG+GG population (p = 0.04). The heterozygous comparison (AA vs. AG) showed a significant difference in the rate of pathological complete response (26.6% vs. 6.8%; p = 0.034). GSTP1 AA+AG patients presented a 5- and 8-year cancer-specific survival longer than GSTP1 GG patients (87.7% and 83.3% vs. 44.4% and 44.4%, respectively) (p = 0.014). Overall survival showed only a trend toward significance in favor of the haplotypes GSTP1 AA+AG. No significant correlations were found for XRCC1 (G28152A).
CONCLUSION
Our results suggest that GSTP1 (A313G) may predict a higher rate of pathological complete response after neoadjuvant radiochemotherapy and a better outcome, and should be considered in a more extensive analysis with the aim of personalization of radiation treatment.

Keyword

Rectal cancer; Radiochemotherapy; Single nucleotide polymorphism; Prognostic factor; Tumor response; Genetic marker

MeSH Terms

Chemoradiotherapy*
Genetic Markers
Genotype
Haplotypes
Humans
Polymorphism, Single Nucleotide*
Rectal Neoplasms*
Genetic Markers
Full Text Links
  • ROJ
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2024 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr