Roles of genetic variants in the PI3K and RAS/RAF pathways in susceptibility to endometrial cancer and clinical outcomes

J Cancer Res Clin Oncol. 2012 Mar;138(3):377-85. doi: 10.1007/s00432-011-1103-0. Epub 2011 Dec 7.

Abstract

Purpose: The phosphatidylinositol 3-kinase (PI3K)/PTEN/AKT/mTOR and Ras/Raf/MEK/ERK pathways have been implicated in endometrial tumorigenesis. In this candidate pathway analysis, we investigated associations between genetic variations in these two pathways and both risk and clinical outcomes of endometrial cancer.

Methods: We genotyped a total of 48 potentially functional SNPs in 11 key genes (AKT1, AKT2, AKT3, BRAF, FRAP1, KRAS, PDPK1, PIK3CA, PIK3CB, PIK3R1, and PTEN) with the Sequenom genotyping platform in 115 endometrial cancer patients and 230 cancer-free women to evaluate their associations with risk, survival, and recurrence of endometrial cancer.

Results: We found the following: (1) PIK3CA rs6443624 and rs9838411 variants either borderline or significantly decreased risk of endometrial cancer in a dominant model (adjusted odds ratio [OR], 0.62; 95% CI, 0.39-1.00 and 0.59; 95% CI, 0.36-0.95, respectively). Furthermore, there was a statistically significant multiplicative interaction (P (int) = 0.036) between these two loci in risk of endometrial cancer. In contrast, the AKT1 rs2498801 genotype significantly increased risk of endometrial cancer (adjusted OR, 1.94; 95% CI, 1.02-3.67 in a recessive model). (2) In Cox regression analyses, three SNPs (PIK3R1 rs1862162, AKT2 rs892119, and PIK3CA rs2699887) showed significant associations with survival of endometrial cancer patients. (3) KRAS rs7312175 and PIK3CA rs6443624 had significant effects on recurrence of endometrial cancer individually and combined in a locus-dosage manner (adjusted P (trend) = 0.003).

Conclusion: These results suggest that common genetic variations in these pathways may modulate risk and clinical outcomes of endometrial cancer. Further replication and functional studies are needed to confirm these findings.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Case-Control Studies
  • Class I Phosphatidylinositol 3-Kinases
  • Endometrial Neoplasms / genetics*
  • Endometrial Neoplasms / metabolism
  • Endometrial Neoplasms / mortality
  • Endometrial Neoplasms / pathology
  • Endometrial Neoplasms / therapy
  • Female
  • Genetic Predisposition to Disease
  • Genotype
  • Humans
  • Kaplan-Meier Estimate
  • Logistic Models
  • Middle Aged
  • Odds Ratio
  • PTEN Phosphohydrolase / genetics
  • Phosphatidylinositol 3-Kinases / genetics*
  • Pilot Projects
  • Polymorphism, Single Nucleotide*
  • Proportional Hazards Models
  • Proto-Oncogene Proteins c-akt / genetics*
  • Proto-Oncogene Proteins p21(ras) / genetics
  • Risk Assessment
  • Risk Factors
  • Signal Transduction* / genetics
  • TOR Serine-Threonine Kinases / genetics
  • Treatment Outcome
  • raf Kinases / genetics

Substances

  • Phosphatidylinositol 3-Kinases
  • MTOR protein, human
  • TOR Serine-Threonine Kinases
  • Class I Phosphatidylinositol 3-Kinases
  • PIK3CA protein, human
  • AKT1 protein, human
  • Proto-Oncogene Proteins c-akt
  • raf Kinases
  • PTEN Phosphohydrolase
  • PTEN protein, human
  • Proto-Oncogene Proteins p21(ras)