1. VEGF and VEGFR1 Gene expression levels predict tumor recurrence in adjuvant colon cancer
Yan Ning1, Georg Lurje1, Kathleen Danenberg2, Janine Cooc2, Dongyun Yang1, Alexandra Pohl1, Wu Zhang1, and Heinz-Josef Lenz1
1.USC/Norris Comprehensive Cancer Center, Los Angeles, CA
2. Response Genetics, Inc. Los Angeles, CA
Introduction
Results
Tumor recurrence after curative resection is still a major problem in the management of adjuvant colon cancer, with recurrence rate approximately 30-40%. Identifying molecular markers for tumor recurrence is critical for successfully selecting patients who are more likely to benefit from adjuvant chemotherapy. Our group previously showed that angiogenesis gene polymorphisms (VEGF and IL-8) may associated with tumor recurrence in adjuvant colon cancer (Lurje Ann Oncol, 2008). Here we tested the hypothesis whether gene expression levels of angiogenesis pathway (COX-2, EGFR, VEGF, VEGFR1, VEGFR2 and IL-8) could also predict the risk of tumor recurrence in stage II and III colon cancer patients treated with adjuvant chemotherapy.
Figure 2. high VEGFR1 mRNA levels associated with high tumor recurrence risk in adjuvant colon cancer
Patients and method
Figure 1. high VEGF mRNA levels associated with high tumor recurrence risk in adjuvant colon cancer
Tissue samples from 140 adjuvant colon cancer patients (69 females and 71 males with a median age of 59 years; range=28-86) were available for gene expression assays. These tissue samples were obtained at the University of Southern California/Norris Comprehensive Cancer Center (USC/NCCC) and LAC+USC medical center between 1999 and Sixty-three patients had stage II and 77 had stage III colon cancer. The median follow-up was 5.4 years (range= ). 51 of 140 patients (36.4%) developed tumor recurrence with a 5-year probability of 0.28 ± 0.06 for stage II and 0.40 ± 0.06 for stage III colon cancer patients. mRNA was extracted from laser-capture-microdissected tumor tissue. After cDNA was prepared by reverse transcription, quantitation
of the candidate genes and an internal reference gene (ß-actin) was performed using a fluorescence-based real-time detection method (TaqMan®). Primers and probes for the target gene was described previously. (Azuma, pharmacogenomics, 2007; Vallbohmer, JCO, 2005)
Conclusion
VEGF and VEGFR1 gene expression levels may predict tumor recurrence risk in adjuvant colon
cancer patients. Our exploratory data warrant future confirmatory trial..