4004 Background: Despite recent advances in the treatment of metastatic colorectal cancer, tailoring adjuvant treatment of stage II and III colon cancer patients remains controversial. Identifying a reliable panel of prognostic and predictive markers for tumor recurrence is critical in selecting an individualized and tailored chemotherapy. Tumor angiogenesis plays an important role in tumor development, progression and metastasis. In this retrospective study, we tested whether a specific pattern of 40 functionally significant polymorphisms in 37 genes involved in angiogenesis and tumor microenvironment will predict the risk of tumor recurrence in stage II and III colon cancer patients treated with adjuvant chemotherapy. Methods: Between 1999 and 2006 blood specimens from 140 patients (69 females and 71 males with a median age of 59 years; range=28–86) were obtained at the University of Southern California/Norris Comprehensive Cancer Center (USC/NCCC). Sixty-three patients had stage II and 77 had stage III colon cancer. The median follow-up was 5.4 years (range=2.0–16.8). 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. Genomic DNA was extracted from peripheral blood and genotypes were determined using PCR based RFLP. Results: Polymorphisms in VEGF (C936T; p=0.009, log-rank) and VEGFR2 (+4422 AC- repeat; p=0.04, log-rank and +1416 T/A; p=0.0009, log-rank) were associated with risk of tumor recurrence in stage III colon cancer patients (n=77). VEGFR2 AC-repeat polymorphisms were additionally associated with risk of recurrence in Stage II colon cancer patients (n=63, p=0.02, log-rank). Conclusion: VEGF C936T and VEGFR2 (+4422 AC-repeat and +1416 T/A) polymorphisms may help to identify Stage II and III colon cancer patients who are at increased risk for developing tumor recurrence. Angiogenesis seems to play a crucial role in tumor recurrence, thus targeting VEGF and VEGFR2 may be of clinical benefit for stage II and stage III colon cancer patients. Large prospective trials are needed to validate these preliminary data. No significant financial relationships to disclose.
Cancer Stem Cell Gene Variants in CD44 Predict Outcome in Stage II and Stage III Colon Cancer Patients