ABSTRACT
PURPOSE: We tested whether 18 polymorphisms in 16 genes (GSTP1, COX2, IL10, EGFR, EGF, FGFR4, CCDN1, VEGFR2, VEGF, CXCR2, IL8, MMP3, ICAM1, ERCC1, RAD51, and XRCC3) would predict disease-free survival (DFS), overall survival (OS), and toxicity in the INT0144 trial, which was designed to investigate different postoperative regimens of 5-fluorouracil (5-FU)-based chemoradiation (CRT) in locally advanced rectal cancers: Arm 1 consisted of bolus 5-FU followed by 5-FU protracted venous infusion (PVI) with radiotherapy; arm 2 was induction and concomitant PVI 5-FU with radiotherapy and arm 3 was induction and concomitant bolus 5-FU with radiotherapy. EXPERIMENTAL DESIGN: DNA from 746 stage II/III rectal patients enrolled in the Southwest Oncology Group (SWOG) S9304 phase III trial was analyzed. Genomic DNA was extracted from formalin-fixed, paraffin-embedded (FFPE) tumor tissue. The polymorphisms were analyzed using direct DNA-sequencing or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: GSTP1-Ile105Val (rs1695) was significantly associated with DFS and OS and its effect did not vary by treatment arm. The five-year DFS and OS were 53% and 58%, respectively, for G/G, 66% and 72% for G/A, and 57% and 66% for A/A patients. In arm 2, IL8-251A/A genotype (rs4073) was associated with a lower risk of toxicities (P = 0.04). The VEGFR2 H472Q Q/Q genotype (rs1870377) was associated with a higher risk of grade 3-5 proximal upper gastrointestinal tract (PUGIT) mucositis (P = 0.04) in arm 2. However, in arm 1, this genotype was associated with a lower risk of PUGIT mucositis (P = 0.004). CONCLUSION: rs1695 may be prognostic in patients with rectal cancer treated with adjuvant CRT. rs4073 and rs1870377 may exhibit different associations with toxicity, according to the 5-FU schedule.
Subject(s)
Glutathione S-Transferase pi/genetics , Polymorphism, Single Nucleotide , Rectal Neoplasms/genetics , Rectal Neoplasms/mortality , Rectal Neoplasms/therapy , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/administration & dosage , Chemoradiotherapy , Disease-Free Survival , Female , Fluorouracil/administration & dosage , Genotype , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Polymorphism, Restriction Fragment Length , Prognosis , Reverse Transcriptase Polymerase Chain Reaction , Young AdultABSTRACT
High performance liquid chromatographic (HPLC) techniques for the quantification of 5-fluorouracil (5-FU) in human plasma have been reported in the literature, however, a low limit of detection was generally found to result in a comparatively low extraction yield. We have developed a simple, rapid and sensitive HPLC method for the measurement of 5-FU in plasma which provides both a low limit of quantification and a high extraction yield. This method involves the solid phase extraction of 5-FU from a 500 microl plasma sample. The extract is then injected into an HPLC system equipped with a C18 (mu)Bondapak column, and a UV detector set at 260 nm. Ethyl acetate and potassium dihydrogen phosphate are used for the solid phase extraction and the HPLC mobile phase, respectively. This method provides in a good baseline, a sharp and symmetrical peak for 5-FU, and a high resolution between 5-FU and the internal standard. The retention time of 5-FU using this method is 4.7 min with a limit of detection of 5 ng/ml, and an extraction yield of 96.2+/-0.5% (SE). The next injection is possible in 11 min, and the coefficients of variation are 4.2-8.9% for interday precision, and 5.2-10.6% for day-to-day reproducibility. An HPLC method has been developed that has a low limit of detection and a high extraction yield. This technique was successfully applied in a clinical pharmacokinetic study of 5-FU.
