Abstract
PURPOSE: To explore the effect of dihydropyrimidine dehydrogenase (DPD) single nucleotide polymorphisms (SNP) and haplotypes on outcome of capecitabine.
EXPERIMENTAL DESIGN: Germline DNA was available from 568 previously untreated patients with advanced colorectal cancer participating in the CAIRO2 trial, assigned to capecitabine, oxaliplatin, and bevacizumab ± cetuximab. The coding region of dihydropyrimidine dehydrogenase gene (DPYD) was sequenced in 45 cases with grade 3 or more capecitabine-related toxicity and in 100 randomly selected controls (cohort). Most discriminating (P < 0.1) or frequently occurring (>1%) nonsynonymous SNPs were analyzed in all 568 patients. SNPs and haplotypes were associated with toxicity, capecitabine dose modifications, and survival.
RESULTS: A total of 29 SNPs were detected in the case-cohort analysis, of which 8 were analyzed in all 568 patients. Of the patients polymorphic for DPYD IVS14+1G>A, 2846A>T, and 1236G>A, 71% (5 of 7), 63% (5 of 8), and 50% (14 of 28) developed grade 3 to 4 diarrhea, respectively, compared with 24% in the overall population. All patients polymorphic for IVS14+1G>A developed any grade 3 to 4 toxicity, including one possibly capecitabine-related death. Because of toxicity, a mean capecitabine dose reduction of 50% was applied in IVS14+1G>A and 25% in 2846A>T variant allele carriers. Patients were categorized into six haplotype groups: one predicted for reduced (10%), and two for increased risks (41% and 33%) for severe diarrhea. Individual SNPs were not associated with overall survival, whereas one haplotype was associated with overall survival [HR (95% CI) = 0.57 (0.35-0.95)].
CONCLUSIONS: DPYD IVS14+1G>A and 2846A>T predict for severe toxicity to capecitabine, for which patients require dose reductions. Haplotypes assist in selecting patients at risk for toxicity to capecitabine.
Original language | English |
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Pages (from-to) | 3455-68 |
Number of pages | 14 |
Journal | Clinical Cancer Research |
Volume | 17 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2011 |
Keywords
- Adult
- Aged
- Aged, 80 and over
- Antimetabolites, Antineoplastic
- Biomarkers, Pharmacological
- Carcinoma
- Case-Control Studies
- Clinical Trials, Phase III as Topic
- Cohort Studies
- Colorectal Neoplasms
- Deoxycytidine
- Dihydrouracil Dehydrogenase (NADP)
- Disease Progression
- Dose-Response Relationship, Drug
- Drug-Related Side Effects and Adverse Reactions
- Female
- Fluorouracil
- Haplotypes
- Humans
- Male
- Middle Aged
- Polymorphism, Single Nucleotide
- Randomized Controlled Trials as Topic
- Retrospective Studies
- Treatment Outcome
- Tumor Markers, Biological