Table 1.
Patient characteristics.
|
DPYDvariant_no DPDnormal_activity (n = 182) |
DPYDvariant_yes DPDnormal_activity (n = 16) |
DPYDvariant_no DPDlow_activity (n = 24) |
DPYDvariant_yes DPDlow_activity (n = 6) |
p-value | Total (n = 228) | |
|---|---|---|---|---|---|---|
| Male gender | 106 (58.2%) | 9 (56.3%) | 14 (58.3%) | 2 (33.3%) | 0.72 | 131 (57.5%) |
| Age | 62.5 (10.8) | 66.3 (6.3) | 62.0 (9.83) | 59.2 (10.5) | 0.44 | 62.6 (10.4) |
| BSA | 1.91 (0.21) | 1.92 (0.21) | 1.94 (0.20) | 1.94 (0.12) | 0.91 | 1.91 (0.21) |
| Tumor type | 0.91 | |||||
| • Colorectal cancer | 120 (65.9%) | 11 (68.8%) | 16 (66.7%) | 4 (66.7%) | 151 (66.2%) | |
| • Pancreatic cancer | 16 (8.8%) | 1 (6.3%) | 4 (16.7%) | 0 (0%) | 21 (9.2%) | |
| • Metastatic breast cancer | 16 (8.8%) | 2 (12.5%) | 1 (4.2%) | 1 (16.7%) | 20 (8.8%) | |
| • Other | 30 (16.5%) | 2 (12.5%) | 3 (12.5%) | 1 (16.7%) | 36 (15.8%) | |
| Treatmenta | 0.47 | |||||
|
150 (82.4%) | 12 (75%) | 18 (75%) | 6 (100%) | 186 (81.6%) | |
| 32 (17.6%) | 4 (25%) | 6 (25%) | 0 (0%) | 42 (18.4%) | ||
| Starting dose | <0.001 | |||||
| • 100% of standard dose | 148 (81.3%) | 6 (37.5%) | 13 (54.2%) | 1 (16.7%) | 168 (73.7%) | |
| • 75% of standard dose | 27 (14.8%) | 8 (50.0%) | 8 (33.3%) | 2 (33.3%) | 45 (19.8%) | |
| • 50% of standard dose | 2 (1.1%) | 1 (6.3%) | 3 (12.5%) | 2 (33.3%) | 8 (3.5%) | |
| • Other | 5 (2.7%) | 1 (6.3%) | 0 (0%) | 1 (16.7%) | 7 (3.1%) | |
| Radiotherapy | 34 (18.7%) | 3 (18.8%) | 1 (4.2%) | 1 (16.7%) | 0.30 | 39 (17.1%) |
| Number of treatment cyclesa | 5.4 (3.7) | 5.13 (2.68) | 5.67 (2.76) | 4.17 (2.56) | 0.034 | 5.4 (3.25) |
| DPYD variant | <0.001 | |||||
|
182 (100%) | 0 (0%) | 24 (100%) | 0 (0%) | 206 (90.4%) | |
| 0 (0%) | 1 (6.3%) | 0 (0%) | 2 (33.3%) | 3 (1.3%) | ||
| 0 (0%) | 5 (3.3%) | 0 (0%) | 2 (33.3%) | 7 (3.1%) | ||
| 0 (0%) | 1 (6.3%) | 0 (0%) | 1 (16.7%) | 2 (0.9%) | ||
| 0 (0%) | 9 (56.3%) | 0 (0%) | 1 (16.7%) | 10 (4.4%) | ||
| DPD enzyme activity (nmol/mg protein/h) | 15.96 (4.43) | 14.08 (4.85) | 6.69 (1.25) | 6.02 (2.08) | <0.001 | 14.59 (5.3) |
|
182 (100%) | 16 (100%) | 0 (0%) | 0 (0%) | <0.001 | 198 (87%) |
|
0 (0%) | 0 (0%) | 24 (100%) | 6 (100%) | 30 (13%) |
BSA: body surface area; 5-FU: 5-fluorouracil; het.: heterozygote; DPD: dihydropyrimidine dehydrogenase; DPYD: gene encoding DPD protein.
Relevant characteristics with corresponding percentages of the total number of patients are shown for the categorical data. The mean and standard deviation are shown for the numerical data since these data follow a normal distribution (age, BSA, and number of treatment cycles, DPD enzyme activity). Groups: DPDnormal_activity = normal DPD enzyme activity, DPDlow_activity = decreased DPD enzyme activity below 8.69 nmol/mg protein/hour, DPYDvariant_no = no variant, DPYDvariant_yes = carrier of one of four variants affecting DPD activity (DPYD*2A (c. 1905+1 G>A; rs3918290), c. 2846A>T p.(Asp949Val); rs67376798), DPYD*13 (c. 1679T>G p.[Ile560Ser]; rs55886062), and c.1129-5923C>G (rs75017182)).
This applies only to the first treatment plan, any other treatment plans received by patients were not included.
A patient was considered to have a decreased DPD activity when the DPD enzyme activity was below 8.69 nmol/hour per mg protein.