Table 3.
Baseline characteristics.
| Variable | rs4680-GG group (n = 59) | rs4680-Non-GG group (n = 80) | ||||
|---|---|---|---|---|---|---|
| Opioid group | Group M (n = 29) |
Group O (n = 30) |
P value | Group M (n = 41) |
Group O (n = 39) |
P value |
| Age (years), mean (SD) | 66.8 (13.07) | 67.5 (9.23) | .81 | 69.2 (1.2) | 70.5 (1.4) | .51 |
| Sex, no. (%) | .42 | 1.00 | ||||
| Male | 20 (69.0) | 17 (56.7) | 22 (53.7) | 21 (53.8) | ||
| Female | 9 (31.0) | 13 (43.3) | 19 (46.3) | 18 (46.2) | ||
| Performance status, no. (%) | .83 | .25 | ||||
| 0 | 2 (6.9) | 2 (6.7) | 1 (2.4) | 5 (12.8) | ||
| 1 | 15 (51.7) | 16 (53.3) | 26 (63.4) | 22 (56.4) | ||
| 2 | 11 (37.9) | 9 (30.0) | 7 (17.1) | 9 (23.1) | ||
| 3 | 1 (3.4) | 1 (3.3) | 5 (12.2) | 3 (7.6) | ||
| 4 | 0 (0.0) | 2 (6.7) | 2 (4.9) | 0 (0.0) | ||
| Cancer type, no. (%) | .94 | .88 | ||||
| Lung | 12 (41.4) | 7 (23.3) | 15 (36.6) | 12 (30.8) | ||
| Breast | 2 (6.9) | 6 (20.0) | 4 (9.8) | 9 (23.1) | ||
| Colon | 3 (10.3) | 3 (10.0) | 2 (4.9) | 3 (7.7) | ||
| Head and neck | 3 (10.3) | 3 (10.0) | 5 (12.2) | 1 (2.6) | ||
| Esophageal | 2 (6.9) | 0 (0.0) | 5 (12.2) | 3 (7.7) | ||
| Gastric | 2 (6.9) | 3 (10.0) | 1 (2.4) | 1 (2.6) | ||
| Primary unknown | 2 (6.9) | 1 (3.3) | 1 (2.4) | 4 (10.3) | ||
| Pancreas | 0 (0.0) | 2 (6.7) | 3 (7.3) | 1 (2.6) | ||
| Mesothelioma | 0 (0.0) | 2 (6.7) | 1 (2.4) | 2 (5.1) | ||
| Gallbladder/bile duct | 0 (0.0) | 1 (3.3) | 1 (2.4) | 2 (5.1) | ||
| Others | 3 (10.3) | 2 (6.7) | 3 (7.3) | 1 (2.6) | ||
| Most painful areas, No. (%) | .70 | .58 | ||||
| Frontal pain (chest and abdomen) | 12 (41.4) | 11 (36.7) | 15 (36.6) | 12 (30.8) | ||
| Back pain (upper and lower) | 11 (37.9) | 11 (36.7) | 14 (34.1) | 10 (25.6) | ||
| Head and neck | 2 (6.9) | 4 (13.3) | 4 (9.8) | 4 (10.3) | ||
| Extremities | 2 (6.9) | 4 (13.3) | 6 (14.6) | 7 (17.9) | ||
| Others | 2 (6.9) | 0 (0.0) | 2 (4.9) | 6 (15.4) | ||
| BPI item 5, mean (SD) | 5.34 (2.09) | 5.47 (1.96) | .82 | 5.27 (2.10) | 5.46 (2.05) | .67 |
| BPI item 5 ≥ 8, No. (%) | 5 (17.2) | 6 (20.0) | 1.00 | 6 (14.6) | 8 (20.5) | .56 |
| SF-MPQ-2 | ||||||
| Continuous pain | 17.14 (10.59) | 21.57 (13.02) | .16 | 16.98 (9.54) | 20.74 (12.89) | .14 |
| Intermittent pain | 8.17 (12.28) | 18.47 (16.48) | .01 | 10.83 (10.58) | 13.87 (14.80) | .29 |
| Neuropathic pain | 5.66 (7.58) | 12.03 (10.93) | .01 | 7.24 (7.19) | 8.69 (9.36) | .44 |
| Affective descriptors | 7.86 (9.36) | 10.17 (8.98) | .34 | 7.61 (8.27) | 10.05 (10.37) | .25 |
| Total score | 38.83 (34.01) | 62.23 (42.05) | .02 | 42.66 (26.27) | 53.36 (38.42) | .15 |
| HADS ≥ 11, No. (%) | 22 (75.9) | 18 (60.0) | .27 | 33 (80.5) | 29 (74.4) | .60 |
| HADS ≥ 20, No. (%) | 9 (31.0) | 7 (23.3) | .57 | 12 (29.3) | 11 (28.2) | 1.00 |
| EORTC-QLQ-C15-PAL | ||||||
| Overall quality of life | 30.09 (22.16) | 38.77 (26.37) | .18 | 41.05 (22.08) | 35.90 (24.94) | .33 |
| Physical functioning | 58.84 (28.16) | 57.99 (30.67) | .91 | 62.10 (29.18) | 55.38 (26.57) | .29 |
| Emotional functioning | 59.78 (29.88) | 61.79 (31.53) | .80 | 61.12 (33.51) | 57.74 (23.96) | .61 |
| Fatigue | 58.99 (25.06) | 62.83 (24.38) | .56 | 64.77 (27.56) | 64.38 (27.25) | .95 |
| Nausea/vomiting | 8.06 (13.82) | 10.56 (25.33) | .64 | 10.17 (18.96) | 12.40 (24.10) | .65 |
| Pain | 70.69 (25.85) | 76.43 (24.20) | .39 | 73.57 (24.72) | 77.77 (24.58) | .46 |
| Dyspnea | 35.62 (32.04) | 28.88 (25.87) | .38 | 24.38 (26.90) | 33.33 (39.52) | .25 |
| Insomnia | 55.17 (37.04) | 58.89 (38.84) | .71 | 52.84 (36.50) | 52.99 (33.10) | .99 |
| Appetite loss | 36.77 (28.66) | 51.11 (41.74) | .13 | 52.85 (35.74) | 52.13 (38.85) | .93 |
| Constipation | 34.48 (32.72) | 35.63 (39.78) | .91 | 33.33 (30.74) | 29.90 (29.42) | .61 |
| Pain catastrophizing scale (SD) | 34.2 (9.5) | 33.0 (11.7) | .665 | 31.9 (11.3) | 32.1 (13.0) | .921 |
Abbreviations: BPI, Brief Pain Inventory; HADS, Hospital Anxiety and Depression Scale; SD, standard deviation; group M, morphine-treated group; group O, oxycodone-treated group; SF-MPQ-2, Short-Form McGill Pain Questionnaire 2; EORTC, European Organisation for Research and Treatment of Cancer.