Table 1.
Baseline characteristics of dmNPC patients receiving LRRT versus non-LRRT in unadjusted and IPTW-adjusted study populations
| Variable | Overall cohort |
IPTW-adjusted cohort |
||||||
|---|---|---|---|---|---|---|---|---|
| LRRT group n = 105 | Non-LRRT group n = 58 | P value | SMD | LRRT group n = 164 | Non-LRRT group n = 161 | P value | SMD | |
| Age, median (IQR) (years) | 47 (38-56) | 48 (41-56) | 0.40 | 0.17 | 49 (40-56) | 45 (38-54) | 0.57 | 0.04 |
| Sex | 0.60 | 0.12 | 0.63 | 0.09 | ||||
| Male | 78 (74.3) | 46 (79.3) | 128 (78.2) | 131 (81.6) | ||||
| Female | 27 (25.7) | 12 (20.7) | 36 (21.8) | 30 (18.4) | ||||
| Smoking | 0.03 | 0.39 | 0.78 | 0.05 | ||||
| No | 82 (78.1) | 35 (60.3) | 115 (70.2) | 117 (72.5) | ||||
| Yes | 23 (21.9) | 23 (39.7) | 49 (29.8) | 44 (27.5) | ||||
| Drinking | 0.03 | 0.38 | 0.84 | 0.04 | ||||
| No | 93 (88.6) | 43 (74.1) | 134 (81.7) | 135 (83.9) | ||||
| Yes | 12 (11.4) | 15 (25.9) | 30 (18.3) | 26 (16.1) | ||||
| Comorbiditiesa | 1.0 | 0.02 | 0.95 | 0.01 | ||||
| No | 79 (75.2) | 44 (75.9) | 119 (72.6) | 117 (72.7) | ||||
| Yes | 26 (24.8) | 14 (24.1) | 45 (27.4) | 44 (29.3) | ||||
| Histology | 0.59 | 0.23 | 0.38 | 0.16 | ||||
| I | 1 (1.0) | 0 (0.0) | 1 (0.6) | 0 (0.0) | ||||
| II | 0 (0.0) | 1 (1.7) | 0 (0.0) | 1 (0.6) | ||||
| III | 104 (99.0) | 57 (98.3) | 163 (99.4) | 160 (99.4) | ||||
| Tumor categoryb | 0.44 | 0.29 | 0.79 | 0.19 | ||||
| T1 | 6 (5.7) | 3 (5.2) | 8 (4.9) | 8 (5.0) | ||||
| T2 | 11 (10.5) | 2 (3.4) | 13 (7.9) | 6 (3.7) | ||||
| T3 | 50 (47.6) | 32 (55.2) | 84 (51.2) | 84 (52.2) | ||||
| T4 | 38 (36.2) | 21 (36.2) | 59 (36.0) | 63 (39.1) | ||||
| Node categoryb | 0.23 | 0.30 | 0.95 | 0.07 | ||||
| N1 | 19 (18.1) | 5 (8.6) | 24 (14.6) | 22 (13.7) | ||||
| N2 | 30 (28.6) | 21 (36.2) | 51 (31.1) | 55 (34.2) | ||||
| N3 | 56 (53.3) | 32 (55.2) | 89 (54.3) | 84 (52.1) | ||||
| Liver metastases | 0.09 | 0.31 | 0.96 | 0.01 | ||||
| No | 70 (66.7) | 30 (51.7) | 104 (63.4) | 101 (62.7) | ||||
| Yes | 35 (33.3) | 28 (48.3) | 60 (36.6) | 60 (37.3) | ||||
| Bone metastases | 0.75 | 0.06 | ||||||
| No | 34 (32.4) | 25 (43.1) | 0.23 | 0.23 | 63 (38.4) | 57 (35.4) | ||
| Yes | 71 (67.6) | 33 (56.9) | 101 (61.6) | 104 (64.6) | ||||
| Lung metastases | 0.26 | 0.21 | 0.70 | 0.07 | ||||
| No | 79 (75.2) | 38 (65.5) | 114 (69.5) | 117 (72.7) | ||||
| Yes | 26 (24.8) | 20 (34.5) | 50 (30.5) | 44 (27.3) | ||||
| Other site metastases | 0.06 | 0.33 | 0.76 | 0.06 | ||||
| No | 84 (80.0) | 38 (65.5) | 121 (73.8) | 123 (76.4) | ||||
| Yes | 21 (20.0) | 20 (34.5) | 43 (26.2) | 38 (23.6) | ||||
| No. of metastatic sites | 0.07 | 0.33 | 0.96 | 0.009 | ||||
| ≤2 | 98 (93.3) | 48 (82.8) | 148 (90.2) | 146 (90.7) | ||||
| >2 | 7 (6.7) | 10 (17.2) | 16 (9.8) | 15 (9.3) | ||||
| No. of metastatic lesions | 0.006 | 0.49 | 0.99 | 0.001 | ||||
| ≤5 | 63 (60.0) | 21 (36.2) | 84 (51.2) | 82 (50.9) | ||||
| >5 | 42 (40.0) | 37 (63.8) | 80 (48.8) | 79 (49.1) | ||||
| Pretreatment LDH (U/l) | 0.70 | 0.09 | 0.57 | 0.12 | ||||
| Normal | 75 (71.4) | 39 (67.2) | 117 (71.3) | 106 (65.8) | ||||
| Abnormalc | 30 (28.6) | 19 (32.8) | 47 (28.7) | 55 (34.2) | ||||
| Pretreatment EBV DNA | 0.92 | 0.05 | 0.84 | 0.12 | ||||
| Undetectable | 8 (7.6) | 5 (8.6) | 12(7.3) | 17 (10.6) | ||||
| Detectabled | 94 (89.5) | 51 (88.0) | 147 (89.7) | 139 (86.3) | ||||
| NA | 3 (2.9) | 2 (3.4) | 5 (3.0) | 5 (3.1) | ||||
| Cycle of first-line PCT | 0.35 | 0.18 | 0.83 | 0.04 | ||||
| <6 | 34 (32.4) | 14 (24.1) | 50 (30.5) | 52 (32.3) | ||||
| ≥6 | 71 (67.6) | 44 (75.9) | 114 (69.5) | 109 (67.7) | ||||
dmNPC, de novo metastatic nasopharyngeal carcinoma; EBV, Epstein–Barr virus; IPTW, inverse probability of treatment weighting; SMD, standardized mean difference; IQR, interquartile range; LDH, lactate dehydrogenase; LRRT, locoregional radiotherapy; PCT, palliative chemotherapy .
a
Comorbidities include hypertension, diabetes, hepatitis B or tuberculosis.
b
According to the 8th edition of the American Joint Committee on Cancer/Union for International Cancer Control cancer staging manual.
c
Abnormal values (for all four centers), >250 U/l.
d
Detectable values (for all four centers), 0 copies/ml.