Table 2.
Patient baseline characteristics stratified by half-life clearance of plasma EBV DNA.
| Characteristic | No. of Patients (%) | p | ||
|---|---|---|---|---|
| Total (n = 44) | Half-life of EBV clearance | |||
|
≤15 days (n = 36) |
>15 days (n = 8) |
|||
| Median follow-up (months) (range) | 30.3 (6.0–74.2) |
30.8 (16.3–74.2) |
28.9 (6.0–51.5) |
0.39 |
| Median age in years (range) | 58 (20–78) | 57.5 (20–74) | 63 (46–78) | 0.27 |
| Male/female | 32 (72.7)/ 12 (27.3) |
26 (72.2)/10 (27.8) | 6 (75)/2 (25) | 0.93 |
| T-classification | 0.76 | |||
| T1 | 11 (25.0) | 10 (27.8) | 1 (12.5) | |
| T2 | 6 (13.6) | 5 (13.9) | 1(12.5) | |
| T3 | 20 (45.5) | 16 (44.4) | 4(50.0) | |
| T4 | 7 (15.9) | 5 (13.9) | 2 (5.0) | |
| N-classification | 0.24 | |||
| N0 | 2 (4.5) | 1 (2.8) | 1 (12.5) | |
| N1 | 16 (36.4) | 15 (41.7) | 1 (12.5) | |
| N2 | 18 (40.9) | 13 (36.1) | 5 (62.5) | |
| N3 | 8 (18.2) | 7 (19.4) | 1 (12.5) | |
| Overall Stage | 0.28 | |||
| II | 9 (20.5) | 9 (25.0) | 0 (0) | |
| III | 21 (47.7) | 16 (44.4) | 5 (62.5) | |
| IVA | 14 (31.8) | 11 (30.6) | 3 (37.5) | |
| Median pretreatment plasma EBV DNA in copies/milliliter (range) | 436.5 (16–54,437) |
396.5 (16–34,000) |
1,033 (43–54,437) |
0.39 |
| Stage II | 282 (16–987) | 282 (16–987) | Inapplicable | |
| Stage III | 339 (20–54,437) |
317.5 (20–34,000) |
683 (105–54,437) |
0.24 |
| Stage IVA | 1,107.5 (43–11,563) |
940 (79–11,563) |
1,383 (43–1,538) |
0.69 |
| Mean/ median half-life of EBV clearance (days) (range) | 9.82/7.92 (0.9–40.77) |
6.64/6.45 (0.9–13.3) |
24.09/20.73 (16.9–40.77) |
<0.001 |
| Median gross tumor volume of the primary tumor (GTV_P) (cm3) (range) | 19.7 (3.6–171.5) |
18.5 (3.6–107.3) |
31.8 (9.8–171.5) |
0.22 |
| Median gross tumor volume of the positive neck nodes (GTV_N) (cm3) (range) | 9.5 (0.7–62.2) |
9.5 (0.7–62.2) |
11.4 (1.5–55.3) |
0.73 |
| Median gross tumor volume of the primary tumor and the positive neck nodes (GTV_P+N) (cm3) (range) | 35.6 (5.6–173) |
33.45 (5.6–111.3) |
37.9 (30.5–173) |
0.09 |
| Concurrent chemoradiation only | 10 (22.7) | 10 (27.8) | 0 (0) | 0.09 |
| Induction chemotherapy then concurrent chemoradiation | 18 (40.9) | 14 (38.9) | 4 (50.0) | 0.56 |
| Concurrent chemoradiation then adjuvant chemotherapy | 16 (36.4) | 12 (33.3) | 4 (50.0) | 0.69 |
EBV DNA, Epstein–Barr virus deoxyribonucleic acid; ECOG, Eastern Cooperative Oncology Group.