Table 1. Patient characteristics.
| PD-L1 | Before treatment | Negative | Negative | Positive | Positive | All | P | P |
|---|---|---|---|---|---|---|---|---|
| After treatment | Negative | Positive | Negative | Positive | ||||
| N = 4 | N = 9 | N = 4 | N = 18 | N = 35 | Baseline PD-L1* | 4 groups | ||
| Age | Median years (range) | 68 (52–78) | 63 (51–70) | 42 (26–76) | 62 (16–75) | 63 (16–78) | 0.260 | 0.443 |
| Sex | Men, N (%) | 3 (75.0) | 8 (88.9) | 4 (100.0) | 16 (88.9) | 31 (88.6) | ||
| Women, N (%) | 1 (25.0) | 1 (11.1) | 0 (0) | 2 (11.1) | 4 (11.4) | 0.478 | 0.860 | |
| Smoking | Non-smoker, N (%) | 2 (50.0) | 5 (55.6) | 3 (75.0) | 14 (77.8) | 24 (68.6) | ||
| Ex/Current-smoker, N (%) | 2 (50.0) | 4 (44.4) | 1 (25.0) | 4 (22.2) | 11 (31.4) | 0.144 | 0.528 | |
| ECOG | 0, N (%) | 0 (0) | 1 (11.1) | 1 (25.0) | 8 (44.4) | 10 (28.6) | ||
| 1, N (%) | 4 (100) | 8 (88.9) | 3 (75.0) | 10 (55.6) | 25 (71.4) | 0.055 | 0.078 | |
| Location | Oropharynx, N (%) | 0 (0) | 1 (11.1) | 2 (50.0) | 5 (27.8) | 8 (22.9) | ||
| Non-oropharynx*, N (%) | 4 (100) | 8 (88.9) | 2 (50.0) | 13 (72.2) | 27 (77.1) | 0.108 | 0.346 | |
| p16 | Positive, N (%) | 0 (0) | 1 (11.1) | 3 (75.0) | 3 (16.7) | 7 (20.0) | ||
| Negative, N (%) | 4 (100) | 8 (88.9) | 1 (25.0) | 15 (83.3) | 28 (80.0) | 0.170 | 0.058 | |
| Pathology | SqCC P/D, N (%) | 2 (50.0) | 3 (33.3) | 1 (25.0) | 6 (33.3) | 12 (34.3) | ||
| SqCC M/D, N (%) | 1 (25.0) | 5 (55.6) | 2 (50.0) | 2 (11.1) | 10 (28.6) | |||
| SqCC W/D, N (%) | 1 (25.0) | 1 (11.1) | 1 (25.0) | 8 (44.4) | 11 (31.4) | |||
| Non-keratinizing type, N (%) | 0 (0) | 0 (0) | 0 (0) | 2 (11.1) | 2 (5.7) | 0.189 | 0.375 | |
| Stage | I, N (%) | 1 (15.0) | 0 (0) | 1 (25.0) | 3 (16.7) | 5 (14.3) | ||
| II, N (%) | 0 (0) | 0 (0) | 0 (0) | 1 (5.6) | 1 (2.9) | |||
| III, N (%) | 3 (75.0) | 2 (22.2) | 0 (0) | 2 (11.1) | 7 (20.0) | |||
| IVA, N (%) | 0 (0) | 7 (77.8) | 3 (75.0) | 12 (66.7) | 22 (62.9) | 0.187 | 0.254 | |
| Definitive treatment | Concurrent chemoradiotherapy, N (%) | 3 (75.0) | 4 (44.4) | 1 (25.0) | 6 (33.3) | 14 (40.0) | ||
| Surgery, N (%) | 1 (25.0) | 5 (55.6) | 3 (75.0) | 12 (66.7) | 21 (60.0) | 0.177 | 0.507 | |
| Cisplatin treatment | No (never), N (%) | 3 (75.0) | 4 (44.4) | 3 (75.0) | 8 (44.4) | 18 (51.4) | ||
| Yes (ever), N (%) | 1 (25.0) | 5 (55.6) | 1 (25.0) | 10 (55.6) | 17 (48.6) | 0.552 | 0.212 | |
| Interval between harvesting tissues | Median months (range) | 12.4 (1.0–44.5) | 14.9 (1.5–33.4) | 9.4 (3.3–11.6) | 8.7 (1.8–39.9) | 11.6 (1.0–44.5) | 0.246 | 0.603 |
| Overall survival | Median months (95% CI) | 25.0 (15.9–NR) | 50.1 (22.6–NR) | NR (35.7–NR) | 43.7 (30–NR) | 50.1 (32.6–NR) | 0.451 | 0.859 |
| 3-year survival rate | 37.5% | 72.9% | 66.7% | 61.5% | 63.0% | |||
| 5-year survival rate | 37.5% | 18.2% | 0% | 49.2% | 38.6% | |||
| Median follow-up | Median months (range) | 75.1 (46.3–88.2) | 62.4 (27.4–119.6) | 73.7 (23–111.7) | 45.1 (29–104.5) | 62.4 (23–119.6) | 0.306 | 0.641 |
*P value of comparison of PD-L1-negative before treatment (1st and 2nd columns) and PD-L1-positive before treatment (3rd and 4th columns).
** Non-oropharynx included hypopharynx, larynx, nasal cavity, paranasal sinus, and oral cavity, which were not significant according to PD-L1 positivity.
Abbreviation: ECOG, Eastern Cooperative Oncology Group performance status; SqCC, Squamous cell carcinoma; P/D, poorly-differentiated squamous cell carcinoma; M/D; moderate-differentiated squamous cell carcinoma; W/D, well-differentiated squamous cell carcinoma; CI, confidence interval; NR, not reached.