Table 1.
Characteristics of the patients, according to early use of antibiotics (EUA) and citrulline rates at baseline
| All (n = 72) | No EUA (n = 42) | EUA (n = 30) | p-value | High citrulline (n = 25) | Low citrulline (n = 10) | p-value | |
|---|---|---|---|---|---|---|---|
| Age (median, IQR) | 68.8 (62.7–73.7) | 69.0 (63.4–73.4) | 67.8 (58.4–73.7) | 0.479 | 69.3 (63.5–72.7) | 63.6 (56.5–67.1) | 0.07 |
| Sex | |||||||
| male | 45 (62) | 26 (62%) | 19 (63%) | 0.902 | 16 (64%) | 5 (50%) | 0.445 |
| female | 27 (38) | 16 (38%) | 11 (37%) | 9 (36%) | 5 (50%) | ||
| Smoking status | |||||||
| current | 29 (40) | 20 (48%) | 9 (30%) | 0.062 | 11 (44%) | 3 (30%) | 0.534 |
| former | 34 (47) | 15 (35%) | 19 (63%) | 12 (48%) | 5 (50%) | ||
| never | 9 (13) | 7 (17%) | 2 (7%) | 2 (8%) | 2 (20%) | ||
| Histological type | |||||||
| adenocarcinoma | 45 (63) | 27 (64%) | 18 (60%) | 0.592 | 19 (76%) | 4 (40%) | 0.019 |
| squamous carcinoma | 14 (19) | 9 (22%) | 5 (17%) | 5 (20%) | 2 (20%) | ||
| other | 13 (18) | 6 (14%) | 7 (23%) | 1 (4%) | 4 (40%) | ||
| Mutational status | |||||||
| KRAS | 26 (36) | 12 (29%) | 14 (47%) | 0.292 | 10 (40%) | 3 (30%) | 0.394 |
| EGFR | 2 (3) | 1 (2%) | 1 (3%) | 1 (4%) | 1 (10%) | ||
| BRAF | 3 (4) | 1 (2%) | 2 (7%) | 1 (4%) | 2 (20%) | ||
| None or rare mutation | 41 (57) | 28 (67%) | 13 (43%) | 13 (52%) | 4 (40%) | ||
| Albumin | 0.889 | 0.104 | |||||
| < 30 g/l | 12 (17) | 7 (17) | 5 (17) | 2 (8) | 3 (30) | ||
| ≥ 30 g/l | 57 (79) | 32 (76) | 25 (83) | 22 (88) | 7 (70) | ||
| unknown | 3 (4) | 3 (7) | 0 (0) | 1 (4) | 0 (0) | ||
| Hemoglobin (median, IQR) | 11.6 (10.0–12.7) | 12.1 (11.3–13.0 | 10.5 (9.5–11.8) | 0.006 | 12.3 (11.3–13.4) | 9.9 (8.7–11.2) | 0.006 |
| Metastatic sites | |||||||
| brain | 8 (11%) | 5 (12%) | 3 (10%) | 0.800 | 6 (24%) | 0 | 0.089 |
| liver | 10 (14%) | 5 (12%) | 5 (17%) | 0.565 | 2 (8%) | 2 (20%) | 0.313 |
| ≥ 3 sites | 16 (22%) | 7 (17%) | 9 (30%) | 0.180 | 3 (12%) | 2 (20%) | 0.541 |
| Stage | |||||||
| IIIB | 10 (14) | 5 (12%) | 1 (3%) | 0.195 | 3 (12%) | 2 (20%) | 0.541 |
| IV | 62 (86) | 37 (88%) | 29 (97%) | 22 (88%) | 8 (80%) | ||
| Performance status | |||||||
| 0–1 | 45/71 (63) | 27/41 (66%) | 18 (60%) | 0.216 | 22 (88%) | 3 (30%) | 0.001 |
| 2 | 26/71 (37) | 14/41 (34%) | 12 (40%) | 3 (12%) | 7 (70%) | ||
| Number of lines before nivolumab | |||||||
| 1 | 62 (86%) | 37 (88%) | 26 (87%) | 0.587 | 22 (88%) | 9 (90%) | 0.867 |
| > 2 | 10 (14) | 5 (12%) | 4 (13%) | 3 (12%) | 1 (10%) | ||
| PD-L1 IHC | |||||||
| < 1% | 8 (11) | 6 (14) | 2 (7) | 0.072 | 6 (24) | 2 (20) | 0.900 |
| ≥ 1% | 15 (21) | 5 (12) | 10 (33) | 11 (44) | 4 (40) | ||
| unknown | 49 (68) | 31 (74) | 18 (60) | 8 (32) | 4 (40) | ||
EUA early use of antibiotics. Variables expressed as n (%) unless otherwise specified. High citrulline: ≥20 μM; low citrulline: < 20 μM. P-values calculated by Mann-Whitney test or Chi2 test