Table 1.
Baseline characteristics.
| Characteristic | Total Patients (n = 242) |
Original Cohort | IPTW Cohort * | ||||
|---|---|---|---|---|---|---|---|
| Standard-Dose (n = 147) |
Low-Dose (n = 95) |
p Value | Standard-Dose (n = 263) |
Low-Dose (n = 150) |
p Value | ||
| Age, mean years (range) | 62.0 (56.0–72.0) | 63.7 (58.0–73.0) | 62.0 (54.0–72.0) | 0.09 | 63.6 (58.0–73.0) | 63.7 (58.0–73.0) | 0.92 |
| Male (%) | 63.2% | 62.6% | 64.2% | 0.79 | 61.5% | 67.5% | 0.17 |
| Body weight, mean kg (range) | 61.5 (52.8–69.4) | 60.5 (50.0–68.8) | 63.9 (55.0–73.8) | 0.03 | 60.4 (50.0–68.8) | 65.4 (59.5–73.8) | <0.01 |
| Alcohol (%) | 17.4% | 15.6% | 20.0% | 0.38 | 16.5% | 14.0% | 0.30 |
| Smoking (%) | 28.5% | 29.9% | 26.3% | 0.50 | 29.5% | 29.8% | 0.95 |
| CCI, mean (range) | 5.4 (4.0–6.0) | 5.3 (4.0–6.0) | 5.0 (4.0–6.0) | 0.37 | 5.5 (4.0–6.0) | 5.5 (5.0–6.0) | 0.94 |
| Line of pembrolizumab (%) | |||||||
| 1 | 63.6% | 64.6% | 62.1% | 0.53 | 64.2% | 58.4% | 0.20 |
| ≥2 | 36.4% | 35.4% | 37.9% | 35.8% | 41.6% | ||
| Concomitant chemotherapy (%) | 54.5% | 50.3% | 61.0% | 0.10 | 54.0% | 51.1% | 0.52 |
| ECOG (%) | |||||||
| <2 | 86.8% | 84.4% | 90.5% | 0.16 | 85.1% | 88.8% | 0.23 |
| ≥2 | 13.2% | 15.6% | 9.5% | 14.9% | 11.2% | ||
| Stage (%) | |||||||
| 3 | 13.2% | 12.2% | 14.7% | 0.57 | 13.0% | 12.5% | 0.86 |
| 4 | 86.8% | 87.8% | 85.3% | 87.0% | 87.5% | ||
| Histologic features (%) | |||||||
| Adenocarcinoma | 67.7% | 66.7% | 69.5% | 0.76 | 67.7% | 76.1% | 0.08 |
| Squamous | 24.4% | 24.5% | 24.2% | 23.7% | 18.9% | ||
| Others | 7.9% | 8.8% | 6.3% | 8.6% | 5.0% | ||
| Metastasis status (%) | |||||||
| Brain | 14.9% | 14.9% | 14.7% | 0.96 | 14.6% | 16.5% | 0.59 |
| Bone | 31.0% | 34.6% | 25.2% | 0.12 | 33.6% | 33.6% | 0.99 |
| Liver | 12.0% | 10.8% | 13.6% | 0.51 | 12.3% | 9.8% | 0.36 |
| Others | 84.7% | 85.0% | 84.2% | 0.86 | 84.9% | 87.2% | 0.46 |
| PD-L1 tumor proportion score (%) | |||||||
| <1% | 11.6% | 11.7% | 11.6% | 0.50 | 12.1% | 9.5% | 0.86 |
| 1–49% | 21.9% | 20.4% | 24.2% | 22.4% | 21.3% | ||
| ≥50% | 47.1% | 51.0% | 41.0% | 48.0% | 51.2% | ||
| Unknown | 19.4% | 16.9% | 23.2% | 17.5% | 18.0% | ||
| Comorbidity | |||||||
| Hypertension (%) | 28.5% | 30.6% | 25.3% | 0.36 | 29.0% | 35.7% | 0.12 |
| Diabetes (%) | 14.8% | 15.6% | 13.6% | 0.67 | 14.5% | 15.7% | 0.71 |
| Dyslipidemia (%) | 11.9% | 12.2% | 11.5% | 0.87 | 13.1% | 8.4% | 0.08 |
| Ischemic heart disease (%) | 5.3% | 4.1% | 7.3% | 0.26 | 4.4% | 3.2% | 0.49 |
| Heart failure (%) | 1.6% | 0.6% | 3.1% | 0.13 | 0.5% | 0.9% | 0.57 |
| Cerebrovascular disease (%) | 4.5% | 4.7% | 4.2% | 0.84 | 5.2% | 2.5% | 0.11 |
| Hypothyroidism (%) | 0.4% | 0.6% | 0.0% | 0.42 | 0.5% | 0.0% | 0.20 |
| COPD (%) | 21.4% | 26.5% | 13.6% | 0.01 | 23.4% | 22.1% | 0.75 |
| Chronic kidney disease (%) | 7.0% | 8.8% | 4.2% | 0.16 | 8.8% | 11.7% | 0.29 |
| Biochemical data | |||||||
| eGFR (mL/min/1.73 m2) | 98.7 (71.6–118.2) | 100.7 (69.8–119.1) | 95.6 (77.4–117.8) | 0.35 | 100.8 (69.8–119.1) | 90.2 (77.4–117.8) | 0.06 |
| ALT (U/L) | 29.0(14–37) | 28.6 (13.0–36.0) | 29.7 (18.0–39.0) | 0.01 | 28.5 (13.0–36.0) | 29.4 (18.0–39.0) | 0.68 |
| AST (U/L) | 31.4(19–33) | 31.6 (18.0–31.0) | 31.0 (20.0–36.0) | 0.05 | 31.6 (18.0–31.0) | 28.3 (20.0–36.0) | 0.22 |
| Total bilirubin (mg/dL) | 0.6 (0.4–0.6) | 0.7 (0.4–0.6) | 0.6 (0.4–0.7) | 0.32 | 0.7 (0.4–0.6) | 0.7 (0.4–0.7) | 0.92 |
| Fasting glucose (mg/dL) | 126.0 (97–132) | 126.3 (98–133) | 125.6 (94–131) | 0.07 | 126.1 (98–133) | 118.8 (94–131) | 0.13 |
| HbA1c (%) | 6.2 (5.6–6.5) | 6.2 (5.6–6.5) | 6.3 (5.6–6.7) | 0.29 | 6.2 (5.6–6.5) | 6.3 (5.6–6.7) | 0.44 |
| WBC (103/uL) | 8.8 (5.9–10.9) | 9.4 (6.1–11.2) | 8.0 (5.7–9.8) | 0.02 | 9.4 (6.1–11.2) | 8.6 (5.7–9.8) | 0.06 |
| Hemoglobin (g/dL) | 11.6 (10.5–13.0) | 11.5 (10.4–13.1) | 11.7 (10.6–13.0) | 0.31 | 11.5 (10.4–13.1) | 11.6 (10.6–13.0) | 0.65 |
| Platelet (103/uL) | 273.7 (187.5–328.5) | 277.8 (196–323) | 267.3 (177–344) | 0.27 | 278.7 (196–323) | 269.0 (177–344) | 0.61 |
Abbreviations—CCI: Charlson comorbidity index, ECOG: Eastern Cooperative Oncology Group, PD-L1: programmed death-ligand 1, COPD: chronic obstructive pulmonary disease, eGFR: estimated glomerular filtration rate, ALT: alanine aminotransferase, AST: aspartate aminotransferase, TSH: thyroid-stimulating hormone, WBC: white blood cell. Note: Continuous variables are expressed as mean (Q1–Q3) and dichotomous variables are expressed as percentage (%). * Since the patients were adjusted by IPTW, the total patient number was not identical to that in the original cohort.