Table 1. Bivariate comparisons of demographic and clinical variables for pneumonitis.
(a) p-value: probability-value; Based on separate chi-square tests for categorical variables, Student’s t-test for age as a normally distributed continuous variable, and Mann Whitney rank-sum test for ECOG score as an ordinal variable. (b) PD-1: programmed cell death-1; (c) PD-L1: programmed death-ligand 1; (d) COPD: chronic obstructive pulmonary disease; (e) ECOG: Eastern Cooperative Oncology Group; (f) Gy: Gray, a unit of ionizing radiation dose in the International System of Units (SI)
| Pneumonitis: grade ≥3 (n = 89) | No pneumonitis: grade 0-2 (n = 257) | p-value (a) | |
| Type of Immunotherapy (n, %) | Neither (14, 8.8%) | Neither (146, 91.3%) | < 0.001 |
| Anti-PD1 (b) (53, 46.1%) | Anti-PD1 (62, 53.9%) | ||
| Anti-PDL1 (c) (22, 31.0%) | Anti-PDL1 (49, 69.0%) | ||
| Age in years (mean ± standard deviation) | (68.1 ± 10.0) | (70.0 ± 9.8) | 0.07 |
| Gender (n, %) | Female (33, 20.4%) | Female (129, 79.6%) | 0.03 |
| Male (56, 30.4%) | Male (128, 69.6%) | ||
| Race (n, %) | Caucasian (84, 26.8%) | Caucasian (230, 73.2%) | 0.17 |
| Non-Caucasian (5, 15.6%) | Non-Caucasian (27, 84.4%) | ||
| Smoking within 5 Years of Lung Cancer Diagnosis (n, %) | Yes (52, 27.1%) | Yes (140, 72.9%) | 0.52 |
| No (37, 24.0%) | No (117, 76.0%) | ||
| Smoking Pack-Years (n, %) | 0-10 pack-years (7, 16.7%) | 0-10 pack-years (35, 83.3%) | 0.24 |
| 10-40 pack-years (32, 24.4%) | 10-40 pack-years (99, 75.6%) | ||
| > 40 pack years (50, 28.9%) | > 40 pack years (123, 71.1%) | ||
| Pre-existing COPD (d) (n, %) | None, mild, or unknown (42, 26.1%) | None, mild, or unknown (119, 73.9%) | 0.89 |
| Moderate to very severe (47, 25.4%) | Moderate to very severe (138, 74.6%) | ||
| Pre-existing Emphysema (n, %) | None, mild, or unknown (65, 25.1%) | None, mild, or unknown (194, 74.9%) | 0.65 |
| Moderate to very severe (24, 27.6%) | Moderate to very severe (63, 72.4%) | ||
| ECOG (e) Score (Median, range) | 1 (0 – 3) | 1 (0 – 4) | 0.01 |
| Type of Lung Cancer (n, %) | Adenocarcinoma (39, 25.8%) | Adenocarcinoma (112, 74.2%) | 0.02 |
| Squamous cell (36, 34.0%) | Squamous cell (70, 66.0%) | ||
| Small cell (8, 23.5%) | Small cell (26, 76.5%) | ||
| Other (6, 11.1%) | Other (48, 88.9%) | ||
| Stage of Lung Cancer (n, %) | Stage I, II, or limited (22, 15.5%) | Stage I, II, or limited (120, 84.5%) | < .001 |
| Stage III, IV, or extensive (67, 32.8%) | Stage III, IV, or extensive (137, 67.2%) | ||
| Lung Radiation (Gy) (f) Within 6 Months of Pneumonitis (n, %) | None (34, 55.7%) | None (27, 44.3%) | 0.13 |
| 1-30 Gy (8, 57.1%) | 1-30 Gy (6, 42.9%) | ||
| 31-60 Gy (41, 41.8%) | 31-60 Gy (57, 58.2%) | ||
| > 60 Gy (6, 75.0%) | > 60 Gy (2, 25.0%) | ||
| Lung Radiation Fraction Within 6 Months of Pneumonitis (n, %) | None (34, 55.7%) | None (27, 44.3%) | 0.31 |
| < 15 (15, 39.5%) | < 15 (23, 60.5%) | ||
| 15-30 (33, 46.5%) | 15-30 (38, 53.5%) | ||
| > 30 (7, 63.6%) | > 30 (4, 36.4%) | ||
| Total Lifetime Lung Radiation Gy (n, %) | < 30: 25 (42.4%) | < 30: 34 (57.6%) | 0.001 |
| > 30 (64, 22.3%) | > 30 (223, 77.7%) | ||
| Total Lifetime Lung Radiation Fraction (n, %) | < 15 (41, 22.4%) | < 15 (142, 77.6%) | 0.14 |
| > 15 (48, 29.4%) | > 15 (115, 70.6%) |