Table 1.
Distributions of study predictors with outcome categories: Screen-Detected; True Interval (defined as a cancer not present on previous screening x-ray and clinically detected prior to subsequent screen); Probably Present (defined as an interval cancer detected but present on review of preceding screening image); and Not Reviewed Interval (defined as an interval lung cancer whose x-rays were not available for review); N=450.
| Screen-Detected N = 299 | True Interval N=82 | Probably Present N=45 | Not Reviewed Interval N=24 | |
|---|---|---|---|---|
|
Sociodemographic & Exposure Predictors
|
||||
| Sex | ||||
| Female | 120 (40.1%) | 24 (29.3%) | 15 (33.3%) | 13 (54.2%) |
| Male | 179 (59.9%) | 58 (70.7%) | 30 (66.7%) | 11 (45.8%) |
| P-value | 0.09† | 0.42* | 0.20‡ | |
| Race/Ethnicity | ||||
| White | 252 (84.3%) | 70 (85.4%) | 39 (86.7%) | 23 (95.8%) |
| Black | 32 (10.7%) | 7 (8.5%) | 3 (6.7%) | 1 (4.2%) |
| Other (non-white & non-black) | 15 (5.0%) | 5 (6.1%) | 3 (6.7%) | 0 (0.0%) |
| P-value | 1.00† | 1.00* | 1.00‡ | |
| Education | ||||
| Less than high school complete | 39 (13.0%) | 18 (21.9%) | 7 (15.6%) | 4 (16.7%) |
| High school graduate | 88 (29.4%) | 24 (29.3%) | 12 (26.7%) | 6 (25.0%) |
| Some post-high school | 100 (33.4%) | 20 (24.4%) | 14 (31.1%) | 6 (25.0%) |
| College or professional school complete | 70 (23.4%) | 20 (24.4%) | 11 (24.4%) | 8 (33.3%) |
| Missing | 2 (0.66) | 0 (0.0%) | 1 (2.2%) | 0 (0.0%) |
| P-value | 0.34† | 1.00* | 1.00‡ | |
| Smoking status | ||||
| Never-smoker | 23 (7.7%) | 2 (2.4%) | 4 (8.9%) | 2 (8.3%) |
| Former-smoker | 164 (54.9%) | 45 (54.9%) | 22 (48.9%) | 13 (54.2%) |
| Current smoker | 111 (37.1%) | 35 (42.7%) | 18 (40.0%) | 9 (37.5%) |
| Missing | 1 (0.3%) | 0 (0.0%) | 1 (2.2%) | 0 (0.0%) |
| P-value | 0.42† | 1.00* | 1.00‡ | |
|
Tumor-Related Predictors
|
||||
| Histology | ||||
| Adenocarcinoma | 168 (56.2%) | 21 (25.6%) | 24 (53.3%) | 13 (54.2%) |
| Squamous cell | 59 (19.7%) | 15 (18.3%) | 8 (17.8%) | 4 (16.7%) |
| Large cell | 21 (7.0%) | 6 (7.3%) | 2 (4.4%) | 1 (4.2%) |
| Other NSCLC | 29 (9.7%) | 17 (20.7%) | 6 (13.3%) | 3 (12.5%) |
| Small cell | 22 (7.4%) | 23 (28.1%) | 5 (11.1%) | 3 (12.5%) |
| P-value | 0.001† | 1.00* | 1.00‡ | |
| Tumor grade in NSCLC§ | ||||
| Well differentiated | 32 (11.6%) | 2 (3.4%) | 5 (12.5%) | 2 (9.5%) |
| Moderately differentiated | 81 (29.2%) | 12 (20.3%) | 6 (15.0%) | 1 (4.8%) |
| Poorly differentiated | 105 (37.9%) | 16 (27.1%) | 16 (40.0%) | 10 (47.6%) |
| Undifferentiated | 21 (7.6%) | 3 (5.1%) | 0 (0.0%) | 0 (0.0%) |
| Missing | 38 (13.7%) | 26 (44.1%) | 13 (32,5%) | 8 (38.1%) |
| P-value | 0.74† | 0.16* | 0.08‡ | |
| Stage in NSCLC§ | ||||
| I | 139 (50.2%) | 16 (27.1%) | 12 (30.0%) | 3 (14.3%) |
| II | 26 (9.4%) | 6 (10.2%) | 1 (2.5%) | 2 (9.5%) |
| III | 65 (23.5%) | 17 (28.8%) | 7 (17.5%) | 11 (52.4%) |
| IV | 46 (16.6%) | 18 (30.5%) | 20 (50.0%) | 5 (23.8%) |
| Missing | 1 (0.4%) | 2 (3.4%) | 0 (0.0%) | 0 (0.0%) |
| P-value | 0.02† | 0.001* | 0.006‡ | |
| Tumor Lung Location | ||||
| Main stem bronchus | 5 (1.7%) | 4 (4.9%) | 2 (4.4%) | 3 (12.5%) |
| Carina | 1 (0.3%) | 1 (1.2%) | 0 (0.0%) | 0 (0.0%) |
| Left hilum | 7 (2.3%) | 5 (6.1%) | 1 (2.2%) | 0 (0.0%) |
| Lingulum | 4 (1.3%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) |
| Left lower lobe | 33 (11.0%) | 12 (14.6%) | 2 (4.4%) | 5 (20.8%) |
| Left upper lobe | 73 (24.4%) | 16 (19.5%) | 14 (31.1%) | 3 (12.5%) |
| Right hilum | 7 (2.3%) | 4 (4.9%) | 1 (2.2%) | 0 (0.0%) |
| Right lower lobe | 47 (15.7%) | 13 (15.9%) | 9 (20.0%) | 2 (8.3%) |
| Right middle lobe | 11 (3.7%) | 5 (6.1%) | 3 (6.7%) | 1 (4.2%) |
| Right upper lobe | 108 (36.1%) | 14 (17.1%) | 12 (26.7%) | 7 (29.2%) |
| Missing | 3 (1.0%) | 8 (9.8%) | 1 (2.2%) | 3 (12.5%) |
| P-value | 0.02† | 1.00* | 0.24‡ |
Abbreviations: N, number; NSCLC; non-small cell lung cancer.
This is the two-sided Fisher's exact test p-value comparing the variable in those with true interval cancers to those with screen-detected lung cancers. Missing values were excluded from the computation.
This is the two-sided Fisher's exact test p-value comparing the variable in those with interval cancers missed in screening to those with screen-detected lung cancers. Missing values were excluded from the computation.
This is the two-sided Fisher's exact test p-value comparing the variable in those with un-reviewed interval cancers to those with screen-detected lung cancers. Missing values were excluded from the computation.
Small cell lung cancers were excluded from these analyses because they were not staged or graded in the same manner as the NSCLC (n=397).