Table. Baseline Characteristics of Patients Receiving Adjuvant Chemotherapy vs Observation for Node-Negative Tumors of 7 cm or Smaller.
| Characteristic | Patients, No. (%)a | P value | |
|---|---|---|---|
| Observation (n = 46 594) | Adjuvant chemotherapy (n = 4220) | ||
| Age, median (IQR), y | 68 (62-75) | 64 (57-70) | <.001 |
| Age category, y | |||
| <65 | 15 789 (33.9) | 2145 (50.8) | <.001 |
| 65-74 | 19 014 (40.1) | 1681 (39.8) | |
| ≥75 | 11 791 (25.1) | 394 (9.3) | |
| Male | 21 357 (45.4) | 2092 (49.6) | <.001 |
| White race | 40 753 (87.5) | 3675 (87.1) | .48 |
| Ethnicity | |||
| Non-Hispanic | 43 804 (94.0) | 3984 (94.4) | .53 |
| Hispanic | 1221 (2.6) | 107 (2.5) | |
| Unknown | 1569 (3.4) | 129 (3.1) | |
| Insurance | |||
| Not insured | 867 (1.9) | 110 (2.6) | <.001 |
| Private insurance | 13 020 (27.9) | 1675 (39.7) | |
| Medicaid | 2370 (5.1) | 294 (7.0) | |
| Medicare | 29 313 (62.9) | 2035 (48.2) | |
| Other government insurance | 498 (1.1) | 54 (1.3) | |
| Unknown | 526 (1.1) | 52 (1.2) | |
| Facility type | |||
| Nonacademicb | 30 608 (65.7) | 2848 (67.5) | .02 |
| Academic | 15 986 (34.3) | 1372 (32.5) | |
| Facility location | |||
| Northeast | 9332 (20.0) | 868 (20.6) | .001 |
| Midwest | 12 252 (26.3) | 1131 (26.8) | |
| South | 19 262 (41.3) | 1794 (42.5) | |
| West | 5748 (12.3) | 427 (10.1) | |
| Area of residencec | |||
| Rural | 982 (2.1) | 109 (2.6) | .01 |
| Urban | 7238 (15.5) | 692 (16.4) | |
| Metropolitan | 37 246 (79.9) | 3339 (79.1) | |
| Unknown | 1128 (2.4) | 80 (1.9) | |
| Distance from facility, km | |||
| ≤16.1 | 21 556 (46.3) | 1974 (46.8) | <.001 |
| 16.2-32.2 | 9733 (20.9) | 889 (21.1) | |
| 32.3-80.5 | 9704 (20.8) | 934 (22.1) | |
| 80.6-161.0 | 3731 (8.0) | 316 (7.5) | |
| >162.0 | 1870 (4.0) | 107 (2.5) | |
| Median annual income, $ | |||
| <38 000 | 8583 (18.4) | 810 (19.2) | .06 |
| 38 000-47 999 | 11 506 (24.7) | 1083 (25.7) | |
| 48 000-62 999 | 12 497 (26.8) | 1143 (27.1) | |
| >63 000 | 13 910 (29.9) | 1179 (27.9) | |
| Unknown | 98 (0.2) | NRd | |
| Educational level, %e | |||
| ≥21 | 7907 (17.0) | 731 (17.3) | .06 |
| 13-20.9 | 12 989 (27.9) | 1229 (29.1) | |
| 7-12.9 | 15 641 (33.6) | 1418 (33.6) | |
| <7 | 9977 (21.4) | 839 (19.9) | |
| Unknown | 80 (0.2) | NRd | |
| Year of diagnosis | |||
| 2010 | 6901 (14.8) | 646 (15.3) | .07 |
| 2011 | 7344 (15.8) | 605 (14.3) | |
| 2012 | 7370 (15.8) | 705 (16.7) | |
| 2013 | 7925 (17.0) | 688 (16.3) | |
| 2014 | 8288 (17.8) | 746 (17.7) | |
| 2015 | 8766 (18.8) | 830 (19.7) | |
| Histologic type | |||
| Adenocarcinoma | 29 653 (63.6) | 2332 (55.3) | <.001 |
| Squamous cell carcinoma | 14 963 (32.1) | 1502 (35.6) | |
| Large cell | 923 (2.0) | 247 (5.9) | |
| Otherf | 1055 (2.3) | 139 (3.3) | |
| Laterality | |||
| Unknown | 124 (0.3) | 28 (0.7) | <.001 |
| Right | 27 795 (59.7) | 2529 (59.9) | |
| Left | 18 675 (40.1) | 1663 (39.4) | |
| Primary site | |||
| Main bronchus | 102 (0.2) | 23 (0.6) | <.001 |
| Lobe | |||
| Upper | 28 259 (60.7) | 2516 (59.6) | |
| Middle | 2320 (5.0) | 200 (4.7) | |
| Lower | 15 000 (32.2) | 1343 (31.8) | |
| Overlapping lesion | 340 (0.7) | 79 (1.9) | |
| Lung, NOS | 573 (1.2) | 59 (1.4) | |
| VPI | |||
| Absent | 33 737 (72.4) | 3159 (74.9) | <.001 |
| Present | 4578 (9.8) | 794 (18.8) | |
| Unknown | 9143 (19.6) | 267 (6.3) | |
| LVI | |||
| Absent | 37 660 (80.8) | 3075 (72.9) | <.001 |
| Present | 5715 (12.3) | 858 (20.3) | |
| Unknown | 3219 (6.9) | 287 (6.8) | |
| Grade | |||
| Well differentiated | 7798 (16.7) | 262 (6.2) | <.001 |
| Moderately differentiated | 19 433 (41.7) | 1278 (30.3) | |
| Poorly differentiated or undifferentiated | 17 253 (37.0) | 2447 (58.0) | |
| Unknown | 2110 (4.5) | 233 (5.5) | |
| Surgical resection | |||
| Sublobar resection | 7921 (17.0) | 299 (7.1) | <.001 |
| Lobectomy | 38 123 (81.8) | 3735 (88.5) | |
| Pneumonectomy | 550 (1.2) | 186 (4.4) | |
| Charlson-Deyo Comorbidity Index score | |||
| 0 | 21 981 (47.2) | 2214 (52.5) | <.001 |
| 1 | 16 475 (35.4) | 1412 (33.5) | |
| ≥2 | 8138 (17.5) | 594 (14.1) | |
| Length of stay after surgery, wk | |||
| ≤2 | 41 477 (89.0) | 3713 (88.0) | <.001 |
| >2 | 2609 (5.6) | 158 (3.7) | |
| Unknown | 2508 (5.4) | 349 (8.3) | |
| Readmission within 30 d after discharge | |||
| No | 42 927 (92.1) | 3552 (84.2) | <.001 |
| Yes | 1919 (4.1) | 136 (3.2) | |
| Unknown | 1748 (3.8) | 532 (12.6) | |
| Died within 90 d after surgery | |||
| No | 45 417 (97.5) | 4145 (98.2) | .007 |
| Yes | 502 (1.1) | 27 (0.6) | |
| Unknown | 675 (1.5) | 48 (1.1) | |
Abbreviations: IQR, interquartile range; LVI, lymphovascular invasion; NOS, not otherwise specified; NR, not reported; SCC, squamous cell carcinoma; VPI, visceral pleural invasion.
a
Data are presented as number (percentage) of patients unless otherwise indicated. Percentages might not total 100% owing to approximation.
b
Includes community cancer program, comprehensive community cancer program, integrated network cancer program, and other specified types of cancer programs.
c
Based on patient’s zip code area.
d
Frequencies less than 10 not reported per National Cancer Database guidelines.
e
Percent of people in the patient’s zip code area with no high-school diploma.
f
Non–small cell cancer not further defined.