Table 1.
Summary of all patient, tumor, and treatment characteristics of the entire study population stratified by treatment received.
| Covariate | Statistics | Level | No Treatment (N=407) | Surgery Alone (N=807) | Short Course RT Then Surgery (N=137) | CRT Then Surgery (N=1233) | Surgery Then CRT (N=139) | P-Value |
|---|---|---|---|---|---|---|---|---|
| Patient Characteristics | ||||||||
| Age at Diagnosis | Median (Range) | 86 (80–90) | 84.9 (80–90) | 83.0 (80–90) | 82.8 (81–91) | 83.0 (80–91) | <0.01 | |
| Sex | N (Col %) | Male | 178 (43.7) | 349 (43.2) | 70 (51.1) | 655 (53.1) | 66 (47.5) | <0.01 |
| N (Col %) | Female | 229 (56.3) | 458 (56.8) | 67 (48.9) | 578 (46.9) | 73 (52.5) | ||
| Race | N (Col %) | White | 351 (87.5) | 732 (91.7) | 125 (92.6) | 1109 (90.8) | 126 (91.3) | 0.11 |
| N (Col %) | Black | 36 (9.0) | 40 (5.0) | 3 (2.2) | 67 (5.5) | 8 (5.8) | ||
| N (Col %) | Other | 14 (3.5) | 26 (3.3) | 7 (5.2) | 46 (3.8) | 4 (2.9) | ||
| Missing | 6 | 9 | 2 | 11 | 1 | |||
| Insurance Type | N (Col %) | Private Insurance + Medicare | 35 (8.7) | 77 (9.8) | 14 (10.3) | 126 (10.7) | 10 (7.4) | 0.79 |
| N (Col %) | Medicare | 366 (91.3) | 716 (90.2) | 122 (89.0) | 1093 (89.3) | 126 (92.6) | ||
| Missing | 6 | 14 | 1 | 14 | 3 | |||
| Distance from ZIP Code of Residence to Treatment Facility | N (Col %) | <10 miles | 253 (64.2) | 476 (59.9) | 82 (60.3) | 714 (58.5) | 79 (56.8) | 0.08 |
| N (Col %) | 10–50 miles | 116 (29.4) | 245 (30.8) | 35 (25.7) | 388 (31.8) | 52 (37.4) | ||
| N (Col %) | >50 miles | 25 (6.3) | 74 (9.3) | 19 (14.0) | 118 (9.7) | 8 (5.8) | ||
| Missing | 13 | 12 | 1 | 13 | 0 | |||
| Median Income of Census Tract of Residence | N (Col %) | < $30,000 | 56 (14.4) | 85 (10.8) | 10 (7.5) | 137 (11.4) | 15 (10.9) | 0.49 |
| N (Col %) | $30,000 – $35,999 | 76 (19.6) | 159 (20.3) | 32 (24.1) | 214 (17.9) | 24 (17.5) | ||
| N (Col %) | $36,000 – $45,999 | 116 (29.9) | 226 (28.8) | 43 (32.3) | 364 (30.4) | 41 (29.9) | ||
| N (Col %) | $46,000 + | 140 (36.1) | 314 (40.1) | 48 (36.1) | 483 (40.3) | 57 (41.6) | ||
| Missing | 19 | 23 | 4 | 35 | 2 | |||
| Percent of Census Tract of Residence without a High School Degree | N (Col %) | >=29% | 68 (17.5) | 116 (14.8) | 15 (11.3) | 165 (13.8) | 22 (16.1) | 0.19 |
| N (Col %) | 20–28.9% | 102 (26.3) | 171 (21.8) | 31 (23.3) | 263 (22.0) | 24 (17.5) | ||
| N (Col %) | 14–19.9% | 91 (23.5) | 199 (25.4) | 33 (24.8) | 319 (26.6) | 48 (35.0) | ||
| N (Col %) | < 14% | 127 (32.7) | 298 (38.0) | 54 (40.6) | 450 (37.6) | 43 (31.4) | ||
| Missing | 19 | 23 | 4 | 36 | 2 | |||
| County Type | N (Col %) | Metro | 308 (79.6) | 665 (85.3) | 101 (74.8) | 964 (80.3) | 104 (76.5) | 0.02 |
| N (Col %) | Urban | 74 (19.1) | 103 (13.2) | 30 (22.2) | 215 (17.9) | 28 (20.6) | ||
| N (Col %) | Rural | 10 (2.6) | 12 (1.5) | 4 (3.0) | 22 (1.8) | 4 (2.9) | ||
| Missing | 20 | 27 | 2 | 32 | 3 | |||
| Charlson-Deyo Score | N (Col %) | 0 | 282 (69.3) | 515 (63.8) | 97 (70.8) | 920 (74.6) | 98 (70.5) | <0.01 |
| N (Col %) | 1+ | 125 (30.7) | 292 (36.2) | 40 (29.2) | 313 (25.4) | 41 (29.5) | ||
| Year of Diagnosis | N (Col %) | 2004 – 2007 | 151 (37.1) | 268 (33.2) | 45 (32.8) | 248 (20.1) | 36 (25.9) | <0.01 |
| N (Col %) | 2008 – 2010 | 111 (27.3) | 286 (35.4) | 45 (32.8) | 468 (38.0) | 56 (40.3) | ||
| N (Col %) | 2011 – 2013 | 145 (35/6) | 253 (31.4) | 47 (34.3) | 517 (41.9) | 47 (33.8) | ||
| Tumor Characteristics | ||||||||
| Stage | N (Col %) | Stage II | 256 (62.9) | 541 (67.0) | 80 (58.4) | 675 (54.7) | 71 (51.1) | <0.01 |
| N (Col %) | Stage III | 151 (37.1) | 266 (33.0) | 57 (41.6) | 558 (42.3) | 68 (48.9) | ||
| Size of Tumor (cm) | Median (Range) | 5.0 (0.5–15.0) | 4.5 (3.0–14.0) | 4.6 (0.8–9.0) | 4.3 (0.9–9.1) | 5.3 (1.1–9.5) | <0.01 | |
| Tumor Grade | N (Col %) | Well Differentiated | 20 (7.1) | 58 (7.3) | 12 (10.0) | 92 (8.8) | 9 (7.0) | 0.32 |
| N (Col %) | Moderately Differentiated | 217 (76.7) | 601 (75.8) | 82 (68.3) | 811 (77.4) | 97 (75.2) | ||
| N (Col %) | Poorly Differentiated | 46 (16.3) | 134 (16.9) | 26 (21.7) | 145 (13.8) | 23 (17.8) | ||
| Missing | 124 | 14 | 17 | 185 | 10 | |||
| Lymphovascular Invasion | N (Col %) | Not present | 22 (91.7) | 242 (73.3) | 39 (72.2) | 463 (86.9) | 32 (68.1) | <0.01 |
| N (Col %) | Present | 2 (8.3) | 88 (26.7) | 15 (27.8) | 70 (13.1) | 15 (31.9) | ||
| Missing | 383 | 477 | 83 | 700 | 92 | |||
| Carcinoembryonic Antigen (CEA) | N (Col %) | Elevated | 125 (57.1) | 212 (47.0) | 43 (53.1) | 357 (45.6) | 44 (48.4) | 0.10 |
| N (Col %) | Undetermined | 3 (1.4) | 3 (0.7) | 0 (0.0) | 5 (0.6) | 0 (0) | ||
| N (Col %) | Normal | 91 (41.6) | 236 (52.3) | 38 (46.9) | 421 (53.8) | 47 (51.6) | ||
| Missing | 188 | 356 | 56 | 450 | 48 | |||
| Treatment Characteristics | ||||||||
| Extent of Resection | N (Col %) | R0 | N/A | 701 (89.0) | 119 (90.2) | 1141 (94.8) | 109 (85.8) | <0.01 |
| N (Col %) | R1 | 87 (11.0) | 13 (9.8) | 63 (5.2) | 18 (14.2) | |||
| N (Col %) | No surgery | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |||
| Missing | 19 | 5 | 29 | 12 | ||||
| Regional Lymph Nodes Examined | N (Col %) | 0 | 388 (98.5) | 66 (8.2) | 16 (11.7) | 162 (13.3) | 28 (20.3) | <0.01 |
| N (Col %) | <10 | 3 (0.8) | 137 (17.0) | 29 (21.2) | 339 (27.9) | 15 (10.9) | ||
| N (Col %) | 10 – 14 | 0 (0) | 177 (22.0) | 37 (27.0) | 322 (26.5) | 24 (17.4) | ||
| N (Col %) | >14 | 0 (0) | 424 (52.7) | 55 (40.1) | 393 (32.3) | 71 (51.4) | ||
| Missing | 16 | 3 | 0 | 17 | 1 | |||
| Regional Lymph Nodes Positive at Surgery | N (Col %) | pN0 | N/A | 426 (57.6) | 77 (63.6) | 787 (74.7) | 36 (32.7) | <0.01 |
| N (Col %) | pN+ | 313 (42.4) | 44 (36.4) | 266 (25.3) | 74 (67.3) | |||
| Missing | 68 | 16 | 180 | 27 | ||||
| Reason for No Radiation (RT) | N (Col %) | RT Given | 0 (0) | 0 (0) | 137 (100.0) | 1233 (100.0) | 139 (100.0) | N/A |
| N (Col %) | RT Not Part of Planned First Course Treatment | 232 (57.0) | 603 (74.7) | 0 (0) | 0 (0) | 0 (0) | ||
| N (Col %) | RT Contraindicated Due to Patient Risk Factors | 51 (12.5) | 79 (9.8) | 0 (0) | 0 (0) | 0 (0) | ||
| N (Col %) | RT Recommended but Refused | 124 (30.5) | 125 (15.5) | 0 (0) | 0 (0) | 0 (0) | ||
| Time from Diagnosis to Treatment Start | N (Col %) | 0–30 days | N/A | 499 (63.8) | 66 (48.5) | 523 (44.9) | 95 (69.9) | <0.01 |
| N (Col %) | 31–90 days | 245 (31.3) | 66 (48.5) | 609 (52.3) | 39 (28.7) | |||
| N (Col %) | >90 days | 38 (4.9) | 4 (2.9) | 33 (2.8) | 2 (1.5) | |||
| Missing | 25 | 1 | 68 | 3 | ||||
| Facility Type | N (Col %) | Community Cancer Center | 89 (21.9) | 159 (19.7) | 24 (17.5) | 226 (18.3) | 22 (15.8) | 0.62 |
| N (Col %) | Comprehensive Community Cancer Program | 212 (52.1) | 423 (52.4) | 73 (53.3) | 637 (51.7) | 82 (59.0) | ||
| N (Col %) | Academic Center | 106 (26.0) | 225 (27.9) | 40 (29.2) | 370 (30.0) | 35 (25.2) | ||
| Facility Location | N (Col %) | Northeast | 96 (23.6) | 199 (24.7) | 32 (23.4) | 289 (23.4) | 29 (20.9) | <0.01 |
| N (Col %) | South | 112 (27.5) | 246 (30.5) | 26 (19.0) | 325 (26.4) | 41 (29.5) | ||
| N (Col %) | Midwest | 125 (30.7) | 201 (24.9) | 51 (37.2) | 421 (34.1) | 43 (30.9) | ||
| N (Col %) | West | 74 (18.2) | 161 (20.0) | 28 (20.4) | 198 (16.1) | 26 (18.7) | ||
The parametric p-value is calculated by ANOVA for numerical covariates and chi-square test for categorical variates.
RT = Radiation Therapy
CRT = Concurrent chemotherapy and radiation
N/A = Not applicable
For variables comparing treatment results, the reported p-value is a log-rank comparison of the four groups that received therapy (the no treatment group was not included).
Bold indicates statistical significance.