Background
Methods
Study design and participants
Variables
The outcomes of interest are: 1) disseminated or stage IV disease, assessed according to the Pathologic staging of the 7th Edition of the American Joint Committee on Cancer (AJCC) TNM Cancer Staging Manual, considering data on loco-regional staging obtained from histopathological reports, and the diagnosis of distant metastasis based on chest radiography and liver ultrasonography or tomography; and 2) use of preoperative radiotherapy (yes vs no), reflecting whether or not the patient received radiotherapy before surgery.Data were obtained from medical records at cohort inception [22].
Statistical analysis
Results
Men N = 522 | Women N = 248 | p-value1 | |
---|---|---|---|
Pathological stage | |||
0, I | 192 (36.8) | 100 (40.3) | 0.09 |
II | 144 (27.6) | 53 (21.4) | |
III | 152 (29.1) | 69 (27.8) | |
IV | 34 (6.5) | 26 (10.5) | |
Preoperative radiotherapy | |||
No | 233 (44.6) | 124 (50.0) | 0.16 |
Yes | 289 (55.4) | 124 (50.0) | |
Unknown | 25 (4.8) | 17 (6.9) | |
Age | |||
65 years | 221 (42.3) | 108 (43.5) | 0.682 |
65–80 years | 245 (46.9) | 105 (42.3) | |
> 80 years | 56 (10.7) | 35 (14.1) | |
Charlson index | |||
0 | 258 (49.4) | 165 (66.5) | < 0.0005 |
≥ 1 | 264 (50.6) | 83 (33.5) | |
Screening | |||
No | 429 (82.2) | 201 (81.0) | 0.48 |
Yes | 68 (13.0) | 30 (12.1) | |
Unknown | 25 (4.8) | 17 (6.9) | |
Diagnostic delay | |||
≤ 3 months | 374 (71.6) | 155 (62.5) | 0.02 |
> 3 months | 83 (15.9) | 59 (23.8) | |
Unknown | 65 (12.5) | 34 (13.7) | |
Distance from anal verge | |||
< 5 cm | 100 (19.2) | 57 (23.0) | 0.16 |
5–10 cm | 218 (41.8) | 83 (33.5) | |
> 10 cm | 167 (32.0) | 90 (36.3) | |
Unknown | 37 (7.1) | 18 (7.3) | |
Histological classification | |||
Adenocarcinoma | 474 (90.8) | 208 (83.9) | 0.04 |
Mucinous adenocarcinoma | 18 (3.4) | 14 (5.6) | |
Undifferentiated carcinomas | 6 (1.1) | 4 (1.6) | |
Unknown | 24 (4.6) | 22 (8.9) | |
Tumor depth (cT) | |||
cT1 - cT2 | 91 (17.4) | 55 (22.2) | < 0.0005 |
cT3 | 273 (52.3) | 120 (48.4) | |
cT4 | 28 (5.4) | 34 (13.7) | |
Unknown | 130 (24.9) | 39 (15.7) |
Differences in disseminated disease
Stage IV | |||||||
---|---|---|---|---|---|---|---|
Men | Women | p-value for gender interaction3 | |||||
N | n (%) | P1 | N | n (%) | P1 | ||
Age | 0.382 | 0.202 | 0.80 | ||||
< 65 years | 221 | 17 (7.7) | 108 | 14 (13.0) | |||
65–80 years | 245 | 14 (5.7) | 105 | 10 (9.5) | |||
> 80 years | 56 | 3 (5.4) | 35 | 2 (5.7) | |||
Charlson index | 0.44 | 0.10 | 0.33 | ||||
0 | 258 | 19 (7.4) | 165 | 21 (12.7) | |||
≥ 1 | 264 | 15 (5.7) | 83 | 5 (6.0) | |||
Screening | 0.43 | 0.07 | 0.002 | ||||
No | 429 | 30 (7.0) | 201 | 17 (8.5) | |||
Yes | 68 | 2 (2.9) | 30 | 5 (16.7) | |||
Unknown | 25 | 2 (8.0) | 17 | 4 (23.5) | |||
Diagnostic delay | 0.16 | 0.37 | 0.004 | ||||
≤ 3 months | 374 | 29 (7.8) | 155 | 13 (8.4) | |||
> 3 months | 83 | 2 (2.4) | 59 | 8 (13.6) | |||
Unknown | 65 | 3 (4.6) | 34 | 5 (14.7) | |||
Distance from anal verge | 0.34 | 0.83 | 0.67 | ||||
< 5 cm | 100 | 3 (3.0) | 57 | 5 (8.8) | |||
5–10 cm | 218 | 15 (6.9) | 83 | 10 (12.0) | |||
> 10 cm | 167 | 12 (7.2) | 90 | 10 (11.1) | |||
Unknown | 37 | 4 (10.8) | 18 | 1 (3.8) | |||
Histological classification | 0.49 | 0.04 | 0.25 | ||||
Adenocarcinoma | 474 | 31 (6.5) | 208 | 18 (8.7) | |||
Mucinous adenocarcinoma | 18 | 0 (0) | 14 | 1 (7.1) | |||
Undifferentiated carcinomas | 6 | 1 (16.7) | 4 | 1 (25.0) | |||
Unknown | 24 | 2 (8.3) | 22 | 6 (27.3) | |||
Preoperative radiotherapy | 0.52 | 0.10 | 0.21 | ||||
No | 233 | 17 (7.3) | 124 | 17 (13.7) | |||
Yes | 289 | 17 (5.9) | 124 | 9 (7.3) |
Stage IV | ||||
---|---|---|---|---|
Unadjusteda | Adjusteda,b | |||
OR (95% CI) | p-value | OR (95%) | p-value | |
Screening | ||||
No | 1.23 (0.67–2.16) | 0.48 | 1.04 (0.61–1.77) | 0.89 |
Yes | 6.9 (0.88–53.96) | 0.06 | 7.20 (0.93–55.79) | 0.05 |
Unknown | 3.05 (2.27–4.11) | < 0.0005 | 4.26 (3.18–5.72) | < 0.0005 |
Diagnostic delay | ||||
≤ 3 months | 1.07 (0.56–2.08) | 0.83 | 0.95 (0.49–1.85) | 0.99 |
> 3 months | 6.25 (1.57–24.89) | 0.009 | 5.05 (1.18–21.58) | 0.03 |
Unknown | 3.61 (1.19–10.96) | 0.02 | 3.91 (1.13–13.53) | 0.03 |
Differences in the use of preoperative radiotherapy
Preoperative radiotherapy | p-value for gender interaction3 | ||||||
---|---|---|---|---|---|---|---|
Men | Women | ||||||
N | n (%) | P1 | N | n (%) | P1 | ||
Age | < 0.00052 | 0.322 | 0.015 | ||||
< 65 years | 221 | 140 (63.3) | 108 | 55 (50.9) | |||
65–80 years | 245 | 132 (53.9) | 105 | 56 (53.3) | |||
> 80 years | 56 | 17 (30.4) | 35 | 13 (37.1) | |||
Charlson index | 0.05 | 0.02 | 0.73 | ||||
0 | 258 | 154 (59.7) | 165 | 91 (55.2) | |||
≥ 1 | 264 | 135 (51.1) | 83 | 33 (39.8) | |||
Tumor depth | < 0.0005 | < 0.0005 | 0.20 | ||||
cT1 - cT2 | 91 | 18 (19.8) | 55 | 10 (18.2) | |||
cT3 | 273 | 211 (77.3) | 120 | 81 (67.5) | |||
cT4 | 28 | 24 (85.7) | 34 | 23 (67.6) | |||
Unknown | 130 | 36 (27.7) | 39 | 10 (25.6) | |||
Distance from anal verge | < 0.0005 | 0.01 | 0.95 | ||||
< 5 cm | 100 | 69 (69.0) | 57 | 34 (59.6) | |||
5–10 cm | 218 | 141 (64.7) | 83 | 48 (57.8) | |||
> 10 cm | 167 | 67 (40.1) | 90 | 37 (41.1) | |||
Unknown | 37 | 12 (32.4) | 18 | 5 (27.8) | |||
Histological classification | 0.20 | 0.63 | 0.97 | ||||
Adenocarcinoma | 474 | 267 (56.3) | 208 | 103 (49.5) | |||
Mucinous adenocarcinoma | 18 | 8 (44.4) | 14 | 7 (50.0) | |||
Undifferentiated carcinomas | 6 | 1 (16.7) | 4 | 1 (25.0) | |||
Unknown | 24 | 13 (54.2) | 22 | 13 (59.1) |
Preoperative radiotherapy | ||||
---|---|---|---|---|
Unadjusteda | Adjusteda,b | |||
OR (95%CI) | p- value | OR (95%CI) | p-value | |
Agec | ||||
< 65 years | 0.60 (0.37–0.97) | 0.04 | 0.58 (0.34–0.99) | 0.04 |
≥ 65 years | 0.96 (0.69–1.31) | 0.78 | 0.90 (0.64–1.25) | 0.52 |
Tumor depthc | ||||
cT1-cT2 | 1.03 (0.47–2.27) | 0.72 | 1.16 (0.52–2.60) | 0.72 |
cT3-cT4 | 0.58 (0.41–0.84) | 0.003 | 0.51 (0.36–0.74) | < 0.0005 |
Unknown | 0.86 (0.51–1.44) | 0.56 | 0.83 (0.50–1.37) | 0.47 |