Table 2.
Surgical and Pathological Secondary and Exploratory End Points in Patients in the Per-Protocol Population Who Underwent Surgery.
| End Point | FOLFOX Group (N = 535) | Chemoradiotherapy Group (N = 510) |
|---|---|---|
| Secondary end points | ||
| Completeness of rectal resection — no. (%)* | ||
| R0 | 529 (98.9) | 495 (97.1) |
| R1 | 6 (1.1) | 14 (2.7) |
| R2 | 0 | 1 (02) |
| Pathological complete response — no. (%)† | ||
| Yes | 117 (21.9) | 124 (24.3) |
| No | 418 (78.1) | 386 (75.7) |
| Other surgical and pathological end points | ||
| Median time from randomization to surgery (interquartile range) — wk | 19.0 (17.1–21.1) | 15.6 (14.6–17.0) |
| Median time from end of preoperative therapy to surgery (interquartile range) — wk‡ | 4.6 (3.1–6.3) | 7.7 (6.9–9.0) |
| Type of surgery — no. (%) | ||
| Abdominal perineal resection | 13 (2.4) | 10 (2.0) |
| Low anterior resection | 522 (97.6) | 500 (98.0) |
| Histologic grade — no./total no. (%)§ | ||
| G1 or G2 | 396/535 (74.0) | 344/504 (68.3) |
| G3 or G4 | 22/535 (4.1) | 27/504 (5.4) |
| GX | 117/535 (21.9) | 133/504 (26.4) |
| Radial margin category — no./total no. (%)¶ | ||
| ≤1 mm | 6/509 (1.2) | 7/469 (1.5) |
| >1 mm but ≤3 mm | 26/509 (5.1) | 31/469 (6.6) |
| >3 mm | 477/509 (93.7) | 431/469 (91.9) |
| Pathological tumor stage after neoadjuvant therapy — no./total no. (%) | ||
| ypT0 | 121/534 (22.7) | 125/506 (24.7) |
| ypT1 | 56/534 (10.5) | 50/506 (9.9) |
| ypT2 | 183/534 (34.3) | 156/506 (30.8) |
| ypT3 | 169/534 (31.6) | 173/506 (34.2) |
| ypT4 | 5/534 (0.9) | 2/506 (0.4) |
| Pathological node status after neoadjuvant therapy — no. (%) | ||
| ypN0 | 400 (74.8) | 390 (76.5) |
| ypN1 | 108 (20.2) | 104 (20.4) |
| ypN2 | 27 (5.0) | 16 (3.1) |
| Pathological metastatic status — no./total no. (%) | ||
| M0 | 520/521 (99.8) | 494/499 (99.0) |
| M1a | 1/521 (0.2) | 5/499 (1.0) |
| Tumor regression grade — no./total no. (%)‖ | ||
| Pathological complete response or grade 0 | 123/533 (23.1) | 127/510 (24.9) |
| Grade 1 | 161/533 (30.2) | 200/510 (39.2) |
| Grade 2 | 146/533 (27.4) | 151/510 (29.6) |
| Grade 3 | 103/533 (19.3) | 32/510 (6.3) |
An R0 (complete) resection was defined as a surgical specimen with no tumor identified within 1 mm of any surgical margin and no macroscopic evidence of residual tumor.
Pathological complete response was confirmed if the surgical pathology report showed no evidence of tumor.
The end of neoadjuvant therapy was defined as the start date of the last cycle of FOLFOX plus 2 weeks for patients who received neoadjuvant FOLFOX only and as the end date of preoperative radiation treatment for patients in either group who received neoadjuvant chemoradiotherapy.
A histologic grade of G1 indicates well differentiated, G2 moderately differentiated, G3 poorly differentiated, G4 undifferentiated or anaplastic, and GX not assessable.
A margin of 1 mm or less was considered positive in accordance with the Cancer Staging Manual of the American Joint Committee on Cancer, 7th edition; greater than 1 mm but no greater than 3 mm is considered negative (but close to positive), and greater than 3 mm is considered negative.
Tumor regression grades range from 0 to 3, with higher grades indicating greater degrees of pathological response.