Table 1.
Characteristics and treatments of the included studies
| Author/year | Country | Arm | No. of Pts | Treatment regimens | Type of surgery | Duration | Design | Median age (years) | Clinical T category (T2/T3/T4) | Clinical N category (N0/N1/N2/N3) | Clinical stage (I/II/III/IV) | Follow-up (months) | pCR | R0 | NOS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Matsumoto, 2015 [17] | Japan | NAC | 15 | FOLFOX: 6 cycles, IRIS: 3 cycles, FOLFIRI: 5 cycles | LAR (12), APR/ASR (2), ISR (1) | 2005–2010 | Retrospective | 64 (56–68) | 0/12/3 | NA | NA | 44.2 (30.7–59.5) | 2 | 15 | 7 |
| NACRT | 109 | NA | LAR (75), APR/ASR (22), ISR (3) | 67 (61–74) | 0/92/17 | NA | NA | 0 | 105 | ||||||
| Sakuyama, 2016 [26] | Japan | NAC | 44 | FOLFOX: 6 cycles | ISR (34), other (10) | 2001–2014 | Retrospective | 57.4 (28–76) | 0/38/6 | 5/16/7/16 | 0/5/35/4 | NA | 4 | NA | 7 |
| NACRT | 44 | 5FU+RT (45 Gy/25 F) | ISR (44) | 56 (27–77) | 9/35/0 | 27/10/6/1 | 6/19/29/0 | 9 | NA | ||||||
| Okuyama, 2018 [18] | Japan | NAC | 27 | SOX+cetuximab, SOX+mFOLFOX6 | LAR (19), APR (8) | 2010–2016 | Retrospective | 66 (40–79) | 0/24/3 | 0/18/9/0 | NA | 45.4 | 1 | 26 | 6 |
| NACRT | 28 | 5FU+RT (45 Gy/25 F) | LAR (8), APR (20) | 68 (42–78) | 0/22/5 | 0/17/11/0 | NA | 4 | 26 | ||||||
| Sada, 2018 [27] | American | NAC | 410 | NA | NA | 2006–2010 | Retrospective | NA | NA | NA | NA | NA | 35 | NA | 5 |
| NACRT | 11614 | NA | NA | NA | NA | NA | NA | 1352 | NA | ||||||
| Sato, 2019 [28] | Japan | NAC | 16 | SOX:S1+Ox: 3 cycles | Laparoscopically | 2002–2016 | Retrospective | 67.5 (43–77) | NA | NA | NA | NA | 2 | NA | 8 |
| NACRT | 10 | 5FU+RT (40–45Gy) | Laparotomy | 66 (53–71) | NA | NA | NA | 0 | NA | ||||||
| Deng, 2019 [29] | China | NAC | 165 | mFOLFOX6 | NA | 2010–2015 | RCT | 54.1 | 1/114/50 | 46/76/43/0 | 0/46/119/0 | NA | 10 | 136 | 7 |
| NACRT | 330 | 5FU/mFOLFOX6+RT (46–50.4 Gy/23–25 F) | NA | 54.1/52.1 | 11/206/113 | 67/172/91 | 0/67/263/0 | 61 | 262 |
Note: No. of Pts Number of patients, RCT randomized controlled trial, pCR pathologic complete response, NAC neoadjuvant chemotherapy without radiation, NACRT neoadjuvant chemoradiotherapy, 5FU 5-fluorauracil, OX oxaliplatin, RT radiotherapy, FOLFOX fluorouracil, leucovorin, and oxaliplatin, IRIS irinotecan, tegafurgimeracil-oteracil potassium, FOLFIRI fluorouracil, leucovorin, and irinotecan, SOX S-1+ oxaliplatin, S-1 tegafurgimeracil-oteracil potassium, mFOLFOX6 modified infusional fluorouracil, leucovorin, and oxaliplatinm, XELOX capecitabine + oxaliplatinm, APR, abdominoperineal resection, ISR intersphincteric resection, LAR low anterior resection, ASR abdominosacral resection, NOS Newcastle-Ottawa Scale, NA not available