Table 1.
The baseline characteristics of included studies
| Study | Country&year | Study design | NO. of patients (M/F) | Age mean ± SD/median (range) | Definition of pCR | Different groups of tumor regression | Follow-up median (range) | TNM stage (0/I/II/III) |
Neoadjuvant treatment regimen | Outcome |
|---|---|---|---|---|---|---|---|---|---|---|
| Erlandsson |
Sweden 2019 |
RCT |
697 (416/281) |
NR | ypT0N0M0 | ①②③④⑤ | 5.7y (IQR, 4.9–14.3y) | yp:42/213/215/201 | RT | OS, DFS |
| Marco |
USA 2018 |
Prospective study |
211 (124/87) |
NR | No residual tumor cells | ①② | 59 m (9–125 m) | yp:65/58/41/47 | RT + FU/ RT + FU + mFOLFOX6 | OS, DFS |
| Song |
Korea 2018 |
Retrospective study |
331 (229/102) |
≤61y: n = 161 >61y: n = 170 |
No residual tumor cells | ①②③④⑤⑥⑦⑧ | 65.0 m (8.4–159.3 m) | yp:45/94/80/112 | RT + CAP/ RT + FU + LV/ RT + cetuximab + irinotecan + capecitabine | OS, DFS |
| Karagkounis |
USA 2018 |
Post hoc study |
305 (224/81) |
57.5y(25.9–85.9y) | No residual tumor cells | ①②③④⑤⑥⑦⑧ | 4.9y (range 0.3–15.8y) | yp:−/123/182/− | RT + FU/ RT + CAP | OS |
| Kuan |
China 2017 |
Retrospective study |
1914 (1300/614) |
59.97 ± 12.10y: n = 1655 59.59 ± 12.36: n = 259 |
ypT0N0M0 | ①② | 37.0 m | c:−/523/1391/− | RT + FU/ LV, tegafur or capecitabine | OS |
| Fokas |
German 2017 |
RCT |
1179 (838/341) |
NR | No residual tumor cells | ①②⑥⑦⑧ | 50 m (38–61 m) | NR | RT + FU/ RT + FU + OX | OS, DFS |
| De Felice |
Italy 2016 |
Prospective study |
100 (67/33) |
64y (38-76y) | No residual tumor cells | ①② | NR | NR | RT + OX + FU | DFS |
| Zhang |
China 2015 |
Retrospective study |
295 (203/92) |
<55y: n = 153 ≥55y: n = 142 |
ypT0N0M0 | ①②③④⑤⑥⑦⑧ | 36 m (5–120 m) | yp:77/53/97/68 | RT + XELOX/ RT + FOLFOX/ RT + Xeloda | OS, DFS |
| Fokas |
German 2014 |
RCT |
391 (283/108) |
≤61y: n = 205 >61y: n = 186 |
No residual tumor cells | ①②⑥⑦⑧ | 132 m (90–184 m) | NR | RT + FU | DFS |
| de Campos-Lobato |
Brazil 2011 |
Post hoc study |
238 (174/64) |
57y (49–67y) | ypT0N0M0 | ①② | 55 m (IQR, 36–77 m) | NR | RT + 5-FU/ RT + CAP | OS, DFS |
| Belluco |
Italy 2011 |
Retrospective study |
139 (93/46) |
62y | No residual tumor cells | ①② | 55.4 m | NR | RT + 5-FU + LV/ RT + 5-FU + gefitinib/ RT + CAP/ RT + CAP + OX/ RT + raltitrexed | DFS |
| Bujko |
Poland 2010 |
RCT |
131 (88/43) |
TRG 0: 58y (39–72y) TRG 1: 62y (44–70y) TRG 2: 59y (41–72y) TRG 3: 59y (34–73y) |
No residual tumor cells | ①②③④⑤ | 4y | NR | RT + FU + LV | DFS |
M/F male/female; pCR pathological complete response; RCT randomized control trial; m month; y year; TRG tumor regression grade; IQR interquartile range; ①: pCR group; ②: non-pCR group; ③: near pCR group; ④: good regression group; ⑤: poor regression group; ⑥: major regression group; ⑦: moderate regression group; ⑧:minor regression group; c clinical stage; yp pathologic stage after receiving neoadjuvant chemotherapy; RT radiotherapy; FU fluorouracil; mFOLFOX6 fluorouracil + leucovorin + oxaliplatin; FOLFOX fluorouracil + leucovorin + oxaliplatin; LV leucovorin; CAP capecitabine; OX oxaliplatin; XELOX capecitabine + oxaliplatin; OS overall survival; DFS disease-free survival; NR not reported