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 |