Table 2.

Studies for CEA on the response to nCRT in rectal cancer.

Author (Reference)	Year	Number of Samples	Blood Collection	Cut off Values for CEA (ng/mL)	p-Value
Das et al. [92]	2007	562	pre-nCRT	≤2.5	p = 0.015
Yoon et al. [93]	2007	351	pre-nCRT	≤5	p = 0.004
Moreno Garcia et al. [94]	2009	148	pre-nCRT and post-surgery	≤2.5	p = 0.05
Kalady et al. [95]	2009	242	Not Reported	≤2.5	p = 0.19
Park et al. [96]	2009	352	pre and post-nCRT	≤3	p < 0.001
Lee et al. [97]	2009	490	pre-nCRT	≤5	p = 0.004
Kang et al. [98]	2010	84	pre and post-nCRT	≤3	p = 0.01
Aldulaymi et al. [99]	2010	33	pre-nCRT	≤5	p = 0.002
Yan et al. [100]	2011	98	pre-nCRT	≤3	p = 0.002
Hur et al. [101]	2011	37	pre-nCRT	≤3	p = 0.54
Moureau-Zabotto et al. [102]	2011	168	pre-nCRT	≤5	p = 0.019
Wallin et al. [103]	2013	267	pre-nCRT	≤3.4	p = 0.008
Restivo et al. [104]	2013	260	pre-nCRT	≤5	p = 0.001
Lee et al. [105]	2013	345	pre-nCRT	≤5	p = 0.002
Huh et al. [22]	2013	391	pre-nCRT	≤5	p = 0.002
Yeo et al. [106]	2013	609	pre-nCRT	≤5	p < 0.001
Yang et al. [107]	2013	138	pre-nCRT	≤6	p = 0.152
Wang et al. [108]	2014	240	pre-nCRT	≤5	p = 0.047
Zeng et al. [21]	2015	323	pre-nCRT	≤5	p = 0.007
Kim et al. [90]	2015	419	pre-nCRT	Not Reported
Kleiman et al. [109]	2015	141	pre and post-nCRT	Not Reported	p = 0.003
Song et al. [91]	2016	1782	pre-nCRT	Not Reported
Probst et al. [89]	2016	18,113	pre-nCRT	Not Reported	p < 0.001

Abbreviation: nCRT, neoadjuvant chemoradiation; CEA, carcinoembryonic antigen.