Carcinoembryonic antigen as a predictor of pathologic response and a prognostic factor in locally advanced rectal cancer patients treated with preoperative chemoradiotherapy and surgery.
OBJECTIVE
To evaluate the role of serum carcinoembryonic antigen (CEA) as a predictor of response to preoperative chemoradiotherapy (CRT) and prognostic factor for rectal cancer.


METHODS
The study retrospectively evaluated 352 locally advanced rectal cancer patients who underwent preoperative CRT followed by surgery. Serum CEA levels were determined before CRT administration (pre-CRT CEA) and before surgery (post-CRT CEA). Correlations between pre-CRT CEA levels and rates of good response (Tumor regression grade 3/4) were explored. Patients were categorized into three CEA groups according to their pre-/post-CRT CEA levels (ng/mL) (Group A: pre-CRT CEA <or= 3; B: pre-CRT CEA >3, post-CRT CEA <or=3; C: pre- and post-CRT CEA >3 ng/mL), and their oncologic outcomes were compared.


RESULTS
Of 352 patients, good responses were achieved in 94 patients (26.7%). The rates of good response decreased significantly as the pre-CRT CEA levels became more elevated (CEA [ng/mL]: <or=3, 36.4%; 3-6, 23.6%; 6-9, 15.6%; >9, 7.8%; p < 0.001). The rates of good response were significantly higher in Group A than in Groups B and C (36.4% vs. 17.3% and 14.3%, respectively; p < 0.001). The 3-year disease-free survival rate was significantly better in Groups A and B than in Group C (82% and 79% vs. 57%, respectively; p = 0.005); the CEA grouping was identified as an independent prognostic factor (p = 0.025).


CONCLUSIONS
In locally advanced rectal cancer patients, CEA levels could be of clinical value as a predictor of response to preoperative CRT and as an independent prognostic factor after preoperative CRT and curative surgery.
Park
Ji Won
JW
Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Republic of Korea.
Lim
Seok-Byung
SB
Kim
Dae Yong
DY
Jung
Kyung Hae
KH
Hong
Yong Sang
YS
Chang
Hee Jin
HJ
Choi
Hyo Seong
HS
Jeong
Seung-Yong
SY
D000230:Adenocarcinoma / Q000097:blood* / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood*; D003131:Combined Modality Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011379:Prognosis; D012004:Rectal Neoplasms / Q000097:blood* / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome
D002272:Carcinoembryonic Antigen