Clinical parameters predicting pathologic tumor response after preoperative chemoradiotherapy for rectal cancer.
OBJECTIVE
To identify pretreatment clinical parameters that could predict pathologic tumor response to preoperative chemoradiotherapy (CRT) for rectal cancer.


METHODS
The study involved 351 patients who underwent preoperative CRT followed by surgery between October 2001 and July 2006. Tumor responses to preoperative CRT were assessed in terms of tumor downstaging and tumor regression. Statistical analyses were performed to identify clinical factors associated with pathologic tumor response.


RESULTS
Tumor downstaging (defined as ypT2 or less) was observed in 167 patients (47.6%), whereas tumor regression (defined as Dworak's Regression Grades 3 or 4) was observed in 103 patients (29.3%) and complete regression in 51 patients (14.5%). Multivariate analysis found that predictors of downstaging were pretreatment hemoglobin level (p = 0.045), cN0 classification (p < 0.001), and serum carcinoembryonic antigen (CEA) level (p < 0.001), that predictors of tumor regression were cN0 classification (p = 0.044) and CEA level (p < 0.001), and that the predictor of complete regression was CEA level (p = 0.004).


CONCLUSIONS
The data suggest that pretreatment CEA level is the most important clinical predictor of pathologic tumor response. It may be of benefit in the selection of treatment options as well as the assessment of individual prognosis.
Yoon
Sang Min
SM
Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
Kim
Dae Yong
DY
Kim
Tae Hyun
TH
Jung
Kyung Hae
KH
Chang
Hee Jin
HJ
Koom
Woong Sub
WS
Lim
Seok-Byung
SB
Choi
Hyo Seong
HS
Jeong
Seung-Yong
SY
Park
Jae-Gahb
JG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002272:Carcinoembryonic Antigen / Q000097:blood*; D003131:Combined Modality Therapy; D005260:Female; D006441:Hemoglobin A / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D012074:Remission Induction
D002272:Carcinoembryonic Antigen; D006441:Hemoglobin A