Predicting tumor response after preoperative chemoradiation using clinical parameters in rectal cancer.
OBJECTIVE
To evaluate the clinical parameters and identify a better method of predicting pathological complete response (pCR).


METHODS
We enrolled 249 patients from a database of 544 consecutive rectal cancer patients who underwent surgical resection after preoperative chemoradiation therapy (PCRT). A retrospective review of morphological characteristics was then performed to collect data regarding rectal examination findings. A scoring model to predict pCR was then created. To validate the ability of the scoring model to predict complete regression.


RESULTS
Seventy patients (12.9%) achieved a pCR. A multivariate analysis found that pre-CRT movability (P = 0.024), post-CRT size (P = 0.018), post-CRT morphology (P = 0.023), and gross change (P = 0.009) were independent predictors of pCR. The accuracy of the scoring model was 76.8% for predicting pCR with the threshold set at 4.5. In the validation set, the accuracy was 86.7%.


CONCLUSIONS
Gross changes and morphological findings are important predictors of pathological response. Accordingly, PCRT response is best predicted by a combination of clinical, laboratory and metabolic information.
Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-dong 50, Gangnam-gu, Seoul 135-710, South Korea.
Chan Ho
CH
Park
Hee Cheol
HC
Kim
Yong Beom
YB
Cho
Seong Hyeon
SH
Yun
Woo Yong
WY
Lee
Young Suk
YS
Park
Doo Ho
DH
Choi
Ho-Kyung
HK
Chun
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D059248:Chemoradiotherapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult