Sensitivity of Various Evaluating Modalities for Predicting a Pathologic Complete Response After Preoperative Chemoradiation Therapy for Locally Advanced Rectal Cancer
- Author:
Sungwoo JUNG
1
;
Anuj PARAJULI
;
Chang Sik YU
;
Seong Ho PARK
;
Jong Seok LEE
;
Ah Young KIM
;
Jong Lyul LEE
;
Chan Wook KIM
;
Yong Sik YOON
;
In Ja PARK
;
Seok Byung LIM
;
Jin Cheon KIM
Author Information
- Publication Type:Original Article
- Keywords: Preoperative chemoradiotherapy; Complete regression; Response prediction
- MeSH: Chungcheongnam-do; Endoscopy; Humans; Korea; Lymph Nodes; Magnetic Resonance Imaging; Polymerase Chain Reaction; Rectal Neoplasms; Retrospective Studies; Seoul; Ultrasonography
- From:Annals of Coloproctology 2019;35(5):275-281
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: We investigated the sensitivity of various evaluating modalities in predicting a pathologic complete response (pCR) after preoperative chemoradiation therapy (PCRT) for locally advanced rectal cancer (LARC). METHODS: From a population of 2,247 LARC patients who underwent PCRT followed by surgery at Asan Medical Center, Seoul, Korea from January 2007 to June 2016, we retrospectively analyzed 313 patients (14.1%) who showed a pCR after surgery. Transrectal ultrasound (TRUS), high-resolution magnetic resonance imaging (MRI), abdominopelvic computed tomography (AP-CT), and endoscopy were performed within 2 weeks prior to surgery. RESULTS: Of the 313 patients analyzed, 256 (81.8%) had a pCR after radical surgery and 57 (18.2%) showed total regression after local excision. Preoperative TRUS, MRI, and AP-CT were performed in 283, 305, and 139 patients, respectively. Among these 3 groups, a prediction of a pCR of the primary tumor was made in 41 (14.5%), 51 (16.7%), and 27 patients (19.4%), respectively, before surgery. A prediction of a clinical N0 stage was made in 204 patients (88.3%) using TRUS, 130 (52.2%) using MRI, and 78 (65.5%) using AP-CT. Of the 211 patients who underwent endoscopy, 87 (41.2%) had a mention of clinical CR in their records. A prediction of a pathologic CR was made for 124 patients (39.6%) through at least one diagnostic modality. CONCLUSION: The various evaluation methods for predicting a pCR after PCRT show a predictive sensitivity of 0.15–0.41 for primary tumors and 0.52–0.88 for lymph nodes. Endoscopy is a relatively superior modality for predicting the pCR of the primary tumor of LARC patients.
