Prevalence and clinical significance of acellular mucin in locally advanced rectal cancer patients showing pathologic complete response to preoperative chemoradiotherapy.
Occasionally, patients with locally advanced rectal adenocarcinoma who receive preoperative chemoradiotherapy (CRT) show acellular mucin in resection specimens that had shown pathologic complete response (pCR), but the clinical and prognostic significance of this finding has been controversial. This study analyzed data from 217 consecutive patients showing pCR to preoperative CRT followed by resection to evaluate the clinicopathologic features and prognostic significance of acellular mucin. Patients were categorized according to the presence of acellular mucin, as identified by pathologic analysis. The clinicopathologic findings and oncologic results were compared. Acellular mucins were identified in 35 (16.1%) of 217 pCR patients. Acellular mucins were found predominantly in male patients (20.8% vs. 9.8%, P=0.039) and in those with mucinous/signet ring cell differentiation (66.7% vs. 15.1%, P=0.008). The presence of acellular mucin was more frequent in patients with a shorter (<42 d) CRT-operation interval (22.6% vs. 10.3%, P=0.017). With a mean follow-up of 41 months (range, 2 to 119 mo), the 3-year overall survival (96.8% with mucin vs. 95.9% without mucin, P=0.314) and the 3-year disease-free survival (97.0% with mucin vs. 93.0% without mucin, P=0.131) did not differ between the groups. The presence of acellular mucin in rectal cancer patients showing pCR to preoperative CRT is associated with male sex and mucinous differentiation and does not have a significant impact on oncologic outcomes. Acellular mucins are also associated with the CRT-operation interval as a phenomenon of time-dependent response to CRT.
Department of Surgery, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea. sblim@amc.seoul.kr
Seok-Byung
SB
Lim
Seung-Mo
SM
Hong
Chang Sik
CS
Yu
Yong Sang
YS
Hong
Tae Won
TW
Kim
Jin-hong
JH
Park
Jong Hoon
JH
Kim
Jin Cheon
JC
Kim
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D014408:Biomarkers, Tumor / Q000378:metabolism*; D059186:Chemoradiotherapy, Adjuvant / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000378:metabolism*; D020360:Neoadjuvant Therapy; D011300:Preoperative Care; D015995:Prevalence; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D015996:Survival Rate
D014408:Biomarkers, Tumor; D009077:Mucins