Biopsy specimens obtained 7 days after starting chemoradiotherapy (CRT) provide reliable predictors of response to CRT for rectal cancer.

Abstract

PURPOSE:

Preoperative chemoradiation therapy (CRT) significantly decreases local recurrence in locally advanced rectal cancer. Various biomarkers in biopsy specimens obtained before CRT have been proposed as predictors of response. However, reliable biomarkers remain to be established.

METHODS AND MATERIALS:

The study group comprised 101 consecutive patients with locally advanced rectal cancer who received preoperative CRT with oral uracil/tegafur (UFT) or S-1. We evaluated histologic findings on hematoxylin and eosin (H&E) staining and immunohistochemical expressions of Ki67, p53, p21, and apoptosis in biopsy specimens obtained before CRT and 7 days after starting CRT. These findings were contrasted with the histologic response and the degree of tumor shrinkage.

RESULTS:

In biopsy specimens obtained before CRT, histologic marked regression according to the Japanese Classification of Colorectal Carcinoma (JCCC) criteria and the degree of tumor shrinkage on barium enema examination (BE) were significantly greater in patients with p21-positive tumors than in those with p21-negative tumors (P=.04 and P<.01, respectively). In biopsy specimens obtained 7 days after starting CRT, pathologic complete response, histologic marked regression according to both the tumor regression criteria and JCCC criteria, and T downstaging were significantly greater in patients with apoptosis-positive and p21-positive tumors than in those with apoptosis-negative (P<.01, P=.02, P=.01, and P<.01, respectively) or p21-negative tumors (P=.03, P<.01, P<.01, and P=.02, respectively). The degree of tumor shrinkage on both BE as well as MRI was significantly greater in patients with apoptosis-positive and with p21-positive tumors than in those with apoptosis-negative or p21-negative tumors, respectively. Histologic changes in H&E-stained biopsy specimens 7 days after starting CRT significantly correlated with pathologic complete response and marked regression on both JCCC and tumor regression criteria, as well as with tumor shrinkage on BE and MRI (P<.01, P<.01, P<.01, P<.01, and P=.03, respectively).

CONCLUSIONS:

Immunohistochemical expressions of p21 and apoptosis together with histologic changes on H&E-stained biopsy specimens obtained 7 days after starting CRT are strong predictors of the response to CRT.

• Authors: Toshiyuki Suzuki, Sotaro Sadahiro, Akira Tanaka, Kazutake Okada, Hiroko Kamata, Akemi Kamijo, Chieko Murayama, Takeshi Akiba, Shuichi Kawada
• Journal: International journal of radiation oncology, biology, physics (Int J Radiat Oncol Biol Phys) Vol. 85 Issue 5 Pg. 1232-8 (Apr 01 2013) ISSN: 1879-355X [Electronic] United States
• PMID: 23158058 (Publication Type: Journal Article)
• Copyright: Copyright © 2013 Elsevier Inc. All rights reserved.

Chemical References

• Antimetabolites, Antineoplastic
• Biomarkers, Tumor
• CDKN1A protein, human
• Cyclin-Dependent Kinase Inhibitor p21
• Drug Combinations
• Ki-67 Antigen
• Tumor Suppressor Protein p53
• S 1 (combination)
• Tegafur
• Oxonic Acid

Topics

• Adenocarcinoma (chemistry, pathology, therapy)
• Adult
• Aged
• Aged, 80 and over
• Antimetabolites, Antineoplastic (therapeutic use)
• Apoptosis
• Biomarkers, Tumor (analysis)
• Biopsy
• Chemoradiotherapy
• Cyclin-Dependent Kinase Inhibitor p21 (analysis)
• Drug Combinations
• Female
• Humans
• Ki-67 Antigen (analysis)
• Male
• Middle Aged
• Oxonic Acid (therapeutic use)
• Rectal Neoplasms (chemistry, pathology, therapy)
• Rectum (chemistry, pathology)
• Tegafur (therapeutic use)
• Time Factors
• Treatment Outcome
• Tumor Burden (drug effects, radiation effects)
• Tumor Suppressor Protein p53 (analysis)