Gene expression profiles of tumor regression grade in locally advanced rectal cancer after neoadjuvant chemoradiotherapy

Susumu Saigusa, Koji Tanaka, Yuji Toiyama, Kohei Matsushita, Mikio Kawamura, Yoshinaga Okugawa, Junichiro Hiro, Yasuhiro Inoue, Keiichi Uchida, Yasuhiko Mohri, Masato Kusunoki

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


Tumor regression grading (TRG) reportedly has prognostic value in rectal cancer patients after pre-operative chemoradiotherapy (CRT). The aim of this retrospective study was to differentiate gene expression profiles based on TRG in residual cancer cells after CRT. We evaluated pathological response using the criteria of four TRG systems: the Japanese Society for the Cancer of Colon and Rectum (JSCCR), Mandard, Dworak and Rödel. Total RNA was obtained using microdissection from 52 locally advanced rectal cancer specimens from patients who underwent pre-operative CRT to examine the expression levels of 20 genes [PCNA, MKI67, CDKN1A (p21 Cip1), CDK2, CHEK1, PDRG1, LGR5, PROM1 (CD133), CD44, SOX2, POU5F1 (OCT4), LKB1, VEGF, EGFR, HGF, MET, HIF1, GLUT1, BAX and BCL2] using real-time quantitative RT-PCR. Gene expression was compared across the four TRG systems. LGR5 gene expression levels in CRT non-responders were significantly higher than in responders in all four grading systems. Patients with elevated PDRG1 and GLUT1 gene expression had poor pathological response in three TRG systems (JSCCR, Dworak and Rödel). MKI67 gene expression in non-responders was significantly higher than in responders in two grading systems (JSCCR and Rödel). While, BAX gene expression in responders was significantly higher than in non-responders in the Mandard TRG system. The results of this study suggest that TRG may reflect characteristics, such as proliferative activity, stemness potency and resistance to hypoxia, of residual cancer cells following pre-operative CRT.

Original languageEnglish
Pages (from-to)855-861
Number of pages7
JournalOncology reports
Issue number3
Publication statusPublished - 09-2012
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Oncology
  • Cancer Research


Dive into the research topics of 'Gene expression profiles of tumor regression grade in locally advanced rectal cancer after neoadjuvant chemoradiotherapy'. Together they form a unique fingerprint.

Cite this