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Updated: Jun 27, 2026
Detection of a Circulating MicroRNA Custom Panel in Patients with Metastatic Colorectal Cancer
Published on: March 14, 2019
mRNA expression of platelet-derived growth factor receptor-beta and C-KIT: correlation with pathologic response to
Philipp Erben1, Karoline Horisberger, Benjamin Muessle
1III. Medizinische Klinik, Medizinische Fakultät Mannheim der Universität Heidelberg, Mannheim, Germany.
Purpose:
Deviant expression of platelet-derived growth factor receptor-beta (PDGFRbeta) and c-kit was shown in patients with colorectal cancer. In the present study, mRNA expression of PDGFRbeta and c-kit in 33 patients with locally advanced rectal cancer undergoing preoperative chemoradiotherapy with cetuximab/capecitabine/irinotecan in correlation with the tumor regression rate was investigated.
Methods And Materials:
Pretherapeutic biopsy cores and tumor material from the resected specimens were collected in parallel with normal rectal mucosa. The expression levels of PDGFRbeta and c-kit were measured by quantitative polymerase chain reaction. Tumors were classified as good responders (tumor regression grade [TRG], 2-3) or poor responders (TRG, 0-1).
Results:
The TRG evaluation of the resected specimen was TRG 0-1 in 11 and TRG 2-3 in 22. The median normalized ratios in the pretreatment mucosa vs. tumor biopsy cores was as follows: PDGFRbeta ratio of 15.2 vs. 49.5 (p <0.0001) and c-kit ratio of 0.94 vs. 0.67 (p = 0.014). The same tendency was observed for the median PDGFRbeta ratios after chemoradiotherapy completion: 34.2 vs. 170.0 (p <0.0001). The PDGFRbeta and c-kit mRNA expression values in the pretreatment tumor biopsy cores were lower than the values in the resected specimens: PDGFRbeta ratio 49.5 vs. 170.0 (p = 0.0002) and c-kit ratio 0.67 vs. 1.1 (p = 0.0003). Nevertheless, no correlation was seen between the pretherapeutic PDGFRbeta and c-kit mRNA expression and the pathologic regression rate.
Conclusion:
Cetuximab-based chemoradiotherapy increased PDGFRbeta levels even further compared with the pretreatment samples and deserves further investigation.
