Questioning the IGF1 receptor's assigned role in CRC - a case for rehabilitation?

• Published in: BMC cancer 2020-07, Vol.20 (1), p.704-12, Article 704
• Main Authors: Heckl, Steffen M, Pellinghaus, Marie, Behrens, Hans-Michael, Krüger, Sandra, Schreiber, Stefan, Röcken, Christoph
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Antibodies; Cancer prognosis; Cancer risk factor; Cancer therapy; Carcinogenesis; Cloning; Colon cancer; Colonic Neoplasms - metabolism; Colonic Neoplasms - mortality; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - metabolism; Colorectal Neoplasms - mortality; Cytoplasm - chemistry; Deoxyribonucleic acid; DNA; DNA Repair; EDTA; Evaluation; Female; Genes, ras - genetics; Genotyping Techniques; Health aspects; Humans; IGF1 receptor; Immunohistochemistry; Insulin; Insulin-like growth factor I; Laboratories; Localization; Male; Membrane Proteins - analysis; Middle Aged; Mismatch repair; Neoplasm Proteins - analysis; Neoplasm Proteins - metabolism; Patients; Prognosis; Receptor, IGF Type 1 - analysis; Receptor, IGF Type 1 - metabolism; Receptor, Insulin - analysis; Receptor, Insulin - metabolism; Rehabilitation; Signal transduction; Survival Analysis; Tissue Array Analysis; Tumor cells
• ISSN: 1471-2407; 1471-2407
• DOI: 10.1186/s12885-020-07173-w

The insulin-like growth factor 1 receptor (IGF1R) is suspected to be involved in colorectal carcinogenesis and has been associated with worse survival in colorectal cancer (CRC). We hypothesized that the alleged suspect might be in truth beyond any suspicion. We investigated if the expression of the IGF1R in CRC correlates with (1) clinicopathological patient characteristics, including survival, and hence is involved in colon cancer biology; (2) the expression of the IGF1R in CRC is linked to the expression of the insulin receptor (IR). We evaluated 4497 CRC samples from 1499 patients for the expression of IGF1R in tumor cells by immunohistochemistry. Cytoplasmic (cCC-IGF1R) and membranous (mCC-IGF1R) immunostaining was evaluated by employing a modified HistoScore (HScore), which was dichotomized into low or high IGF1R expressions. The IGF1R status was correlated with clinicopathological patient characteristics, survival and the IR expression status. cCC-IGF1R and mCC-IGF1R (HScore> 0) were found in 85.4 and 60.8% of all CRCs. After dichotomization of the HScores, 54.9 and 48.6% were classified as cCC-IGF1R-high and mCC-IGF1R-high, respectively. IGF1R was associated with tumor localization, local tumor growth, lymphatic vessel invasion, grading, mismatch repair protein expression status and IR-expression. We found no significant association with overall or tumor-specific survival, with a tendency for an even improved overall survival for cCC-IGF1R. IGF1R expression is frequent and biologically relevant in CRC, but does not correlate with patient survival. The IGF1R might be beyond suspicion in CRC after all.