Prognostic value of insulin-like growth factor-1 receptors in patients with colon/rectal cancer: Correlation with plasma prolactin

Prognostic value of IGF-1 receptors (IGF-1R) was evaluated and compared with circulating prolactin (PRL) in 59 patients with Dukes B or C colon/rectal cancer. IGF-1R was estimated by radioligand binding assay and PRL was estimated by immunoradiometric assay. Eighty-five percent (50/59) of patients had IGF-1R— tumours while IGF-1R positivity was observed in only 15% (9/59) of patients. None of the clinicopathological parameters showed any association with IGF-1R status. No significant difference was observed in overall survival period between patients with IGF-1R+ tumours and those with IGF-1R—tumours. However, a significant difference in overall survival time was observed between patients with PRL < 20.0 and > 20.0 ng/ml plasma (X2 = 4.70, df = 1, P < 0.05). In bivariate analysis, patients with IGF-1R—tumours and concomitant hyperprolactinemia had unfavourable prognosis compared to their counterpart (X2 = 4.21, df = 1, P < 0.05). We conclude that there was a trend of better overall survival in patients with IGF-1R+ tumours, and PRL < 20.0 ng/ml plasma when compared to patients with IGF-1R— tumours, and PRL > 20.0 ng/ml plasma. Further, IGF-1R negativity in conjunction with hyperprolactinemia could be used as an indicator of unfavourable prognosis in patients with Dukes B or C colon/rectal cancer.