Do patients with oral squamous cell carcinoma express receptor tyrosine kinase-like orphan receptor 1? Results of an observational study

Context: The receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a transmembrane protein of the receptor tyrosine kinase family. The expression of ROR1 has been linked to cancers. Aims: This study aimed to investigate the expression of ROR1 in oral squamous cell carcinoma (OSCC). Settings and Design: This prospective observational study was conducted at a tertiary referral center for treatment of oral carcinoma from November 2013 to December 2016. Subjects and Methods: One-step quantitative reverse transcription-polymerase chain reaction (30 oral cancer tissues and ten normal oral tissue samples) was performed to characterize the expression of the ROR1 gene in oral cancer. Statistical Analysis Used: Analyses of all tumor samples were carried out at least twice, and the mean value was calculated. The differences in ROR1 messenger RNA (mRNA) expression between OSCC tissue and nontumorous gingival tissue was statistically analyzed using Mann–Whitney U-test. The correlations between the clinicopathological parameters and ROR1 mRNA expression were analyzed using Kruskal–Wallis test χ2 value. Results: There were 17, 5, 3 and 1 cases of OSCC of buccal mucosa, tongue and lower alveolus lip, respectively. Nearly 88.5% of cases had a history of tobacco consumption. The most common OSCC type was T2N1M0. There was no difference in ROR1 fold change between controls and cases (P = 0.06), but there was a trend for downregulation of ROR1 expression from controls to cases. Subgroup analysis revealed the downregulation of ROR1 expression in controls versus Grade II that was significant (P = 0.04). Conclusions: There was no change in the expression of ROR1 between cases and controls. A study involving a larger sample size needs to be formulated and conducted for investigating the relation between expression and regulation of ROR1 in OSCC.