Cyclin D1 expression as a potential prognostic factor in advanced -mutant non-small cell lung cancer.

BACKGROUND

East Asian, including Thailand, lung cancer population may have a relatively lower prevalence of mutations than Caucasians. We investigated the prevalence and clinical characteristics of -driven non-small cell lung cancer (NSCLC) patients and the expression of cyclin D1, one of the KRAS downstream targets.

METHODS

Lung cancer patients who received treatment at the King Chulalongkorn Memorial Hospital between January 2015 and July 2017 were enrolled. We identified mutations using allele specific PCR mutation testing. Cyclin D1 expression was determined using immunohistochemistry.

RESULTS

After excluding 376 mutations and inadequate samples, we enrolled 95 patients eligible for mutation testing. mutations were identified in 28 out of 95 patients. There were 26 patients with codon 12/13 and 2 patients with codon 61 mutations. The prevalence of mutations among informative samples was 28 out of 357 (7.8%) which was relatively lower than that reported in Caucasian population. Smoking and male were significantly associated with mutations. The prognosis of -mutant NSCLC patients in particular codon 61 mutations was worse than that found in and wild-type ( WT/ WT) NSCLC patients (P0.048). The levels of cyclin D1 expression in -mutant NSCLC were significantly higher than those in WT/ WT NSCLC (P0.02). A better prognosis of mutant NSCLC patients with low cyclin D1 expression was observed when compared with those with high cyclin D1 expression (median overall survival 41.7 . 3.5 months, P0.037).

CONCLUSIONS

We found a moderate prevalence of mutations in lung cancer in Thailand. Clinical characteristics were similar to those of Caucasian population. Most mutant NSCLC had high cyclin D1 expression. Cyclin D1 expression may serve as a useful prognostic biomarker in -mutant lung cancer. Validation of this finding in larger cohort is required.