Evaluation of p53 and BCL2 expression, mutation, and aneuploidy status on treatment response in an Indian cohort of primary Ca larynx

Abstract

e17057 Background: Organ-sparing therapy consisting of cisplatin and 5-fluorouracil, combined with radiation for advanced head and neck squamous cell carcinoma (HNSCC) have been advocated in Ca larynx patients. However, failure of some tumors to respond to treatment or tumor recurrence limits the overall success of these therapies. P53 mutations have been linked to cisplatin resistance in other solid tumors. In this study we evaluate the relationships between P53 overexpression/mutations, BCL2 expression and ploidy status on treatment response in retrospective cohort of Ca Larynx patients. Methods: Samples from 18 patients with histopathologically confirmed Ca Larynx were analysed from our biorepository after consent. Clinical, sociodemographic information and response to treatment were abstracted from case records. P53 and BCL2 over expression were checked by IHC and p53 mutation by PCR and direct sequencing. DNA ploidy and S-phase fractions were also analysed. Bivariate relationships were determined between these variables using Spearmans rank correlation. Independent samples t tests were used to determine changes in P53 over expression, BCL2 expression Ploidy status and S phase fractions in both responders and non responders. Results: There was a trend for increase in P53 over expression and BCL2 expression and decrease in S phase fractions in responders vs non responders. Neither p53 over expression (75% of cases) and BCL2 over expression (17% of cases) correlated significantly with treatment response. However, BCL2 expression correlated negatively with disease stage (r = - 0.57, p = 0.02). Aneuploidy was observed in node positive tumors (p = 0.04). Conclusions: The results suggest poor association of molecular markers with treatment response and should not be relied as a marker for treatment response. Though there is a trend for association a larger sample size is required to demonstrate the findings. No significant financial relationships to disclose.