A Cytological Study Enlightening the Unseen Effects of Concomitant Chemoradiotherapy in Contralateral Normal Buccal Mucosa of Oral Squamous Cell Carcinoma Patients

Background/objectives In patients receiving concomitant chemoradiotherapy (CCRT) as a treatment for oral squamous cell carcinoma (OSCC), cytological changes were seen not only in neoplastic epithelial cells but the non-neoplastic epithelial cells are also affected, resulting in cytopathological atypical changes. The present study was designed to observe oral epithelial atypical cytopathologic changes induced in contralateral normal buccal mucosa in OSCC patients receiving CCRT. Methods The study included 150 patients with OSCC treated by CCRT whose details were collected from the Institute of Nuclear Medicine and Oncology Lahore (INMOL) Hospital Lahore. Cytological smears were obtained from the contralateral normal buccal mucosa of OSCC patients. The serial scrape smears were taken before, immediately after, on the 17th day (mid of treatment), and at the end of CCRT, whereas 20 patients were taken as normal healthy controls and were not exposed to CCRT. The smears were stained with hematoxylin and eosin and Papanicolaou stain. SPSS version 20 (Armonk, NY: IBM Corp.) was used for statistical analysis and p > 0.05 was considered to be significant. Results CCRT-induced oral epithelial atypical cytological changes were predominantly noted at end of therapy (19.7%) in the contralateral normal buccal mucosa. Nuclear atypia features were higher on the 17th day and end of treatment; whereas, epithelial atypia was mainly observed on the 17th day of CCRT (40%). A highly significant association was observed between epithelial atypia and radio-chemotherapy dose (p = 0.045), between CCRT-induced epithelial atypical cytological changes and days of treatment (p = 0.001), and between days of CCRT and nuclear atypia (0.000) accordingly. Atypia was not observed in any control group. Conclusion Varying degrees of oral epithelial atypical cytological changes may occur in otherwise normal contralateral mucosa of the patients receiving CCRT.