Factors associated with the survival of oral cavity cancer patients: a single institution experience from Karachi, Pakistan

Background: Oral cavity cancer (OCC) represents a significant public health burden in South Asia, ranking as the most prevalent cancer affecting males in Pakistan and contributing considerably to morbidity and mortality. The objective of this study was to evaluate the survival rates in patients diagnosed with OCC in the Pakistani population and identify the factors influencing survival. Methods: This was a retrospective cohort study conducted at the Aga Khan University Hospital Karachi, Pakistan. A total of 2238 cases diagnosed with OCC from May 2011 through December 2020, who met the inclusion criteria, were included. Survival analyses at 1-, 3- and 5-year intervals were performed using the Kaplan-Meier method. Adjusted hazard ratios (HR) and their 95% confidence intervals (CIs) were estimated using a Cox regression model to identify the factors significantly influencing survival. Results: Among all cases, 54.0% were diagnosed in individuals 50 years of age and below and 73.0% were tobacco users. Overall survival, 1-year, 3-year, and 5-year survival rates were 54.9%, 88.9%, 81.6%, and 75.9% respectively. After adjustment for all the significant confounding and prognostic factors, age was an important factor showing that adults > 50 years had poorer survival compared to ≤ 50 years (HR = 1.43, 95% CI = 1.11–1.83). Poorly differentiated grade of OCC compared to well-differentiated grade (HR = 2.49, 95% CI = 1.61–3.84) and stage IV compared to earlier stages (HR = 3.56, 95% CI = 2.13–5.94) were also associated with poor survival. Conclusion: Notably, there was a high occurrence of late stage (III and IV) OCC in individuals aged ≤ 50 years, with the buccal mucosa being the most common site involved. Moreover, a large proportion of our patients had a history of tobacco use. Patients with advanced-stage disease and poorly differentiated grade showed poor survival. Therefore, public awareness about tobacco control for OCC prevention and earlier diagnosis of OCC is urgently needed in our Pakistani population.