Incidence, Survival and Mortality of Oral and Oropharyngeal Cancer: A Surveillance, Epidemiology and End Results program-based analysis
Oral and oropharyngeal cancer (OOC) represents a significant public health burden, with approximately 275,000 cases diagnosed annually world-wide. There are known trends and differences in reference to race, gender and age. Moreover sub-site analysis has brought to light important etiologic factors such as Human Papilloma Virus (HPV) that carries valuable prognostic and treatment implications. This study evaluated trends in OOC with particular emphasis on sub-site, race and age measuring crude outcomes. The goal of this investigation was to further define trends that have occurred over the past 40 years.
Methods:
Data were extracted and analyzed from the population-based registry Surveillance, Epidemiology and End Results (SEER) database. Datasets included all neoplasms of malignant behavior specific to the following sub-sites: tongue, floor of mouth (FOM), gingiva and oropharynx. Patients were grouped into three age cohorts: 0-39, 40-64 and 65+. Incidence, survival and mortality trends were analyzed in time periods: 1973-79, 1980-86, 1987-94, 1995-2001, 2002-08 and stratified by race, gender and anatomic sub-site. Outcomes were measured by number of occurrences per 100,000 people.
Results:
The overall incidence of OOC was stable over time. Males had higher incidence of OOC with a marked difference between Black males and females (11.72 and 3.82 respectively). In a collective analysis there was a decreased incidence (18.39 to 9.21) amongst Blacks 40-64. There was increased incidence of tongue cancer amongst Whites in particular age groups; 3.84 to 5.65 in the 40-64 and 8.45 to 10.6 in the 65+. Blacks had an interval decrease of tongue cancer; 6.63 to 4.06 in the 40-64 age cohort. There was a significant decrease in the incidence of FOM cancer in all races (1.49 to 0.65). The incidence of gingival cancer was stable over time, however it was significantly decreased in Blacks 40-64 (6.02 to 2.31). White females >65 had a higher incidence of gingival cancer than Black females of the same age; 7.54 versus 5.32. Oropharyngeal cancer had the lowest incidence amongst the measured sub-sites; however, Blacks demonstrated an increased trend in both the 40-64 and 65 + cohorts. The overall 3 and 5-year observed survival (OS) rates for all sub-sites improved over time. Older age groups demonstrated a 34% mean improvement in survival. Blacks demonstrated the poorest OS irrespective of age, gender and sub-site. The mean difference in survival between Blacks and Whites ranged 10-30%. The disease specific mortality has decreased over time in tongue, gingival and FOM cancer. Whites and Blacks had proportionate decreases in mortality in ages 40-64. Whites aged 65 + had a greater decrease in mortality compared to Blacks; 30% reduction versus 21%. Increased mortality was noted for oropharyngeal cancer; Blacks 65 + had a 110% increase compared to 40% in Whites of the same age.
Conclusions:
This study was designed to raise awareness among practitioners of OOC trends. The data confirms known trends with respect to gender and age and will serve as a framework to develop early diagnostics and focus therapeutics in high-risk demographic sub-sites such as Black males, White males with tongue cancer and females with gingival cancer. Overall disease specific survival has improved in both Blacks and Whites, but less so for Blacks. Mortality for oropharyngeal cancers increased two-fold. These points re-emphasize the importance of potential etiologic factors other than smoking and alcohol abuse, such as HPV. Further investigations will focus on factors that contribute to these differences in an effort to improve outcomes.
References:
1. Surveillance, Epidemiology, and End Results (SEER) Program Data. http://seer.cancer.gov/seerstat.
2. Pulte D, Brenner H. Changes in survival in head and neck cancers in late 20th and early 21st century: A period analysis. The Oncologist 2010;15:994–1001.