We have carefully reviewed the paper entitled "Epidemiological study of oral cancer in Colombia 1989-2008" 1 and would like to make some comments about it. While the author estimates incidence rates of oral cancer in Colombia during that period based on the data from the Instituto Nacional de Cancerología (INC), the denominator used to calculate the frequency, either incidence or prevalence, is not provided; this makes the comparison with the published literature difficult. Motivated by this work, we conducted an analysis of the Individual Records of Health Services Provision (RIPS by its acronym in Spanish) obtained from the Sispro database between 2010 and 2014, using the same ICD-10 codes of the aforementioned study and the denominator population projections of the National Administrative Department of Statistics (DANE) for the middle term (that is 2012). The results were classified by age in five-year periods and gender.
According to RIPS, during those five years, 57 657 people were diagnosed, 31 435 women (53.7%), with some malignant disease in the oral cavity, with an average rate of patients seen per year of 26.7 per 100 000, with a progressive increase during life span, most dramatically manifested after age 50. The highest prevalence is found in the senior group (80 years or more), where incidence reaches 123 per 100 000.
During the five-year period analyzed, there does not seem to be a trend toward increasing or decreasing frequency, although it is an inadequate lapse of time to draw conclusions. According to the records of the INC presented in the study, a progressive reduction appears to be seen in the incidence of oral cancer, so it is not clear why the author begins his discussion declaring a "dramatic increase". Bernal also suggested that oral cancer associated with human papillomavirus (HPV) could be increasing, while associated smoking would be decreasing 2; however, the overall incidence reported in the literature has not shown variations in the last two decades 3.
Although the literature and the study by Bernal have in common that males are more affected by oral and oropharyngeal cancer 1,4,5, according to the Colombian RIPS, this would only be true in patients younger than 14 years, where the male: female ratio was 1.21. In all older age groups, we found an inverse ratio of 1.28 women for every affected man. This epidemiological finding is certainly interesting and should encourage new research on the particularities of oral cancer in Colombia.