This study identified that cases of hospital admissions due to oral and oropharyngeal cancer in Brazil, from 2000 to 2015, comprised mostly men, with a predominance of individuals aged 50-59 years, with low level of schooling, white and brown ethnicity, and with more advanced stage tumors, with metastasis already identified. In addition, the temporal trend of the in-hospital morbidity rates for oral cavity cancer in the period 2002-2013 showed to be increasing, both for males and females. The analysis of this information is unprecedented, considering the in-hospital morbidity of this disease in Brazil.
In all regions, the smoking and alcohol consumption factors were relevant to the development of the disease among hospitalized patients, as the consumption or ex-consumption of alcohol and tobacco was shown to be at higher amounts than those who declared they had never drunk alcoholic beverages or used tobacco products. Moreover, the observed increase in the consumption of alcohol-tobacco19,20 has been associated with the increase in the disease prevalence, especially in female patients.
In all regions, the cases diagnosed at advanced staging (with metastasis) at the time of the first hospital admission showed higher percentages than cases classified as initial staging/with localized involvement. Data from the INCA Hospital Cancer Records warn that, as most patients arrive at hospitals at an advanced stage of the disease, the treatment is no longer curative, being in most cases mutilating21.
It was found that, for the entire Brazilian territory, the trend of in-hospital morbidity rates for oral cancer, between the years 2002 and 2013, was increasing, both for males and females. An increasing trend was also observed when analyzing both genders together. According to this finding, a study analyzing the granting of social security benefits in Brazil for cancer of the oral cavity (2006- 2013) showed this trend was increasing. Social security benefits related to cancer involvement in other parts of the mouth, nasopharynx, oropharynx, floor of the mouth and palate showed the same increasing trend22.
The growing trend in the evidenced overall picture of hospitalizations may be linked to the initial hypothesis of better case registration after the consolidation of the nationwide hospital integrated information system. As the analysis of these data is unprecedented in the literature, it was not possible to compare them with other studies on hospitalization trends due to oral cavity cancer. However, considering the results of studies that indicate a stability or decrease in mortality rates related to neoplastic conditions of the oral cavity19,23 in contrast to the growing trend of hospitalization observed in the present study, this investigation suggests better access to health services throughout the historical series.
Users of the public health system who previously did not have access to treatment may be able to have access to the hospital network and attempt to be cured24. This reasoning would also be compatible with the results indicated with advanced staging, since, as this is a chronic disease, people would come to the health service network with a previously established case severity25.
It is worth mentioning that the inclusion and expansion of the family health network close to Brazilian communities experienced during the analyzed historical period has shown the potential to reach the population at risk for the development of oral cavity cancer 26,27. In this sense, a recent study shows that the inclusion of oral health teams is associated with early and timely detection of these diseases8. Which, associated with the possibility of access to treatments in the hospital network, would result in lower mortality rates, while in-hospital morbidity is increasing28. A recent study indicated the association between the number of oral health teams and the timely diagnosis of oral cavity cancer8.
Therefore, it is reiterated that studies of epidemiological surveys for oral cancer diagnosis and surveillance are of utmost importance, allowing better management of public policies in the health area and data that support planning by health professionals, so that users have greater chances of treatment and cure29,30.
As Brazil is a country with a large territorial extension and has many regional variations, both geographical and populational, the importance of developing research by state to assess the specific characteristics of its population is highlighted. Thus, this study met its purpose of identifying trends and characterizing epidemiological aspects related to morbidity from oral and oropharyngeal cancer in Brazil, showing data that had not been published before in the literature.
We point out some limitations of the present study, since by using public information systems, it was observed that some data were under-recorded (classified as not applicable or missing), which seems to correspond to the failure to complete the medical records at the time of hospitalization and also the migration of some databases from regional platforms to a national platform, particularly in the state of São Paulo, which has a single state database15.
Nevertheless, it is considered that the data shown here constitute the best and most comprehensive information on oral cancer morbidity available in the Brazilian territory. In addition, these data are already consolidated and have a policy of information monitoring and checking at state and national levels to avoid duplication of information13, giving them reliability and robustness.
Our results demonstrate that greater attention should be paid to the early detection and treatment of oral cancer, reinforcing that dedicated professional action is still required in the fight against the disease and educating the population about risk factors and signs and symptoms of oral cavity cancer. Also, it is necessary to expand cancer care, by involving the Primary Health Care level and high complexity centers.
We conclude that the distribution of in-hospital morbidity rates for oral cavity cancer in the country is irregular, with a predominance of the male gender and in the Southeast and South regions, and that there is a trend for this rate to increase in both genders.