Abstracts

INTRODUCTION

Cancer of lip, mouth and pharynx is a serious and increasing public health problem in many parts of the globe. The latest global estimates indicated that about 300 thousand new cases and 145.000 deaths occurred in 2012¹1. Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, et al. GLOBOCAN 2012 v1.0, Cancer incidence and mortality worldwide: IARC Cancer Base nº. 11 . Lyon, France: International Agency for Research on Cancer; 2013. Disponível em http://globocan.iarc.fr (Acessado em 1º de maio de 2014).
http://globocan.iarc.fr... . High incidence rates are found in South and Central Asia, Western Europe, and Oceania¹1. Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, et al. GLOBOCAN 2012 v1.0, Cancer incidence and mortality worldwide: IARC Cancer Base nº. 11 . Lyon, France: International Agency for Research on Cancer; 2013. Disponível em http://globocan.iarc.fr (Acessado em 1º de maio de 2014).
http://globocan.iarc.fr... . The male population carries the highest risk of developing this type of cancer; in Brazil, for each one new case in female population there are three cases in male population²2. Ministério da Saúde. Instituto Nacional de Câncer José Alencar Gomes da Silva. Coordenação de Prevenção e Vigilância. Estimativa 2014: incidência de câncer no Brasil. Rio de Janeiro: INCA; 2014. Disponível em http://www.inca.gov.br/estimativa/2014/sintese-de-resultados-comentarios.asp (Acessado em 1º de maio de 2014). . The Southern and Southeastern Brazilian regions have the highest incidences in the country²2. Ministério da Saúde. Instituto Nacional de Câncer José Alencar Gomes da Silva. Coordenação de Prevenção e Vigilância. Estimativa 2014: incidência de câncer no Brasil. Rio de Janeiro: INCA; 2014. Disponível em http://www.inca.gov.br/estimativa/2014/sintese-de-resultados-comentarios.asp (Acessado em 1º de maio de 2014). .

The main factors associated with cancer of the lip, mouth and pharynx are the use of tobacco and alcohol and exposure to UVA radiation (lip cancer)³3. Galbiatti ALS, Padovani-Junior JA, Maníglia JV, Rodrigues CDS, Pavarino EC, Goloni-Bertollo EM. Head and neck cancer: causes, prevention and treatment. Braz J Otorhinolaryngol 2013; 79(2): 239-47.. The frequent and combined use of tobacco and alcohol causes a synergistic effect, increasing the risk of developing the disease²2. Ministério da Saúde. Instituto Nacional de Câncer José Alencar Gomes da Silva. Coordenação de Prevenção e Vigilância. Estimativa 2014: incidência de câncer no Brasil. Rio de Janeiro: INCA; 2014. Disponível em http://www.inca.gov.br/estimativa/2014/sintese-de-resultados-comentarios.asp (Acessado em 1º de maio de 2014). ^{, 3}3. Galbiatti ALS, Padovani-Junior JA, Maníglia JV, Rodrigues CDS, Pavarino EC, Goloni-Bertollo EM. Head and neck cancer: causes, prevention and treatment. Braz J Otorhinolaryngol 2013; 79(2): 239-47.. Furthermore, heavy intake of alcoholic beverages is associated with nutrient deficiency. Occupational risk factors have also been cited in literature, such as exposure to toxic agents or solar radiation during the labor. Dietary patterns may be associated with reduced the risk of cancer. Evidence shows that high intake of fiber, fruits and vegetables reduce the risk of head and neck cancer, as well as the poor intake of red meat⁴4. Edefonti V, Hashibe M, Ambrogi F, Parpinel M, Bravi1 F, Talamini R, et al. Nutrient-based dietary patterns and the risk of head and neck cancer: a pooled analysis in the International Head and Neck Cancer Epidemiology consortium. Ann Oncol 2012; 23: 1869-80..

Cancer of the lip, mouth and pharynx may cause important functional and esthetic changes, which requires a multidisciplinary approach for treatment⁵5. Kelly SL, Jackson JE, Hickey BE, Szallasi FG, Bond CA. Multidisciplinary clinic care improves adherence to best practice in head and neck cancer. Am J Otolaryngol 2013; 34(1): 57-60.. The clinical background may include persistent pain, dyspnea, dysphagia, odynophagia, xerostomia, voice changes, weight loss, rigidity of tissues and decrease or loss of work capacity. The functions often compromised are related to the anatomo-physiology of the head and neck⁶6. Almeida AF, Alves RC, Felix JD, Castro DS, Zandonade E, Rocha RM. Qualidade de vida das pessoas acometidas por câncer no trato aerodigestivo superior em um Hospital Universitário. Rev Bras Cancerol 2013; 59(2): 229-37.. Speech, swallowing, phonation and appearance are adversely affected by both the disease and its treatment; some treatment options are associated with relevant dysphonia, dysphagia and facial disfiguring, with loss of function and a considerable impact on social relationships⁶6. Almeida AF, Alves RC, Felix JD, Castro DS, Zandonade E, Rocha RM. Qualidade de vida das pessoas acometidas por câncer no trato aerodigestivo superior em um Hospital Universitário. Rev Bras Cancerol 2013; 59(2): 229-37..

Approximately a third of the patients develop malnutrition, which is not exclusively caused by tumor growth, but also by associated factors such as the aerodigestive tract location of the tumor and the sequelae of surgical treatment⁷7. Gouvea SA, Nogueira MX, Oliveira ZFL, Podestá JRV, von Zeidler SV. Aspectos clínicos e epidemiológicos do câncer bucal em um hospital oncológico: predomínio de doença localmente avançada. Rev Bras Cir Cabeça Pescoço 2010; 39(4): 261-5.. Malnutrition is associated to higher rates of post-operative complications, poor response to treatment and higher risk of disease recurrence⁸8. Alshadwi A, Nadershah M, Carlson ER, Young LS, Burke PA, Daley BJ. Nutritional considerations for head and neck cancer patients: a review of the literature. J Oral Maxillofac Surg 2013; 71: 1853-60..

Cancer originates mostly in the mucosa, where squamous cell carcinoma is the commonest and usually developed from premalignant lesions as leukoplakia and erythroleukoplakia³3. Galbiatti ALS, Padovani-Junior JA, Maníglia JV, Rodrigues CDS, Pavarino EC, Goloni-Bertollo EM. Head and neck cancer: causes, prevention and treatment. Braz J Otorhinolaryngol 2013; 79(2): 239-47.. Periodic examinations by health professionals are recommended, thus there is possibility to referral for diagnostic investigation of premalignant suspected lesions, and not present major difficulties for trained professionals since the groups at highest risks are known and the site is easy to access for clinical examination and biopsy⁹9. Shanks LA, Walker TWM, McCann PJ, Kerin MJ. Oral cavity examination: beyond the core curriculum? Br J Oral Maxillof Surg 2001; 49: 640-2.. Careful visual examination of the oral mucosa by a dentist with adequate illumination may result in early detection of the disease. In addition, palpation of the adjacent structures, such as the neck, submandibular regions and jaw bones is of paramount importance. The diagnosis of small early lesions is fundamental for good prognosis¹⁰10. Cimardi ACB, Fernandes APS. Oral cancer - the real and practices of dentists of Santa Catarina. RFO UPF 2009; 14(2): 99-104., which is dictated by tumor site, size, lymph node involvement and age of the patient¹¹11. Cojocariu OM, Huguet F, Lefévre M, Périé S. Prognosis and predictive factors in head and neck cancers. Bull Cancer 2009; 96(4): 369-78..

Survival studies are the method used in epidemiological research to analyze prognosis. Furthermore, survival data is useful to assess the general impact of disease on public health programs, since they estimate the effectiveness of health systems which depend upon the quality and availability of healthcare. Survival knowledge is essential for planning and managing disease in each region as well as to help monitoring and controlling prognostic factors in the population¹²12. Pruegsanusak K, Peeravut S, Leelamanit V, Sinkijcharoenchai W, Jongsatitpaiboon J, Phungrassami T, et al. Survival and prognostic factors of different sites of head and neck cancer: an analysis from Thailand. Asian Pac J Cancer Prev 2012; 13(3): 885-90..

In most countries, the 5-year survival rate for cancer of the tongue, mouth and oropharynx is approximately 50%, where cancer of the lip carries the best prognosis, which is higher than 90%¹²12. Pruegsanusak K, Peeravut S, Leelamanit V, Sinkijcharoenchai W, Jongsatitpaiboon J, Phungrassami T, et al. Survival and prognostic factors of different sites of head and neck cancer: an analysis from Thailand. Asian Pac J Cancer Prev 2012; 13(3): 885-90. ^{, 13}13. Tiwana MS, Wu J, Hay J, Wong F, Cheung W, Olson RA. 25 Year survival outcomes for squamous cell carcinomas of the head and neck: Population-based outcomes from a Canadian province. Oral Oncol 2014; 50(7): 651-6.. Disease stage at diagnosis affects survival rates; for mouth, the survival rate at stage I is 70%, whereas for stage IV, it drops to 30%¹³13. Tiwana MS, Wu J, Hay J, Wong F, Cheung W, Olson RA. 25 Year survival outcomes for squamous cell carcinomas of the head and neck: Population-based outcomes from a Canadian province. Oral Oncol 2014; 50(7): 651-6..

One study reported that the 5-year survival rate in patients with cancer of the head and neck, mouth, oropharynx, hypopharynx and larynx was 24.1, 25.91, 19.2, 13.4 and 38%, respectively. This reality highlights the need for early diagnosis to increase treatment effectiveness in order to improve outcome¹²12. Pruegsanusak K, Peeravut S, Leelamanit V, Sinkijcharoenchai W, Jongsatitpaiboon J, Phungrassami T, et al. Survival and prognostic factors of different sites of head and neck cancer: an analysis from Thailand. Asian Pac J Cancer Prev 2012; 13(3): 885-90..

There are only a few cancer survival studies in Brazil. The knowledge of cancer survival rates may contribute towards monitoring treatment outcome in order to increase population survival as well as to identify prognostic factors. Therefore, the aim of this study was to describe the survival rates at 5 and 10-year follow-up periods for patients with cancer of the lip, mouth and pharynx, who were treated at a referral center in Florianópolis, capital of the State of Santa Catarina, Southern region of Brazil.

METHODS

This was a retrospective cohort study¹⁴14. Szklo M, Nieto FJ. Epidemiology: beyond the basics. Maryland: Aspen Publishers Inc.; 2000. performed with data from patients with cancer of the lip, mouth and pharynx (ICD-O C00 to C06, C09 to C10 and C12 to C14), who were diagnosed between January 1st and December 31^st, 2001, treated at the Center for Oncologic Research (CEPON) of Florianópolis and registered at the Hospital Cancer Registry System¹⁵15. Brasil. Ministério da Saúde. Secretaria de Atenção à Saúde. Instituto Nacional de Câncer. Coordenação de Prevenção e Vigilância. Manual de rotinas e procedimentos para registros de câncer de base populacional. Rio de Janeiro: INCA; 2006. Disponível em http://www.inca.gov.br/vigilancia/download/manual_rotinas_procedimentos_rcbp.pdf (Acessado em 1º de maio de 2013).
http://www.inca.gov.br/vigilancia/downlo... of this institution. The cancer cases of parothid gland C07 (n = 5) and nasopharynx C11 (n = 17) were excluded from the sample. The only reported cancer case of other lip, mouth and pharynx sites C14 (n = 1) were maintained in the sample.

These registries are systematic sources of information on malignant neoplasia diagnosed and treated at the hospital they were managed, following criteria established by the Brazilian National Institute of Cancer (INCA). CEPON is the core institute for cancer care in the State of Santa Catarina.

Data regarding death, such as date and cause, were gathered from the Mortality Information System of the Brazilian Ministry of Health, based on death certificates. This database was made available by the Health Secretariat of Santa Catarina and analyzed between 2001 and 2011. The final follow-up date was December 31^st, 2011.

In order to carry out patient follow-up, the probabilistic relationship method of registration was used¹⁶16. Camargo Jr KR, Coeli CM. Reclink: an application for database linkage implementing the probabilistic record linkage method. Cad Saude Publica 2000; 16(2): 439-47., relating the Hospital Cancer Registry System database with Mortality Information System. The RecLink III software was used (http://www.iesc.ufrj.br/reclink/RecLink_arquivos/RecLinkdl.html). The association rules were determined between the two databases, using variables from each of them. The Mortality Information System variables were death certificate number, patient name, date of birth, date of death, cause of death and town of residence. The Hospital Cancer Registry variables were patient record number, patient name, date of birth and town of residence. A single database was then created containing all the information pertinent to this study.

The independent variables were sex, age at diagnosis (years), ethnicity (white/black and mixed), level of education (higher education and high school, complete primary school, incomplete primary school or illiterate), previous diagnosis and treatment (with diagnosis/with treatment, with diagnosis/no treatment or no diagnosis/no treatment), clinical stage at diagnosis (stages I and II: early; stages III and IV: advanced).

Survival was calculated as the interval between date of diagnosis (biopsy or surgery) from the Hospitalar Cancer Registry database and date of death or last date of follow-up. The maximum follow-up was ten years - patients not found on Mortality Information System or who did not have a date of death on Hospitalar Cancer Registry were censored at the last follow-up date.

The survival curves were estimated using Kaplan-Meier, with or without stratification. The probability of survival up to the specified date was estimated, considering that survival up to each studied time was independent from the survival up to other times. In order to compare the stratified survival curves, log-rank test was used, which compared values observed and the expected values for each stratum, considering the null hypothesis that the risk was the same for all strata¹⁷17. Carvalho MS, Andreozzi VL, Codeço CT, Campos DP, Barbosa MTS, Shimakura SE. Análise de sobrevida: teoria e aplicações em saúde. Rio de Janeiro: FIOCRUZ; 2005..

The estimation of the effect of the independent variables was performed based on the semi-parametric model of proportional risks, Cox model, which estimates proportionalities of risks along the period of observation¹⁷17. Carvalho MS, Andreozzi VL, Codeço CT, Campos DP, Barbosa MTS, Shimakura SE. Análise de sobrevida: teoria e aplicações em saúde. Rio de Janeiro: FIOCRUZ; 2005.. The variables included in the model were those that presented a p-value < 0.20. All analyses were carried out for 5 and 10 years of follow-up using the Stata SE 9.0 software.

The research project was approved by the Ethics Committee in Research of the CEPON.

RESULTS

In the period studied, 141 people had a diagnosis of cancer of the lip, mouth and other pharynx. Tumors of the tongue (17.7%) and oropharynx (15.6%) were the most incident. The data on death incidence as well as on 5 and 10-year survival rates by specific sites are described in Table 1. Amongst the patients analyzed, 81.6% were male, with a mean age of 57.1 years (standard deviation - SD = 12.0). In terms of ethnicity, the vast majority was white (93.6%); 60.7% did not complete primary education and only 8.9% completed high school or higher education. Most tumors were diagnosed at stage III (47.9%) or IV (44.3%); 64.1% of the patients presented to the service with a diagnosis, however without previous treatment (Table 2).

The survival rates and factors were analyzed together: lip, mouth and other pharynx, because the groups were very small, and they did not differ statistically among them. In 5 years, 94 subjects were deceased (66.7%) (Table 1). From the total of followed men and women, 70.4% (n = 81) and 50.0% (n = 13) had died, respectively (Table 2). At 10-year follow-up, 103 subjects were deceased (73.0%) (Table 1); 77.4% (n = 89) of all men and 53.9% (n = 14) of all women were died (Table 3). All causes of death were due or related with cancer.

The overall 5-year survival was 33.3% (95%CI 25.7 - 41.1) (Table 1). Female patients showed a better survival rate, 50.0% (95%CI 26.6 - 63.6), against 29.5% (95%CI 2&&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda&nda-ash; - 38.0) of males; however, such difference did not reach significance (p = 0.102). "This also occurred with ethnicity (p = 0.083), level of education (p = 0.276) as well as diagnosis and previous treatment (p = 0.856). Cancer stage was a significant variable on bivariate analysis, i.e., those at stages I and II had a likely survival of 63.6% (95%CI 22.8 - 78.0), whilst those at stages III and IV, 30.8% (95%CI 23.7 - 38.8), thus making clinical stage an independent variable, increasing the chance of death by 2.88 (95%CI 1.04 - 7.92) (Table 2).

The overall 10-year survival rate was 26.9% (95%CI 19.9 - 34.4) (Table 1). Females had a better survival, 46.1% (95%CI 26.6 - 63.6), against 22.6% (95%CI 15.5 - 30.6) in males, however, the difference only just reached significance (p = 0.051). Non-significant difference was also observed for ethnicity (p = 0.098), level of education (p = 0.441) as well as for previous diagnosis and treatment (p = 0.905). The variable age showed an increase of death risk of 2% every year from diagnosis, however statistical significance was missed in the adjusted analysis. The variable stage was significant on bivariate analysis, i.e., those at stage I and II had a survival rate of 54.5% (95%CI 22.8 - 78.0), against 24.6% (95%CI 17.6 - 32.3), making it an independent variable increasing death risk by 2.51 (95%CI 1.01 - 6.23) (Table 3). Figure 1 shows the overall survival curves for each variable studied.

DISCUSSION

This study aimed at estimating survival rates at five and ten years from a diagnosis of cancer of the lip, mouth and pharynx. The high incidence, prevalence and mortality rates observed as well as the low survival¹⁸18. American Cancer Society. Cancer Facts & Figures 2013. Atlanta: American Cancer Society; 2013. reported in some studies warranted the importance of the present study. This type of cancer can be curable at the time of diagnosis; however, it is associated with a low survival rate due to the conditions presented by the patient, which are related to an unhealthy lifestyle, which involves smoking and alcohol consumption¹⁹19. Rodriguez CP, Adelstein DJ. Survival trends in head and neck cancer: opportunities for improving outcomes. Oncologist 2010; 15: 921-3. ^{, 20}20. Pöschl G, Seitz HK. Alcohol and cancer. Alcohol 2004; 39(3): 155-65.. The synergistic effect between tobacco and alcohol results in a 30-fold increase in the risk of developing the disease¹⁸18. American Cancer Society. Cancer Facts & Figures 2013. Atlanta: American Cancer Society; 2013..

Tobacco smoking is the main risk factor for cancer of the lip, mouth and pharynx, especially regarding long-term heavy smoking (20 or more cigarettes a day) or users of black tobacco with a high tar content²¹21. Hashibe M, Brennan P, Benhamou S, Castellsague X, Chen C, Curado MP. Alcohol drinking in never users of tobacco, cigarette smoking in never drinkers, and the risk of head and neck cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium. J Natl Cancer Inst 2007; 99(10): 777-89.. A study performed by Rodriguez and Adelstein¹⁹19. Rodriguez CP, Adelstein DJ. Survival trends in head and neck cancer: opportunities for improving outcomes. Oncologist 2010; 15: 921-3. reported a negative impact on survival with the continued use of tobacco after treatment, thus suggesting that smoking cessation may improve survival. According to Galbiatti et al.²²22. Galbiatti ALS, Padovani-Junior JA, Maníglia JV, Rodrigues CDS, Pavarino EC, Bertollo EMG. Head and neck cancer: causes, prevention and treatment. Braz J Otorhinolaryngol 2013; 79(2):239-47., there is a significant reduction in the risk of developing the disease when the patient quits smoking.

Alcohol intake also increases the risk of developing this type of cancer - a heavy drinker (a weekly intake of more than 300 mL) has a risk 10 times higher than non-drinkers or those who drink sporadically. This risk factor seems to be related to exposure to an intermediate metabolite of ethanol, acetaldehyde, which is a known carcinogen²⁰20. Pöschl G, Seitz HK. Alcohol and cancer. Alcohol 2004; 39(3): 155-65..

When analyzing the socio-demographic profile of the patients included in this study, a higher prevalence of cancer diagnoses and deaths was observed amongst males, which was also reported in other studies²³23. Santos VTG, Santos VS, Carvalho RAS, Guedes SAG, Trento CV. Mortality from oral cancer in Aracaju/SE, Brazil: 2000-2009. Rev Odontol UNESP 2013; 42(3): 204-10.

24. Santos LCO, Batista OM, Cangussu MCT. Characterization of oral cancer diagnostic delay in the state of Alagoas. Braz J Otorhinolaryngol 2010; 76(4): 416-22. ^{- 25}25. Attar E, Deya S, Hablasb A, Seifeldinb IA, Ramadanb M, Rozekc LS, et al. Head and neck cancer in a developing country: a population-based perspective across 8 years. Oral Oncol 2010; 46(8): 591-6.. There is evidence that exposure to tobacco is higher in men than in women²⁶26. Olson CM, Burda BU, Beil T, Whitlock EP. Screening for oral cancer: a targeted evidence update for the U.S. preventive services task force. Evidence Synthesis No. 102. AHRQ Publication No. 13-05186-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2013., and that women notice the symptoms of the disease more easily than men, which may lead them to seek medical assistance earlier²³23. Santos VTG, Santos VS, Carvalho RAS, Guedes SAG, Trento CV. Mortality from oral cancer in Aracaju/SE, Brazil: 2000-2009. Rev Odontol UNESP 2013; 42(3): 204-10., thus resulting in earlier diagnosis and improved survival. However, in this study, no significant difference was observed either at five or ten years of follow-up.

The information reported in this study regarding age at diagnosis does not corroborate the findings of another study²⁷27. Pulte D, Brenner H. Changes in survival in head and neck cancers in the late 20th and early 21st century: a period analysis. Oncologist 2010; 15: 994-1001., which reported a decrease in survival with an age increase. The authors pointed out that older patients at the time of diagnosis may die as a result of complications of treatment, as they may be unable to tolerate the aggressiveness of the therapeutic approach²⁷27. Pulte D, Brenner H. Changes in survival in head and neck cancers in the late 20th and early 21st century: a period analysis. Oncologist 2010; 15: 994-1001..

Regarding ethnicity, both diagnosis and death rates were higher in white individuals, although this did not reach statistical significance. The results of this study are therefore inconclusive and one must take into account the data in the literature, which shows death rates higher in individuals of mixed ethnic background²³23. Santos VTG, Santos VS, Carvalho RAS, Guedes SAG, Trento CV. Mortality from oral cancer in Aracaju/SE, Brazil: 2000-2009. Rev Odontol UNESP 2013; 42(3): 204-10.. Regarding level of education, no significant difference was found at five or ten years of follow-up. The literature reports that death rates are higher in less educated individuals²³23. Santos VTG, Santos VS, Carvalho RAS, Guedes SAG, Trento CV. Mortality from oral cancer in Aracaju/SE, Brazil: 2000-2009. Rev Odontol UNESP 2013; 42(3): 204-10..

Regarding previous diagnosis and treatment, the death rates found were similar in the three categories. Although this study has been carried out in a referral center, it is worth to highlight that nearly 10% of the subjects arrived with no previous diagnosis and consequently with no treatment. The literature shows that the most frequently performed treatment for cancer of the lip, mouth and pharynx is radiotherapy; however, for patients with loco-regional disease, the use of radiotherapy did not alter survival²⁷27. Pulte D, Brenner H. Changes in survival in head and neck cancers in the late 20th and early 21st century: a period analysis. Oncologist 2010; 15: 994-1001..

On the other hand, the clinical stage at diagnosis was an independent factor associated with survival, both at five and ten years of follow-up. This finding corroborates that of a different study, which described a higher prevalence of stage IV disease associated with a decrease in survival for all sites¹³13. Tiwana MS, Wu J, Hay J, Wong F, Cheung W, Olson RA. 25 Year survival outcomes for squamous cell carcinomas of the head and neck: Population-based outcomes from a Canadian province. Oral Oncol 2014; 50(7): 651-6.. Furthermore, another study has reported poorer survival rates in metastatic disease, in which survival decreased from 41.5 to 32.5% during the follow-up period²⁷27. Pulte D, Brenner H. Changes in survival in head and neck cancers in the late 20th and early 21st century: a period analysis. Oncologist 2010; 15: 994-1001..

The most effective way to improve the prognosis of patients with cancer of the lip, mouth and pharynx is the prevention of risk factors and early diagnosis, since early treatment results in a high percentage of resolution. The main causes of delayed diagnosis are lack of information and symptom neglect by the patients, as well as health professional failure at routinely screening patients²²22. Galbiatti ALS, Padovani-Junior JA, Maníglia JV, Rodrigues CDS, Pavarino EC, Bertollo EMG. Head and neck cancer: causes, prevention and treatment. Braz J Otorhinolaryngol 2013; 79(2):239-47.. The reason for a low rate of early diagnosis is related to a low level of preparation of dentists, as other health professionals, to actively screen and recognize potentially malignant oral lesions, which could be diagnosed and treated before malignant transformation¹⁰10. Cimardi ACB, Fernandes APS. Oral cancer - the real and practices of dentists of Santa Catarina. RFO UPF 2009; 14(2): 99-104.. Such lack of preparation makes health professionals underprepared to establish an earlier diagnosis. This limitation, in turn, affects patient referral to the appropriate services, which further complicates treatment and reduces the chances of a cure¹⁰10. Cimardi ACB, Fernandes APS. Oral cancer - the real and practices of dentists of Santa Catarina. RFO UPF 2009; 14(2): 99-104..

Health professionals have the obligation to be prepared to recognize suspicious lesions and carry out a diagnostic biopsy or, at least, refer the patient. Therefore, periodic visits to the dentist are paramount to increase detection of early lesions and to monitor changes. Furthermore, the dental professional must instruct their patients to examine their own mouth, aiming at detecting lesions as early as possible¹⁰10. Cimardi ACB, Fernandes APS. Oral cancer - the real and practices of dentists of Santa Catarina. RFO UPF 2009; 14(2): 99-104.. Hopefully, higher levels of awareness to the problem and appropriately trained health professionals, especially dentists, both at the undergraduate and the following professional development levels, may cause an impact on the rates of early diagnosis and, consequently, on higher survival rates⁹9. Shanks LA, Walker TWM, McCann PJ, Kerin MJ. Oral cavity examination: beyond the core curriculum? Br J Oral Maxillof Surg 2001; 49: 640-2..

The strong points of this study were the reports of data from official sources, as established by INCA, as well as the inclusion of the follow-up time of ten years, which permitted an insight into survival rates over a long period of time and is not commonly encountered in Brazilian studies. However, the limitations must be taken into consideration when interpreting the results; one of them was the dependence on information stored on the database system used, which did not provide some important data, such as the presence of other relevant risk factors. Furthermore, the database used for this study generated a considerably high number of cases, for which no information on smoking or alcohol intake was available, which led to the exclusion of those variables. Another aspect to be considered is the difficulty imposed by the need of including cancer cases with different topographies in this survival study, in order to compose a minimum sample for analysis.

CONCLUSION

Survival rate at 5 years was 33.3% and, at 10 years, 26.9%. Advanced stage at diagnosis was an independent risk factor of death due to cancer of the lip, mouth and pharynx in both periods analyzed.

REFERENCES

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