Correspondence: Maria Cássia Ferreira de Aguiar, Laboratório de Patologia Bucal, Faculdade de Odontologia, UFMG, Rua Conde de Linhares, 141, Cidade Jardim, 30380-030 Belo Horizonte, MG, Brasil. e-mail: fluiz@metalink.com.br

Braz Dent J (2001) 12(1): 57-61 ISSN 0103-6440

The purpose of this study was to evaluate, retrospectively, the profile of patients with oral squamous cell carcinoma. They were referred to two hospitals of Belo Horizonte (MG, Brazil) between 1986 and 1996. The medical records of 740 patients presenting oral squamous cell carcinoma were reviewed in detail. The TNM classification and staging, age, gender, race, occupation, and site of the primary tumor were recorded. The male-to-female ratio was 4.8:1. The mean age was 58.6 years. Most of the patients were in their sixties and were farm workers. The tumors were found principally on the tongue. There was a close relationship between some habits (tobacco and alcohol consumption) and the development of oral squamous cell carcinoma. Most of the patients sought medical care in the first year, even though almost half of them had lesions in stage T4. The identification of the characteristics of this specific population might reflect either accomplishments or problems in oral cancer control and can enable the development of a primary prevention program for oral squamous cell carcinoma.

Key Words: oral squamous cell carcinoma, epidemiology, Brazil.

INTRODUCTION

Squamous cell carcinoma is the most frequently occurring malignant tumor of the oral structures, accounting for about 90% of the malignant oral lesions. Epidemiological studies have shown that the incidence of oral cancer varies significantly among the continents and within developed and developing countries (1).

Mortality rates for carcinoma of the mouth and oropharynx in some areas in Brazil are among the highest in the world (2). The most important determinant of poor prognosis is advanced disease stage at diagnosis (3). The dental practitioner plays a particularly important role in the detection of oral cancer in its early stages when treatment is most effective and mor
bidity is minimal (4).

The etiology of head and neck cancer is multi-factorial. Genetic, environment, social and behavioral effects may all be implicated (5). However, alcohol and tobacco are two of the most important risk factors for development of oral squamous cell carcinoma. The consumption of alcohol and tobacco is closely associated not only with the development of oral cancer, but also with the course of the disease and this consumption is associated with a poor prognosis (6).

The purpose of this retrospective study was to evaluate the profile of patients with squamous cell carcinoma of the oral cavity referred by dentists and physicians to two hospitals of Belo Horizonte (MG, Brazil).

MATERIAL AND METHODS

The population studied consisted of Brazilian adults with a histologically confirmed diagnosis of oral squamous cell carcinoma (International Classification of Disease - [ICD]) treated between January, 1986 and December, 1996 in two hospitals of Belo Horizonte, MG, Brazil (Mário Penna and Luxemburgo Hospitals). The medical records of the patients were reviewed to determine the TNM classification and staging, age, gender, race, occupation, symptoms, habits (tobacco and alcohol consumption), and site of the primary tumor. However, it was not possible to analyze alcohol and tobacco use in terms of quantity, quality and frequency of use.

TNM (tumor-nodes-metastasis) is the most popular form of quantifying tumor size and the extent of metastatic spread of oral squamous cell carcinoma. Individualized TNM systems are used for most human cancers. Each specific TNM system depends on three
basic clinical features: the size, in centimeters, of the tumor itself (T), the presence and type of spread to the local lymph nodes (N), and the presence or absence of distant metastasis (M). The higher the stage classification, the worse the prognosis.

RESULTS

There were 740 cases of squamous cell carcinoma of the oral cavity confirmed by biopsy between 1986 and 1996. The gender of the patients was known in 723 cases, 598 (82.7%) male and 125 (17.3%) female (4.8:1). The ages at the time of diagnosis ranged from 25 to 97 years with the average age being 58.6 years (58.2 for men and 63.9 for women). Most of the patients were in their sixties (32.5%), with the majority between 40 and 80 years of age (85.2%). In all but those in their nineties, the number of male patients was higher than the number of female patients. The gender distribution is shown in Figure 1. A total of 33.5% of the patients were black, 23.7% white, and 42.8% mulatto.

The site distribution of the lesions is listed in Table 1. The tongue was the most frequently involved site, accounting for 320 cases (44%), followed by the floor of the mouth with 115 cases (16%).

The occupations were known in 652 cases and are reported in Table 2. The most frequent occupation was farming (36.2%). The most common locations of the lesions for this group is shown in Table 3.

The alcohol and tobacco consumption, when recorded in the medical files, is shown in Table 4. The association of these two habits was present in the majority of the patients (64%), followed by tobacco consumption (32%). Less than 2% of the patients did not report any of these habits.

The time that elapsed between the beginning of the symptoms and the diagnosis was reported by 430 patients. Most of the patients sought medical care in the first year (Figure 2). The T and N staging were known in 385 and 362 cases, respectively. These data were associated with the duration of symptoms and are shown in Figures 3 and 4

DISCUSSION

Information from 740 medical files was recorded. In this study the rate of incidence showed a tendency to increase through the years researched, despite the lower number of recorded cases in 1996 (119 cases vs 190 in 1995). Other studies (7-9) have registered similar results, although some authors have found no significant differences during the late 1970s and early 1980s (10).

The male-to-female distribution (4.8:1) was higher than that reported in some studies, except the study in a Greek population (11), that found a ratio of 9.2:1. Pinholt et al. (12) observed almost equivalent numbers between men and women (1.2:1), even though other studies (3,10,13,14) reported higher ratios (1.5:1, 1.48:1, 1.5:1 and 2.4:1, respectively).

Oral squamous cell carcinoma has long been considered to be a tumor of the elderly and has been seen only sporadically before the third decade of life. In our study, the average age (58.6) is in agreement with the study of Oliver et al. (3) even though it was lower than the data reported by Krutchkoff et al. (4). When the average ages were compared between sexes, the result was similar to that of the literature (11-13): men showed an incidence peak at younger ages than women.

In spite of the different geographic locations, a number of studies have shown a prevalence of white patients with squamous cell carcinoma (3,10,13,15,16). In Brazil the expressive miscegenation of the population brings some difficulties in analyzing this subject. When "mulattos" (white and black miscegenation) are considered, this group was the most prevalent followed by blacks and whites.

Epidemiological studies have shown that the sites of occurrence for oral cancer differ widely. Tongue, lip and floor of the mouth are the most frequent sites of lesions of squamous cell carcinoma in the oral cavity. This study is in agreement with the literature (3,4,10,17,18) since the tongue was the most frequent site. Epidemiological investigations in Brazil have shown that the rate of tongue carcinoma is increasing (19). Other studies (9,11) have shown that the lip is the most constant site of squamous cell carcinoma in the oral cavity, even though the tongue was the second site in the majority of these studies.

Farming was the most frequent occupation of patients with squamous cell carcinoma in our study and the second in the study of Almodovar et al. (20). As reported by Antoniades et al. (11), these patients generally have squamous cell carcinoma of the lip. This fact can be explained by the higher UV ray exposure. Surprisingly, the patients of our study showed a higher rate of tongue carcinoma than of lip carcinoma. This was
also observed by Link et al. (21) not only in smokers but also in non-smokers. The increased incidence of the tobacco and alcohol consumption habits among farmers can explain that fact. Zheng et al. (22) established a significant association between tobacco smoking and the risk of tongue cancer. The risk associated with non-filter cigarettes was two-fold higher than that associated with filter cigarettes (23), and this also applies to those who hand rolled their own cigarettes or inhaled smoke, habits that are very common in rural areas.

In this study, the alcohol and tobacco consumption was known for 404 patients. Only 6 of these patients did not report any habit. Tobacco users had concomitant use of alcohol in 63.8% of cases. Andre et al. (23) observed a deleterious effect of the consumption of alcohol even with non-smokers or casual smokers. Although our data are not very different from that of other studies (20,24), they are important because in Brazil there are no published studies which correlate the role of tobacco and alcohol with the increased risk of oral cancer.

The delay in diagnosis of oral squamous cell carcinoma could be correlated to professional delay (in reading a diagnosis), to patient delay (in looking for professional care) or both and presumably has some bearing on the size of the tumor presented.

In our study, the tumor size (T) was known in 385 cases. Of these, approximately half were in the T4 stage which represents lesions involving adjacent structures at diagnosis. The size of many lesions did not vary significantly as the duration of symptoms was increased. Since the mouth is an anatomical region easy to examine, we can conclude that any patient or professional is prepared to detect small cancer lesions before the symptoms become recognizable. This requires prophylactic initiatives with on-going screening programs or standard procedures in routine check-ups of the oral cavity of the risk groups.

While the size of the lesions did not show significant variations related to the delay in diagnosis, we observed a higher frequency of N3 lesions with the progression of the disease. This fact means a poorer prognosis and a more difficult and complex treatment.

It was possible to record the information about metastasis (M) and duration of symptoms in only 190 medical files. This can be explained partially by the difficulty for the physician to establish M stage based only on the clinical exam.

This study described the epidemiological profile of a specific population with the diagnosis of oral squamous cell carcinoma. The major goal should be to establish a scientific basis for initiating educational programs for prevention and early diagnosis of oral cancer.

ACKNOWLEDGMENTS

We express our gratitude to the administration of the Mario Penna and Luxemburgo Hospitals and heads of the Service of Head and Neck Surgery for permission to use the records of their patients presenting oral squamous cell carcinoma.

This study was supported by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil).

RESUMO

Gervásio OLAS, Dutra RA, Tartaglia SMA, Vasconcellos WA, Barbosa AA, Aguiar MCF. Carcinoma epidermóide de boca: um estudo retrospectivo de 740 casos no Brasil. Braz Dent J 2001;12(1):57-61.

O objetivo deste trabalho foi avaliar, retrospectivamente, o perfil de pacientes com carcinoma epidermóide de boca encaminhados a dois hospitais de Belo Horizonte entre 1986 e 1996. Os prontuários médicos de 740 pacientes foram revistos em detalhe. Foram analisados os dados do estadiamento clínico (TNM), idade, sexo, raça, profissão do paciente e localização do tumor. A incidência homem/mulher foi de 4.8:1. A idade média dos pacientes foi de 58,6 anos. A maioria dos pacientes eram trabalhadores rurais. A localização mais freqüente para as lesões foi a língua. O consumo de álcool e tabaco estiveram intimamente relacionados com o desenvolvimento dos carcinomas. A maioria dos pacientes procurou assistência médica no primeiro ano de desenvolvimento da doença, quase a metade desses pacientes apresentavam lesões no estágio T4. A caracterização desta população específica pode ajudar no desenvolvimento de programas de prevenção para o carcinoma epidermóide de boca.

Unitermos: carcinoma epidermóide de boca, epidemiologia, Brasil.

REFERENCES

1. Jovanovic A, Schulten EAJM, Kostense PJ, Snow GB, van der Waal I. Tobacco and alcohol related to the anatomical site of oral squamous cell carcinoma. J Oral Pathol Med 1993;22:459-462.

2. Ministério da Saúde. Brasil. Instituto Nacional do Câncer. Manual de detecção de lesões suspeitas - Câncer de boca. Brasília. 1996. Available from: <http:www.inca.org.br./manual/boca/.html> via the internet. Accessed 26 May 2000.

3. Oliver AJ, Helfrick JF, Gard D. Primary oral squamous cell carcinoma: a review of 92 cases. J Oral Maxillofac Surg 1996;54:949-954.

4. Krutchkoff KJ, Chen J, Eisenberg E, Katz RV. Oral cancer: a survey of 566 cases from the University of Connecticut Oral Pathology Biopsy Service, 1975-1986. Oral Surg Oral Med Oral Pathol 1990;70:192-198.

5. Wake M. The urban/rural divide in head and neck cancer - the effect of atmospheric pollution. Clin Otolaryngol 1993;18:
298-302.

6. Bundgaard T, Bentzen SM, Wildt J. The prognostic effect of tobacco and alcohol consumption in intra-oral squamous cell carcinoma. Oral Oncol, Eur J Cancer 1994;30B:323-328.

7. Cowan CG, Gregg TA, Kee F. Trends in the incidence of histologically diagnosed intra-oral squamous cell carcinoma in Northern Ireland, 1975-89. Br Dent J 1992;173:231-233.

8. MacFarlane, GJ, McCredie M, Coates M. Patterns of oral and pharyngeal cancer incidence in New South Wales, Australia. J Oral Pathol Med 1994;23:241-245.

9. Cox B, Taylor K, Treasure E. Trends in oral cancer by subsite in New Zealand. Oral Oncol, Eur J Cancer 1995;31B:113-117.

10. Silverman Jr S, Gorsky M. Epidemiologic and demographic update in oral cancer: California and national data - 1973 to 1985. J Am Dent Assoc 1990;120:495-499.

11. Antoniades DZ, Styanidis K, Papanayotou P, Trigonidis G. Squamous cell carcinoma of the lips in a northern Greek population. Evaluation of prognostic factors on 5-year survival rate - I. Oral Oncol, Eur J Cancer 1995;31B:333-339.

12. Pinholt EM, Rindum J, Pindborg JJ. Oral cancer: a retrospective study of 100 Danish cases. Br J Oral Maxillofac Surg 1997;35:77-80.

13. Heng LTC, Rossi EP. A report on 222 cases of oral squamous cell carcinoma. Military Medicine 1995;160:319-323.

14. Wildt J, Bundgaard T, Bentzen SM. Delay in the diagnosis of oral squamous cell carcinoma. Clin Otolaryngol 1995;20:21-25.

15. Summerlin DJ. Oral squamous cell carcinoma in Indiana. IDA J 1991;12:10-13.

16. Muscat JE, Richie Jr JP, Thompson S, Wynder EL. Gender differences in smoking and risk for oral cancer. Cancer Research 1996;56:5192-5197.

17. Kowalski LP, Franco EL, Torloni H, Fava AS, Sobrinho JA, Ramos G, Oliveira BV, Curado MP. Lateness of diagnosis of oral and oropharyngeal carcinoma: factors related to the tumour, the patient and health professionals. Oral Oncol, Eur J Cancer 1994;30B:167-173.

18. Barasch A, Morse DE, Krutchkoff DJ, Eisenberg E. Smoking, gender, and age as risk factors for site-specific intraoral squamous cell carcinoma. Cancer 1994;73:509-513.

19. Torloni H, Brumini R. Registro Nacional de Tumores. Rio de Janeiro, Ministério da Saúde, Divisão Nacional de Doenças Crônico Degenerativas, 1978. 170 p.

20. Almodovar J, Perez SI, Arruza M, Morell CA, Baez A. Descriptive epidemiology of head and neck squamous cell carcinoma in Puerto Ricans. Puerto Rico Health Sci J 1996;15:251-255.

21. Link MJO, Kaugars GE, Burns JC. Comparison of oral carcinomas in smokeless tobacco users end nonusers. J Oral Maxillofac Surg 1992;50:452-455.

22. Zheng T, Holford T, Chen Y, Jiang P, Zhang B, Boyle P. Risk of tongue cancer associated with tobacco smoking and alcohol consumption: a case-control study. Oral Oncology 1997;33:82-85.

23. Andre K, Schraub S, Mercier M, Bontemps P. Role of alcohol and tobacco in the aetiology of head and neck cancer: a case-control study in the Doubs region of France. Oral Oncol, Eur J Cancer 1995;31B:301-309.

24. MacFarlane GJ, Zheng T, Marshall JR, Boffeta P, Niu S, Brasure J, Marletti F, Boyle P. Alcohol, tobacco, diet and the risk of oral cancer: a pooled analysis of three case-control studies. Oral Oncol, Eur J Cancer 1995;31B:181-187.

Accepted October 29, 1999
Braz Dent J 12(1) 2001