British Journal of Oral and Maxillofacial Surgery 45 (2007) 298–301
Oral cancer in Enugu, Nigeria, 1998–2003 Chima Oji ∗ , F.N. Chukwuneke Department of Oral & Maxillofacial Surgery, University of Nigeria Teaching Hospital, Enugu, Nigeria Accepted 14 September 2006 Available online 23 October 2006
Abstract Cancers of the oral cavity make up 3–4% of all cancers, being in eighth place in men and eleventh in women when the cancer is caused by smoking and alcohol misuse. In this study we recorded all oral cancers in Enugu, eastern Nigeria over the 6-year period from 1998 to 2003. We reviewed all patients who had a diagnosis of invasive oral cancer during this period from notes kept in the Records Department of the University of Nigeria Teaching Hospital (UNTH), Enugu, Nigeria. Carcinoma-in-situ, lymphoma, and leukaemia were not included. All cases were categorised by the site of the tumour and the age and sex of the patient. Eighty one cases of oral cancer were recorded during that period, accounting for 2.7% of all cancers. Forty-eight men and thirty-three women were affected, and the most common site was other sites of the oral cavity (28, 35%), followed by the tongue (24, 30%), floor of the mouth (17, 21%) and finally the lip (12, 15%). They were all advanced at the time of presentation. The patients gave no history of alcohol or tobacco misuse, and their conditions should be seen in terms of chronic illnesses, malnutrition, poverty, and ignorance. We need an urgent awareness campaign, and programmes for the prevention and early detection of oral cancer, in Nigeria. © 2006 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Oral cancer; Occurrence; Enugu; Nigeria
Introduction The term oral cancer typically includes the following sites: lip, tongue, buccal cavity, gum, floor of mouth, pharynx, larynx, and nasopharynx. Worldwide, oral cancer is a serious cause of morbidity and mortality and its incidence varies widely according to geographical location,1 varying among groups within one geographic location that are characterised by age, sex, or race.2 Ultraviolet light from exposure to sunlight is thought to be a major aetiological factor for cancer of the lip, unlike cancers of intraoral sites, although other factors, including tobacco smoking and viruses may also be involved.3 Because cancer of the lip is associated with working out of doors, most lip cancers occur on the sun-exposed vermillion of the lower lip and are relatively uncommon on the inner aspect, or on the upper lip. The geographical distribution of areas of ∗
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high incidence of lip cancer differs from those of intraoral cancer.3–5 There are many reasons why descriptive data about oral cancer for specific geographical areas are important, and they include understanding the extent of the problem, finding out which groups within the population are at highest and lowest risk, and relating the burden of oral cancer to that of other cancers to evaluate the allocation of resources for research, prevention, treatment, and support services. As we know of no previous descriptive study of the incidence of oral cancer in eastern Nigeria, we undertook a 6-year retrospective study in a major tertiary hospital in the region.
Patients and methods We retrieved the records of all patients with invasive cancer from the records department of the University of Nigeria Teaching Hospital (UNTH), Enugu, Nigeria from January 1998 to December 2003. These records contained the TNM
0266-4356/$ – see front matter © 2006 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bjoms.2006.09.001
C. Oji, F.N. Chukwuneke / British Journal of Oral and Maxillofacial Surgery 45 (2007) 298–301
classification (tumour, nodes, and metastasis) and a detailed dietary history of each patient. We focused our attention on the results of the following laboratory tests: concentrations of glucose, haemoglobin, albumin, and electrolytes in the blood; urine examination and culture; presence of malarial parasites, and HIV titre. Eighty-one cases of oral cancer were recorded during this period, and we classified them according to the 9th revision of the International Classification of Diseases (ICD).6 The anatomical sites used to calculate the total number of cases were ICD-9 140 to 146. Cancer of the lip (ICD-9 140) was analysed separately. Cancer of the skin of the lip is coded as skin cancer and is not included. Tongue (ICD-9 141), gum (ICD-9 143), floor of the mouth (ICD-9 144), other mouth (ICD-9 145, includes buccal mucosa, labial mucosa, palatal mucosa, uvula, retromolar areas, and unspecified mouth), and tonsil/oropharynx (ICD-9 146) cancers were grouped together as “intraoral cancer” for analysis. Major salivary gland tumours (ICD-9 142) were excluded from the intraoral cancer group, whereas minor salivary gland tumours were included among intraoral cancer groups. Nasopharynx (ICD 9-147), hypopharynx (ICD-9 148), and other buccal/pharynx (ICD-9 149) cancers were excluded, as were data for carcinoma-in-situ or haematological malignancies such as oral lymphoma. The cases were categorised by site of primary tumour, sex and age group of the patient, and by histological type.
Fig. 1. Oral cancer with extraoral ulceration.
Results All the patients were Nigerians, who came from the lower economic class of society, had little or no formal education, and lived at subsistence level. Twelve were farmers and the rest were small traders, casual workers, and artisans. Their diet consisted of starchy food that lacked vitamins and protein. In addition to poor oral hygiene, the laboratory results showed that they all had varying numbers of malarial parasites, hypoalbuminaemia, hypoproteinaemia (low concentrations of transferrin, essential amino acids, and lipoprotein), and hypoglycaemia. Electrolytes, particularly potassium and magnesium, were depleted. Most patients had iron deficiency anaemia. Two of the patients had HIV. Seventy of the eightyone cases were in TNM stage III, and 11 in stage IV at the time of presentation (Figs. 1–3). There was no history of alcohol or tobacco misuse. Table 1 lists the number of all the cases of oral cancer according to the site of the primary tumour, and the age and sex of the patient. During the same period, the records department of the hospital recorded 2953 cases of cancer of all types, so oral cancer comprised about 2.7% of all cancers. Of all specified histological types, 78 (96%) were squamous cell carcinomas, two (3%) were sarcomas, and one (1%) was a malignant melanoma. All the tumours of the lip involved the vermillion border of the lower lip. The sites are shown in Table 2.
Fig. 2. Oral cancer with destruction of the lower jaw.
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Table 1 Cases of oral cancer in UNTH, Enugu, Nigeria from 1998–2003 Site
ICD-9
Sex
Age group (years) 10–19
20–29
30–39
40–49
50–59
60+
Total
Lip
140 140
M F
0 0
1 0
1 2
2 1
0 0
3 2
7 5
Tongue
141 141
M F
2 1
0 0
3 2
2 1
2 2
5 4
14 10
Floor of mouth
144 144
M F
1 0
1 0
0 1
3 1
2 1
3 4
10 7
Other sites
145 145
M F
2 1
1 0
2 3
3 2
4 2
5 3
17 11
7
3
14
15
13
29
81
Total
Age
Table 2 Yearly occurrence in men and women.
The number of cases was lowest in the third decade and highest in the seventh decade (Table 1). Just under a third developed in patients under the age of 40 years and just over a third in patients 60 years and older.
Year
Men
1998 1999 2000 2001 2002 2003
7 8 5 7 8 13
Total
48 (59)
Sex A total of 48 oral cancers (59%) were diagnosed in men and 33 (41%) in women, giving an overall male:female ratio of 1.5:1 (Table 2). There was a variation in the male:female ratio for different age groups and sites (Table 1). In the age group 60 years and older, the number of cancers of the floor of the mouth (ICD-9 144) in women was greater than in men. Again
Women 7 8 4 3 4 7 33 (41)
Total 14 16 9 10 12 20 81
Data are number (%)
in the age group of 30–39 years, the number of women with lip cancer (ICD-9 140) and cancers of other sites in the oral cavity (ICD-9 145) exceeded the number of men. However, cancer of other sites of the oral cavity was far more common in men, as evidenced by the overall male:female ratio of about 1.5:1. Occurrence Table 2 shows all oral cancers recorded during the 6-year study by sex of the patient and year of diagnosis. The number of cases of oral cancer during this period varied only minimally, and so does not differ significantly.
Discussion
Fig. 3. Cancer with extensive destruction of the oral cavity and jaw bones.
The main findings in this 6-year review show how late patients present with oral cancer, the absence of alcohol and tobacco in the aetiology, and the varying distribution of the disease. Male:female ratios varied during the study according to site of tumour and age of the patient. Twenty-nine patients (36%) were 60 years or over while seven patients (9%) were under 20. This is in sharp contrast to the findings of Howell et al.7 in Nova Scotia. They had only six patients (0.5%) in the age group 1–20 years in a 15-year review. The lowest number of oral cancer cases occurred in the age range of 20–29 years, while Howell et al.7 had the fewest in the age range 0–9 years. It was not possible to find
C. Oji, F.N. Chukwuneke / British Journal of Oral and Maxillofacial Surgery 45 (2007) 298–301
out when the disease started in each patient, because all our patients presented with advanced disease. Early detection of oral cancer – for example, as premalignant oral epithelial dysplasia or early oral squamous cell carcinoma – was not possible because our patients consulted medical quacks at the onset of the disease. Usually these malignancies present as clinically obvious lesions, often leukoplakias, erythroleukoplakias, or chronic ulcers, which should be easily detected by trained medical personnel. All the patients practised poor oral hygiene and had objective signs of malnutrition, as shown by the laboratory results. None of them, however, had a history of alcohol or tobacco misuse, which are the main risk factors for oral cancer in the west. In the industrialised regions of the world, the increased consumption of tobacco or alcohol, or both, has been held responsible for the pronounced increase in oral cancer in the 20th century.8,9 Because alcohol and tobacco did not play a part in the social and dietary history of our patients, we can only assume that a vicious circle of poverty, malnutrition, lack of education, poor hygiene, and chronic malaria have contributed to their dismal condition. In the light of our findings, we agree with Lawoyin et al.10 who in their study in south-western Nigeria, expressed the opinion that the association between the incidence of oral cancer and known risky behaviour is an obvious indication for investigation of other predisposing factors such as nutrients, genetic predisposition, and the role of chronic illnesses. Nigeria has no formal programme for the early detection of premalignant or malignant oral lesions. Considering the magnitude of the problem and the late presentation of the cases reported in this study, the government and other stakeholders
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in society should give serious thought to plans for prevention and early detection of premalignant and malignant oral disease. These plans should include awareness campaigns in the print and electronic media, and routine examination of the oral cavity by dental practitioners and other health care providers.
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