J Oral Pathol Med (2011) 40: 20–26 ª 2010 John Wiley & Sons A/S Æ All rights reserved
doi: 10.1111/j.1600-0714.2010.00938.x
wileyonlinelibrary.com/journal/jop
Oral cancer in Myanmar: a preliminary survey based on hospital-based cancer registries Htun Naing Oo1, Yi Yi Myint1, Chan Nyein Maung1, Phyu Sin Oo1, Jun Cheng2, Satoshi Maruyama3, Manabu Yamazaki2, Minoru Yagi4, Faleh A. Sawair5, Takashi Saku2,3 1
Department of Medical Research (Central Myanmar), Ministry of Health, Nay Pyi Taw, Myanmar; 2Division of Oral Pathology, Department of Tissue Regeneration and Reconstruction, Niigata University Hospital, Niigata, Japan; 3Surgical Pathology Section, Niigata University Hospital, Niigata, Japan; 4Department of Oral Health and Welfare, Niigata University Graduate School of Medical and Dental Sciences, Niigata University Hospital, Niigata, Japan; 5Department of Oral and Maxillofacial Surgery, Oral Medicine, Oral Pathology and Periodontology, Faculty of Dentistry, University of Jordan, Amman, Jordan
The occurrence of oral cancer is not clearly known in Myanmar, where betel quid chewing habits are widely spread. Since betel quid chewing has been considered to be one of the important causative factors for oral cancer, the circumstantial situation for oral cancer should be investigated in this country. We surveyed oral cancer cases as well as whole body cancers from two cancer registries from Yangon and Mandalay cities, both of which have representative referral hospitals in Myanmar, and we showed that oral cancer stood at the 6th position in males and 10th in females, contributing to 3.5% of whole body cancers. There was a male predominance with a ratio of 2.1:1. Their most frequent site was the tongue, followed by the palate, which was different from that in other countries with betel quid chewing habits. About 90% of male and 44% of female patients had habitual backgrounds of chewing and smoking for more than 15 years. The results revealed for the first time reliable oral cancer frequencies in Myanmar, suggesting that longstanding chewing and smoking habits are etiological backgrounds for oral cancer patients. J Oral Pathol Med (2011) 40: 20–26 Keywords: betel quid chewing habits; cancer registry; Myanmar; oral cancer; relative frequency
Introduction The world is facing today the double burden of both communicable and non-communicable diseases. Among the latter, cancer must be ranked as one of the most devastating diseases. Although it is incurable in its late stage, it is basically preventable to a certain extent as 90– 95% of cancers are caused by factors related to Correspondence: Takashi Saku, Division of Oral Pathology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkochodori, Chuo-ku, Niigata 951-8514, Japan. Tel: +81 25 227 2832, Fax: +81 25 227 0805, E-mail:
[email protected] Accepted for publication June 1, 2010
environments and human lifestyle, and the remaining 5–10% are due to genetic defect (1). The total number of new cancer cases, excluding melanoma skin cancer, in both developed and developing countries was about 11 million in 2002 alone, and more than half of them occurred in developing countries (2). Among whole body cancers, oral cancer occurred globally in more than 200 000 people in 2002 alone, and nearly half of them died by the disease. Frequencies of oral cancer may be different from area to area (3, 4), although oral cancer has been considered as one of the 8th (male) to 14th (female) most common among all human cancers (5). These frequencies have been well known to be higher in Asia, especially in south Asian countries, such as India (6) and Pakistan (7), where widely spread habits of betel quid chewing have been closely associated with extremely high incidences of oral cancers (8, 9). In Myanmar, a country in southeastern Asia, cancer is one of the ten leading diseases, and the average annual incidence rate of oral cancer (1963–1972) was reported to be about 363 per 100 000 population (10). However, these oral cancer data represented cases which were four decades old, and it is unknown how reliable the survey itself was. Other available data showed a 0.03% prevalence of oral cancer in the southeastern part of Myanmar in 1982 (11). Therefore, up-to-date data are needed to better understand the actual situation of oral cancer incidence or frequency in this country, where betel quid chewing habits are also prevalent. The present study was conducted based on city- or hospital-based cancer registries with the following objectives: (i) to determine the case load of oral cancer in Myanmar, (ii) to ascertain the male female ratio of oral cancer incidence, (iii) to assess the trend of oral cancer morbidity during the study period, and (iv) to study the habitual background of patients with oral cancer.
Materials and methods Records including patient names, ages, genders, organs, and histology of tumors on all of the malignant solid
Oral cancer in Myanmar Oo et al.
tumors including oral cancer cases (2002–2007) were obtained from cancer registry departments of Yangon General Hospital (YGH), a referral hospital in the lower part of Myanmar as well as from Mandalay General Hospital (MGH), a referral hospital in the upper part of Myanmar. Data for tumors of the hematopoietic systems were not available. The official computerized cancer registry system in the two hospitals was started in 2002. These are the two largest and well-facilitated public hospitals in Myanmar. Since these two hospitals with most of their specialties are fully equipped with modernized facilities, most cancer patients in the country are referred to them. Therefore, the collection was regarded as the most reliable mass data collection of cancer in Myanmar. The case definition in the present study involved histologically proven malignant tumors diagnosed from 2002 to 2007. Benign tumors were not collected because their registrations were obviously partial. The tumor sites and morphology were coded by using the International Statistical Classification of Diseases, ICD-10 (12). The names of all the patients were checked for detecting duplicate recordings of the same cancer. Since the cancer registries from the two hospitals did not contain information for habitual backgrounds of patients, we carried out an oral cancer survey from 2006 to 2007 at MGH. General information about cancer, predisposing habits, such as the use of tobacco for smoking and chewing as well as chewing of betel quid, was obtained directly from the patients or their family members using questionnaires which included the patient name, age, sex, site of oral cancer, daily consumption quantities, and duration of smoking, tobacco chewing, betel chewing, association with white lesions (leukoplakia), erosion, or ulceration. Clinical features such as exact locations of cancer, association with leukoplakia or ulceration as well as their histopathological diagnoses were collected from individual patient records. The data were finally numerically coded with private information of patients excluded. Data entry was done using SPSS 11.5 software. After data cleaning, descriptive analysis of the oral cancer cases was done by age group, gender difference, site, and types of oral cancers on a yearly basis. In addition, they were correlated with smoking, tobacco chewing, and betel chewing habits in the MGH survey. The difference in the case numbers in the 6-year-period from 2002 to 2007 was analyzed by regression analysis using Instat, version 3.06 for Windows (GraphPad Software, San Diego, CA, USA). Tendencies of increases in yearly case numbers with P < 0.05 were considered to be statistically significant.
Results Data collected from the cancer registry departments of YGH and MGH from 2002 to 2007 are shown in Tables 1 and 2. Among male patients, the most common cancer was in the bronchus and lungs (11.9–22.1%, average 19.4%) followed by liver cancer (17.1%, ranging from 15.1% to 19.6%) and non-Hodgkin lymphoma
(7.5%, ranging from 5.5% to 9.8%) (Table 1). Among the females, the most common cancer was in the uterine cervix (22%, ranging from 19.1% to 25.9%) followed by cancers of the breast (20%, ranging from 17.5% to 4.1%) and ovary (6.9%, ranging from 5.4% to 8.4%) (Table 2). Oral cancer (ICD-10, C00–C06) stood at the 10th position ranging from 9th to 12th in females (2.2%, ranging from 1.2% to 2.9%) (Table 2) and at the 6th position ranging from 5th to 6th in males (5.3%, ranging from 4.4% to 5.8%) (Table 1). Based on the total population of 56.52 million in Myanmar, which was officially announced by the Ministry of Health (13), the incidence of the whole body cancer during the 6-year period from 2002 to 2007 was estimated to be 57.7 per 100 000 population. By gender, it was about 54.5 per 100 000 males and 60.9 per 100 000 females, although these rates cannot be regarded as the true values of incidence. The frequencies of oral cancers in the 6-year period from 2002 to 2007 showed more or less upward tendencies both in the males and females (Tables 3–5), although the tendency was statistically significant only in men (P = 0.03) as a result of the regression analysis. The whole body cancers increased in number year by year during the 6-year period, and their increasing tendency was statistically significant (male, P = 0.017, female P = 0.009). However, as to the ratios of oral cancer against the whole body cancer, there was no statistically significant upward tendency. Generally, among all types of cancers for both sexes, oral cancer accounted for 3.5% ranging from 3.1% to 4.0%. By gender, oral cancer was a disease of male preponderance with a ratio of 2.1:1 (Table 3). There were 1203 cases of oral cancer within the 6-year period, totaling an average of about 201 cases each year. Based on the total population of 56.52 million in Myanmar (13), the oral cancer incidence in 2007 was estimated to be 2.1 per 100 000 population. By gender, it was about 2.9 in 100 000 males and 1.4 in 100 000 females. Individuals in both genders in the age group of 45–54 year (26.9%) were mostly affected by oral cancer (Table 4). Out of all sites affected by oral cancer, the tongue (39.0%) was the most stricken area followed by the palate (35.7%), floor of the mouth (8.2%), buccal mucosa (6.2%), gingiva (5.6%), and lip (5.2%) (Table 5). More detailed data collected in the survey at MGH for the 2-year period of 2006–2007 showed that the total number of patients with oral squamous cell carcinoma including verrucous carcinoma was 111, i.e., 87 males (78.4%) and 24 females (21.6%) with a male-female ratio of 3.6:1. The mean age for both genders was 50.8 years ranging from 24 to 79. By gender, it was 49.8 years ranging from 24 to 79 in males and 54.1 years ranging from 27 to 73 in females. The use of tobacco and betel quid chewing among these patients from MGH is shown in Table 6. Out of the 111 patients with squamous cell carcinoma, only 15.3% (8 males and 9 females) of the patients were found to use neither tobacco nor betel. Of the 111 patients, 36.0% (36 males and 4 females) were betel quid chewers, 50.5% (46 males, 3 females) were tobacco chewers, and 46.0% (40
21
J Oral Pathol Med
Oral cancer in Myanmar Oo et al.
22
Table 1 Malignant neoplasms among Myanmar males by location based on cancer registries of Yangon General Hospital and Mandaley General Hospital Number of cases by year (%) Sites (ICD 10)
2002
Lip and Oral cavity (C00-06) 71 Salivary glands (C07–08) 2 Pharynx (C09–14) 43 Oesophagus (C15) 71 Stomach (C16) 103 Small intestine (C17) 4 Colon (C18) 39 Rectum (C19–21) 36 Liver (C22) 256 Gall bladder (C23–24) 2 Pancreas (C25) 9 Larynx (C30–32) 25 Bronchus and Lungs (C33–34) 156 Thymus, mediastinum (C37–38) 3 Bone (C40–41) 45 Melanoma of skin (C43) 4 Other skin (C44) 6 Mesothelioma (C45) 0 Kaposi’s sarcoma (C46) 0 Connective tissue (C47–49) 8 Breast (C53) 1 Penis (C60) 25 Prostate (C61) 33 Testis (C62) 9 Epididymis (C63) 0 Kidney (C64–66, 68) 4 Bladder (C67) 21 Eye (C69) 3 Brain, nervous system (C70–72) 17 Thyroid (C73) 1 Other endocrine glands (C74–75) 2 Hodgkin’s disease (C81) 2 Non-Hodgkin’s lymphoma (C82–85) 78 Multiple myeloma (C90) 3 Ill-defined sites & secondary (C76–80) 227 Total 1309
2003
(5.4) 135 (0.2) 10 (3.3) 99 (5.4) 161 (7.9) 170 (0.3) 10 (3.0) 54 (2.8) 66 (19.6) 381 (0.2) 9 (0.7) 26 (1.9) 83 (11.9) 508 (0.2) 10 (3.4) 63 (0.3) 0 (0.5) 23 (0.0) 0 (0.0) 0 (0.6) 24 (0.1) 0 (1.9) 36 (2.5) 33 (0.7) 15 (0.0) 1 (0.3) 16 (1.6) 32 (0.2) 10 (1.3) 17 (0.1) 23 (0.2) 6 (0.2) 15 (6.0) 211 (0.2) 11 (17.3) 260 (100.0) 2518
(5.4) 105 (0.4) 1 (3.9) 75 (6.4) 154 (6.8) 144 (0.4) 2 (2.1) 81 (2.9) 66 (15.1) 366 (0.4) 5 (1.0) 15 (3.3) 76 (20.2) 466 (0.4) 7 (2.5) 89 (0.0) 10 (0.9) 20 (0.0) 0 (0.0) 0 (1.0) 35 (0.0) 3 (1.4) 43 (1.3) 57 (0.6) 11 (0.0) 0 (0.6) 9 (1.3) 38 (0.4) 5 (0.7) 23 (0.9) 17 (0.2) 3 (0.6) 18 (8.4) 167 (0.4) 21 (10.3) 233 (100.0) 2365
males, 11 females) were smokers. Out of the 87 males, 36 (41.3%) were betel quid chewers, 46 (52.9%) were tobacco chewers, and 40 (45.9%) were smokers. Out of the 24 females, 4 (16.7%) were betel quid chewers, 3 (12.5%) were tobacco chewers and 11 (45.8%) were smokers. Six males (6.9%) and none of the females were chewers of betel and tobacco and smokers at the same time. Of the 87 males, 13 (14.9%) were chewers of both betel and tobacco, while none of the females was such chewers. Regardless of betel chewing, 64 males (73.6%) and 12 females (50%) were users of tobacco (either chewing or smoking). Among the tobacco users, 22 males (25.3%) and 2 females (8.3%) chewed and smoked simultaneously. The mean duration of smoking among oral cancer patients was 17 ± 12.0 years ranging from 5 months to 50 years. There were no patients who quit their chewing or smoking habits before visiting the hospital. By gender, it was 16 ± 11.5 years ranging from 5 months to 40 years in males and 21 ± 13.3 years ranging 5– 50 years in females. The mean duration of tobacco chewing among them was 15 ± 10.6 years ranging from 1 to 50 years. By gender, it was 15 ± 10.6 years ranging from 1 to 50 years in males and 15 ± 12.1 years ranging J Oral Pathol Med
2004
2005
(4.4) 152 (0.0) 0 (3.1) 84 (6.5) 194 (6.1) 158 (0.1) 4 (3.4) 95 (2.8) 77 (15.5) 461 (0.2) 10 (0.6) 34 (3.2) 110 (19.7) 580 (0.3) 12 (3.8) 96 (0.4) 8 (0.8) 15 (0.0) 1 (0.0) 0 (1.5) 42 (0.1) 20 (1.8) 50 (2.4) 58 (0.5) 10 (0.0) 2 (0.4) 18 (1.6) 52 (0.2) 6 (1.0) 36 (0.7) 9 (0.1) 5 (0.8) 6 (7.1) 152 (0.9) 31 (9.9) 163 (100.0) 2751
2006
(5.5) 189 (0.0) 11 (3.0) 88 (7.1) 205 (5.7) 162 (0.1) 3 (3.5) 100 (2.8) 136 (16.8) 551 (0.4) 11 (1.2) 30 (3.1) 104 (21.1) 720 (0.4) 14 (3.5) 139 (0.3) 8 (0.5) 21 (0.1) 1 (0.0) 0 (1.5) 59 (0.7) 3 (1.8) 60 (2.1) 49 (0.4) 45 (0.1) 1 (0.7) 18 (1.9) 52 (0.2) 9 (1.3) 29 (0.3) 31 (0.2) 3 (0.2) 23 (5.5) 234 (1.1) 21 (5.9) 126 (100.0) 3256
2007
(5.8) 165 (0.3) 7 (2.1) 57 (6.3) 197 (4.1) 240 (0.1) 4 (3.1) 110 (4.2) 165 (16.1) 605 (0.3) 12 (0.9) 17 (3.2) 93 (22.1) 519 (0.4) 18 (4.3) 108 (0.2) 2 (0.6) 14 (0.1) 0 (0.0) 1 (1.8) 57 (0.1) 8 (1.8) 69 (1.5) 30 (1.4) 33 (0.0) 2 (0.6) 17 (1.6) 64 (0.3) 8 (0.9) 26 (1.0) 18 (0.1) 1 (0.7) 6 (7.2) 305 (0.6) 47 (3.9) 93 (100.0) 3118
Total number of cases (%) Rank
(5.3) 817 (5.3) (0.2) 31 (0.2) (1.8) 446 (2.9) (6.3) 982 (6.4) (7.7) 977 (6.4) (0.1) 27 (0.2) (3.5) 479 (3.1) (5.8) 546 (3.6) (19.4) 2620 (17.1) (0.4) 49 (0.3) (0.5) 131 (0.9) (2.1) 491 (3.2) (16.6) 2949 (19.3) (0.6) 64 (0.4) (3.5) 540 (3.5) (0.1) 32 (0.2) (0.4) 99 (0.6) (0.0) 2 (0.0) (0.1) 1 (0.0) (1.8) 225 (1.5) (0.3) 35 (0.2) (2.2) 283 (1.8) (1.0) 260 (1.7) (1.1) 123 (0.8) (0.1) 6 (0.0) (0.5) 82 (0.5) (2.1) 259 (1.7) (0.3) 41 (0.3) (0.8) 148 (1.0) (0.6) 99 (0.6) (0.1) 20 (0.1) (0.2) 70 (0.5) (9.8) 1147 (7.5) (1.5) 134 (0.9) (2.1) 1102 (7.2) (100.0) 15 317 (100.0)
6 29 11 4 5 30 10 7 2 25 18 9 1 24 8 28 20 33 34 15 27 12 13 19 32 22 14 26 16 20 31 23 3 17
from 2 to 25 years in females. Their mean duration of betel chewing was 15 ± 10.6 years ranging from 1 to 38 years. There was no definite correlation between habit types or their combinations and durations. By gender, it is 15 ± 10.6 years ranging from 1 to 38 years in males and 17 ± 12.5 years ranging from 1 to 30 years in females.
Discussion In the present study, we reported for the first time the actual situation of oral cancer occurrence in Myanmar based on hospital-based surveys. From these data, the relative frequency of oral cancer in the country was shown to be at least one of the leading group causes of morbidity and mortality in Myanmar, which was estimated in the review article by Reichart and Way (10). In the present study, we conducted two kinds of surveys. One was reviewing public cancer registries during the 6-year period from 2002 to 2007, and the second was a cross-sectional survey among 111 oral cancer patients admitted to MGH alone during the 2-year period from 2006 to 2007. Almost all the cancer patients in this country were referred to YGH and
Oral cancer in Myanmar Oo et al.
Table 2 Malignant neoplasms among Myanmar females by location based on cancer registries of Yangon General Hospital and Mandaley General Hospital Number of cases by year (%) Sites (ICD 10)
2002
Lip and Oral cavity (C00–06) 16 Salivary glands (C07–08) 0 Pharynx (C09–14) 15 Oesophagus (C15) 25 Stomach (C16) 53 Small intestine (C17) 0 Colon (C18) 36 Rectum (C19–21) 27 Liver (C22) 77 Gall bladder (C23–24) 6 Pancreas (C25) 16 Larynx (C30–32) 8 Bronchus and Lungs (C33–34) 75 Thymus, Mediastinum (C37–38) 2 Bone (C40–41) 13 Melanoma of skin (C43) 4 Other skin (C44) 7 Mesothelioma (C45) 1 Connective tissue (C47–49) 14 Breast (C50) 232 Cervix (C53) 344 Uterus (C54–55) 31 Ovary (C56) 112 Other female genital (C51–52, C57) 17 Placenta (C58) 11 Kidney (C64–66);(C68) 7 Bladder (C67) 7 Eye (C69) 3 Brain, Nervous system (C70–72) 10 Thyroid (C73) 6 Other endocrine glands (C74–75) 0 Hodgkin’s disease (C81) 3 Non-Hodgkin’s lymphoma (C82–85) 34 Multiple myeloma (C90) 4 Ill-defined sites & secondary (C76–80) 113 Total 1329
Table 3
2003
(1.2) 65 (0.0) 2 (1.1) 42 (1.9) 55 (4.0) 94 (0.0) 0 (2.7) 73 (2.0) 76 (5.8) 135 (0.5) 7 (1.3) 24 (0.6) 13 (5.6) 287 (0.2) 12 (1.0) 33 (0.3) 7 (0.5) 14 (0.1) 0 (1.1) 34 (17.5) 562 (25.9) 571 (2.3) 23 (8.4) 145 (1.3) 31 (0.8) 25 (0.5) 7 (0.5) 16 (0.2) 6 (0.8) 16 (0.4) 60 (0.0) 1 (0.2) 7 (2.5) 97 (0.3) 2 (8.5) 119 (100.0) 2661
2004
(2.4) 52 (0.1) 2 (1.6) 25 (2.1) 46 (3.5) 86 (0.0) 3 (2.7) 84 (2.9) 84 (5.1) 137 (0.3) 6 (0.9) 25 (0.5) 25 (10.8) 251 (0.5) 14 (1.2) 46 (0.3) 2 (0.5) 13 (0.0) 0 (1.3) 36 (21.1) 507 (21.4) 708 (0.9) 22 (5.4) 226 (1.2) 25 (0.9) 40 (0.3) 2 (0.6) 19 (0.2) 7 (0.6) 17 (2.3) 36 (0.0) 2 (0.3) 4 (3.6) 102 (0.1) 20 (4.5) 104 (100.0) 2778
2005
(1.9) 94 (0.1) 6 (0.9) 49 (1.7) 59 (3.1) 122 (0.1) 1 (3.0) 123 (3.0) 104 (4.9) 165 (0.2) 20 (0.9) 22 (0.9) 43 (9.0) 294 (0.5) 9 (1.7) 57 (0.1) 4 (0.5) 11 (0.0) 1 (1.3) 38 (18.3) 627 (25.5) 755 (0.8) 58 (8.1) 219 (0.9) 17 (1.4) 67 (0.1) 13 (0.7) 31 (0.3) 10 (0.6) 25 (1.3) 33 (0.1) 2 (0.1) 16 (3.7) 138 (0.7) 24 (3.7) 68 (100.0) 3325
2006
(2.8) 103 (0.2) 5 (1.5) 28 (1.8) 94 (3.7) 154 (0.0) 1 (3.7) 117 (3.1) 89 (5.0) 193 (0.6) 15 (0.7) 25 (1.3) 27 (8.8) 448 (0.3) 13 (1.7) 80 (0.1) 3 (0.3) 15 (0.0) 1 (1.1) 36 (18.9) 658 (23.4) 734 (1.7) 34 (6.6) 231 (0.5) 15 (2.0) 69 (0.4) 11 (0.9) 15 (0.3) 14 (0.7) 19 (1.0) 72 (0.1) 7 (0.5) 14 (4.2) 160 (0.7) 26 (2.0) 84 (100.0) 3610
2007
(2.9) 56 (0.1) 4 (0.8) 25 (2.6) 86 (4.3) 147 (0.0) 6 (3.2) 139 (2.5) 124 (5.3) 220 (0.4) 19 (0.7) 28 (0.7) 33 (12.4) 248 (0.4) 13 (2.2) 67 (0.1) 2 (0.4) 15 (0.0) 1 (1.0) 45 (18.2) 875 (20.3) 694 (0.9) 28 (6.4) 270 (0.4) 13 (1.9) 46 (0.3) 22 (0.4) 21 (0.4) 13 (0.5) 21 (1.0) 29 (0.2) 5 (0.4) 8 (4.4) 189 (0.7) 47 (2.3) 70 (100.0) 3,269
23
Total number of cases (%) Rank
(1.5) 386 (0.1) 19 (0.7) 184 (2.4) 365 (4.1) 656 (0.2) 11 (3.8) 572 (3.4) 504 (6.7) 927 (0.5) 73 (0.8) 140 (0.9) 149 (6.8) 1603 (0.4) 63 (1.8) 296 (0.1) 22 (0.4) 75 (0.0) 4 (1.2) 203 (24.1) 3461 (19.1) 3806 (0.8) 196 (7.4) 1203 (0.4) 118 (1.3) 258 (0.6) 62 (0.6) 109 (0.4) 53 (0.6) 108 (0.8) 236 (0.1) 17 (0.2) 52 (5.2) 720 (1.3) 123 (1.9) 558 (100.0) 17 332
(2.2) (0.1) (1.1) (2.1) (3.8) (0.1) (3.3) (2.9) (5.3) (0.4) (0.8) (0.9) (9.2) (0.4) (1.7) (0.1) (0.4) (0.0) (1.2) (20.0) (22.0) (1.1) (6.9) (0.7) (1.5) (0.4) (0.6) (0.3) (0.6) (1.4) (0.1) (0.3) (4.2) (0.7) (3.2) (100.0)
10 31 17 11 7 33 8 9 5 25 19 18 3 26 12 30 24 34 15 2 1 16 4 21 13 27 22 28 23 14 32 29 6 20
Frequencies of oral cancer among whole body cancers in Myanmar Number of cases by year (%)
Cancer location Whole body
Oral cavity
Male Female Total M:F ratio Male Female Total M:F ratio
2002
2003
2004
2005
2006
2007
Total number (%)
1309 1329 2638 1:1 71 (5.4) 16 (1.2) 87 (3.3) 4.4:1
2518 2661 5179 0.9:1 135 (5.4) 65 (2.4) 200 (3.9) 2.1:1
2365 2778 5143 0.9:1 105 (4.4) 52 (1.9) 157 (3.1) 2:1
2751 3325 6076 0.8:1 152 (5.5) 94 (2.8) 246 (4.0) 1.6:1
3256 3610 6866 0.9:1 189 (5.8) 103 (2.9) 292 (3.3) 1.8:1
3118 3629 6747 0.9:1 165 (5.3) 56 (1.5) 221 (3.3) 2.9:1
15317 17332 32649 0.9:1 817 (5.3) 386 (2.2) 1203 (3.7) 2.1:1
MGH where only reasonable cancer therapies are available. Hence, the data in the present study can be reliable showing the number of cases, age groups, sex, and the sites of cancers, in which at least the magnitude of oral cancer is reflected, although all the data were hospital-based. This study revealed that oral cancer was one of the top ten cancers for both males (2002–2007) and females (2004 and 2006), and these results are similar to those found in the worldwide data (2–4). Globally, oral cancer is considered to be the 8th to 14th
most common cancer accounting for an estimated 3% of all cancers (5). According to the review article by Reichart and Way (10), the average annual incidence of oral cancer (1963– 1972) in Myanmar was estimated to be about 363 per 100 000 population by referring to the data from the Department of Medical Research, Myanmar in 1974, although we could not find any data in the Department. Nevertheless, this rate seems to be extraordinarily larger than what we estimate from our present data. According J Oral Pathol Med
Oral cancer in Myanmar Oo et al.
24
Table 4 Oral cancer cases by age group for both sexes in Myanmar Case numbers by age group (years) Year 2002 2003 2004 2005 2006 2007 Total (%) Average case #
