Seroprevalence of HHV-8 has been studied in Malaysia, India, Sri Lanka, Thailand, Trinidad, Jamaica and the USA, in both healthy individuals and those infected with HIV. Seroprevalence was found to be low in these countries in both the healthy and the HIV-infected populations. This correlates with the fact that hardly any AIDS-related Kaposi's sarcoma has been reported in these countries. In contrast, the African countries of Ghana, Uganda and Zambia showed high seroprevalences in both healthy and HIV-infected populations. This suggests that human herpes virus-8 (HHV-8) may be either a recently introduced virus or one that has extremely low infectivity. Nasopharyngeal and oral carcinoma patients from Malaysia, Hong Kong and Sri Lanka who have very high EBV titres show that only 3/82 (3.7%) have antibody to HHV-8, demonstrating that there is little, if any, cross-reactivity between antibodies to these two gamma viruses.
BACKGROUND: During 1990-1992, 282 Chinese residents of Selangor and the Federal Territory, Malaysia with histologically confirmed nasopharyngeal carcinoma (NPC) were interviewed about occupational history, diet, alcohol consumption, and tobacco use, as were an equal number of Malaysian Chinese population controls, pair-matched to cases by age and sex.
METHODS: Exposures to 20 kinds of workplace substances, solar and industrial heat, and cigarette smoke, were analysed by univariate and multivariate methods.
RESULTS: Nasopharyngeal carcinoma was associated with occupational exposures to construction, metal and wood dusts; motor fuel and oil; paints and varnishes; certain other chemicals; industrial heat; solar heat from outdoor occupations; certain smokes; cigarette smoking; and childhood exposure to parental smoking. After adjustment for risk from diet and cigarette smoke, only wood dust (OR = 2.36; 95% CI : 1.33- 4.19), and industrial heat (OR = 2.21; 95% CI : 1.12-4.33) remained clearly associated. Wood dust remained statistically significant after further adjustment for social class. No significant crude or adjusted association was found between NPC and formaldehyde (adjusted OR = 0.71; 95% CI : 0.34-1.43).
CONCLUSIONS: This study supports previous findings that some occupational inhalants are risk factors for NPC. The statistical effect of wood dust remained substantial after adjustment for diet, cigarette smoke, and social class. Intense industrial heat emerged as a previously unreported risk factor, statistically significant even after adjustment for diet and cigarette smoke. No association was found between NPC and formaldehyde.
One hundred consecutive newly diagnosed patients with nasopharyngeal carcinoma (NPC) since January 1994 were the subjects for studying various factors that contribute to the delay in the confirmation of the diagnosis. Seventy-nine of them were males and the peak age of incidence was the fifth decade. Ninety two percent were Chinese, 7% Malay and 1% Indian. Seventy six percent were agriculture workers or labourers with 66% having either no formal education (16%) or only primary level education (50%). In 50% of patients neck swelling was the first presenting symptom, 26% had nasal symptoms, 12% ear symptoms and 11% has symptoms due to intracranial extension of tumour. As many as 80% were at UICC Stage IV at the time of diagnosis. While the median delay, on the part of patients, in consulting a doctor was 2.5 days, the median delay on the part of the doctors to confirm the diagnosis of NPC was 127 days, the delays was particularly worse when the patients presented with ear symptoms (266 days) followed by those with neck swelling (94 days). For those patients who were required to undergo more than one nasopharyngoscopy and biopsy the median doctor's delay was 144 days. Since 82% of patient's had first consulted general practitioners, it is suggested that their level of awareness with regards to the diagnosis of NPC be significantly raised so that the delay on their part be greatly minimized.
Nasopharyngeal cancer (NPC) is generally a rare malignancy with a few well-known exceptions, notably South-East China. In this article, we describe evidence of a high risk of NPC in the population of Sarawak State, Malaysia, and particularly in one native ethnic group. Sarawak State is one of the two provinces of Malaysia located on the island of Borneo. The native population (71.6%) includes the Iban, Malay, Bidayuh, Melanau, and diverse smaller ethnic groups. The Chinese are the largest nonindigenous group (27.5%). We identified 392 newly diagnosed cases (292 males and 100 females) of NPC in 1996-1998 in Malaysian citizens, permanent residents of Sarawak. Age-standardized rates by sex and ethnic group were compared with the highest rates in the world. The age-adjusted rate (ASR) in Sarawak residents was 13.5/100,000 [95% confidence interval (CI) 12.2-15.0] and 6.2/100,000 (95% CI 5.7-6.7) in males and females, respectively. The risk in the Bidayuh people was 2.3-fold (M) and 1.9-fold (F) higher than the Sarawak average, and about 50% higher than that in Hong Kong-the highest recorded by any population-based registry for the same period. Local dietary habits, environmental exposures, and genetic susceptibility deserve investigation in this population.
A "registry" of all known cases of nasopharyngeal carcinoma in Malaysia, 1968-72, was established. Attention was focused on the State of Selangor where conditions are best for case finding. Age-adjusted incidence rates among Chinese males and females were 17·3 and 7·3 per 100,000; among Malay males and females, the rates were 2·5 and 0·3 and among Indian males, 1·1. The detailed ethnicity of 192 cases in Selangor was established. Estimated incidence rates for the Chinese sub-groups agreed with the pattern observed elsewhere: highest among the Cantonese, lowest among the Hokkien/Teochiu, with the Khek in between. There was no correlation between histological type and sub-ethnic group among the Chinese cases.
Nasopharyngeal carcinoma (NPC) is one of the most difficult diseases to diagnose at an early stage. The clinical presentation of 122 patients with confirmed NPC is described and the findings analysed. The common modes of presentation and cases where detailed nasopharyngeal examination need to be performed are highlighted. We emphasize the importance of health education and training for primary care physicians for early detection of these cases.
With a five-year survival rate of 20% in 1970 and 40-45% in 1990, and highest incidence and mortality in early and middle adult years, nasopharyngeal carcinoma (NPC) may have a severe social impact on families and households. The aim of this study was to measure the social impact of NPC in the Chinese population of Selangor, Malaysia.
Nasopharyngeal carcinoma (NPC) is an Epstein-Barr Virus (EBV)-associated cancer that is the fifth most common cancer in Malaysia. Early and accurate diagnoses are critical for patient prognosis. Unfortunately, early detection of NPC is still a challenge and the cost of more accurate imaging protocols is prohibitive in developing countries like Malaysia.
Nasopharyngeal carcinoma (NPC) is a human epithelial tumour with high prevalence amongst Chinese in Southern China and South East Asia and is associated with the Epstein-Barr virus (EBV). The viral genome harbours an oncogene, namely, the latent membrane protein 1 (LMP1) gene and known variants such as the 30-bp deletion and loss of XhoI restriction site have been found. Less is known about the relationship between these variants and the population characteristics and histological type.
Little or no information is available on the prevalence of nasopharyngeal carcinoma (NPC) among different ethnic groups in Brunei, or how useful plasma IgA antibodies are against viral capsid antigen (VCA) and early antigen (EA) in the diagnosis of NPC, even though they are routinely measured in patients suspected to have NPC.
Nasopharyngeal carcinoma, a malignancy associated closely with Epstein-Barr virus (EBV), is prevalent among Chinese of Southern China origin. Epidemiological studies indicate a high prevalence of EBV in Asia with viral isolates having typical characteristics of the putative viral oncogene, latent membrane protein 1 (LMP-1), such as the loss of the Xho1 restriction site in Exon 1 and the 30-bp deletion in Exon 3. The EBV LMP-1 gene from throat washings of 120 nasopharyngeal carcinoma patients and 14 healthy individuals were analyzed. Similar analyses were also carried out on 30 and 12 postnasal space biopsies from nasopharyngeal carcinoma patients and healthy individuals, respectively. The 30-bp deletion was detected in 20% of nasopharyngeal carcinoma throat washes and in 100% of nasopharyngeal carcinoma postnasal space biopsies. Interestingly, 16% of the nasopharyngeal carcinoma biopsies possessed both the deleted and the undeleted variants, suggestive of dual infections. The notion of dual infections in nasopharyngeal carcinoma was further supported by the coexistence of both "F" and "f" (BamH1F region) EBV variants in 11% of the nasopharyngeal carcinoma biopsies. All of the throat washes and biopsies from the healthy controls showed the undeleted variant. The loss of the Xho1 restriction site was found with higher frequency both in throat washes and biopsies from patients with nasopharyngeal carcinoma. The discrepancy in the frequency of the 30-bp deletion between throat washes (20%) and postnasal space biopsies (100%) was an indication that this deletion is specific for viral isolates from primary tumour sites.
Epstein-Barr virus (EBV) type B, a less potent transformer of B lymphocytes than type A, has rarely been detected in EBV-associated neoplasms except in AIDS-related lymphomas, in which about 50% of the cases contained this sub-type. In this study we analyzed the association of EBV and the distribution of virus sub-types in Asian non-Hodgkin's lymphoma (NHL) of the upper aerodigestive tract. We studied archival material of 29 NHL cases from Malaysia. B- and T-cell associated antigens were demonstrated by immunohistochemistry, and EBV early RNA EBER-1 was demonstrated using the RNA in situ hybridization technique. EBV was detected in the majority of tumour cells in 11/13 T-NHL but in only 1/16 B-NHL. EBV was sub-typed by single-step polymerase chain reaction of the EBNA-2 gene. This was successful in 9/10 cases of EBER-1-positive tumours and all contained type-A virus only. Our results showed a preponderance of T-cell lymphoma of the upper aerodigestive tract in the ethnic Chinese group of Malaysian patients, and EBV was strongly associated with T-NHL but not with B-NHL. Our results suggest that type-A EBV is the prevalent sub-type in Asian NHL of the upper aerodigestive tract, similarly to findings in Asian nasopharyngeal carcinoma.