Supplemental folic acid and/or multivitamins in pregnancy is associated with a decreased risk of childhood and adolescent nasopharyngeal carcinoma.

The aim of this study was to evaluate the association between prenatal and neonatal period exposures and the risk of childhood and adolescent nasopharyngeal carcinoma (NPC). From January 2009 to January 2016, a total of 46 patients with childhood and adolescent NPC (i.e., less than 18 years of age) who were treated at Sun Yat-sen University Cancer Center were screened as cases, and a total of 45 cancer-free patients who were treated at Sun Yat-sen University Zhongshan Ophthalmic Center were selected as controls. The association between maternal exposures during pregnancy and obstetric variables and the risk of childhood and adolescent NPC was evaluated using logistic regression analysis. Univariate analysis revealed that compared to children and adolescents without a family history of cancer, those with a family history of cancer had a significantly higher risk of childhood and adolescent NPC [odds ratios (OR) = 3.15, 95% confidence interval (CI) = 1.02-9.75, P = 0.046], and the maternal use of folic acid and/or multivitamins during pregnancy was associated with a reduced risk of childhood and adolescent NPC in the offspring (OR = 0.07, 95% CI = 0.02-0.25, P < 0.001). After multivariate analysis, only the maternal use of folic acid and/or multivitamins during pregnancy remained statistically significant. These findings suggest that maternal consumption of folic acid and/or multivitamins during pregnancy is associated with a decreased risk of childhood and adolescent NPC in the offspring.

Two-year outcome of concurrent chemoradiation with carboplatin with or without adjuvant carboplatin/fluorouracil in nasopharyngeal cancer: A multicenter randomized trial.

BACKGROUND: According to the noninferiority result of chemoradiation with carboplatin in our previous nasopharyngeal carcinoma (NPC) study along with the inconclusive data on the efficacy of adjuvant chemotherapy (AC) following concurrent chemoradiotherapy (CCRT), we designed to assess the role of adjuvant carboplatin/fluorouracil following CCRT with carboplatin in locoregionally advanced NPC. MATERIALS AND METHODS: A multicenter randomized trial was conducted at 5 cancer centers in Thailand. We enrolled in stage T2N0M0-T4N2M0 (American Joint Cancer Committee 7th edition) WHO Type 2 NPC patients. N3 or metastatic disease patients were excluded. Participants were randomized into 2 groups: CCRT plus AC group vs the CCRT alone group. Patients in both groups received weekly carboplatin 100 mg/m2 for 6 cycles concurrently with radiotherapy 69.96-70 Gy. Patients in the AC group subsequently received 3 cycles of carboplatin area under curve-5 plus 1000 mg/m2/day of fluorouracil infusion within 96 hours every 3 weeks. We report the 2-year overall survival (OS), disease-free survival (DFS), loco-regional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS). Treatment-related toxicities and compliance were also explored. RESULTS: Of 175 patients, 82 (46.9%) were assigned to the AC group, and 93 (53.1%) to the CCRT group. The compliance rate during CCRT was 90% and 86% in the AC and CCRT group, whereas 81.7% during adjuvant treatment in the AC group. With a median follow-up time of 24.4 months (interquartile range 17.9-24.4), the 2-year OS rate was 89.6% in the AC group and 81.8% in the CCRT group (P= 0.167). The 2-year DFS rate was 86.8% in the AC group and 74.6% in the CCRT group (P = 0.042). The 2-year LRFS rate was 91.5% in the AC group and 88.2% in the CCRT group (P = 0.443). The 2-year DMFS rate was 85.4% in the AC group and 79.6% in the CCRT group (P = 0.294). The most frequent serious (grade 3/4) nonhematologic toxicity was acute mucositis, which occurred 5% in the AC group vs 4% in the CCRT group (P = 0.498). For hematologic toxicity, grade 3-4 leukopenia were found 10% and 5% in the adjuvant and CCRT groups, respectively (P = 0.003). Multivariate analyses determined stage N2 disease was an adverse prognostic factor associated with shorter OS, DFS, and DMFS. And the adjuvant treatment was a significant protective factor for only DFS. CONCLUSIONS: The addition of adjuvant carboplatin/fluorouracil following CCRT with carboplatin significantly improved 2-year DFS in stage T2N0M0-T4N2M0 NPC albeit there was a nonsignificant trend in favor of a higher 2-year OS, LRFS, and DMFS. Long-term efficacy and late toxicities of AC still require exploration.

The Association between Tea Consumption and Nasopharyngeal Cancer: A Systematic Review and Meta-Analysis

Heated debates have been on-going about tea consumption and the incidence of cancer, especially in head and neck cancer types. This study aimed to review the association between tea consumption habits and nasopharyngeal cancer (NPC). Methods: This review was carried out in accordance with the PRISMA-P protocol. Literature search for journal articles that published studies on the relationship between tea consumption and NPC was performed via databases, such as Elsevier, PubMed, Science Direct, Springer Link, Google, and Google Scholar, for 10 years from 2008 to 2018. Relevant studies were obtained by applying the pre-determined keywords, such as nasopharyngeal cancer, tea consumption and NPC, risk factors of NPC and benefits of tea consumption. Results: A total of 126 articles was retrieved. These articles were subjected to eligibility assessment. Six articles remained after applying the inclusion criteria. Results suggest that habitual tea consumption reduces NPC. Tea consumption significantly reduces NPC with all the studies having a p-value ≤0.05. Meta-analysis showed statistical association between tea consumption and NPC risk with OR=0.865 at 95% CI (0.806-0.929). Conclusion: This study suggests that habitual tea consumption could be associated with prevention of NPC development. Additional studies are needed to further understand the molecular role of bioactive compound and potential health benefit of tea consumption in NPC prevention.

Medical History, Medication Use, and Risk of Nasopharyngeal Carcinoma.

Because persistent inflammation may render the nasopharyngeal mucosa susceptible to carcinogenesis, chronic ear-nose-throat (ENT) disease and its treatment might influence the risk of nasopharyngeal carcinoma (NPC). Existing evidence is, however, inconclusive and often based on methodologically suboptimal epidemiologic studies. In a population-based case-control study in southern China, we enrolled 2,532 persons with NPC and 2,597 controls, aged 20-74 years, from 2010 to 2014. Odds ratios were estimated for associations between NPC risk and history of ENT and related medications. Any history of chronic ENT disease was associated with a 34% increased risk of NPC. Similarly, use of nasal drops or aspirin was associated with approximately doubled risk of NPC. However, in secondary analyses restricted to chronic ENT diseases and related medication use at least 5 years prior to diagnosis/interview, most results were statistically nonsignificant, except a history of uncured ENT diseases, untreated nasal polyps, and earlier age at first diagnosis of ENT disease and first or most recent aspirin use. Overall, these findings suggest that ENT disease and related medication use are most likely early indications rather than causes of NPC, although the possibility of a modestly increased NPC risk associated with these diseases and related medications cannot be excluded.

AHNS Series - Do you know your guidelines? Principles of treatment for nasopharyngeal cancer: A review of the National Comprehensive Cancer Network guidelines.

This article is a continuation of the "Do You Know Your Guidelines" series, an initiative of the American Head and Neck Society's Education Committee to increase awareness of current best practices pertaining to head and neck cancer. The National Comprehensive Cancer Network guidelines for the management of nasopharyngeal cancer are reviewed here in a systematic fashion. These guidelines outline the workup, treatment and surveillance of patients with nasopharyngeal cancer. © 2016 Wiley Periodicals, Inc. Head Neck 39: 201-205, 2017.

Familial clustering of nasopharyngeal carcinoma in non-endemic area. Report of three families. / Carcinoma nasofaríngeo familiar en zona no endémica. Presentación de 3 familias.

Nasopharyngeal carcinoma is the predominant tumour type arising in the nasopharynx. Its aetiology is multifactorial; racial and geographical distribution, EBV infection and environmental exposure to specific substances are considered risk factors. This condition is endemic in some Asian areas, where a genetic predisposition in its oncogenesis has been established. There is a strong susceptibility between nasopharyngeal carcinoma and HLA, where related specific haplotypes have been found. In areas where the incidence is low, there are few reported cases of families affected. We report 3 cases of families with nasopharyngeal carcinoma among siblings, in the non-Asian population, probably related to EBV infection.

[Research on the features of DNA damage in nasopharyngeal carcinoma patients of normal constitution and abnormal constitution and in high-risk population of nasopharyngeal carcinoma].

OBJECTIVE: To explore the features of DNA damage in nasopharyngeal carcinoma (NPC) patients of normal constitution and abnormal constitution and in high-risk population of NPC. METHODS: Using single cell gel electrophoresis technique, the DNA damage of peripheral blood lymphocytes was detected in 28 healthy subjects, 27 in high-risk population of NPC, and 13 NPC patients at their first visits. The DNA damage was detected in the populations of normal constitution and of abnormal constitution. The tail length, the tail moment, and the tail DNA% were taken as the indices of DNA damage. RESULTS: The tail length was (35.77 +/- 4.22) microm, the tail moment was (8.10 +/- 1.63) microm, and the tail DNA% was 57.48% +/- 4.63% in NPC patients. They were (15.25 +/- 4.15) microm, (5.01 +/- 1.92) microm, and 31.99% +/- 4. 11% in high-risk population of NPC. They were (14.31 +/- 3.64) microm, (4. 37 +/- 1.80) microm, and 29. 89% +/- 3. 15% in healthy subjects. There was statistical difference in the three indices among the three populations (P <0.05). In all the three populations, more DNA damage existed in those of abnormal constitution than in those of normal constitution (P <0.05). CONCLUSIONS: Obvious instability of genetic materials exists in NPC patients, manifested as severe DNA damage of lymphocytes. In all the three populations, more DNA damage existed in those of abnormal constitution than in those of normal constitution.

[Relationship of alcohol drinking and tea consumption with the risk of nasopharynx cancer among Chinese population: a meta-analysis].

OBJECTIVE: To evaluate the relationship and strength of association for alcohol drinking and tea consumption with the riskS of nasopharynx cancer among Chinese population so as to provide control rationales for nasopharynx cancer in China. METHODS: A systematic search of 3 Chinese electronic databases (CNKI, VIP, Wanfang) and 3 English databases (Pubmed, ScienceDirect and SpringerLink) up to March 2013 was performed. Two reviewers independently conducted the literature search, examined eligibility and performed data extraction and quality evaluations. Pooled odd ratio (OR) value and 95%CI value were calculated with random-effects model weighted with inverse of variances. RESULTS: A total of 14 studies (including 3 cohort and 11 case-control) involving 6559 cases of nasopharynx cancer and 10 567 controls from 6 provinces were included. The pooled OR between alcohol drinking and risks of nasopharynx cancer was 1.12 (95%CI: 0.98-1.26; I(2) = 44.5%, P = 0.037). Compared with the non-drinkers, the risks of nasopharynx cancer for regular drinkers and occasional drinkers were 1.18 (95%CI: 1.00-1.38; I(2) = 0.0%, P = 0.578) and 0.76 (95%CI: 0.65-0.89; I(2) = 33.4%, P = 0.212). And the association of tea consumption with the risks of nasopharynx cancer was 0.53 (95%CI: 0.43-0.60; I(2) = 17.9%, P = 0.301). CONCLUSIONS: In China, occasional alcohol drinking may decrease the risks of nasopharynx cancer while regular drinking elevates the risks. And there is significantly protective effect for tea consumption on the risks of nasopharynx cancer.

Lowered risk of nasopharyngeal carcinoma and intake of plant vitamin, fresh fish, green tea and coffee: a case-control study in Taiwan.

BACKGROUND: A case-control study was conducted to evaluate the role of adult diet on nasopharyngeal carcinoma (NPC) in Taiwan. METHODS: A total of 375 incident NPC cases and 327 controls matched to the cases on sex, age, and residence were recruited between July 1991 and December 1994. A structured questionnaire inquiring complete dietary history, socio-demographic characteristics, and other potential confounding factors was used in the personal interview. Unconditional logistic regression analysis was used to estimate multivariate-adjusted odds ratio (OR(adj)) with 95% confidence interval (CI) after accounting for known risk factors. RESULTS: Fresh fish (OR(adj), 0.56; 95% CI, 0.38-0.83 for the highest vs. lowest tertile of intake), green tea (OR(adj), 0.61; 95% CI, 0.40-0.91 for drinking ≥1 times/week vs. never) and coffee (OR(adj), 0.56; 95% CI, 0.37-0.85 for drinking ≥0.5 times/week vs. never) were inversely associated with the NPC risk. No association with NPC risk was observed for the intake of meats, salted fish, fresh vegetables, fruits and milk. Intake of vitamin A from plant sources was associated with a decreased NPC risk (OR(adj), 0.62; 95% CI, 0.41-0.94 for the highest vs. lowest tertile). CONCLUSION: The study findings suggest that certain adult dietary patterns might protect against the development of NPC.

Concurrent chemoradiotherapy plus adjuvant chemotherapy versus concurrent chemoradiotherapy alone in patients with locoregionally advanced nasopharyngeal carcinoma: a phase 3 multicentre randomised controlled trial.

BACKGROUND: The effect of the addition of adjuvant chemotherapy to concurrent chemoradiotherapy in locoregionally advanced nasopharyngeal carcinoma is unclear. We aimed to assess the contribution of adjuvant chemotherapy to concurrent chemoradiotherapy versus concurrent chemoradiotherapy alone. METHODS: We did an open-label phase 3 multicentre randomised controlled trial at seven institutions in China. Randomisation was by a computer-generated random number code. Patients were stratified by treatment centre and randomly assigned in blocks of four. Treatment allocation was not masked. We randomly assigned patients with non-metastatic stage III or IV (except T3-4N0) nasopharyngeal carcinoma to receive concurrent chemoradiotherapy plus adjuvant chemotherapy or concurrent chemoradiotherapy alone. Patients in both groups received 40 mg/m(2) cisplatin weekly up to 7 weeks, concurrently with radiotherapy. Radiotherapy was given as 2·0-2·27 Gy per fraction with five daily fractions per week for 6-7 weeks to a total dose of 66 Gy or greater to the primary tumour and 60-66 Gy to the involved neck area. The concurrent chemoradiotherapy plus adjuvant chemotherapy group subsequently received 80 mg/m(2) adjuvant cisplatin and 800 mg/m(2) per day fluorouracil for 120 h every 4 weeks for three cycles. Our primary endpoint was failure-free survival. We did efficacy analyses in our intention-to-treat population. Our trial is ongoing; in this report we present the 2 year survival results and acute toxic effects. This trial is registered with ClinicalTrials.gov, number NCT00677118. FINDINGS: 251 patients were assigned to the concurrent chemoradiotherapy plus adjuvant chemotherapy group and 257 to the concurrent chemoradiotherapy alone group. After a median follow-up of 37·8 months (range 1·3-61·0), the estimated 2 year failure-free survival rate was 86% (95% CI 81-90) in the concurrent chemoradiotherapy plus adjuvant chemotherapy group and 84% (78-88) in concurrent chemoradiotherapy only group (hazard ratio 0·74, 95% CI 0·49-1·10; p=0·13). Stomatitis was the most commonly reported grade 3 or 4 adverse event during both radiotherapy (76 of 249 patients in the concurrent chemoradiotherapy plus adjuvant chemotherapy group and 82 of 254 in the concurrent chemoradiotherapy alone group) and adjuvant chemotherapy (43 [21%] of 205 patients treated with adjuvant chemotherapy). INTERPRETATION: Adjuvant cisplatin and fluorouracil chemotherapy did not significantly improve failure-free survival after concurrent chemoradiotherapy in locoregionally advanced nasopharyngeal carcinoma. Longer follow-up is needed to fully assess survival and late toxic effects, but such regimens should not, at present, be used outside well-designed clinical trials. FUNDING: Sun Yat-sen University Clinical Research 5010 Programme (No 2007037), Science Foundation of Key Hospital Clinical Programme of Ministry of Health PR China (No 2010-178), and Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2010).

Alcohol and tea consumption in relation to the risk of nasopharyngeal carcinoma in Guangdong, China.

To investigate whether alcohol and tea consumption has an etiological association with nasopharyngeal carcinoma (NPC) in a high-incident population, a large scale case-control study was conducted. The study included 2846 individuals in Guangdong Province, China, with 1387 newly diagnosed cases of NPC and 1459 frequency-matched controls. Exposure histories of alcohol and tea consumption were obtained via personal interviews. Information regarding socio-demographic characteristics (age, sex, education, dialect and household type), family history of NPC, Epstein-Barr virus (EBV) infection, dietary habits and other potential confounding factors was also studied. An analysis was performed using unconditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI). The risk of NPC was found to be associated with habitual alcohol consumption and tea consumption. Tea consumption has been associated with a decreased occurrence of NPC (OR = 0.62), while consumption of alcohol was associated with a complex effect. Specifically, moderate consumption of alcohol was associated with decreased risk of NPC, while overuse, especially strong distillate spirits, appeared to be a risk factor.

Is nasopharyngeal cancer really a "Cantonese cancer"?

Nasopharyngeal cancer (NPC) is endemic in Southern China, with Guandong province and Hong Kong reporting some of the highest incidences in the world. The journal Science has called it a "Cantonese cancer". We propose that in fact NPC is a cancer that originated in the Bai Yue ("proto Tai Kadai" or "proto Austronesian" or "proto Zhuang") peoples and was transmitted to the Han Chinese in southern China through intermarriage. However, the work by John Ho raised the profile of NPC, and because of the high incidence of NPC in Hong Kong and Guangzhou, NPC became known as a Cantonese cancer. We searched historical articles, articles cited in PubMed, Google, monographs, books and Internet articles relating to genetics of the peoples with high populations of NPC. The migration history of these various peoples was extensively researched, and where possible, their genetic fingerprint identified to corroborate with historical accounts. Genetic and anthropological evidence suggest there are a lot of similarities between the Bai Yue and the aboriginal peoples of Borneo and Northeast India; between Inuit of Greenland, Austronesian Mayalo Polynesians of Southeast Asia and Polynesians of Oceania, suggesting some common ancestry. Genetic studies also suggest the present Cantonese, Minnans and Hakkas are probably an admixture of northern Han and southern Bai Yue. All these populations have a high incidence of NPC. Very early contact between southern Chinese and peoples of East Africa and Arabia can also account for the intermediate incidence of NPC in these regions.

[Pediatric nasopharyngeal carcinoma: Anatomoclinic aspects, therapeutic results and evolutive particularities]. / Le cancer du cavum de l'enfant et l'adulte jeune : aspects anatomocliniques, thérapeutiques et particularités évolutives.

PURPOSE: We retrospectively analyzed anatomoclinic, therapeutic and evolutive particularities of 74 young patients (< or =20 years) with nasopharyngeal carcinoma treated between 1993 and 2005. PATIENTS AND METHODS: Initial work-up included a fiberoptic nasofibroscopy with biopsy, tomodensitometry and/or MRI of nasopharynx and neck, chest X-ray, abdominal ultrasonography and bone scan. Patients were treated with either primary chemotherapy (epirubicin and cisplatin) followed by radiotherapy or concomitant radiochemotherapy (five fluorouracil and cisplatin). Radiotherapy was delivered to a total dose of 70 to 75 Gy to nasopharynx and involved cervical lymph nodes and 50 Gy to the remainder cervical areas. RESULTS: The median age was 16 years. Sixty-three percent of patients had undifferentiated tumors. Sixty-six percent had locally advanced tumor. With a median follow-up of 107 months, one patient presented a local relapse, 24 patients developed distant metastases with a median delay of 7 months. The 5 years overall survival and disease-free survival were 66 and 65 %. Late complications were dominated by dry mouth and endocrine disorders. COMMENTS: Pediatric nasopharyngeal carcinoma is characterized by an early metastatic diffusion. Local control is excellent but with severe late toxicities. New techniques of radiotherapy and new molecules of chemotherapy could improve these results.

Caracterización de la evolución clínica del carcinoma de la nasofaringe en una población portuguesa / Characterization of the clinical evolution of nasopharyngeal carcinoma in a portuguese population

Objetivo: Caracterización de la evolución clínica del carcinoma de la nasofaringe en una población portuguesa en 31 años de seguimiento. Material y método: Trescientos veinte enfermos portadores de carcinoma epidermoide nasofaríngeo fueron seleccionados para este trabajo. Los siguientes parámetros fueron analizados: variante histológica, tasas de supervivencia después de diferentes modalidades de tratamiento y diferentes estadios (AJCC y UICC). Resultados: La variante histológica más frecuente fue el carcinoma indiferenciado del tipo nasofaríngeo. La clasificación de la AJCC de 2001 se consideró la más adecuada para el pronóstico de los enfermos. Los enfermos tratados con quimioterapia adyuvante han obtenido mejores tasas de supervivencia, sobre todo los que recibieron tratamiento con cisplatino y 5-fluorouracilo (resultados similares a los obtenidos en otros trabajos). Conclusiones: Aunque la quimioterapia adyuvante reduzca la probabilidad de metástasis a distancia, continúa siendo la principal causa de muerte constatada en nuestro estudio. La tasa de metástasis a distancia sigue siendo el problema crucial, y disminuirla es una meta cada vez más próxima y un desafío para el futuro

Objective: Characterization of the clinical evolution of nasopharyngeal cancer (NPC) patients in a Portuguese population during 31 years of follow-up. Materials and method: Three hundred and twenty patients with epidermoid nasopharyngeal carcinoma were selected for this study. Histological subtypes were analyzed along with survival rates after different treatment schemes and according to AJCC and UICC staging classification systems. Results: The most frequent histological subtype was undifferentiated nasopharyngeal carcinoma. The AJCC-2001 staging classification was considered the most suitable system for survival prediction. Better survival rates were found in patients treated with adjuvant chemotherapy (cisplatin and 5-fluorouracil) and these findings were similar to other published results. Conclusions: Although adjuvant chemotherapy may reduce the likelihood of distant metastasis, the latter is still the main cause of death in our study. The distant metastasis rate remains the crucial problem and bringing it down is an ever closer goal and a challenge for the future

Nasopharyngeal carcinoma in the pediatric age group: the northern Israel (Rambam) medical center experience, 1989-2004.

Nasopharyngeal carcinoma (NPC) is rare in children, accounting for less than 1% of all malignancies. Radiation therapy has been the mainstay of treatment of many years, but to improve survival, the use of chemotherapy has been advocated. This is a retrospective analysis of 13 patients less than 20 years of age treated for NPC the Rambam Medical Center during 1989 to 2004. Eight boys and five girls with a median age of 14.5 years (range 10-19) were included. Median follow up (including patients who died) was 6.15 years (range 1-15 years). Duration of symptoms was 1 to 24 months (median 5 months). Of the 13 patients, one patient had stage I, 6 had stage III, 5 had stage IV-A, and 1 had stage IV-B disease. Ten patients (77%) had undifferentiated carcinoma (WHO type III) and three patients (23%) had nonkeratinizing carcinoma (WHO type II). Most of the children received two or three courses of neoadjuvant multiagent chemotherapy consisting of cisplatin and 5-FU, followed by radiotherapy with doses in excess of 60 Gy. One child received concomitant chemoradiation. Ten of the 13 patients (77%) are alive without disease 6 years after diagnosis (range 1-15 years). One patient developed local and distant metastases 1 year after diagnosis and is currently receiving combined radiochemotherapy. Two patients died. Overall survival was 84%; event-free survival was 77%. Nine patients (69%) developed moderate to severe long-term complications. Pediatric NPC is curable by combined radiation and chemotherapy, with doses of radiation in excess of 60 Gy. Long-term follow-up is important for early detection of second malignancies as well as for radiation-induced endocrinologic deficiencies and other normal tissue complications.

Epidemiology of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a rare malignancy in most parts of the world, with an incidence well under 1 per 100,000 person-years. Exceptions are the Chinese, especially the Cantonese living in the central region of Guangdong Province in Southern China. Other populations with elevated rates include the natives of Southeast Asia, the natives of the Artic region, and the Arabs of North Africa and parts of the Middle East. Intake of preserved foods at an early age has been linked to NPC risk in all population groups with increased NPC rates. Other recognized risk factors for NPC are cigarette smoking, and occupational exposure to formaldehyde and wood dust.

Risk factors for cancer nasopharynx: a case-control study from Nagaland, India.

BACKGROUND: A high incidence of nasopharyngeal carcinoma has been reported from Nagaland, though it is considered to be a rare neoplasm in India. No case-control study to identify the risk factors of cancer nasopharynx has been conducted in this region. This study was undertaken to identify dietary and environmental risk factors for nasopharyngeal carcinoma relevant to this region. METHODS: A matched case-control study using neighbourhood controls was conducted. For each of the 47 cases identified, 2 apparently healthy neighbourhood controls were matched for age, sex and ethnicity. All information on dietary, environmental, social and demographic factors was collected. Univariate and multivariate logistic regression analysis using maximum likelihood method was used to analyse data. RESULTS: Consumption of smoked meat was found to be the risk factor for nasopharyngeal carcinoma (adjusted odds ratio = 10.8; 95% CI 3.0-39.0). History of using herbal nasal medicine was also found to be associated with nasopharyngeal carcinoma (OR = 21.9, CI = 6.8-71.4). However, exposure to a smoky atmosphere, betel-nut chewing, use of smokeless tobacco products, smoking and drinking habits were not found to be associated with nasopharyngeal carcinoma. CONCLUSION: This study reveals an association of nasopharyngeal carcinoma with consumption of smoked meat in Nagaland. The use of herbal nasal medicine seems to be an additional risk factor for nasopharyngeal carcinoma in Nagaland and needs further assessment.

Environmental and dietary risk factors for nasopharyngeal carcinoma: a case-control study in Zangwu County, Guangxi, China.

A case-control study was conducted on 88 incident cases of histologically confirmed undifferentiated nasopharyngeal carcinoma (NPC) in Zangwu County, China, and 176 age- sex- and neighbourhood-matched controls. The design of this study was defined after an anthropological survey on living habits in regions of high NPC incidence and the evidence of carcinogenic substances in some commonly consumed preserved foods. Subjects were interviewed regarding living conditions and diet in the year preceding the diagnosis of NPC and, with the help of their families, during childhood and weaning. After adjustment for a living conditions score to eliminate a confounding effect, an increased risk associated with consumption of salted fish during weaning and childhood was confirmed, especially for salted fish in rice porridge. The consumption of leafy vegetables was associated with a reduced risk for NPC, and consumption of melon seeds between 2 and 10 years of age with an increased risk. After multivariate analysis and adjustment according to the living conditions score, the consumption of salted fish in rice porridge before age 2 (OR = 3.8, P = 0.005), exposure to domestic woodfire (OR = 5.4, P = 0.01) and consumption of herbal tea (OR = 4.2, P = 0.02) were found to be independently related to the risk of NPC. The excess risk associated with the use of domestic wood fire increased if there were no windows in the house and with poor ventilation and cooking outside the house in a shack. As well as confirming the importance of the consumption of salted fish in childhood, this study has been the first to provide unequivocal evidence for two other factors implicated in increasing the risk of NPC in China, the adult consumption of traditional medicines (herbal tea) and exposure to domestic wood fumes.

Non-viral risk factors for nasopharyngeal carcinoma in the Philippines: results from a case-control study.

In a case-control study of NPC conducted in the Philippines, 104 predominantly non-Chinese (< 10% ethnically Chinese) cases of nasopharyngeal carcinoma (NPC) and 205 hospital and community controls were recruited. Risk factor information was obtained through personal interview. The occupational history of each subject was reviewed "blind" by an industrial hygienist to determine estimates of exposure to formaldehyde, solvents, dusts, exhaust and pesticides. After control for confounding, subjects who were first exposed to formaldehyde 25 or more years prior to diagnosis/interview or wo were first exposed before the age of 25 were found, in relation to those never exposed, to be at a 4.0-fold excess risk of disease. Similarly, those first exposed to dust and/or exhaust 35 or more years prior to diagnosis/interview were at a 4.4-fold excess risk of disease and those first exposed before the age of 20 were at a 3.5-fold excess risk of disease. Salted fish consumption was not associated with risk, while consumption of processed meats protected against NPC. Smoking was positively associated with NPC, but only when cases were compared to community controls. Relative to non-smokers, subjects reporting more than 30 years of smoking were at an adjusted 7.2-fold excess risk of disease. Herbal medicine use and burning of anti-mosquito coils were both independently associated with risk of NPC, with ever-users of herbal medicines being at a 2.5-fold excess risk of disease and those reporting daily use of anti-mosquito coils being at a 5.9-fold excess risk of disease relative to never users. Exposure to solvents, pesticides, or use of betel nuts were not associated with NPC risk.