Effect of smoking on folate levels in buccal mucosal cells.

The objective of the study was to document the existence of localized deficiency of folate in a tissue exposed to cigarette smoke, by analysis of oral and circulatory levels of this vitamin in smokers and non-smokers. Buccal mucosal cells and blood samples were collected from 25 smokers and 34 non-smokers. The Health Habits and History Questionnaire was completed by each subject. A 96-well plate L. casei assay, along with preincubation with a folate-free chick pancreas pteroyl-gamma-glutamyl hydrolase, was used to quantitate total buccal mucosal cell folates. The reproducibility (CV 5 to 7%) and recovery (95 to 106%) of the folate assay were satisfactory. Smokers had significantly lower buccal mucosal cell folate levels than did non-smokers. The mean plasma folate level of smokers although within normal limits, was also significantly lower than that of non-smokers. There were no significant differences in mean dietary folate intake or in alcohol consumption between the 2 groups. The strength of the positive association between smoking and plasma and buccal mucosal cell folate deficiency (by any definition) was moderate to strong and statistically significant. Our results indicate that cigarette smoking may result in a localized folate deficiency in buccal mucosal cells, independent of the plasma folate levels.     

叶酸干预对食管贲门癌前病变影响的初步研究

目的:探讨叶酸对食管/贲门各级癌前病变的影响.方法:对河南省林州市食管癌(EC)高发区普查发现的384例食管/贲门正常及各级癌前病变居民进行为期1年的叶酸和安慰剂双盲对照研究,最终58位参与者(叶酸组30位,对照组28位)符合分析条件.结果:膳食补充药剂后叶酸组食管各级癌前病变好转率为50%(15/30),低于对照组的64%(18/28);无变化率为40%(12/30),高于对照组的21%(6/28);而恶化率为10%(3/30),低于对照组的14%(4/28),X2=2.349,P>0.05.叶酸组贲门各级癌前病变好转率为20%(6/30),低于对照组的17%(5/28),无变化率为23%(7/30),低于对照组的50%(14/28);而恶化率为17%(5/30),低于对照组的21%(6/28),X2=4.376,P>0.05.结论:未观察到叶酸干预对食管/贲门各级癌前病变有明显影响,尚需进一步扩大样本量验证.     

Effect of maternal and postweaning folic acid supplementation on mammary tumor risk in the offspring

Intrauterine and early life exposure to folic acid has significantly increased in North America owing to folic acid fortification, widespread supplemental use, and periconceptional supplementation. We investigated the effects of maternal and postweaning folic acid supplementation on mammary tumor risk in the offspring. Female rats were placed on a control or folic acid-supplemented diet prior to mating and during pregnancy and lactation. At weaning, female pups from each maternal diet group were randomized to the control or supplemented diet and mammary tumors were induced with 7,12 dimethylbenz[a]anthracene at puberty. At necropsy, mammary tumor parameters, genomic DNA methylation, and DNA methyltransferase activity were determined in the offspring. Both maternal and postweaning folic acid supplementation significantly increased the risk of mammary adenocarcinomas in the offspring (OR = 2.1, 95% CI 1.2-3.8, P = 0.008 and OR = 1.9, 95% CI 1.1-3.3, P = 0.03, respectively). Maternal folic acid supplementation also significantly accelerated the rate of mammary adenocarcinoma appearance (P = 0.002) and increased the multiplicity of mammary adenocarcinomas (P = 0.008) in the offspring. Maternal, but not postweaning, folic acid supplementation significantly reduced global DNA methylation (P = 0.03), whereas postweaning, but not maternal, folic acid supplementation significantly decreased DNA methyltransferase activity (P = 0.05) in nonneoplastic mammary glands of the offspring. Our findings suggest that a high intrauterine and postweaning dietary exposure to folic acid may increase the risk of mammary tumors in the offspring. Further, they suggest that this tumor-promoting effect may be mediated in part by altered DNA methylation and DNMT activity.     

Effects of folate deficiency and supplementation on methylnitrosourea-induced rat mammary tumors.

BACKGROUND: There are metabolic and epidemiologic data consistent with the hypothesis that folate deficiency increases the likelihood of cancer. Conversely, it is also known that folate is necessary for cancer growth, but few experiments in laboratory animals have evaluated the effects of folate deficiency on the development of chemically induced cancers. PURPOSE: Our purpose was to determine the effects of nutritional folate deficiency in female Fischer 344 rats on initiation and early promotion of methylnitrosourea (MNU)-induced mammary cancer. METHODS: Rats (age, 27 days) were fed a folic acid-deficient diet (AIN-76A) supplemented with glycine and succinylsulfathiazole [FA(0)]; the FA(0) diet supplemented with 2 or 40 mg of folic acid per kilogram [FA(2) or FA(40), respectively]; or the FA(0) diet supplemented with 20 mg of folinic acid per kilogram [FL(20)]. At 57 days of age, each diet-treated group (30 rats in each group) received MNU (50 mg/kg) by intravenous injection. Immediately after MNU treatment, all animals were fed the AIN-76A complete diet containing 2 mg of folic acid per kilogram. Control groups were fed the AIN-76A complete diet throughout the entire experiment. RESULTS: After 4 weeks, folate deficiency, but not anemia or growth suppression, was documented by lower folate levels in plasma and red blood cells in the group receiving the FA(0) diet. Cancer multiplicity (i.e., number of mammary cancers per number of tumor-bearing animals) at 180 days after MNU injection was 1.32, 1.90, 2.14, and 2.73 mammary cancers per tumor-bearing animal in the FA(0), FA(2), FA(40), and FL(20) groups, respectively; the value in the FA(0) group was statistically significant compared with the values in the other groups. The time required for 50% of the rats to develop palpable mammary cancer was 170, 142, 100, and 85 days, respectively. The value of 170 days for the FA(0) group was statistically significant compared with the values of 100 and 85 days. Mammary cancer incidence was 63%, 70%, 72%, and 73%, respectively; these percentages were not significantly different. CONCLUSIONS: Folate deficiency suppresses and folate supplementation enhances initiation or early promotion of MNU-induced mammary cancer in rats, even when the folate-deficient rats do not have anemia or growth suppression. IMPLICATION: Since the rat is relatively resistant to folate deficiency anemia, other animal models should be used to test the effect of folate nutriture on carcinogenesis.     

Radiotherapy of carcinoma of the buccal mucosa

A retrospective study of 399 cases of buccal cancer, presenting to the Tata Memorial Hospital, Bombay, during January to December 1984 was undertaken to define the efficacy of various treatment modalities in different clinical stages. Analysis of treatment technique and response was carried out in 185 cases that completed adequate therapy. Sixty percent of patients with stage I and II disease (21/35) received radiation therapy alone as the primary modality of treatment. Patients (150) with stage III or IV disease received palliative irradiation (57 cases), radical surgery (54 cases), or a combination of both (39 cases). The 2-year disease-free survival (DFS) rates were 48% for radiotherapy and 46% for surgery in the early stages and 5% and 33%, respectively, for advanced stages. Radiotherapy with a modified technique is recommended for the early-stage cancers and preoperative irradiation with adjuvant chemotherapy or hyperthermia for the advanced stages.     

Surgery for cancer of the buccal mucosa

Buccal Mucosa cancer is common in India, T4 tumours being the most common (66%). T1 tumours are rarely seen (4%). Disease-free survival (DFS) at 18 mo with surgery alone for T2, T3, and T4 tumours is 57%, 43%, and 21%, respectively. Addition of postoperative radiation therapy (RT) for T3 and T4 lesions increases DFS to 60% and 35%, respectively. Marginal mandibulectomy is advocated for lesions close to the lower gingiva when the bone is clinically and radiologically uninvolved. The local control rate with marginal mandibulectomy is 79%. In T3/T4 tumours, results with supraomohyoid dissection are comparable to radical neck dissection when the upper jugular nodes are histologically negative. In T4 tumours, histological grading forms an important parameter for identification of a favourable subset. In well-differentiated tumours DFS was 48% with surgery and 72% with surgery and postoperative RT; in moderately differentiated tumours it was 12% and 21%, respectively; and in the poorly differentiated group there were no survivors.     

Responses of biomarkers of folate and riboflavin status to folate and riboflavin supplementation in healthy and colorectal polyp patients (the FAB2 Study).

Epidemiologic data suggest that increasing folate intake may protect against colorectal cancer. Riboflavin may interact with folate to modulate the effect. A double-blind randomized placebo-controlled intervention study (the FAB2 Study) was carried out in healthy controls and patients with colorectal polyps (adenomatous and hyperplastic) to examine effects of folic acid and riboflavin supplements on biomarkers of nutrient status and on putative biomarkers of colorectal cancer risk (DNA methylation and DNA damage; to be reported elsewhere). Ninety-eight healthy controls and 106 patients with colorectal polyps were stratified for the thermolabile variant of methylene tetrahydrofolate reductase, MTHFR C677T, and were randomized to receive 400 microg of folic acid, 1,200 microg of folic acid, or 400 microg of folic acid plus 5 mg of riboflavin or placebo for 6 to 8 weeks. Blood samples and colon biopsy samples were collected for the measurement of biomarkers of folate and riboflavin status. Supplementation with folic acid elicited a significant increase in mucosal 5-methyl tetrahydrofolate, and a marked increase in RBC and plasma, with a dose-response. Measures of riboflavin status improved in response to riboflavin supplementation. Riboflavin supplement enhanced the response to low-dose folate in people carrying at least one T allele and having polyps. The magnitude of the response in mucosal folate was positively related to the increase in plasma 5-methyl tetrahydrofolate but was not different between the healthy group and polyp patients. Colorectal mucosal folate concentration responds to folic acid supplementation to an extent comparable to that seen in plasma, but with a suggestion of an upper limit.     

Extraskeletal myxoid chondrosarcoma of the left buccal mucosa

Extraskeletal chondrosarcoma (ECS) is a rare malignant neoplasm of bone or soft-tissue origin, characterized by the presence of spindle cells admixed with well-differentiated cartilage or chondroid stroma. A case of ECS is reported in a 102-year-old woman who presented with a painful swelling of 2 cm in the left buccal vestibular area. Orthopantomography was insignificant. Biopsy and histopathological examination revealed a tumor composed of an undifferentiated small round cell component that surrounded a myxoid matrix of malignant cartilage. Immunohistochemical studies showed the tumor cells to be positive for nuclear S-100 protein immunostaining, focally positive for vimentin and synaptophysin, and negative for epithelial membrane antigen, desmin, chromogranin, Leu-7, glial fibrillary acid protein, actin muscle-specific, cytokeratin, carcinoembryonic antigen, and CD99 (MIC2). The proliferative index (MIB-1) was 20%. The tumor was treated by surgery with wide margins. There was no evidence of disease at one-year follow-up. This report presents a very rare case of ECS of the left buccal mucosa of the maxilla, and describes the histological characteristics and the immunoprofile.     

Effect of pan masala with tobacco in buccal mucosa of albino rats

The effects of application of Pan Parag with tobacco on buccal mucosa of 21 albino rats (Wistar strain) were studied. The paste made up of pan Parag (instant betel nut preparation with tobacco) was painted over the entire buccal mocosa of the experimental group (n=21) on every alternate day from the 46th to 255th day of the study with a total of 42 days intervening rest period. Whereas in the control group (N=14), the painting brush dipped in tap water was rubbed over the buccal mucosa in the same frequency. Punch biopsies were taken from the buccal mucosa of all the animals on the 31st day, 106th day, 181st day and 256th day of the study. The animals were left untouched for 15 days following each biopsy procedure. The biopsy specimens in the experimental group after 2 months painting revealed changes of Papillomatosis in 22% and dysplasia in 39% of rats. Dysplastic changes were observed in 83% of the animals at the end of 4th months, which increased to 95% after 6 months. The control group revealed no significant pathological changes. Our study shows that the application of Instant betel nut preparation with tobacco (Pan Parag) causes significant histopathological changes in a short period of time and are responsible for the production of the various premalignant lesions affecting the oral cavity.     

Tumour thickness and relationship to locoregional failure in cancer of the buccal mucosa.

AIMS: The TNM system is the main parameter in treatment planning and the prediction of survival in oral cancer. Here, we investigate the role of tumour thickness as a predictor of locoregional failure and survival in node-negative patients. METHODS: We studied 176 node-negative and early stage gingivo-buccal squamous cell carcinoma patients retrospectively. Clinico-pathological factors investigated for tumour failure prediction were: T stage; tumour differentiation; tumour thickness; and treatment. Tumour thickness was measured using an ocular micrometer. RESULTS: Locoregional tumour failure was found in 34% of cases (60 of 176). Tumour differentiation was found not to be statistically significant in predicting tumour failure. The covariates predicting tumour failure were T stage (P<0.05); type of surgical treatment (P<0.05); and tumour thickness (P<0.001). The mean tumour thickness found was 4 mm. Tumours 4 mm in thickness behaved similarly in all three stages and those >4 mm had a higher rate of lymph-node metastasis. No distant metastasis was found in this series. CONCLUSION: Tumour thickness was found to be an accurate predictor of locoregional failure in early stage cancer of the buccal mucosa.     

Cervical metastasis from Spitz nevus of the buccal mucosa

A 23-year-old woman was presented with a prolonged history of a small lump in the buccal mucosa. A local excision was performed. The morphology diagnosed a Spitz nevus and she underwent supplementary excision of scar tissue. Two years later a submandibular lump appeared on the ipsilateral side of the neck. Cytology from fine needle aspiration indicated spread of a melanocytic tumor and she underwent a modified supraomohyiod neck dissection. One of the lymph nodes showed an inclusion of cells in the deep layers with epitheloid and spindle cells in a pattern similar to that of the primary oral lesion. The finding suggests a mechanical spread of melanocytes from the Spitz nevus to the regional lymph node. After more than 3 years of follow-up there is no further manifestation of disease. It is believed that this may be an example of how a Spitz tumor, although inherently benign, can spread along lymphatics in a pseudometastatic fashion. To our knowledge this is the first report of an oral Spitz melanoma with metastatic behavior.     

Influence of folate status on genomic DNA methylation in colonic mucosa of subjects without colorectal adenoma or cancer

DNA hypomethylation may increase the risk of colorectal cancer. The main aim of this study was to assess the influence of folate status (serum and erythrocyte folate and plasma homocysteine concentrations) on DNA methylation. Methylenetetrahydrofolate reductase (MTHFR 677C --> T and 1298A --> C), methionine synthase (MS 2756A --> G) and cystathionine synthase (CBS 844ins68) polymorphisms were measured to account for potential confounding effects on folate status and DNA methylation. A total of 68 subjects (33 men and 35 women, 36-78 years) free from colorectal polyps or cancer were recruited in a cross-sectional study. Tissue biopsies were obtained at colonoscopy for the determination of DNA methylation in colonic mucosa using an in vitro radiolabelled methyl acceptance assay. Serum and erythrocyte folate were inversely correlated with plasma homocysteine (r=-0.573, P<0.001 and r=-0.307, P=0.01 respectively) and DNA hypomethylation in colonic mucosa (r=-0.311, P=0.01 and r=-0.356, P=0.03). After adjusting for gender, age, body mass index, smoking and genotype, there were weak negative associations between serum and erythrocyte folate and colonic DNA hypomethylation (P=0.07 and P=0.08, respectively).     

Evaluation of the nucleolar organizer region associated proteins in exfoliative cytology of normal buccal mucosa. Effect of smoking

An evaluation of cellular alterations in the smoker's oral mucosal cells was performed. The Exfoliative Cytology technique was applied and the cytological smears stained with silver for the enumeration of Argyrophilic nucleolar organizer regions (AgNORs). Cytological smears were collected from two anatomic sites: floor of the mouth and tongue border, in both groups, smokers and non smokers, with a purpose of correlating the smoking habit to possible cellular alterations. The enumeration of the AgNORs showed that the average number of AgNORs is higher in smokers. There is a significant difference (P=0.0001) between smears from the floor of the mouth and from tongue border in the smoking group. In this study, no correlation between number of cigarettes, age and gender was found, but the results suggest that there might be a correlation between the smoking habit and an increased rate of cellular proliferation in the oral mucosal cells.     

Squamous cell carcinoma of the buccal mucosa with metastases to the pericardial cavity, lung and thyroid.

Pericardial metastasis from the oral cavity is a rare event. Squamous cell carcinoma of the buccal mucosa is not known to spread to the pericardium. We present a case of buccal mucosal carcinoma with distant metastases diagnosed by pericardial biopsy.     

Colonic mucosal concentrations of folate are accurately predicted by blood measurements of folate status among individuals ingesting physiologic quantities of folate.

Folate status is inversely related to the risk of colorectal cancer. Whether conventional blood measurements of folate status accurately reflect folate concentrations in the colorectal mucosa has been a controversial topic. This is an important issue because accurate measures of folate status in the colorectal mucosa are important for ascertaining the risk of colorectal cancer in epidemiological studies and for determining the effects of folate supplementation in clinical trials. We examined whether conventional blood measurements of folate and a more sensitive, inverse indicator of systemic folate status, serum homocysteine, accurately reflect folate concentrations in human colonic mucosa obtained by endoscopic biopsy. Study subjects (n = 20) were participants in a randomized trial that investigated the effect of folate supplementation (5 mg daily for 1 year) on provisional molecular markers of colon cancer. Blood samples and biopsies of normal rectosigmoid mucosa were obtained at baseline, at 6 months, and at 1 year. Serum, RBC, and colonic mucosal folate and serum homocysteine concentrations were determined. Colonic mucosal folate concentrations correlated directly with serum folate concentrators at each time point (r = 0.572-0.845; P < 0.015) and with RBC folate concentrations at 6 months and 1 year (r = 0.747-0.771; P < 0.001). Colonic mucosal folate concentrations correlated inversely with serum homocysteine concentrations at each time point (r = -0.622-0.666; P < 0.008). Systemic measures of folate status did not correlate with colonic mucosal folate concentrations among individuals receiving supplemental folate. Our observations indicate that colonic mucosal concentrations of folate may be predicted accurately by blood measurements of folate status only among individuals not ingesting supraphysiological quantities of folate.     

Evaluation of treatment results of squamous cell carcinoma of the buccal mucosa

Of the 49 patients with squamous cell carcinoma of the buccal mucosa referred to the Rotterdam Radio-Therapeutic Institute (RRTI) and Universital Hospital Dijkzigt Rotterdam (AZD) during 1970-1984, 31 patients had an advanced stage of disease, 21 patients had clinical evidence of lymph node metastasis. Forty patients were treated with curative intention. Treatment modalities were: radiation therapy, preoperative radiation followed by surgery, and primary surgery. Eighteen of the 40 patients (45%) developed a local tumor recurrence; nearly all recurrences occurred within 2 years. The incidence was equal in all treatment groups. Of the 22 patients with initial clinically negative neck, regional relapse occurred in 3 of the 14 patients, of whom the neck was not treated electively by radiation therapy; all three in combination with a local recurrence. None of the 8 patients with electively irradiated necks developed a regional relapse. Eight of the 18 patients with initial clinically enlarged lymph nodes treated either by radiotherapy or surgery, developed a regional relapse, 5 in combination with a local recurrence. Treatment of the clinically positive neck by neck dissection was superior to radiotherapy. Local recurrence carried a poor prognosis. Almost 70% died of their disease. The overall and corrected 5-year survival was 38% and 52% respectively.