Summary A case-control study of cancer of the gingiva was carried out in Kerala, Southern India, using 187 cases and 895 hospital-based controls. We investigated the effects on risk in males of pan (betel)-tobacco chewing, bidi and cigarette smoking, drinking alcohol and taking snuff. In females only pan-tobacco chewing was investigated as very few females indulged in the other habits. Among males, significant positive associations with risk were observed for pan-tobacco chewing (P<0.001), bidi smoking (P<0.001), alcohol drinking (P<0.001) and snuff use (P<0.05). In females, pan-tobacco chewing had a similar predisposing effect (P<0.001). Daily frequency of pan-tobacco chewing was the strongest predictor of risk in males, with a relative risk of 15.07 associated with chewing ten or more quids per day. The corresponding relative risk among females was 13.69. In males a relative risk of 3.20 was associated with smoking more than 20 bidis per day, and relative risks of 2.62 and 3.90 were associated with regular use of alcohol and snuff respectively. Surprisingly high relative risks were observed in association with occasional use of pan-tobacco, bidi, cigarettes, alcohol and snuff. A stepwise logistic regression analysis yielded four predictors: pan-tobacco daily frequency, duration of bidi use, and alcohol and snuff use (regular versus never). There were also significantly elevated risks associated with occasional indulgence in these four habits. Total lifetime exposure was no better at predicting risk than daily frequency or duration of habits.Cancer of the gingiva is an uncommon malignancy in many parts of the world. The highest incidence rates which are of the order of 2.3 per 100,000 population per year are reported from the Indian subcontinent (Muir et al., 1987). In many parts of India it constitutes 10-15% of all intra oral cancers and 2-3% of all incident cancers (National Cancer Registry Project, India, 1982-1985Krishnan Nair et al., 1988).The epidemiology of gingival carcinoma has been studied previously as part of a case spectrum consisting of other intra oral and head and neck cancers (Sanghvi et al., 1955;Shanta & Krishnamoorthy, 1959, 1963Wahi et al., 1965;Jussawalla & Deshpande, 1971;Jayant et al., 1977: Notani, 1988 Pan chewing, pan-tobacco chewing, bidi smoking, cigarette smoking, alcohol and nasal snuff inhalation were the habits ascertained for the cases and controls. Pan chewing is defined as chewing of a quid containing fresh betel leaves (Piper betle), arecanut (Areca catechu) and aqueous lime (calcium hydroxide). Locally cured tobacco leaves and/or stem are added to the quid in pan-tobacco. Bidi is a local cigarette containing 0.5 g of coarse tobacco dust rolled in a dried temburni leaf. The alcohol predominantly consumed is either 'toddy' (a locally fermented distilled sap from palm trees) or another locally brewed liquor called 'arrack' (approximately 40% ethanol) or both. Consumption of wine, beer, brandy, whiskey, gin and rum, collectively known as 'foreign liquors' is uncommon. The snu...

A case-control study of oesophageal cancer was carried out in Trivandrum, Kerala, involving 267 cases and 895 controls. Risk factors studied in males were pan (betel)-tobacco chewing, bidi and cigarette smoking, drinking alcohol and taking snuff. Only pan-tobacco chewing was investigated in females as very few indulged in the other habits. Among males significant associations with higher risk were observed for bidi smoking (p less than 0.001), bidi plus cigarette smoking (p greater than 0.05) and drinking alcohol (p less than 0.001). While a significant effect of duration of pan-tobacco chewing (p less than 0.005) was observed in males, there was no significant trend, the risk first falling then rising as duration of use increased. This was partly due to confounding with smoking. No effect of pan-tobacco use was observed in females. A step-wise model was fitted, retaining only those risk factors which were significant when adjusted for other factors; the risk factors included were duration of pan-tobacco chewing, duration of bidi smoking, daily frequency of bidi and cigarette smoking and alcohol use (yes or no). An adjusted relative risk of 2.03 was observed for a pan-tobacco habit of more than 40 years' duration, of 4.70 for more than 20 years of bidi smoking, of 4.80 for more than 20 bidis/cigarettes per day, and of 2.33 for regular alcohol use (in each category relative to a baseline of those never indulging in the relevant habit).

No abstract

No abstract

Fifty-two cases of oral verrucous carcinoma treated with radiotherapy at the Regional Cancer Centre, Trivandrum, Kerala, India in 1982 were evaluated to determine the distribution within the oral cavity, clinical extent, and effectiveness of radiotherapy in controlling the disease. The most common site was the buccal mucosa. Fifty percent of the patients had clinically negative regional lymph nodes and 33% were in earlier stages (T1, T2, N0, and M0). The overall 3-year no evidence of disease (NED) survival rate was 44%. The 3-year NED survival rate with radium implant was 86%. We cannot comment on anaplastic transformation after radiotherapy because our treatment failures have not been subjected for biopsy concerning this matter. Because the results are comparable with those of well-differentiated squamous cell carcinoma, we think that the treatment policies advocated for oral squamous cell carcinoma are also applicable to oral verrucous carcinoma.