Association of tobacco habits, including bidi smoking, with overall and site-specific cancer incidence: results from the Mumbai cohort study.

OBJECTIVE: Bidis are hand-rolled cigarettes commonly smoked in South Asia and are marketed to Western populations as a safer alternative to conventional cigarettes. This study examined the association between bidis and other forms of tobacco use and cancer incidence in an urban developing country population. METHODS: Using data from the large, well-characterized Mumbai cohort study, adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were computed from Cox proportional hazards regression models in order to compare the relative effect of various forms of tobacco use on cancer incidence. RESULTS: During 649,228 person-years of follow-up 1,267 incident cancers occurred in 87,222 male cohort members. Incident oral cancer in bidi smokers (HR = 3.55; 95% CI = 2.40,5.24) was 42% higher than in cigarette smokers (HR = 2.50;95% CI = 1.65,3.78). For all respiratory and intrathoracic organs combined, the increase was 69% (HR = 5.54; 95% CI = 3.46,8.87 vs. HR = 3.28; 95% CI = 1.99,5.39); for lung and larynx, the increases were 35 and 112%, respectively. Smokeless tobacco use was associated with cancers of the lip, oral cavity, pharynx, digestive, respiratory, and intrathoracic organs. CONCLUSIONS: Despite marketing claims to the contrary, we found that smokeless tobacco use and bidi smoking are at least as harmful as cigarette smoking for all incident cancers and are associated with increased risk of oral and respiratory/intrathoracic cancers.

Cancer epidemiology in South Asia - past, present and future.

Pakistan, India, Sri Lanka, Bangladesh, Nepal and Bhutan, with their total population of more than 1,500 million, make up the subcontinent of South Asia. Despite massive diversity across the region, there are sufficient similarities to warrant a collective approach to chronic disease control, including development of cancer control programs. Cancer is already a major problem and there are general similarities in the prevalence patterns. In males, oral and lung cancer are either number one or two, depending on the registry, with the exceptions of Quetta in the far north, Larkana and Chennai. Moderately high numbers of pharyngeal and/or laryngeal cancer are also consistently observed, with prostate cancer now becoming visible in the more developed cities. Breast and cervical cancer share first and second place except in Muslim Pakistan, where oral cancer generally follows breast. The ovary is often included in the five most prevalent types. Markedly increasing rates for breast cancer and distribution shifts in other cancers suggest that, despite improvement in cervical and oral rates, the overall burden will only become heavier over time, especially with increasing obesity and aging of what are still youthful populations. Coordination of activities within South Asia is a high priority for cancer control in the region.

Lifetime risk and trends in lung cancer incidence in greater Mumbai.

OBJECTIVE: To estimate the probability of developing lung cancer in the entire life span of the people of Greater Mumbai and variation according to age and sex. Information on cancer incidence trends in a community forms the scientific basis for planning and organising prevention, diagnosis and treatment. During the last 24 year period, a total of 11,458 lung cancer cases were registered (9,052 male and 2,406 female) by the Bombay Cancer Registry. Lung cancer accounts for 9.4% of all male cancers and 2.7% of those in females (6.2% of all cancers) in Greater Mumbai. The probability of developing cancer in the entire life span of the people of Greater Mumbai was estimated. METHODS: A method based on the cumulative risk of cancer was used to estimate the probabilities using lung cancer data collected by the population-based Bombay Cancer Registry from the years 1982 to 2005. For evaluation of trends, a linear regression model based on the logarithm of the observed incidence rates was applied. The annual percentage change was also computed for the evaluation. The cumulative incidence rate percentage was calculated by adding up the age-specific incidence rates at single ages and then expressed as a percentage. RESULTS: The results show that age-adjusted incidence rates of lung cancer during the period 1982 to 2005 showed a statistically significant decreasing trend in males and a statistically significant increasing trend among females. When these trends were examined across different age-groups (0-39, 40-64 and 65 or older), the rates showed a statistically significant decreasing trend from 0-64 years in males and a statistically significant increasing trend in females aged 65 years and older. The rates proved stable across the other age-groups. The probability estimates indicate that one out of every 74 men and one out of every 242 women will contract lung cancer at some time in their whole life in the absence of other causes of death, assuming that the current trends prevail over the time period. Most of them will acquire the disease after the age of 40 years, after which risk increases with time. CONCLUSIONS: The variation in age-adjusted incidence rate across different age-groups in both sexes clearly indicate that there has been a change in the etiology of lung cancer in Greater Mumbai over time. The most important reason for this would be decrease in smoking prevalence among males. The other reasons for this have to be explored through risk assessment studies, but these findings may be of general interest because changes in diagnostic practices are confounders in time trends of lung cancer in many developed countries, preventing inferences on changes in risk factors.

Trends in the incidence of Non-Hodgkin's lymphoma in India.

Non-Hodgkin's lymphoma is the 11th most common cancer in terms of incidence. It is most frequent in high income countries, with rates more than twice those of middle--to low-income countries. It is usually fatal, with a 5 year survival rate of less than 35 percent. It is not a single cancer, but rather a wide group of cancers (including entities such as Burkitt's lymphoma and diffuse large B-cell lymphoma), each with a district geographical distribution, development path, age profile and prognosis. Non-Hodgkin's lymphoma is increasing in incidence world wide. On this background, in this paper an attempt has been made to study the trends in Non-Hodgkin's lymphoma in various Indian populations in both sexes.

Trends in the brain cancer incidence in India.

Trends in cancers of the central nervous system in both sexes in five Indian population based cancer registries (Mumbai, Chennai, Bangalore, Delhi & Bhopal) were evaluated over a period of the last two decades. For this purpose we applied a model that fits the data is the logarithm of Y=ABx which represents a Linear Regression model. This approach revealed an increasing trend in cancers of nervous system in both sexes throughout the entire period of observation in almost all registries. As CNS cancers are increasing, analytic epidemiological studies should be planned in a near future on a priority basis to understand the etiology of these cancers in depth.

Geriatric cancers in India: an epidemiological and demographic overview.

This article provides an overview of aspects of the burden of cancer in the elderly, in India highlighting certain demographic and epidemiological data. In India the normal retirement age is 60 years, so the definition of the elderly, in India is considered above the age of 60 years. Information on the aging of the Indian population is based on various census figures, cancer incidence figures are taken from Mumbai registry data. Men and women aged > or = 60 years are at high risk for major cancers. Men have a risk 15 times greater risk and in women 8 times greater risk than the persons having age < 60 years. Lung and prostate cancers are most prominent cancer in men having age > or = 60 years while in women breast is the leading site followed by cervix and ovary in the same age group. Demographic and epidemiologic data characterize the aging / cancer interface. The changing demographic structures underscore the current incidence imperative for elderly; suggesting a starting demand will be made in the future requiring physician's abilities and skills to meet these needs.

Trends in cancer incidence in esophagus, stomach, colon, rectum and liver in males in India.

Time trends in cancers of the esophagus, stomach, colon, rectum and liver cancers among the male population in five Indian urban population based cancer registries (Mumbai, Bangalore, Chennai, Delhi, and Bhopal) were examined over the period of the last two decades. The model applied fits data to the logarithm of Y=ABx. This Linear Regression method showed decreasing trends in age-adjusted incidence rates for cancers of the stomach and esophagus, especially in Bjopal, and increasing trends for colon and rectum and liver, throughout the entire period of observation in most of the registries. The five cancers together constitute more than 80% of the total gastro intestinal cancers and are serious diseases in both sexes. To understand the etiology of these cancers in depth, analytic epidemiological studies should be planned in the near future on a priority basis.

Trends in cancer incidence in female breast, cervix uteri, corpus uteri, and ovary in India.

Trends in breast, cervix uteri, corpus uteri and ovarian cancers in six population based cancer registries (Mumbai, Bangalore, Chennai, Delhi, Bhopal, and Barshi) were evaluated over a period of the last two decades. For studying trends we used a model that fits this data is the logarithm of Y=ABx which represents a Linear Regression model. This approach showed a decreasing trend for cancer of the cervix and increasing trends for cancers of breast, ovary and corpus uteri throughout the entire period of observation in most of the registries. The four cancers, breast, cervix, corpus uteri and ovary, constitute more than 50% of total cancers in women. As all these cancers are increasing, to understand their etiology in depth, analytic epidemiology studies should be planned in a near future on a priority basis.

Trends in the prostate cancer incidence in India.

Trends in prostate cancer in five population-based cancer Registries (Mumbai, Chennai, Bangalore, Delhi & Bhopal) in India were studied over a period of two decades using a model that fitting the data as the logarithm of Y=ABx which represents a Linear Regression model. This approach showed increasing trends in the age adjusted incidence rates throughout the entire period of observation for most of the registries, especially in Chennai and Bhopal and to the least extent in Mumbai. Particularly in Asia we face a future major increase in the rates of prostate cancer. Collaborative action now is a high priority to allow the preparations necessary for effective control of prostate cancer.

Trends in incidence of head and neck cancers in India.

Information relating to cancer incidence trends forms the scientific basis for the planning and organization of prevention, diagnosis and treatment of cancer in a community. An attempt was here made to study the trends in the age adjusted incidence rates for the sites of head and neck cancers in Mumbai, Bangalore, Chennai, Delhi, Bhopal, and Barshi registry's populations. For carrying out trend analysis the gum, the floor of mouth, the mucosa of cheek, the hard and soft palate and the uvula were grouped together and assigned as cancers of mouth. The trend analysis was carried out for all sites together, tongue, mouth, hypopharynx and larynx in males and all sites together and mouth in females. Sites such as lip, hypopharynx and nasopharynx were not considered. In males, for all sites together linear regression showed no increase or decrease in age adjusted rates overall for Bangalore and Delhi registries, a significant decrease for Mumbai and Delhi registries, but a rising trend for Chennai and Bhopal registries over a period of time. In females, for all sites together no change was observed in age adjusted incidence rates for Mumbai, Chennai, Bhopal, Bangalore and Barshi registries while a decreasing trend was noted for Delhi registries over a period of time. For the specific sites, variation among registries was also apparent. The results point to local differences in sub-site specific risk factors which might be elucidated by analytical epidemiological assessment.

Geographic variation in cancer incidence and its patterns in urban Maharashtra, 2001.

In this paper an attempt has been made to study the geographic variations in cancer incidence and its pattern in Urban Maharashtra. Data collected by Mumbai, Poona, Nagpur, and Aurangabad, Population based Cancer Registries, for the year 2001 have been utilized. The incidence patterns by sex, age, and religion has been compared between these four agglomerations. Besides this childhood cancers and tobacco related cancers for each registry are also described. Age specific cancer incidence rates show increasing trend with increasing age in all the four populations. The curves for Mumbai, Poona, Nagpur are closed together with fluctuations, indicating similarities in the rise. In all the four registries, amongst males, cancers of the lung, larynx, oesophagus, tongue and prostate while in females breast, cervix, ovary, oesophagus, mouth and leukemias occupy places in ten leading sites. The proportion of childhood cancers varies from 1.9% in females in Poona to 4.5% in males in the Nagpur populations. The proportion of tobacco related cancers varies in males from 38.9% in Poona to 54.4% in Aurangabad, where as in females from 14.1% in Nagpur to 21.7% in Aurangabad. Considerable variations was observed in the incidence of cancer of various sites in both the sexes, professing different religious faiths within this populations. The findings of this paper can be used to estimate the incidence and prevalence of cancer for future for whole Maharashtra state and studies in cancer etiology and control can be planned.

Social inequalities in cancer with special reference to South Asian countries.

There are major differences in cancer burden across socioeconomic classes, as is evident from the data for cancer incidence and mortality from Greater Mumbai, India. Changes over time are also evident and recently there has been a clear shift to increasing breast cancer particularly in well-educated women, who conversely are at much lower risk of cervical cancer. With infection-related and tobacco-related cancers, programs of prevention and early detection will yield desirable results only if it is associated with a program directed towards elimination of poverty, illiteracy and restoring social inequality. Similarly education must play a role in combatting diet-related neoplasia but here the target population may differ, requiring a specific awareness of psychological profiles.

Assessing cancer burden in rural India: an analysis by cause of death statistics.

India lacks nationwide cancer registration and systematic death registration. Gaining insight into the magnitude of the cancer problem in India depends mainly on 14 population based cancer registries, which provide relatively accurate statistics although the area and population cover by these registries is minimal at about 7% (20% Urban and 1 % Rural). With estimation of cancer burden from other sources, paucity of adequate data on the one hand and the complex pathogenesis of disease on other makes for complexity in dealing with rural populations. However, surveys of cause of death do reveal some interesting patterns that may very well be of use for international comparisons. In this paper an attempt has been made to estimate the cancer burden in rural India using the information available from surveys of cause of death for rural populations conducted by the Government of India.

Respiratory cancer population-based survival in Mumbai, India.

Survival experience of patients with cancer of the larynx (ICD-32) or lung (ICD-34) registered by the Mumbai (Bombay) population based cancer registry, India, during the years 1992-94 was determined. The vital statistics of the patients were established by matching with death certificates from the Mumbai Municipal death register and by active methods such as telephone enquiry, reply-paid postal enquiry, house visits and scrutiny of case records. Of the 1905 (675 larynx and 1230 lung) eligible cases for analysis, 1480 were dead (450 larynx and 1030 lung) and 425 were alive (225 larynx and 200 lung). The overall 5-year observed and relative survival rates for laryngeal cancers were 29.1% and 36.4%, and for lung cancers were 12.5% and 15.9% respectively. On multivariate analysis, age, treatment and clinical extent of disease emerged as independent predictors of survival with both cancers. People aged 55 years and above had a relative risk of four or more for laryngeal cancer and 2.3 times and more for lung cancer death as compared to those aged less than 35 years. Early detection and prompt treatment should improve overall survival from lung as well as laryngeal cancer.

An epidemiological assessment of increasing incidence and trends in breast cancer in Mumbai and other sites in India, during the last two decades.

A great deal is known on the epidemiology of breast cancer. In this paper an attempt has been made to discuss the epidemiology and trends in incidence of breast cancer in various populations of India with special reference to the data available at Mumbai Cancer Registry. For discussing descriptive epidemiology of breast cancer the data collected for most recent year, 1999, by Mumbai Cancer Registry has been utilized. For studying time trends in breast cancer the data collected for the Mumbai Cancer Registry for the years 1982-99 and for Bangalore and Chennai 1982-96 and for Barshi, Bhopal and Delhi for the years 1988-96 has been employed. A linear regression model based on the logarithms of the various incidence rates, a method frequently used for studying time trends, was applied to the entire dataset. Age specific incidence rates for breast cancer for most of the urban population in India were found to show steep increase till menopause years, after which the curves plateau. Most of the registries data indicate that Christians in India have the greatest risk of breast risk and Muslims have the lowest rate. In all the populations breast cancer was found to be less prevalent at the lower education level and the incidence increased with the education level. The trends for increase in breast cancer incidence over time for most of the populations in India were found to be statistically significant.