Trends in breast, ovarian and cervical cancer incidence in Mumbai, India over a 30-year period, 1976-2005: an age-period-cohort analysis.

BACKGROUND: Demographic, socioeconomic and cultural changes in India have increased longevity, delayed childbearing, decreased parity and resulted in a more westernised lifestyle, contributing to the increasing burden of cancer, especially among women. METHODS: We evaluated secular changes in the incidence of breast, cervical and ovarian cancer in Mumbai women aged 30-64 between 1976 and 2005. Age-standardised incidence rates were calculated and presented by site and calendar period. An age-period-cohort (APC) analysis quantified recent time trends and the significance of birth cohort and calendar period effects. The estimated annual percent change (EAPC) was obtained from the drift parameter, expressing the linear time trend common to both calendar period and birth cohort. RESULTS: Over the 30-year study period, the age-standardised rates significantly increased for breast cancer (EAPC: 1.1% (95% confidence interval (CI): 1.0, 1.3)), significantly decreased for cervical cancer (EAPC: -1.8% (95% CI: -2.0, -1.6)) and there was no statistically significant change for ovarian cancer (EAPC: 0.3% (95% CI: -0.1, 0.6)). For breast and cervical cancer, the best-fitting model was the APC model. CONCLUSIONS: The rates of breast, cervical and ovarian cancer remain low in comparison with western countries, and the divergent trends of breast (increasing) and cervical cancer (decreasing) in Mumbai were similar to those observed in several other Asian countries. The changing risk profile in successive generations - improved education, higher socioeconomic status, later age at marriage and at first child, and lower parity - may in combination partially explain the diverging generational changes in breast and cervical cancer in Mumbai in the last decades.

Population-based survival from colorectal cancer in Mumbai, (Bombay) India.

Survival estimates of patients registered by population-based cancer registries reflect the average prognosis from a given cancer as they are based on unselected patients with a wide range of natural histories and treatment patterns. In this paper, we report the survival experience of colorectal cancer patients in Mumbai (Bombay), India. Follow-up information on 1642 colorectal cancer patients registered by the Bombay Population-based Cancer Registry for the period 1987-1991 was obtained by matching with death certificates from the Bombay vital statistics registration system, postal/telephone enquiries, home visits and scrutiny of medical records. Cumulative observed and relative survival proportions were calculated by Hakulinen's method. For comparison of results with other populations, age-standardised relative survival (ASRS) was calculated by directly standardising age-specific relative survival to the specific age distributions of the world standard cancer patient population in 1985. The log-rank test was used to identify the potential prognostic variables which were introduced step-wise into a Cox regression model to identify the independent predictors of survival. The 5-year relative survival was 36.6% for colon and 42.2% for rectal cancer. Age, site of cancer and clinical stage of disease emerged as independent predictors of survival. Age-specific 5-year relative survival declined with advancing age. Survival at 5 years was 61.2% for localised colon cancer; 31.9% for regional and 9.0% for distant metastatic disease. These were 65.7, 25.6 and 4.3%, respectively for rectal cancers. Comparison of the results with other populations revealed significant variations, which seem to be related to differences in detection and treatment. The prognosis from colorectal cancer in Mumbai and developing countries, may be further improved through early detection linked with treatment.

Vasectomy and prostate cancer: a case-control study in India.

BACKGROUND: The role of vasectomy in the development of prostate cancer remains controversial. In particular, there has been concern about detection bias and confounding in the previously published epidemiological studies examining this hypothesis. With the goal of minimizing detection bias, we have evaluated the relation between vasectomy and prostate cancer in a population without routine prostate cancer screening. METHODS: A case-control study consisting of 175 prostate cancer cases and 978 controls with cancer diagnoses other than prostate cancer was conducted at hospitals covered by the Bombay Cancer Registry in Bombay, India. History of vasectomy, demographic, and lifestyle factors were obtained by structured interview. Multiple logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Standardizing by age, 8.7% of cases and 8.3% of controls had had a vasectomy. The OR for prostate cancer comparing men who had had a vasectomy to those who did not was 1.48 (95% CI: 0.80-2.72) controlling for age at diagnosis, smoking status, alcohol drinking, and other demographic and lifestyle factors. Risk of prostate cancer associated with vasectomy appeared to be higher among men who underwent vasectomy at least two decades prior to cancer diagnosis or who were at least 40 years old at vasectomy. CONCLUSIONS: Although not statistically significant, the results of this hospital-based case-control study are consistent with the hypothesis of a positive association between vasectomy and prostate cancer. Because routine prostate cancer screening is not common in this population, detection bias was unlikely to account for this association.

PIP: Although several studies have detected an association between vasectomy and subsequent prostate cancer, the research has been marred by detection bias and confounding. This association was reassessed in a hospital-based case-control study conducted in India, where the absence of routine screening for prostate cancer eliminates the potential for detection bias. Enrolled from hospitals covered by the Bombay Cancer Registry were 175 prostate cancer cases and 978 controls with other types of cancers. 17 cases and 83 controls reported a history of vasectomy. After age was controlled, the odds ratio for prostate cancer was 1.31 (95% confidence interval (CI), 0.74-2.33) among vasectomized compared with nonvasectomized men. Further adjustment for confounding factors such as smoking, alcohol consumption, and marital status increased the relative risk to 1.48 (95% CI, 0.80-2.72). Compared with men without a vasectomy history, men who underwent the procedure more than 20 years earlier had 1.56 times the risk (95% CI, 0.79-3.08) of prostate cancer. Men who were 40 years of age or older at vasectomy had a relative risk of prostate cancer of 2.10 (95% CI, 1.02-4.31) compared with controls; this risk was not elevated in younger men. Overall, these findings confirm the hypothesis of a small but positive association between prostate cancer and vasectomy.

Descriptive epidemiology of lymphatic malignancies in Greater Bombay.

Lymphoid malignancies as a group constitute one of the important cancers met in India as elsewhere in the world, but while information on incidence, mortality, survival and trends, are available from most of the developed countries, there are very few reports available from the rest of the world. The basic data utilized for this study was obtained from the Bombay Cancer Registry, the first population based registry to be established in India. Descriptive epidemiology of these malignancies was obtained by utilizing 5-year data of incidence and mortality of different cell types in males and females. For studying time trends in the incidence of these cancers, data of the past 30 years has been used. As a group, the lymphatic malignancies represent only 5% of the incidence and 3.9% of the mortality of the total number of cancers in Greater Bombay. Males in general, seem to be more affected by lymphomas than females. Non-Hodgkin's lymphomas are the commonest lymphatic malignancies to be detected in Bombay. The incidence curves show striking difference in lymphatic malignancies by cell type. In Bombay the incidence of these cancers was found to be the highest in the Parsis. Our data indicates that there is an increasing trend in incidence in all cell types of lymphomas, in both sexes. To obtain the details of the risk factors of these malignancies, more analytic epidemiological studies have to be undertaken of the Indian data and more importance given to lymphomas in the early detection and control of cancer.

Descriptive epidemiological assessment of urinary bladder & kidney cancers in Greater Bombay.

For studying the descriptive epidemiology of cancers of the urinary bladder and kidney, the data reported by Bombay Cancer Registry for the most recent five years have been utilised. For studying time trends in these cancers, data of the past 30 yr have been used. In Bombay, bladder cancer is very uncommon in the first three decades of life; but after the age of 30, the incidence rates increase with age, in log-linear fashion, in both sexes. The incidence of kidney cancer is almost absent between the ages 5 to 35; but later up to the age of 70, it show a steady increase. The incidence of urinary bladder and kidney cancers are found to be associated with the marital status in both sexes. No association was observed between the incidence and educational level attained by the patients having urinary bladder and kidney cancers. An increasing trend was found in the age adjusted incidence rates of cancers of the urinary bladder and kidney in both sexes during the period 1964-1993.

Oral cancers in Mumbai, India: a fifteen years perspective with respect to incidence trend and cumulative risk.

OBJECTIVE: We estimated the time trends in the incidence and the risk of developing an oral cancer in Mumbai, Indian population using the data collected by the Bombay Population Based Cancer Registry during the 15 year period from 1986 to 2000. METHODS: A total of 9,670 oral cancers (8.2% of all neoplasms) were registered, of which 6577 were in males and 3093 in females (10.7% and 5.4% of the respective totals for the two genders). For evaluation of the trend, we applied a linear regression model based on the logarithm of the observed incidence rates. The annual percentage changes were also computed for the incidence rates to evaluate the time trend. RESULTS: In males, a statistically significant decreasing trend in the overall age-adjusted incidence rates were observed during the period 1986 to 2000, with an yearly decrease of 1.70%. This decrease was significant for men above the age of 40, but for young adult men below the age of 40, there was no significant decrease, the level being stable. In females, the overall decreasing trend in the age-adjusted incidence rates of oral cancers was not significant, but in the age group 40-59, a significant decline was observed. The probability estimates indicated that one out of every 57 men and one out of every 95 women will contract any oral cancer at some time in their whole life and 97% of the chance is after he or she completes the age of 40. CONCLUSION: The observed decreasing trend in oral cancers in Indian men may be attributed to a decrease in the usage of pan and tobacco. The high prevalence of the usage of smokeless tobacco among young adult men and women may explain the stable trend in oral cancer incidence in this group. These findings help to strengthen the association between tobacco use and oral cancer risk.

Cumulative risk and trends in prostate cancer incidence in Mumbai, India.

BACKGROUND: Information relating to cancer incidence trends in a community forms the scientific basis for the planning and organization of prevention, diagnosis and treatment of cancer. We here estimated the cumulative risk and trends in incidence of prostate cancer in Mumbai, India, using data collected by the Bombay Population-based Cancer Registry from the year 1986 to 2000. METHODS: During the 15 year period, a total of 2864 prostate cancer cases (4.7% of all male cancers and 2.4% of all cancers) were registered by the Bombay Population-based Cancer Registry. For evaluation of the trend, we applied a linear regression model based on the logarithm of the observed incidence rates. The annual percentage changes were also computed for the evaluation. Cumulative incidence rates percentages were calculated by adding up the age specific incidence rates at single ages and then expressed as a percentage. RESULTS: Analysis of the trends in age-adjusted incidence rates of prostate cancer during the period 1986 to 2000 showed no statistically significant increase or decrease and the rates proved stable across the various age groups (00-49, 50-69 and 70+) also. The probability estimates indicated that one out of every 59 men will contract a prostate cancer at some time in his whole life and 99% of the chance is after he reaches the age of 50. CONCLUSION: The stability in age adjusted-incidence rates indicates that there are no changes in the etiological factors for prostate cancer in Mumbai, India. These findings may be of general interest because changes in diagnostic practices are confounded in the time trends of prostate cancer change in many western countries preventing inferences on the changes in risk.

Decreasing trend in the incidence of stomach cancer in Mumbai, India, during 1988 to 1999.

The time trend in incidence of stomach cancer in males and females in Mumbai, India during 1988 to 1999 was estimated using data collected by the Bombay Population-based Cancer Registry. During the 12-year period, a total of 3657 stomach cancer cases (3.9% of all cancers) were registered by the Bombay Population-based Cancer Registry of which 2467 (5.1% of all male cancers) were in males and 1184 (2.6% of all female cancers) in females. For evaluation of the trend, we applied a linear regression model based on the logarithm of the observed incidence rates. The annual percentage changes were also computed for the incidence rates for evaluating the time trend. A statistically significant decreasing trend in the overall age-adjusted incidence rates of stomach cancer was observed during the period 1988 to 1999, with an yearly decrease of 4.44% in males and 2.56% in females. This decrease was most striking in males in the age groups 40-59 and 60+, and in females only in the age group 40-59. The probability estimates indicated that one out of every 92 men and one out of every 187 women will contract a stomach cancer at some time in their whole life and 95% of the chance is after his or her 40th birthday. The decreasing trend in the age-adjusted incidence rates of stomach cancer in both the sexes indicates that there is a critical change in the etiology of this cancer. The findings may provide clues relating to various life-style and environmental changes impacting on stomach cancer incidence.

Descriptive epidemiology of leukaemias in Greater Mumbai.

BACKGROUND: There is little data available on the occurrence of leukaemias in India. This is despite a large number of patients being diagnosed and treated at various cancer centres all over the country. We, therefore, analysed the available data of the Bombay Cancer Registry to ascertain the epidemiological characteristics of leukaemias in India. METHODS: The incidence and mortality rates of leukaemias by cell type and sex were obtained for the most recent 5 years (1989-93). The data of the past 30 years were used to study the time trends using a linear regression model based on the logarithms of the incidence rates. RESULTS: Leukaemias constituted 3.9% of all registered cancer cases and 5.4% of all registered deaths in Greater Mumbai. Males were affected more frequently than females. Myeloid leukaemias were the commonest. A bimodal age incidence was observed with the first peak in childhood, a trough between 15 to 19 years of age and a slow rise thereafter. Among the various religious groups Hindus had the highest rate. An increasing trend in the incidence of all types of leukaemias was also observed. CONCLUSION: The incidence of leukaemias in Greater Mumbai is comparable to world rates. There is a male preponderance in all cell types and an increase in incidence was observed over the last 30 years. The higher incidence of myeloid leukaemias observed by us might be related to under-reporting of chronic lymphatic leukaemia.

Trends and predictions of cancer incidence cases by site and sex for Mumbai.

In order to estimate the resources needed for the diagnosis, treatment, follow-up and rehabilitation services needed for cancer patients, it is important to know the magnitude of common cancers at present and in future. Keeping this view in mind an attempt has been made to predict cancer incidence cases for most common cancers for Greater Bombay upto the year 2002. The trend analysis is carried out for major 30 cancer sites for both the sexes using age incidence data of Greater Bombay for the period 1968 to 1987. The age-period-cohort model which was fitted to the data for studying trends for each site and sex has also been utilized for prediction also. Prediction was based on the assumption that the characteristic features of the model estimated from the observed rates would continue to hold during the prediction periods. Present trend analysis showed that cancers of the tongue, mouth, oropharynx, oesophagus, stomach and larynx in both sexes and cervix for females have registered a decline in incidence over a period of observation. While, during the same period, cancers of the liver, pancreas, bladder, brain and thyroid in both the sexes, breast, endometrium and ovary in females, and testis in males showed increasing trends in incidence, while cancers of the hypopharynx, lung, bone, connective tissue and lymphomas in both the sexes did not show any significant change in the incidence. In males in 1968-1972 cancer of the oesophagus was the leading cancer, followed by lung, larynx, tongue and stomach, while in 1988-2002 cancer of the lung will be the most predominant cancer, followed by hypopharynx, oesophagus, prostate and tongue. It is believed that the results of the present study will provide a sound basis for planning the cancer control, prevention, diagnostics, treatment and rehabilitation in Mumbai for the years to come.

Descriptive epidemiology of thyroid cancer in greater Bombay.

In this paper an attempt has been made to present a descriptive epidemiology of thyroid cancer in Bombay, and it is discussed in relation to age, demographic and socio economic composition of the population, using the most recent five year date. Time trend analysis of this cancer by sex has also been discussed using the last 30 years data. When international incidence of thyroid cancer was ranked in descending order for various countries, the incidence recorded for Bombay was found to be at the lowest level in both the sexes. Thyroid cancer is about three times more frequent among women than men, but this relative excess varies with the histologic type and age. As in the case of the majority of cancers, the incidence curve for thyroid cancer rises with age. However in men, the increase continues consistently with advancing age, while in women it begins to level off after the age 30, leading to an almost equal sex ratio in old age. In Bombay the incidence of thyroid cancer in men was found to be the highest in Muslims and in Christian women. No association was observed between thyroid cancer and education level attained by these patients. The four main histologic types of thyroid cancers i.e. papillary, follicular, anaplastic and medullary are also observed in Bombay. It has been noted that there is an increasing trend in the age-adjusted incidence rate for thyroid cancer in both the sexes in Bombay in the period under review 1964 to 1993. But the increase in incidence was found to be statistically significant only in males.

Geographic differences in cancer incidence by sex at various sites in city wards in Greater Bombay.

In this paper an attempt has been made to study the geographic variations in cancer incidence at various sites, by sex, in Greater Bombay. Crude incidence rates at each site for individual wards have been calculated using the data collected by the Bombay Cancer Registry, for the years 1979 to 1984. To study the variations highest and lowest crude incidence rates in the different wards and the ratio of the highest to the lowest rates for each primary site were calculated. Detailed analyses show that there is a positive relationship between male and female rates for certain sites such as the Buccal Mucosa, Oesophagus, Stomach, Colon, Rectum and Liver. The Tongue, Oropharynx, Hypopharynx, Lung and Larynx present rates that vary widely in males but only slightly in females. Sites such as the Pancreas, Hodgkin's Disease, Lymphoma and Leukaemias do not seem to present any particular pattern. It was interesting to find that those sites where environmental factors are of likely value, such as excessive tobacco chewing and smoking tend to fall in the second category. Particularly striking is the the fact, that habits of etiological value are those to which men are more frequently addicted to than women, probably explaining the low rates in females of the wide variation in male rates.

Population based survival from prostate cancer in Mumbai (Bombay), India.

Survival from cancer reflects the aggressiveness of the disease, the effectiveness of treatment and host factors such as age. Population based survival reflects the effectiveness of the overall cancer control strategy in the region. Here we report the survival experience of 740 prostate cancer patients registered by the Mumbai (Bombay) Cancer Registry during 1987-1991. There have been very few reports on survival from cancer in India, mainly because of poor patient follow up and inadequate system of registration of death. This has been largely overcome in this study by means of matching with death certificate of Municipal Corporation, telephone and postal enquiries and active follow up through visits of homes of patients. Scrutiny of medical record was also carried out whenever it was possible. Thus information on survival status as on January 1, 1997 was available for 602 patients (82%). The observed survival was 35.1% and the corresponding relative survival was 41.6%. The clinical extent of disease, treatment given and age of the patient were independent predictors of survival. The observed survival was 49.2% for localised disease, 23.5% for direct extention and regional node involvement and 12.7% for distant metastatis patients.

Descriptive epidemiology of the cancers of male genital organs in greater Bombay.

For different reasons cancers of the Prostate, Testis and Penis are important diseases for men. The incidence for prostate and testicular cancers are more commonly seen in developed countries, while penile cancer occurs more frequently in the developing countries. In Mumbai the incidence of prostatic and testicular cancers is low whereas penile cancer is high when compared with international reports. In Mumbai. The incidence of prostatic cancer increases only after the age of 50. The age specific incidence rates for testicular cancers are bimodal whereas the incidence of Penile cancer increases exponentially with age, after the age 30. In Mumbai. The incidence of Prostate cancer was six times higher in the Parsis as compared to other communities. The incidence of cancer of the testis is lowest in Hindus and cancer of penis is not seen in Muslims. The incidence of prostate cancer was highest among Gujrathis and there was an absence of penile cancer in Urdu speaking men. In Bombay the incidence of cancers of the prostate, testis and penis seem to be associated with marital status. The association between incidence and education level of the patients was only found in men having cancer of the testis. There seems to be an increase in age adjusted incidence rates for cancers of the prostate and testis over time period of 30 years, whereas penile cancer incidence was decreasing over the same period.

Descriptive epidemiology of bone cancer in greater Bombay.

Bone tumours are comparatively uncommon, constituting only 0.5% of the total world cancer incidence. As Bone tumors consist of several distinct clinico-pathological entities, descriptive epidemiology of tumors at this site can be based only on studies where they can be distinguished. Ewing's sarcoma Chondrosarcoma and Osteosarcoma are the principal tumors involving bones. The basic data utilized for this study was collected from the Bombay Cancer Registry which was established in 1963, and is the first population based registry to be established in India. For studying the descriptive epidemiological variables the most recent 5 year incidence rates have been used. As a group, bone cancers represent 0.9% of the total number of incident cancer are seen in Greater Bombay. Males in general are seen to have a higher incidence of bone cancers than females. Ewing's sarcoma was found to be the commonest bone cancer in Bombay. The age specific incidence curves present striking differences according to cell types of bone cancer. Time trends in the incidence of these cancers, over the past 30 years have been presented. Our data indicate that there is a decreasing trend in incidence of bone cancers in females, whilst the rates are stable in males. Ionising radiation is the only environmental agent to cause this cancer. The discovery of other risk factors is the key prevention and will depend upon the experimental work undertaken to develop sub-clinical measures of risk that can be applied in interdisciplinary studies to identify more completely the causes of bone cancers.

Increase in breast cancer incidence among older women in Mumbai: 30-year trends and predictions to 2025.

BACKGROUND: Increasing trends in the incidence of breast cancer have been observed in India, including Mumbai. These have likely stemmed from an increasing adoption of lifestyle factors more akin to those commonly observed in westernized countries. Analyses of breast cancer trends and corresponding estimation of the future burden are necessary to better plan rationale cancer control programmes within the country. METHODS: We used data from the population-based Mumbai Cancer Registry to study time trends in breast cancer incidence rates 1976-2005 and stratified them according to younger (25-49) and older age group (50-74). Age-period-cohort models were fitted and the net drift used as a measure of the estimated annual percentage change (EAPC). Age-period-cohort models and population projections were used to predict the age-adjusted rates and number of breast cancer cases circa 2025. RESULTS: Breast cancer incidence increased significantly among older women over three decades (EAPC = 1.6%; 95% CI 1.1-2.0), while lesser but significant 1% increase in incidence among younger women was observed (EAPC = 1.0; 95% CI 0.2-1.8). Non-linear period and cohort effects were observed; a trends-based model predicted a close-to-doubling of incident cases by 2025 from 1300 mean cases per annum in 2001-2005 to over 2500 cases in 2021-2025. CONCLUSIONS: The incidence of breast cancer has increased in Mumbai during last two to three decades, with increases greater among older women. The number of breast cancer cases is predicted to double to over 2500 cases, the vast majority affecting older women.

Cancer survival in Mumbai (Bombay), India, 1992-1999.

The Bombay cancer registry is the second oldest population-based cancer registry in Asia, and the first of its kind in India. It was established in 1963, and registration of cases is done by active methods. Data on survival from 28 cancer sites or types registered during 1992-1999 are reported. Follow-up has been carried out predominantly by active methods, with median follow-up ranging between 1-51 months for different cancers. The proportion of histologically verified diagnosis for various cancers ranged between 41-100%; death certificates only (DCOs) comprised 0-15%; 84-99% of total registered cases were included for survival analysis. Complete follow-up at five years ranged from 85-92% for different cancers. The 5-year age-standardized relative survival rates for common cancers were breast (48%), cervix (44%), lung (11%), oesophagus (14%), oral cavity (35%) and non-Hodgkin lymphoma (34%). The 5-year relative survival by age group portrayed either an inverse relationship or was fluctuating. Cases with a regional spread of disease were the highest for cancers of the tongue, oral cavity, larynx and cervix; survival decreased with the increasing extent of disease for all cancers studied.

Epidemiological review of gastric cancer in India.

Stomach cancer is the one of the leading cause of cancer in southern region of India. Its incidence is decreasing worldwide yet on global scale stomach cancer remains one of the most common causes of cancer death. Etiology of gastric cancer includes Helicobacter pylori infection, diet and lifestyle, tobacco, alcohol and genetic susceptibility. In this review, we tried to find the contribution of Indian scientist in understanding the descriptive and observational epidemiology of stomach cancer. PubMed was used as a search platform using key words such as "stomach cancer, treatment, clinical characteristics, stomach cancer outcome, epidemiology, etiological factor and their corresponding Mesh terms were used in combination with Boolean operators OR, AND". Most of the reported studies on gastric cancer from India are case report or case series and few are case-control studies. Indian studies on this topic are limited and have observed H. pylori infection, salted tea, pickled food, rice intake, spicy food, soda (additive of food), tobacco and alcohol as risk factors for gastric cancer. More research is required to understand the etiology, develop suitable screening test, to demarcate high-risk population and to develop and evaluate the effect of primary prevention programs.