Rajesh Dikshit

Cancer incidence and mortality worldwide: Sources, methods and major patterns in GLOBOCAN 2012

Estimates of the worldwide incidence and mortality from 27 major cancers and for all cancers combined for 2012 are now available in the GLOBOCAN series of the International Agency for Research on Cancer. We review the sources and methods used in compiling the national cancer incidence and mortality estimates, and briefly describe the key results by cancer site and in 20 large “areas” of the world. Overall, there were 14.1 million new cases and 8.2 million deaths in 2012. The most commonly diagnosed cancers were lung (1.82 million), breast (1.67 million), and colorectal (1.36 million); the most common causes of cancer death were lung cancer (1.6 million deaths), liver cancer (745,000 deaths), and stomach cancer (723,000 deaths).

Cancer incidence and mortality worldwide

Estimates of the worldwide incidence and mortality from 27 major cancers and for all cancers combined for 2012 are now available in the GLOBOCAN series of the International Agency for Research on Cancer. We review the sources and methods used in compiling the national cancer incidence and mortality estimates, and briefly describe the key results by cancer site and in 20 large “areas” of the world. Overall, there were 14.1 million new cases and 8.2 million deaths in 2012. The most commonly diagnosed cancers were lung (1.82 million), breast (1.67 million), and colorectal (1.36 million); the most common causes of cancer death were lung cancer (1.6 million deaths), liver cancer (745,000 deaths), and stomach cancer (723,000 deaths).

Suicide mortality in India: a nationally representative survey

BACKGROUND WHO estimates that about 170,000 deaths by suicide occur in India every year, but few epidemiological studies of suicide have been done in the country. We aimed to quantify suicide mortality in India in 2010. METHODS The Registrar General of India implemented a nationally representative mortality survey to determine the cause of deaths occurring between 2001 and 2003 in 1·1 million homes in 6671 small areas chosen randomly from all parts of India. As part of this survey, fieldworkers obtained information about cause of death and risk factors for suicide from close associates or relatives of the deceased individual. Two of 140 trained physicians were randomly allocated (stratified only by their ability to read the local language in which each survey was done) to independently and anonymously assign a cause to each death on the basis of electronic field reports. We then applied the age-specific and sex-specific proportion of suicide deaths in this survey to the 2010 UN estimates of absolute numbers of deaths in India to estimate the number of suicide deaths in India in 2010. FINDINGS About 3% of the surveyed deaths (2684 of 95,335) in individuals aged 15 years or older were due to suicide, corresponding to about 187,000 suicide deaths in India in 2010 at these ages (115,000 men and 72,000 women; age-standardised rates per 100,000 people aged 15 years or older of 26·3 for men and 17·5 for women). For suicide deaths at ages 15 years or older, 40% of suicide deaths in men (45,100 of 114,800) and 56% of suicide deaths in women (40,500 of 72,100) occurred at ages 15-29 years. A 15-year-old individual in India had a cumulative risk of about 1·3% of dying before the age of 80 years by suicide; men had a higher risk (1·7%) than did women (1·0%), with especially high risks in south India (3·5% in men and 1·8% in women). About half of suicide deaths were due to poisoning (mainly ingestions of pesticides). INTERPRETATION Suicide death rates in India are among the highest in the world. A large proportion of adult suicide deaths occur between the ages of 15 years and 29 years, especially in women. Public health interventions such as restrictions in access to pesticides might prevent many suicide deaths in India. FUNDING US National Institutes of Health.

A nationally representative case-control study of smoking and death in India.

BACKGROUND The nationwide effects of smoking on mortality in India have not been assessed reliably. METHODS In a nationally representative sample of 1.1 million homes, we compared the prevalence of smoking among 33,000 deceased women and 41,000 deceased men (case subjects) with the prevalence of smoking among 35,000 living women and 43,000 living men (unmatched control subjects). Mortality risk ratios comparing smokers with nonsmokers were adjusted for age, educational level, and use of alcohol. RESULTS About 5% of female control subjects and 37% of male control subjects between the ages of 30 and 69 years were smokers. In this age group, smoking was associated with an increased risk of death from any medical cause among both women (risk ratio, 2.0; 99% confidence interval [CI], 1.8 to 2.3) and men (risk ratio, 1.7; 99% CI, 1.6 to 1.8). Daily smoking of even a small amount of tobacco was associated with increased mortality. Excess deaths among smokers, as compared with nonsmokers, were chiefly from tuberculosis among both women (risk ratio, 3.0; 99% CI, 2.4 to 3.9) and men (risk ratio, 2.3; 99% CI, 2.1 to 2.6) and from respiratory, vascular, or neoplastic disease. Smoking was associated with a reduction in median survival of 8 years for women (99% CI, 5 to 11) and 6 years for men (99% CI, 5 to 7). If these associations are mainly causal, smoking in persons between the ages of 30 and 69 years is responsible for about 1 in 20 deaths of women and 1 in 5 deaths of men. In 2010, smoking will cause about 930,000 adult deaths in India; of the dead, about 70% (90,000 women and 580,000 men) will be between the ages of 30 and 69 years. Because of population growth, the absolute number of deaths in this age group is rising by about 3% per year. CONCLUSIONS Smoking causes a large and growing number of premature deaths in India.

Cancer survival in Africa, Asia, and Central America: a population-based study

BACKGROUND Population-based cancer survival data, a key indicator for monitoring progress against cancer, are not widely available from countries in Africa, Asia, and Central America. The aim of this study is to describe and discuss cancer survival in these regions. METHODS Survival analysis was done for 341 658 patients diagnosed with various cancers from 1990 to 2001 and followed up to 2003, from 25 population-based cancer registries in 12 countries in sub-Saharan Africa (The Gambia, Uganda), Central America (Costa Rica), and Asia (China, India, Pakistan, Philippines, Saudi Arabia, Singapore, South Korea, Thailand, Turkey). 5-year age-standardised relative survival (ASRS) and observed survival by clinical extent of disease were determined. FINDINGS For cancers in which prognosis depends on stage at diagnosis, survival was highest in China, South Korea, Singapore, and Turkey and lowest in Uganda and The Gambia. 5-year ASRS ranged from 76-82% for breast cancer, 63-79% for cervical cancer, 71-78% for bladder cancer, and 44-60% for large-bowel cancers in China, Singapore, South Korea, and Turkey. Survival did not exceed 22% for any cancer site in The Gambia; in Uganda, survival did not exceed 13% for any cancer site except breast (46%). Variations in survival correlated with early detection initiatives and level of development of health services. INTERPRETATION The wide variation in cancer survival between regions emphasises the need for urgent investments in improving awareness, population-based cancer registration, early detection programmes, health-services infrastructure, and human resources. FUNDING Association for International Cancer Research (AICR; St Andrews, UK), Association pour la Recherche sur le Cancer (ARC, Villejuif, France), and the Bill & Melinda Gates Foundation (Seattle, USA).

Global burden of cancer attributable to high body-mass index in 2012: a population-based study

BACKGROUND High body-mass index (BMI; defined as 25 kg/m(2) or greater) is associated with increased risk of cancer. To inform public health policy and future research, we estimated the global burden of cancer attributable to high BMI in 2012. METHODS In this population-based study, we derived population attributable fractions (PAFs) using relative risks and BMI estimates in adults by age, sex, and country. Assuming a 10-year lag-period between high BMI and cancer occurrence, we calculated PAFs using BMI estimates from 2002 and used GLOBOCAN2012 data to estimate numbers of new cancer cases attributable to high BMI. We also calculated the proportion of cancers that were potentially avoidable had populations maintained their mean BMIs recorded in 1982. We did secondary analyses to test the model and to estimate the effects of hormone replacement therapy (HRT) use and smoking. FINDINGS Worldwide, we estimate that 481,000 or 3.6% of all new cancer cases in adults (aged 30 years and older after the 10-year lag period) in 2012 were attributable to high BMI. PAFs were greater in women than in men (5.4% vs 1.9%). The burden of attributable cases was higher in countries with very high and high human development indices (HDIs; PAF 5.3% and 4.8%, respectively) than in those with moderate (1.6%) and low HDIs (1.0%). Corpus uteri, postmenopausal breast, and colon cancers accounted for 63.6% of cancers attributable to high BMI. A quarter (about 118,000) of the cancer cases related to high BMI in 2012 could be attributed to the increase in BMI since 1982. INTERPRETATION These findings emphasise the need for a global effort to abate the increasing numbers of people with high BMI. Assuming that the association between high BMI and cancer is causal, the continuation of current patterns of population weight gain will lead to continuing increases in the future burden of cancer. FUNDING World Cancer Research Fund International, European Commission (Marie Curie Intra-European Fellowship), Australian National Health and Medical Research Council, and US National Institutes of Health.

Effect of VIA Screening by Primary Health Workers: Randomized Controlled Study in Mumbai, India

BACKGROUND Cervical cancer is the leading cause of cancer mortality among women in India. Because Pap smear screening is not feasible in India, we need to develop effective alternatives. METHODS A cluster-randomized controlled study was initiated in 1998 in Mumbai, India, to investigate the efficacy of visual inspection with acetic acid (VIA) performed by primary health workers in reducing cervical cancer mortality. Four rounds of cancer education and VIA screening were conducted at 24-month intervals in the screening group, whereas cancer education was offered once at entry to the control group. The study was planned for 16 years to include four screening rounds followed by four monitoring rounds. We present results after 12 years of follow-up. Poisson regression method was used to calculate the rate ratios (RRs); two-sided χ(2) was used to calculate the probability. RESULTS We recruited 75360 women from 10 clusters in the screening group and 76178 women from 10 comparable clusters in the control group. In the screening group, we achieved 89% participation for screening and 79.4% compliance for diagnosis confirmation. The incidence of invasive cervical cancer was 26.74 per 100000 (95% confidence interval [CI] = 23.41 to 30.74) in the screening group and 27.49 per 100000 (95% CI = 23.66 to 32.09) in the control group. Compliance to treatment for invasive cancer was 86.3% in the screening group and 72.3% in the control group. The screening group showed a statistically significant 31% reduction in cervical cancer mortality (RR = 0.69; 95% CI = 0.54 to 0.88; P = .003). CONCLUSIONS VIA screening by primary health workers statistically significantly reduced cervical cancer mortality. Our study demonstrates the efficacy of an easily implementable strategy that could prevent 22000 cervical cancer deaths in India and 72600 deaths in resource-poor countries annually.

Lifestyle habits as prognostic factors in survival of laryngeal and hypopharyngeal cancer: A multicentric European study

Little information is available on the role of tobacco, alcohol and diet in the survival of upper aero digestive cancers. Our study analysed the survival of 931 laryngeal and hypopharyngeal cancer patients, enrolled in a population based case‐control study conducted at 5 centres in southeast Europe during 1979–1982. Age at the time of diagnosis and site of origin of tumour were observed to be predictors of the survival. Cigarette smoking, and to a limited extent alcohol drinking, before the diagnosis of tumour seem to influence the overall survival whereas high intakes of vegetables and vitamin C were observed to favourably affect the prognosis. For mortality from upper aerodigestive cancer protective effects of high intakes of vegetables, fibres and vitamin C were observed. Our results support the hypothesis that there is a role for dietary intervention to improve survival of laryngeal and hypopharyngeal cancer patients.

Indoor air pollution from solid fuels and risk of hypopharyngeal/laryngeal and lung cancers: a multicentric case–control study from India

BACKGROUND A recent monograph by the International Agency for Research on Cancer (IARC) has identified indoor air pollution from coal usage as a known human carcinogen, while that from biomass as a probable human carcinogen. Although as much as 74% of the Indian population relies on solid fuels for cooking, very little information is available on cancer risk associated with these fuels in India. METHODS Using data from a multicentric case-control study of 799 lung and 1062 hypopharyngeal/laryngeal cancer cases, and 718 controls, we investigated indoor air pollution from various solid fuels as risk factors for these cancers in India. RESULTS Compared with never users, individuals who always used coal had an increased risk of lung cancer [odds ratio (OR) 3.76, 95% confidence interval (CI) 1.64-8.63]. Long duration of coal usage (>50 years) was a risk factor for hypopharyngeal (OR 3.47, CI 0.95-12.69) and laryngeal (OR 3.65, CI 1.11-11.93) cancers. An increased risk of hypopharyngeal cancer was observed among lifelong users of wood (OR 1.62, CI 1.14-2.32), however this was less apparent among never-smokers. Increasing level of smokiness inside the home was associated with an increasing risk of hypopharyngeal and lung cancer (P(trend) < 0.05). CONCLUSION This study showed differential risks associated with indoor air pollution from wood and coal burning, and provides novel evidence on cancer risks associated with solid fuel usage in India. Our findings suggest that reducing indoor air pollution from solid fuels may contribute to prevention of these cancers in India, in addition to tobacco and alcohol control programs.

Efficient DNA extraction from 25-year-old paraffin-embedded tissues: study of 365 samples

Aims: Archival fixed paraffin‐embedded tissue (PET) is a valuable source for population‐based molecular genetic studies but the extraction of high quality DNA is still a problematic issue. The present study tested the grade of DNA fragmentation and the DNA adequacy for genetic investigations in a large series of tissue specimens that were formalin‐ or Bouin‐fixed and paraffin‐embedded between 1979 and 1983. Specific aims were to: (1) estimate the amount of archival tissue samples from which DNA is recoverable by conventional methods and the influence of variables (origin, fixative, section size) on DNA recovery; and (2) evaluate the feasibility of genetic investigations in large scale population studies. Methods: DNA was extracted in 2005 from 365 PET samples from Italy and Spain and subjected to PCR analysis targeting fragments of 152, 268 and 676 bp of the &bgr;‐globin gene. Results: Amplification of a 152 bp fragment was obtained in 252/365 (69%) PET samples, a 268 bp fragment in 62/365 (17%), a 676 bp fragment in 19/365 (5%) and no amplification for any fragment was obtained in 113/365 (31%). A second processing of newly cut sections performed in a 25% simple random sample gave comparable results, with substantial concordance between the first and second tests (kappa value 0.62 [95% CI 0.59–0.64]). Conclusions: The results of this study show that DNA can be efficiently extracted from PETs archived for more than 20 years, and that large scale population studies based on PCR amplification of short target sequences are feasible.