Article

Dikshit RP, Kanhere S. Cancer patterns of lung, oropharynx and oral cavity cancer in relation to gas exposure at Bhopal

Population Based Cancer Registry, Department of Pathology, Bhopal, India.
Cancer Causes and Control (Impact Factor: 2.74). 12/1999; 10(6):627-36. DOI: 10.1023/A:1008930220304
Source: PubMed

ABSTRACT

In Bhopal, India, on 2 December 1984, a chemical disaster caused by a gas leak mostly of methyl isocyanate (MIC) from the Union Carbide Factory led to massive mortality and morbidity of the population. This is the first study to shed light on the cancer experience of the Bhopal population as a result of exposure to a mixture of gases which have highly toxic and potentially carcinogenic properties. To observe the effect of gas exposure, incidence rates of the three most common cancer sites (lung, oropharynx and oral cavity) from 1987 to 1992 among the municipal wards were studied in males.
Relative risks (RR) using cases from the cancer registry and controls from a tobacco survey were estimated for the gas-affected regions.
Based on a descriptive study the relative risks of 1.4, 1.3 and 0.7 for lung, oropharynx and oral cavity cancer, respectively, for gas-affected regions in the year 1992 in comparison to gas-unaffected regions and the year 1987-1990 combined were estimated. In the case-control study the RRs of 0.9, 1.4 and 1.2 for lung, oropharynx (adjusted for smoking) and oral cavity cancer, respectively, (adjusted for tobacco chewing) were estimated as the effect of the gas accident.
The full potential of excess risk, if any, may not manifest for 15-20 years after the accident.

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Available from: Rajesh Dikshit, Jan 20, 2016
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    • "Almost three decades elapsed of Bhopal disaster, only a few efforts have been made to understand the cancer risk in the MIC-exposed survivors (Malla et al., 2011; Senthilkumar et al., 2011; 2012; 2015). Emerging epidemiological reports from Bhopal, India suggest diverse cancer pattern amongst the MIC-gas exposed survivors (Dikshit and Kanhere, 1999; Ganesh et al., 2005; Senthilkumar et al., 2011). It was therefore, worthwhile to investigate the underlying mechanisms of MIC on epigenetic alterations/DNA methylation using computational methods. "
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    ABSTRACT: DNA methyltransferase 1 (DNMT1) is a relatively large protein family responsible for maintenance of normal methylation, cell growth and survival in mammals. Toxic industrial chemical exposure associated methylation misregulation has been shown to have epigenetic influence. Such misregulation could effectively contribute to cancer development and progression. Methyl isocyanate (MIC) is a noxious industrial chemical used extensively in the production of carbamate pesticides. We here applied an in silico molecular docking approach to study the interaction of MIC with diverse domains of DNMT1, to predict cancer risk in the Bhopal population exposed to MIC during 1984. For the first time, we investigated the interaction of MIC and its hydrolytic product (1,3-dimethylurea) with DNMT1 interacting (such as DMAP1, RFTS, and CXXC) and catalytic (SAM, SAH, and Sinefungin) domains using computer simulations. The results of the present study showed a potential interaction of MIC and 1,3-dimethylurea with these domains. Obviously, strong binding of MIC with DNMT1 interrupting normal methylation will lead to epigenetic alterations in the exposed humans. We suggest therefore that the MIC- exposed individuals surviving after 1984 disaster have excess risk of cancer, which can be attributed to alterations in their epigenome. Our findings will help in better understanding the underlying epigenetic mechanisms in humans exposed to MIC.
    Full-text · Article · Dec 2015 · Asian Pacific journal of cancer prevention: APJCP
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    • "ICMR registry is dedicatedly registering all the cancer cases residing inside Bhopal. This registry studied the most common cancer sites like lung, oropharynx and oral cavity in relation to gas exposure from 1987 to 1992 and recommended that the effect of gas exposure on cancer must be studied in future (Dikshit and Kanhere, 1999). "
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    ABSTRACT: The purpose of this study was to update both researchers and clinicians about the cancer incidence in methyl isocyanate (MIC) exposed long-term survivors and in their offspring, focusing on the etiological plausibility. In the time period 2006-2011, cancer morbidity was evaluated in the population surviving after exposure to (MIC) on December 3rd, 1984, in Bhopal. This descriptive study is based on hospital registration of 1261 cancer patients those are MIC gas victims and theirsubsequently born offspring. Morbidity status was studied on the basis of gender, age, organ and site with relative percentages. Cancers on specific sites, with special reference to breast (n=231) (18.31%), lung (n=103) (8.16%), tongue (n=103)(8.16%), buccal mucosa (n=94) (7.45%), cervix (n=72) (5.70%), and esophagus (n=68) (5.39%) were found in high proportions. Ovary (n=43) (3.40%), brain (n=42) (3.33%), larynx (n=40) (3.17%), non-Hodgkin's (n=31) (2.45%), gallbladder (n=29) (2.29%), stomach (n=28) (2.22%), head and neck (n=28) (2.22%), liver (n=27) (2.14%), acute lymphoid leukemia (n=24) (1.90%), rectum (n=20) (1.58%), colon (n=20) (1.58%), chronic myeloid leukemia (n=17) (1.34%), alveolus (n=17) (1.34%), Hodgkin's (n=14) (1.11%), uterus (n=14) (1.11%), multiple myeloma (n=14) (1.11%), and prostate (n=11) (0.87%) lesions were observed less frequently. Remarkably, gradual increase of cancers on different organs and sites were observed in the longterm survivors and their offspring. The present study observed some cancers which were not previously reported in this population. In addition, we also present the future research directions with systematic approaches to predict cancer risk in long-term survivors and their future generations. On the basis of this morbidity report, we suggest the need of biological surveillance through immune system biomonitoring and cytogenetic screening to predict the cancer risk in the MIC exposed population and their offspring.
    Full-text · Article · Dec 2011 · Asian Pacific journal of cancer prevention: APJCP
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    • ", 2003 ) . A cancer incidence study from 1987 to 1992 , 8 years after the Union Carbide Accident , found no evidence of increased risk for cancer of the lung , oropharynx , or oral cavity due to gas exposures ; however , the authors note that more time may be necessary for the effect to show ( Dikshit & Kanhere , 1999 ) . "
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    ABSTRACT: Events of mass trauma are relatively common global phenomena with widespread impact on human health. We conducted this systematic literature review using the National Library of Medicine's PubMed database. We investigated the effect of disasters on six main topic areas of interest: injury and mortality, health systems and infrastructure, mental health, infectious disease, chronic disease, and health behavior. This review covers 182 articles on both natural and man-made disasters, excluding war. We present the results by topic area, across disaster type. This work highlights the scope and heterogeneity of disaster research today, providing a contextual background in which to formulate interventions and disaster planning efforts.
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