The
International Agency for Research on Cancer (IARC), an intergovernmental agency
affiliated to World Health Organization (WHO) of the United Nations (UN)
published its second report on areca nut / Tambula (betel quid/ Pan) in 2004 in
the form of a monograph (Vol. 85). This monograph was an outcome of a one-year
effort involving 17 member "working group" drawn from India, China/Taiwan, UK, USA, Germany,
Netherlands and South Africa. Senior scientists from
AIIMS New Delhi, TIFR Mumbai, Cancer Research Institute, Tata Memorial Centre
Mumbai etc. were the working group members from India.
IARC claims
that it will select the topic based on two criteria: (a) there is evidence of
human exposure, and (b) there is some evidence or suspicion of carcinogenicity.
As per IARC, a “carcinogen” is defined as any substance which is capable of
increasing the incidence of malignant (cancerous) tumors upon human exposure. Based on these terms, IARC claims that there was sufficient evidence available to probe the carcinogenicity of areca nut & betel quid chewing in Human population.
As per IARC,
Oral cancer is the leading type of malignancy in India and South-east Asia,
whereas lung, breast, prostate and colorectum are the leading cancers in the
Americas, Europe and Oceania. In South Central Asia, cancer of the oral cavity
is the cancer with the highest incidence among the men and the third highest
among women (after the cervix and breast). Large body of evidence arisen from
studies in experimental animals and in-vitro studies (lab studies in petri
plates) that investigated the effects of areca nut alone, as well as those of
betel quid with or without tobacco during 1985 to 2003, provided an impetus for
selecting areca nut / Tambula by the working group of IARC.
The working
group considered the following in their study.
·
Exposure of general population to Tambula (with and
without tobacco) and areca nut.
·
Research studies on oral cancer
·
Research studies on lesions and precancerous lesions
and conditions
·
Studies on stomach, Liver and cervical cancer
·
Studies of cancer in experimental animals
·
Other data relevant to an evaluation of
carcinogenicity and its mechanisms.
Note: To be continued in the next Part.
