Does tobacco really increase the risk of developing cancer?
The association of cancer with tobacco has been known since the 1930s, and the US Surgeon General�s report of 1964 identified that smokers had a 10 fold increase in the risk of developing lung cancer while heavy smokers were 20 times more likely to develop lung cancer than a non smoker. The harmful effect of tobacco is best illustrated in the increased risk of cancer among passive smokers. i.e. those who inhale �second hand� smoke, exhaled by a smoker or from the burning end of a cigarette / bidi etc. ; their risk of developing cancer has been estimated to be 20 � 30 % higher than a person who does not live with a smoker.
Is any form of tobacco safe?
No form of tobacco is safe. Hence cigarettes, bidi, pipe, hookah, tobacco laced pan and pan masala, chewed tobacco as well as snuff (naswar in Hindi) are equally harmful. Chewed tobacco is associated more strongly with cancer of the cheek, tongue and tonsil, while smoked tobacco is associated with a higher risk of lung cancer and cancer of the voice box. All forms of tobacco induce �field cancerisation� wherein, the inner lining of the pathway for food and air, i.e. mouth, throat, food pipe and airways becomes prone to cancer.
Does the quantum of tobacco use, daily as well as cumulative, have any impact on the risk of developing cancer?
Yes, the number of �pack years� determines the risk of developing cancer. In addition, it may worsen the outcome of treatment in some situations. Patients who continue to smoke while receiving treatment for cancer do worse than patients who quit.
Is tobacco implicated in any other cancers besides those of the mouth, throat and lung?
In addition to cancer of the mouth (lips, cheek, tongue), throat ( tonsil, voice box, pharynx), persons consuming tobacco in any form are more likely to have cancer of the food pipe, stomach, pancreas, kidney, urinary bladder, large intestine, cervix ( the opening of the uterus) and ovary. In addition they have a higher chance of developing a form of blood cancer, acute myeloid leukemia
Are women equally at risk of developing tobacco induced cancers?
Women are at least equally at risk of developing cancer, if not more. According to the United States Surgeon General�s report of 2014, women smokers have 27.5 times the risk of developing lung cancer compared to women who do not smoke. According to the same report, this figure is 25 times for men. Certain cancers specific to women i.e. those of the cervix and ovary, occur more commonly in smokers than in women who do not smoke.
Are low tar cigarettes safer or are they a marketing gimmick?
It has been proven that those who smoke low tar cigarettes pull harder on the cigarette to achieve the �desired effect� of tobacco thus making these cigarettes as harmful as regular cigarettes. � Low tar�, � slim� etc. are calculated sub liminal messages that marketers of tobacco send out to women smokers that the latter need to be aware of. In addition, there has been a concerted campaign by the tobacco industry to associate smoking with glamour. In North America, this campaign has been thwarted, somewhat, by the anti smoking movement, which has been successful in reducing rates of smoking. This in turn has lead to a drop in the rate of lung cancer. A similar downward trend has not been noted in India, in either the prevalence of smoking or in the risk of developing tobacco induced cancers.
Is tobacco implicated only in cancer causation or does it cause other diseases too?
While the association of tobacco and heart disease is well known, consuming tobacco also increase the risk of facial wrinkles and osteoporosis; hip fractures are more common among smokers. In addition women (and men) who smoke are more likely to have a severe lung ailment , chronic obstructive lung disease. Tobacco also interferes with fertility and increases the chances of stillbirth and low birth weight babies.