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Tobacco Active and Passive Smoking

2. What kinds of cancer does tobacco cause in smokers?

  • 2.1 Which cancers are caused by cigarette smoking?
  • 2.2 Which cancers do not appear to be caused by cigarette smoking?
  • 2.3 For which cancers does a link remain unclear?
  • 2.4 Does cigar, pipe or bidi smoking also cause cancer?
  • 2.5 For which cancers does a link remain unclear?

Nearly 20 years ago, the International Agency for Research on Cancer (IARC) reported that tobacco smoking increased risks of cancers of the lung, oral cavity (mouth), pharynx, larynx, oesophagus (squamous-cell carcinoma), pancreas, bladder and renal pelvis (the kidney outlet). Smokers are much more likely to develop these cancers than non-smokers: between 3 times more for pancreas cancer and 20 times more for lung cancer.

It is now established that tobacco smoking also increases by about 2 to 3 times the risk of getting cancers of the nasal cavities (nose), nasal sinuses, oesophagus (adenocarcinoma), stomach, liver, kidney and cervix (neck of the uterus) and developing myeloid leukaemia. More...

See Table

2.1 Which cancers are caused by cigarette smoking?

Lung Larynx
Urinary tract (bladder, ureter and kidneys) Pancreas
Oral cavity (mouth) Stomach (mouth)
Nasal caivity (nose) and paranasal sinuses Liver
Oesophagus Cervix (neck of the uterus)
Pharynx (nasopharynx, oropharynx and hypopharynx) Bone marrow (leukemia)

2.1.1 Lung: Lung cancer is the most common cause of cancer deaths in the world and 1.2 million people develop it each year. In populations where tobacco has been widely used for a long-time (e.g. among men in developed countries) smoking is responsible for 90% of the cases of lung cancer. The risk of lung cancer increases in proportion to the duration of smoking and the numbers of cigarettes smoked. The effects are similar in men and women.

Stopping smoking at any age avoids further increasing the risk of lung cancer. The younger the age at which a person quits, the greater is the benefit. More...

2.1.2 Urinary tract: Tobacco smoking is a major cause of several cancers of the urinary tract (bladder, ureter and kidneys). The risk depends on duration of smoking and number of cigarettes smoked. As for lung cancer, stopping smoking at any age avoids further increasing the risk. More...

2.1.3 Oral cavity (mouth): Tobacco smoking causes cancer of the oral cavity in men and women. The risk is increased when smokeless tobacco is used or when smoking is combined with alcohol consumption. There is a strong relationship between risk and duration of smoking and number of cigarettes smoked. The risk tends to decrease after quitting. More...

2.1.4 Nasal cavity (nose) and paranasal sinuses: Sinonasal cancer is increased among cigarette smokers and several studies have shown that its frequency increases with the amount smoked. More...

2.1.5 Pharynx (nasopharynx, oropharynx and hypopharynx): The risk of cancer in the pharynx increases with cigarette smoking, depending on duration and number of cigarettes smoked. The risk decreases with time after quitting. More...

2.1.6 Oesophagus: Tobacco smoking increases the risk of oesophageal cancer in relation to dose. Stopping smoking does not result in a rapid decline in this risk. The risk is increased when smokeless tobacco is used or when smoking is combined with alcohol consumption. More...

2.1.7 Larynx: Laryngeal cancer is causally related with cigarette smoking with the risk increasing with dose. Use of alcohol in smokers and early age at starting smoking increase the risk. More...

2.1.8 Pancreas: Cigarette smoking causes cancer of the pancreas in proportion to consumption More...

2.1.9 Stomach: Many studies have now provided evidence of the role of cigarette smoking in causing stomach tumours, after allowing for other confounding factors. The risk is proportional to the duration of smoking and number of cigarettes smoked. More...

2.1.10 Liver: Many recent studies have now shown that cigarette smoking gives a moderate increased risk of liver cancer, in relation to the duration of smoking and the number of cigarettes smoked. More...

2.1.11 Cervix (neck of the uterus): A large number of studies have demonstrated that smoking induces one type of cervical cancer but the evidence is not consistent for other cervical carcinomas. More...

2.1.12 Bone marrow (leukaemia): Adult myeloid leukaemia is causally related to smoking. No clear evidence has been found for a link with lymphoid leukaemia or lymphoma. More...

2.2 Which cancers do not appear to be caused by cigarette smoking?

Most studies have found no association of breast cancer with smoking. Moreover, smoking appears to reduce the frequency of cancer of the lining of the uterus, especially after menopause. More...

2.3 For which cancers does a link remain unclear?

It is not clear whether cigarette smoking increases the risks of colorectal or prostate cancer due to the presence of confounding factors (additional variables that may be responsible for the effect). More...

2.4 Does cigar, pipe or bidi smoking also cause cancer?

Cigar and/or pipe smoking cause cancers of the oral cavity (mouth) and the upper digestive tract (oropharynx and hypopharynx, larynx and oesophagus). The risk increases with the amount smoked and when smoking is combined with alcohol consumption. Cigar and/or pipe smoking also causes lung cancer and there is evidence that it may cause pancreatic, stomach and bladder cancer.

Bidi smoking causes cancer of the oral cavity (mouth), upper digestive tract (pharynx, larynx and oesophagus), lung and stomach. The risk increases with duration and amount of bidi smoking. More...

2.5 For which cancers does a link remain unclear?

The combination of different cancer factors can produce an effect greater than the sum of their individual effects.

In particular, synergies have been found between smoking and:

  • exposure to arsenic, asbestos and radon at the workplace for lung cancer;
  • alcohol consumption for cancers of the oral cavity, pharynx, larynx and oesophagus;
  • human papillomavirus infection for cervix cancer (neck of the uterus).

The evidence for synergy was inconclusive for other factors, such as hepatitis B and alcohol for liver cancer. More...


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