Myth 1: Smoking marijuana doesn’t increase the risk of lung cancer
Because marijuana is illegal in many countries, conducting proper clinical studies is difficult, says Dr Sze Wai Chan, a medical oncologist at the Sandton Oncology Centre. However, according to Dr Chan, some studies have found pre-cancerous cell changes in marijuana smokers similar to tobacco smokers, which means that marijuana smokers are likely at an increased risk for lung cancer.
Myth 2: There’s no point quitting if you’ve been diagnosed with cancer
“People who continue to smoke after a diagnosis of early-stage lung cancer have been shown to almost double their risk of dying,” says Dr Chan. Continued smoking also increases the risk of a second cancer (such as head and neck cancer, oesophagus cancer, bladder cancer, and another primary lung cancer), and increases the chance of other health problems, such as heart disease and poor circulation to the arms and legs.
“Continued smoking also decreases the chance of successful and effective treatment,” says Dr Chan. “It may slow your recovery after surgery, and it can be counter-productive to chemotherapy or radiotherapy.”
Myth 3: Air pollution is the biggest cause of lung cancer
Although not the biggest cause of lung cancer, air pollution is in fact becoming an important risk. The World Health Organization (WHO) estimates that fine particle matter air pollution causes about 16 percent of lung cancer deaths, 11 percent of chronic obstructive lung disease deaths, and more than 20 percent of ischaemic heart disease and stroke deaths.
Unlike smoking, everybody is exposed to air pollution, so everybody, and especially those who live in cities with poor air quality, is at risk. However, Dr Chan emphasises that the lung cancer risk associated with air pollution is still much lower than that associated with smoking.
Myth 4: If you’ve smoked for years, you can’t undo any of the damage
“Some studies show that former smokers who have been abstinent for more than 15 years had an 80 to 90 percent reduction in risk of lung cancer compared to current smokers,” says Dr Chan. However, lung cancer risk remains higher in former smokers than in those who have never smoked, even after prolonged periods of complete abstinence. “Adults who quit smoking gained six to 10 years of life expectancy, depending upon the age at which they quit smoking. Fifteen years after quitting, the risk of coronary heart disease is that of a non-smoker’s,” says Dr Chan.
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