Melanoma patients who are recent and current smokers have lower survival rates than non-smokers, suggesting that smoking may weaken immune response to the most deadly skin cancer, researchers say.
In a study of more than 700 melanoma patients in the United Kingdom, smokers were 40% less likely to survive melanoma than people who hadn't smoked for at least 10 years before their diagnosis.
Immune system like an orchestra
In addition, in a subset of 156 melanoma patients who had the most genetic indicators for immune cells, smokers were about 4.5 times less likely to survive the disease than non-smokers.
The findings suggest smoking may affect how the body's immune system responds to melanoma, according to the authors of the study published recently in the journal Cancer Research.
"The immune system is like an orchestra, with multiple pieces. This research suggests that smoking might disrupt how it works together in tune, allowing the musicians to continue playing but possibly in a more disorganised way," said lead author Julia Newton-Bishop. She is professor of dermatology at the University of Leeds in England.
"The result is that smokers could still mount an immune response to try and destroy the melanoma, but it appears to have been less effective than in never-smokers, and smokers were less likely to survive their cancer," she explained in a news release from Cancer Research UK, which funded the study.
Based on the study findings, people diagnosed with melanoma should be urged to quit smoking, she added.
While the study found an association between smoking and melanoma patients' chances of survival, it could not confirm that smoking caused poorer survival.
Previous research has shown that smoking can harm the immune system, but the chemicals responsible for this effect haven't been pinpointed.
Julie Sharp, head of health and patient information at Cancer Research UK, suggested patients and physicians heed the findings.
"Overall, these results show that smoking could limit the chances of melanoma patients' survival, so it's especially important that they are given all the support possible to give up smoking for good," Sharp said in the news release.
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