Lung cancer diagnosis on the rise in non-smokers
With lung cancer coming in as the fifth most common type of cancer diagnosed in New Zealand, but ranking as the leading cause of cancer death, experts are calling for more research to help identify it in its early stages and determine risk factors in non-smokers.
An example of a person with lung cancer, despite having never smoked, is US comedian Kathy Griffin who recently revealed she has been diagnosed with the cancer.
Because the cancer was caught early and is confined to her left lung, the 60-year-old comedian will undergo surgery to remove half of her left lung.
Following her surgery, Griffin is on the mend and keeping fans up-to-date with her recovery.
Griffin isn’t alone either, with a growing number of people receiving a lung cancer diagnosis without ever smoking.
Not just a “smoker’s disease”
Though smoking is one of the largest risk factors for lung cancer, the proportion of those diagnosed with the disease who are “never-smokers” is increasing.
According to Health Navigator New Zealand, one in five New Zealanders who have been diagnosed with the condition were life-long non-smokers.
This increase in the condition has been seen in other countries with a 2017 study of lung cancer patients in US hospitals finding the percentage of never-smokers increased from eight percent in 1990 to 1995, to 14.9 percent from 2011 to 2013.
Surgeon Andrew Kaufman, whose program for never-smokers at Mount Sinai Hospital in New York has treated 3,800 patients in 10 years, said: “Since the early 2000s, we have seen what I think is truly an epidemiological shift in lung cancer.”
“It is well-documented that approximately 20 percent of lung cancer cases that occur in women in the US and nine percent of cases in men, are diagnosed in never-smokers,” he confirmed.
However, the reasons why more people are being diagnosed without smoking is not well known.
More research is needed
Dr Marianne Weber, a senior research fellow at the Daffodil Centre, is overseeing a new study to identify potential risk factors for those who don’t smoke.
By poring over two large population studies in Australia and China, the researchers are looking to link lung cancer to factors such as diet, lifestyle, and household air pollution.
“If we can highlight a risk profile for someone who might go on to develop lung cancer when they’re a non-smoker, that would be ideal,” Dr Weber said.
So far, cancer doctors have found one group of people who are more at risk: women.
Worldwide, half of female lung cancer patients have never smoked, while only 15 percent of male lung cancer patients are never-smokers.
Josephine Feliciano, an oncologist at Johns Hopkins University School of Medicine, said that, beyond sex, “nothing stands out as a single large risk factor” for lung cancer in non-smokers.
“But air pollution, radon, family history of lung cancer, [and] genetic predispositions [all play a role],” Feliciano said.
Additionally, chronic lung infections and lung diseases such as chronic obstructive pulmonary disorder (COPD) seems to increase the risk of diagnosis.
“Of all the patients that present with the disease, the current survival rate is only about 17 percent,” said Dr Stirling, a senior respiratory specialist at The Alfred Hospital and leader of the Victorian Lung Cancer Registry.
“For patients with stage four disease the median survival, so that’s the time at which 50 percent of patients will succumb to the disease, is somewhere between seven and 12 months.”