A lung transplant increases COPD patients’ risk of developing cancer, a Swedish study indicates.
The research, “Risk of cancer after lung transplantation for COPD,” was published in the International Journal of Chronic Obstructive Pulmonary Disease.
Transplants increase the odds that people with some end-stage lung diseases will survive. But they also increase the risk that transplant recipients will develop cancer, possibly because they must be on immunosuppressives for a long time. Those drug are aimed at preventing the body from rejecting the transplant.
Other factors that could play a role in lung transplant recipients’ increased risk of cancer include the recipients’ and lung donors’ ages, and whether the recipient receives one or two new lungs.
Risk is particularly high for certain types of cancer, including those associated with viral infections, such as Hodgkin and non-Hodgkin lymphoma and a skin cancer known as cutaneous squamous cell carcinoma.
Although researchers have known for some time about the link between lung transplants and cancer, no studies have focused on the link between transplants and COPD. One reason this is relevant is that most COPD patients who have transplants are former smokers — and smoking increases the risk of lung cancer. In addition, research has shown that COPD patients are susceptible to developing colon and liver cancer in addition to lung cancer.
Researchers at Sweden’s Lund University led a study aimed at discovering how many COPD patients develop cancer after a lung transplant, and what the outlook for the cancer. They focused on non-skin cancers.
The team identified 331 people who had lung transplants for end-stage COPD between 1990 and 2013 at two transplant centers. Ninety-seven percent were former smokers. Sixty-four percent were women. And the patients’ median age was 55.
Researchers followed the patients for a median of 2.8 years after their transplants to see whether they developed cancer or died. To compare the patients’ risk of dying with that in the general population, they matched patients with non-COPD controls by age and sex.
When a transplant recipient developed cancer, the team analyzed the risk factors involved. They also tracked how long patients survived after a cancer diagnosis.
Thirty-five percent of the transplant patients developed cancer. And the risk of a transplant recipient developing a cancer other than skin cancer was five times greater that that of the general population. The greatest risks were for non-Hodgkin lymphoma and lung, liver and colorectal cancer.
In addition, researchers discovered that the median survival rate of a transplant patient who developed a skin cancer was eight years — double the four years of a patient who developed a non-skin cancer.
The increased risk of a transplant recipient developing non-Hodgkin lymphoma could be “a result of the intensity of immunosuppression or the large amount of lymphoid tissue conveyed within the lung graft,” the team wrote.
They also said that heavy smoking and immunosuppressives were likely critical factors in the development of lung cancer.
Another finding was that having a transplant greatly increased the risk of a COPD patient developing a non-melanoma skin cancer.
Researchers said another factor that may have played in to transplant recipients’ higher risk of developing cancer was that most were women. Previous studies have shown that more women than men who have COPD also have other diseases, including heart and respiratory disorders, and lung and other cancers.
Overall, the study showed that the risk of a COPD patient developing cancer jumps after a lung transplant, the team wrote. “Our study shows the importance of regular follow-up after LTx [lung transplants] for the early diagnosis of malignancy,” they wrote.
It also shows the importance of transplant recipients having regular follow-up visits with doctors, obtaining chest X-rays every three to four months, and having regular skin cancer screenings, the researchers wrote.
Double lung transplants might be the best option for COPD patients with a history of smoking, they added.