Study Links IPF With Increased Risk for Several Cancer Types
People with idiopathic pulmonary fibrosis (IPF) are at increased risk of several cancers other than lung cancer, a new study reports.
The study, “Risk of cancer incidence in patients with idiopathic pulmonary fibrosis: A nationwide cohort study,” was published in the journal Respirology.
IPF and cancer share common risk factors (e.g., smoking) and biological mechanisms (e.g., abnormal cell-to-cell communication). Previous research has shown that people with IPF are at increased risk for lung cancer. However, it remains unclear how IPF affects the risk for other types of cancer.
The team analyzed data from 25,241 people who were diagnosed with IPF between 2009 and 2014. For comparison, the researchers assessed data from 75,723 people without IPF (control group). The groups were matched in terms of sex (63% male) and age (mean age 64.6 years). Data for both groups were available through the end of 2016, with an average follow-up time of nearly four years.
People in the IPF group were more likely to have diabetes, be heavy smokers, and live in urban areas, and less likely to exercise. Overall, 2,482 (9.83%) people in the IPF group and 4,374 (5.78%) people in the control group were diagnosed with cancer during the follow-up period.
After making data adjustments for the presence of diabetes, IPF was found to be associated with a roughly twofold higher risk of cancer compared with the control group. Statistical analysis indicated that IPF was associated with a nearly sixfold increased risk of lung cancer, and a significantly increased risk for other cancer types, namely: lymphoma (2.14 times higher risk), skin cancer (2.02 times), cervical cancer (1.94 times), multiple myeloma (1.67 times), thyroid cancer (1.66 times), leukemia (1.63 times), pancreatic cancer (1.38 times), liver cancer (1.3 times), and prostate cancer (1.27 times).
Most of these increased risks were valid in separate analyses of males and females. The exception was liver cancer — a higher risk was seen in males with IPF, but not in females.
Broadly, the increased cancer risks also remained statistically significant after adjustment for other factors, such as smoking, income, and other cancer‐associated characteristics.
“We found that patients with IPF had a higher overall cancer incidence risk than did matched controls,” the researchers wrote.
“Moreover, adjustment for the effects of smoking and other cancer-associated covariates had little effect on the [statistical significance] of overall and specific cancers,” which indicated that “IPF might be an independent risk factor for cancer development,” the team added.
Therefore, “healthcare providers should be aware of this risk when treating patients with IPF.”
Some of the cancer types — specifically skin cancer, multiple myeloma, and leukemia — were not common in the overall data set. As such, “determining clinically important differences was difficult,” the researchers wrote. “Further studies are needed to determine whether these findings represent true findings.”