Patients With IPF Are at Increased Risk for Multiple Cancers

Patients with idiopathic pulmonary fibrosis (IPF) have an increased risk of developing cancer, especially lung cancer, according to a study published in the Asian Pacific Society of Respirology.

IPF is the most common type of idiopathic interstitial pneumonia and causes patients to experience a chronic, progressive and irreversible decline in lung function resulting in respiratory failure.

IPF and cancer share common risk factors such as smoking, chronic tissue injury, viral infection, and environmental exposure. IPF and cancer also have pathogenic similarities including altered cell-to- cell communication, abnormal activation of signal transduction pathways, genetic and epigenetic alterations, uncontrolled proliferation, resistance to apoptosis, and tissue invasion.

“The advances in early cancer detection, cancer treatment and supportive care have contributed to lowering cancer mortality. Therefore, physicians should pay attention to cancer development when treating patients with IPF,” wrote investigators.

The population-based cohort study included 25,241 patients with IPF and 75,723 matched controls from the Republic of Korea and found that the overall cancer incidence in patients with IPF was 29 cases per 1000 person-years compared with the control group (13.89 per 1000 person-years), and had a hazard ratio (HR) of 2.09 (95% CI, 1.96–2.16).

Lung cancer had the highest incidence and adjusted HR (5.89; 95% CI, 5.40–6.42) followed by lymphoma, skin cancer, uterine cervical cancer, multiple myeloma, thyroid cancer, leukemia, pancreatic cancer, liver cancer, and prostate cancer. The adjusted HR of all cancers excluding lung cancer was 1.32 (95% CI, 1.25-1.39).

“Adjustment for the effects of smoking and other cancer-associated covariates had little effect on the HR of overall and specific cancers, suggesting that IPF might be an independent risk factor for cancer development,” noted investigators.

Investigators also noted that chronic inflammation associated with IPF may play a role in cancer pathogenesis.

In addition, investigators found that male and female patients with IPF had a greater cancer incidence risk than the control group, with an adjusted HR of 2.14 (95% CI, 2.02–2.26; P = .013) and 1.84 (95% CI, 1.66–2.04; P = .013) respectively.

Male and female patients with IPF experienced a similar incidence of overall cancers, with male patients with IPF having a significantly higher risk of developing biliary, pancreatic, liver, and colorectal cancers, and female patients with IPF having a significantly higher risk of cancer of the central nervous system, lymphoma, and gastric cancer compared with the control group.

“Moreover, when stratified by sex, the analysis showed similar results between male and female patients. This serves as evidence that patients with IPF have an increased risk of developing lung cancer,” noted investigators.

Prior to the conducting the study, investigators analyzed a previous United Kingdom study that found an increased incidence of lung cancer in patients with IPF. However, investigators found that the sample size of patients with IPF with cancer was too small to evaluate the exact risk of cancer development.

Additionally, there is scarce data available on the risks of cancers other than lung cancer in patients with IPF.

“To our knowledge, this study is the largest study analyzing the cancer incidence risk in patients with IPF and enables the performance of sufficiently powered subgroup analyses in both sexes,” wrote investigators.

Reference

Lee HY, Lee J, Lee C, Han K, Choi SM. Risk of cancer incidence in patients with idiopathic pulmonary fibrosis: A nationwide cohort study. Respirology. July 22 2020. doi: 10.1111/resp.13911.