By Reuters Staff
NEW YORK (Reuters Health) - 25/4/2019
Non-small cell lung cancer (NSCLC) presents differently in patients with idiopathic pulmonary fibrosis (IPF), who also have higher overall and lung-cancer mortality, according to a new study.
"We found that patients with IPF and lung cancer have a greater proportion of early stage disease of squamous histology in a lower lobe distribution," Dr. Stacey-Ann Whittaker Brown of the Icahn School of Medicine at Mount Sinai in New York City and colleagues write in the Annals of the American Thoracic Society, online April 16. "This atypical distribution may need to be incorporated into risk models for lung nodule management in IPF patients."
Lung cancer prevalence may be as high as 30% in patients with IPF, compared to a lifetime prevalence of about 6% in the general U.S. population, Dr. Brown and her team write. Using Surveillance, Epidemiology, and End Results data, they looked at more than 54,000 Medicare beneficiaries with NSCLC diagnosed in 2007-2011, 2% of whom had IPF.
Thirty-one percent of the IPF group was diagnosed with stage I disease, versus 25% of those without IPF (P<0.01), and their tumors were significantly smaller (median size 31 vs. 35 mm). Squamous carcinoma also occurred significantly more frequently in IPF patients (46% vs. 35%), who were also more likely to have lower-lobe tumors (38% vs. 28%).
Overall, roughly half of the NSCLC patients received stage-appropriate therapy. Treatment proportions were similar in patients with stage I or II disease with and without IPF, but IPF patients with stage III or IV disease were significantly less likely to receive treatment.
IPF patients' median overall survival was seven months, versus 11 months for the non-IPF patients (P<0.01), and the difference remained significant after adjustment (hazard ratio, 1.35).
Survival was worse with IPF regardless of whether patients received stage-appropriate treatment.
"The reasons for these findings are likely multifactorial and potentially include poorer tolerability of treatments, the negative impact of competing risks, and/or more aggressive cancer behavior," Dr. Brown and colleagues write.
"Further research is needed to identify the best strategies to control and treat lung cancer in this highly affected population," they conclude.
Dr. Brown was not available for an interview by press time.
Ann Am Thorac Soc 2019