The incidence of cancer in patients with idiopathic pulmonary fibrosis and sarcoidosis in the UK.
BACKGROUND
The aim of this study was to use a longitudinal computerised health care dataset (The Health Improvement Network) to provide information on the overall incidence of cancer, and on the incidence of organ-specific cancers, in people with idiopathic pulmonary fibrosis (IPF) and sarcoidosis in comparison to the general population.


METHODS
Incident cases of IPF and sarcoidosis were identified with up to four controls matched by age, gender and general practice. Cancer incidence rates were compared between cohorts using Cox regression and adjusting for age, gender and smoking habit.


RESULTS
One thousand and sixty-four incident cases of IPF (mean age at diagnosis 71.5 years; 62.4% male) were identified. Overall, the incidence of cancer was increased in people with IPF compared to the general population (rate ratio 1.51; 95% CI 1.20-1.90), but this was largely due to a marked increase in the incidence of lung cancer (rate ratio 4.96; 95% CI 3.00-8.18). One thousand one hundred and fifty-three incident cases of sarcoidosis (mean age at diagnosis 47.0 years; 47.2% male) were identified. There was an overall increased incidence of cancer in sarcoidosis (rate ratio 1.65; 95% CI 1.22-2.24) and this was largely explained by an increase in the incidence of skin cancers (rate ratio 1.86; 95% CI 1.11-3.11).


CONCLUSIONS
This study provides further evidence of a marked increase in the incidence of lung cancer in people with IPF, but we found no increase in the risk of other cancers. People with sarcoidosis did have an increase risk of skin cancers, but not cancers at other sites.
Le Jeune
Ivan
I
Division of Epidemiology and Public Health, University of Nottingham, Clinical Sciences Building, Nottingham City Hospital, Nottingham NG5 1PB, UK.
Gribbin
Jonathan
J
West
Joe
J
Smith
Chris
C
Cullinan
Paul
P
Hubbard
Richard
R
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008175:Lung Neoplasms / Q000150:complications / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000453:epidemiology*; D011320:Primary Health Care / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D011658:Pulmonary Fibrosis / Q000150:complications / Q000453:epidemiology*; D017565:Sarcoidosis, Pulmonary / Q000150:complications / Q000453:epidemiology*; D012737:Sex Factors; D012878:Skin Neoplasms / Q000150:complications / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology