Are patients with non-muscle-invasive bladder cancer a suitable population for a lung cancer screening trial?

Prognosis (case series) Level of Evidence 4.

To estimate the relative risk of developing a second primary neoplasm, in particular lung cancer, after having non-muscle-invasive bladder cancer (NMIBC).

Patients were included in the study if they had developed NMIBC between 1995 and 2003. All clinical data were extracted from the medical records of our institution's database. The interval between neoplasms, smoking habits, histological subtypes and survival were also analysed. Patient follow-up was >or=5 years.

We found 231 patients with NMIBC, 39 of which had a second primary neoplasm: 10 lung cancer, one pancreas, one gastric, one pharynx, one liver, one parathyroid, one oesophageal, five basal cell carcinoma, three larynx, two colon, three rectal and 10 prostate. In patients with lung cancer, NMIBC was the first primary tumour. Overall, the median (range) interval between occurrence of NMIBC and lung cancer was 54.2 (8-168) months. For the relationship between the observed and expected cases of lung cancer, after normalizing our frequencies to the sex ratio and age of our group of patients, the risk of lung cancer was 10.27-fold higher in patients with NMIBC as compared with the general population of Catalonia (95% confidence interval 4.92-18.88).

We consider that an annual examination for the detection and prevention of lung cancer must be included in clinical guides for patients with NMIBC. This proposal is reinforced by the finding that death in our group of patients with both tumours was always derived from lung cancer and not from bladder cancer.