Focal 18F‐FDG Uptake Predicts Progression of Pre‐invasive Squamous Bronchial Lesions to Invasive Cancers

Abstract Introduction Pre‐invasive squamous lesions of the central airways can progress into invasive lung cancers. Identifying these high‐risk patients could enable detection of invasive lung cancers at an early stage. In this study, we investigated the value of 18F‐fluorodeoxyglucose (18F‐FDG) positron emission tomography (PET) scans in predicting progression in patients with pre‐invasive squamous endobronchial lesions. Methods In this retrospective study, patients with pre‐invasive endobronchial lesions, who underwent an 18F‐FDG PET scan at the VU University Medical Center Amsterdam, between January 2000 and December 2016, were included. Autofluorescence bronchoscopy (AFB) was used for tissue sampling and was repeated every 3 months. The minimum and median follow‐up was 3 and 46.5 months. Study endpoints were the occurrence of biopsy proven invasive carcinoma, time‐to‐progression and overall survival (OS). Results A total number of 40 of 225 patients met the inclusion criteria of which 17 (42.5%) patients had a positive baseline 18F‐FDG PET scan. A total of 13 of 17 (76.5%) developed invasive lung carcinoma during follow‐up, with a median time to progression of 5.0 months (range, 3.0–25.0). In 23 (57.5%) patients with a negative 18F‐FDG PET scan at baseline, 6 (26%) developed lung cancer, with a median time to progression of 34.0 months (range, 14.0–42.0 months, p < 0.002). With a median OS of 56.0 months (range, 9.0–60.0 months) versus 49.0 months (range, 6.0–60.0 months) (p = 0.876) for the 18F‐FDG PET positive and negative groups, respectively. Conclusions Patients with pre‐invasive endobronchial squamous lesions and a positive baseline 18F‐FDG PET scan were at high‐risk for developing lung carcinoma, highlighting that this patient group requires early radical treatment.