Different pathways to lung cancer diagnosis in a real-life setting.

Background: Most lung cancers are diagnosed at an advanced stage and therefore have a poor prognosis. One major challenge is to choose the most adapted sampling technique to obtain a rapid pathological diagnosis so as to start treatment as early as possible. A growing number of techniques have been developed in recent years. This study sought to assess the diagnostic efficiency of each, along with the respective duration of the diagnostic pathways.

Methods: This retrospective, bicentric, observational study enrolled patients with inoperable lung cancer (stage III or IV) diagnosed in 2018-2019. Diagnostic efficiency was assessed based on the different examinations performed to achieve a precise diagnosis (pathology, immunohistochemistry, and/or molecular biology). The time between the first medical contact and treatment initiation was also assessed.

Results: Overall, 625 patients were included (median age 67 years; men 67 %; adenocarcinoma 55 %). The most frequent examinations were bronchial endoscopy (n = 469, 75 %), followed by metastasis biopsy (n = 137, 21.9 %) and guided transthoracic core-needle biopsy (TCNB) (n = 116, 18.6 %). 372 patients had only one procedure (59.5 %), mainly bronchial endoscopy (n = 217, 34.7 %) and metastasis biopsy (n = 71, 11 %). The most efficient examination was thoracic surgery (surgical pleural biopsy, (n = 32, 100 %); mediastinoscopy (n = 26, 96.3 %); surgical pulmonary biopsy (n = 14, 93.3 %). The second most efficient examination was metastasis biopsy (n = 126, 94 %) followed by guided TCNB (n = 108, 93.1 %). The median time from first medical contact to first examination was 4 days (interquartile range 25 %-75 % 1-8). The median time from first medical contact to pathological result was 17 days (10-34). The median time from first medical contact to treatment start was 48 days (30-69).

Conclusions: In order to make an accurate and rapid diagnosis of lung cancer, it is crucial to choose the most appropriate technique. Bronchial endoscopy remains the first-line examination for central lesions, as it is efficient and easily accessible. Guided TCNB and metastasis biopsy are the preferred techniques for peripheral lesions. The choice of the diagnostic technique should be part of a multidisciplinary approach and a dedicated pathway to optimize initial management.