[Liquid biopsy as indication of tumour progression in lung cancer: a potential intervention in tertiary prevention]

In the era of personalised therapies, liquid biopsy is considered an important diagnostic tool in the clinical management of cancer patients. Tissue specimen represents the gold standard for molecular evaluation of specific gene targets alterations that lead cancer patients to benefit of a "tailed therapy" based on molecular features of the tumour. This innovative source of nucleic acids was introduced in clinical setting only for non-small-cell lung cancer (NSCLC) patients to test epidermal grow factor receptor (EGFR) mutations when tissue is not available for a number of reasons (difficult access to the lesion, the presence of other disabling pathologies, especially in elderly patients, rejection by the patient, etcetera) or to monitor acquired resistance mutation after a first line of treatment. The present study aimed at assessing the diagnostic potential of liquid biopsy in balanced tertiary screening modelling. The cases relating to 5 years of activity regarding to molecular diagnostics performed on liquid biopsy specimens in the Predictive diagnostic laboratory of the University hospital "Federico II" of Naples (Campania Region, Southern Italy) were reviewed. Laboratory data were collected through the software SPSS. Non-parametric analysis was performed in order to test the differences between "wild type" patients or not. A multivariate logistic model was performed in order to assess the effect of mutation, age, and gender on the tumour progression. The results of the revision concern 515 total cases (almost of all plasma or peripheral blood), which allowed to evaluate the liquid biopsies for women and men. The average age of the patients is 66.3 years, and the 25° percentile is 59 years. The cases are: 221 basal and 294 by progression. The cases with mutation, as expected, have an odds ratio of 4,15, compared to the basal, to have a tumour progression (95%IC 2,7-6,3), regardless of gender and age. The detected mutations were 131 from different types of pulmonary carcinomas. Working on case data, specifying the characteristics of the patients with mutations will drive a further estimate in tertiary prevention screening designs.