1629OPROGNOSTIC FACTORS OF TUMOUR CELLULARITY IN IMAGE-GUIDED BIOPSIES: RESULTS FROM A PROSPECTIVE MOLECULAR TRIAGE TRIAL (MOSCATO)

ABSTRACT Aim: MOSCATO (molecular-screening for cancer treatment optimization) is a prospective molecular triage trial based on on-purpose tumour biopsies to perform molecular portraits. We aimed at identifying factors that predict a high cellularity in image-guided tumour biopsy. Methods: The percentage of tumour cells was evaluated on each biopsy sample. The primary endpoint was the maximum percentage of tumour cells across the different samples. All CT-scan images were centrally reviewed. Non-parametric tests were used to compare the distribution of the maximum percentage of tumour cells, between subsets of patients (pts). Paired samples (central vs. peripheral) were compared when multiple samples were obtained. Results: Among the 460 enrolled pts from November 2011 to March 2014, 335 pts (73%) had an image-guided needle biopsy of the primary tumour (n=39, 12%) or a metastatic lesion (n=296, 88%). Biopsies were performed on liver (n=127, 38%), lung (n=71, 21%), lymph nodes (n=71, 21%), bone (n=11, 3%), and other tumour sites (n=55, 16%). Sixteen pts (5.7%) experienced a complication: pneumothorax in 8 pts treated medically, and haemorrhage in 8 pts requiring embolisation in 3 cases. The median percentage of tumour cells was 50% (Q1-Q3, 30-70%). Age, gender, on-going chemotherapy, target origin (primitive vs. metastasis), number of lesions in the biopsied organ, target lesion size, tumour growth rate, presence of necrosis and size of the needle were not statistically related to a high cellularity (P Conclusions: The majority of tumour biopsies provided molecular screening efficiency with a low rate of complications. Imaging modality used to guide to the biopsy, multiple samples, peripheral and central, and the chosen organ were the prognostic factors of cellularity. Disclosure: All authors have declared no conflicts of interest.