Abstract B174: Baseline and procedural characteristics influencing tumor cell content on on-purpose tumor biopsies: Results from a prospective molecular triage trial (MOSCATO).
Authors: Hollebecque Antoine , Rabahi Yacine , Gajda Dorota , Viehl Philippe , Le Deley Marie-Cécile , Charpy Cécile , Massard Christophe , Angevin Eric , Ngo-Camus Maud , Auger Nathalie , Koubi-Pick Valérie , Lacroix Ludovic , Richon Catherine , Mazoyer Clément , Deschamps Frédéric , De Baere Thierry , Soria Jean-Charles 
Published: August 2014

Background: MOSCATO (molecular-screening for cancer treatment optimization) is a prospective molecular triage trial. On purpose tumor biopsies are required to perform molecular portraits. We aimed at identifying baseline and procedural characteristics that predict a high-cellular tumor content in tumor biopsy.

Methods: The main patient's and tumor's characteristics as well as procedural details (including complications of tumor biopsies) were evaluated. The percentage of tumor cells observed on each biopsy was defined by a real-time pathological control. Univariate logistic regression analysis was used to model percent of tumor cells as a dichotomous outcome. Non-parametric tests were used to compare qualitative values.

Results: From November 2011 to June 2013, among 284 enrolled patients, 217 had a needle biopsy of a tumor. Biopsies were performed on the liver (n=83, 38%), the lung or pleura (n=61, 28%), the lymph nodes (n=37, 17%), the soft tissues (n=27, 12%) and the bone (n=9, 4%). Only twelve patients (5.5%) experienced a complication: pneumothorax (grade 1 or 2, n=7, 11%), hemorrhage (grade 1, n=5, 2%). The mean percentage of tumor cells was 52±27%. The distribution of the percentage of tumor cells was: 10.2%, 9.3%, 26.4% and 54.2% of cases with the following tumor-cell content: 0-10%, 10-30%, 30-60% and ≥60% respectively. Diameter of the lesion &gt;30 mm (vs ≤30mm) (OR=2.4, p=0.02), biopsy performed by a senior radiologist (vs junior) (OR=2.3, p=0.02) and over 6 months training in the trial (vs ≤6) (OR=2.2, p=0.05) were associated with the presence of more than 30% of tumor cells whereas number of biopsy samples obtained on a given site (≥ vs &lt;5) (OR=1.6, p=0.16), &lt; 18G diameter of the needle (vs ≥18G) (OR=1.1, p=0.8), ongoing anti-tumor treatment (vs no) (OR=0.9, p=0.7), method used to guide the biopsy (echo vs CT-scan) (OR=1.0, p=0.9) or central biopsy site (vs peripheral) (OR=0.9, p=0.5) were not. To obtain more than 60% of tumor cells, only number of biopsy samples obtained on a given site (≥ vs &lt;5) (OR=1.8, p=0.03), absence of ongoing anti-tumor treatment (OR=1.8, p=0.03) were predictive factors. There was no statistical difference according to the site of the biopsy (p&lt;0.001), except for the poor performance of bone biopsies (3/9 biopsies with over 10% cellular tumor content).

Conclusion: The majority of tumor biopsies are amenable to molecular screening and the rate of complication is low (5.5%). The number of biopsies obtained on a given site and lack of an ongoing anti-cancer treatment are predictive factors of high cellular tumor content (≥ 60%).

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B174.

Citation Format: Antoine Hollebecque, Yacine Rabahi, Dorota Gajda, Philippe Viehl, Marie-Cécile Le Deley, Cécile Charpy, Christophe Massard, Eric Angevin, Maud Ngo-Camus, Nathalie Auger, Valérie Koubi-Pick, Ludovic Lacroix, Catherine Richon, Clément Mazoyer, Frédéric Deschamps, Thierry De Baere, Jean-Charles Soria. Baseline and procedural characteristics influencing tumor cell content on on-purpose tumor biopsies: Results from a prospective molecular triage trial (MOSCATO). [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B174.