1102 - Immunoscore feasibility study in routine postsurgical pathologic review for early-stage colon cancer (CC) cases risk-assessment

Background

Immunoscore® Colon is an in vitro diagnostic test predicting the risk of relapse in early-stage CC patients, by measuring the host immune response at the tumor site. It is a risk-assessment tool that provides independent and superior prognostic value than the usual tumor risk parameters and is intended to be used as an adjunct to the TNM classification. The availability of the result in a satisfactory turn-around-time (TAT), compatible with adjuvant treatment decisions, is critical for the inclusion of Immunoscore as a new component for a TNM-Immune (TNM-I) classification of CC.

Methods

Patients with stage II and III CC were recruited from 13 centers in Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, India, Israel, Spain, UK. Paraffin blocks or 4 adjacent slides were sent at room temperature for centralized Immunoscore testing to the HalioDx laboratory (Marseille, France). Densities of CD3+ and CD8+ T-cells were determined in core tumor (CT) and invasive margin (IM) by immunohistochemistry, and then quantified by image analysis. Immunoscore was calculated based on predetermined cutoffs established on a multicenter series of early-stage CCr patients (Pagès et al., Lancet 2018). Immunoscore was reported in categorical scores (IS 0 to 4), and clinical groups: Immunoscore High (IS 3-4) for highly infiltrated tumors, Immunoscore Intermediate (IS 2) and Immunoscore Low (IS 0-1, low infiltration).

Results

257 individual patient samples were received and 245 were eligible. A valid Immunoscore result was obtained in 97% of cases (n = 237). Reasons for failures were immunostaining background, torn tissues, insufficient tumor content or absence of IM. Immunoscore classifications were 4%, 16%, 49%, 28% and 3% respectively for IS 0-1-2-3 and 4, corresponding to 48 Immunoscore Low and 73 Immunoscore High tumors. 193 samples were eligible for TAT recording; maximum TAT was 13 days, with 97% of the results reported in 12 days or less from sample reception.

Conclusions

This study shows that the Immunoscore can be performed on most of the surgical specimens and can be included in the pathological report in a timely manner, compatible with postsurgery treatment decisions.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

HalioDx.

Funding

HalioDx.

Disclosure

K. Belaloui: Full-time employee: HalioDx. E. Malifarge, S. Turcan: Share-holder, full-time employee: HalioDx. D. Hatzibougias: Full-time employee: Microdiagnostics. M. van den Eynde: Consultant fees: HalioDx. F. Hermitte: Co-founder, share-holder, full-time employee: HalioDx. All other authors have declared no conflicts of interest.