Abstract 456P
Background
Tumor lymphocyte infiltrates (e.g. Immunoscore) and systemic inflammatory indices (SII) are highly prognostic in colon cancer but combined assessment is less well studied. The aim of this study was to investigate the prognostic and predictive value of CD8 + tumor-infiltrating lymphocytes (TIL) in combination with SII in patients with resected stage II-III colon cancer (CC).
Methods
Patients with stage II-III CC (n=304) diagnosed between 2008-2016 in our hospital were included. Pan-immune inflammation value (PIV) was calculated as; (neutrophil count × platelet count × monocyte count)/lymphocyte count. The mean density of CD8 + TILs in the periphery and center of the tumor was assessed and dichotomized at the 75th percentile. Combined inflammation score (CIS) was classified as “high” in patients with high PIV (>median) and low mean CD8 + TIL density, and “low” in the remaining patients.
Results
Five year DFS was 71% (78% in stage II, 64% in stage III). CD8 + TIL density was lower in node positive tumors and higher in mismatch repair deficient tumors, no association was observed with age, tumor sidedness or systemic inflammation indices. High PIV (>491), low CD8 + (<46 /mm2) and high CIS were associated with shorter disease-free survival (DFS). In multivariate analysis; age > 65 (vs <65) years (HR: 3.12 95% CI 1.78-5.48 p <0.001), stage 3 (vs. 2) disease (HR: 1.82 95% CI 1.06 3.12 p = 0.029) and high (vs low) CIS (HR: 3.82 95% CI 2.21-6.61 p <0.001) were associated with shorter DFS. Among patients with stage II disease, 78 patients (52%) received adjuvant chemotherapy. Patients with high CIS derived significant benefit from adjuvant chemotherapy (5 yr DFS 100% vs 60%, p=0.008) while those with low CIS derived no benefit (5 yr DFS 88 vs 89% p=0,94). (Table) Table: 456P
Predictors of DFS in multivariate analysis
| HR | %95 CI | p | |
| Age ≥ 65 (vs <65) | 3,12 | 1,78-5,48 | <0,001 |
| Stage III (vs II) | 1,82 | 1,06-3,12 | 0,029 |
| Combined inflammation score High (vs low) | 3,82 | 2,21-6,61 | <0,001 |
Conclusions
Combined inflammation score may represent a new prognostic factor for localized colon cancer and predictor of chemotherapy response in patients with stage II disease.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.