Objective: The objective of the study was to evaluate whether any association exists between systemic inflammation score (SIS) and adverse events (AEs) and survival of locally advanced rectal cancer patients treated with total mesorectal excision (TME) followed by adjuvant chemoradiotherapy.
Patients and methods: All of the 109 rectal cancer patients recruited between May 2008 and June 2015 were treated with TME followed by adjuvant chemoradiotherapy. The prognostic ability of SIS for overall survival (OS) was calculated by the receiver operating characteristic (ROC) curves.
Results: According to the classification of the SIS, 22 (20.2%), 59 (54.1%) and 28 (25.7%) patients were classified as a score of 2, 1 and 0, respectively. With an area under the curve (AUC) of 0.616, the SIS score of 1 was defined as the optimal cut-off value. Therefore, we divided the patients into the SIS-low group (SIS score of 1 or 0, n=87) and SIS-high group (SIS score of 2, n=22). Multivariate analysis indicated that SIS was associated with OS (HR 0.390, 95% CI 0.186–0.817, P =0.012). The 5-year OS rate in patients without adjuvant chemotherapy was lower than the patients with adjuvant chemotherapy (53.3% vs 75.8%, P =0.010). Multivariate analysis showed that adjuvant chemotherapy was associated with OS (HR 0.217, 95% CI 0.089–0.529, P =0.001). A marginal statistically significant difference was observed in terms of leukopenia during adjuvant chemoradiotherapy between the SIS-low group and the SIS-high group (P =0.05).
Conclusion: These results suggest that SIS might serve as an independent biomarker for predicting AEs and prognosis in locally advanced rectal cancer treated with TME followed by adjuvant chemoradiotherapy. Strengthening treatment may be administered to locally advanced rectal cancer with high SIS score obtained before adjuvant chemoradiotherapy.
Keywords: rectal cancer, SIS, chemoradiotherapy, acute adverse event, survival