Clinical Prediction Score for Disease Control and Treatment Outcomes of FOLFIRI as Second-line Chemotherapy for Metastatic Colorectal Cancer

Abstract

BACKGROUND: Colorectal cancer is a leading cause of death. The standard treatment for advanced stages is chemotherapy. However patients who have received second-line chemotherapy often feel deteriorated and exhausted after first-line treatment. The disease control of chemotherapy is reduced. This study aimed to identify the predictive factors associated with disease control and predictive score to assess the efficacy of FOLFIRI chemotherapy. The results may help in optimizing treatment for metastatic colorectal cancer

OBJECTIVE: To determine prediction score for disease control to evaluate the efficacy of FOLFIRI as second-line chemotherapy for metastatic colorectal cancer

METHODS: A retrospective case-control study was conducted. Patients at Surin Hospital diagnosed with metastatic colorectal cancer were reviewed between January 1, 2013 and June 30, 2022. All patients previously received the FOLFOX regimen. Clinical characteristics, laboratory tests and treatment outcomes for all patients were collected. Exploratory analyses of the factors associated with disease control and efficacy of FOLFIRI were performed by prediction score.

RESULTS: Two hundred and nine patients with metastatic colorectal cancer at Surin Hospital were recruited and classified into 2 groups comprising 90 patients in the disease control group and 119 patients in the progression group. The predictive factors for disease control of FOLFIRI were body mass index (BMI) ≥18.5 kg/m² (OR, 5.93; 95% CI: 2.19-16.06; p<0.001), number of metastatic sites <4 (OR, 5.44; 95% CI: 1.11-26.64; p=0.03), Hemoglobin (Hb) ≥13 g/dl (OR, 3.74; 95% CI: 1.13-12.33; p=0.03), first-line response (complete response [CR}/partial response [PR]/stable disease [SD]) (OR, 2.54; 95% CI: 1.01-6.42; p=0.04), progression-free survival (PFS) first-line >12 months (OR, 2.41; 95% CI: 1.08-5.35; p=0.03) and lymphovascular invasion (LVI) positive (OR, 2.31; 95% CI: 1.06-5.04; p=0.03). The poor prognostic group (0-2 factors), intermediate prognostic group (3-4 factors) and excellent prognostic group (5-6 factors) had progression-free survival (PFS) of 2.7 months (95%. CI, 2.10-3.33), 4.7 months (95% CI: 3.33-6.24), and 7.8 months (95% CI: 7.64-8.05), respectively. Overall survival (OS) was 17.2 months (95% CI: 15.70- 18.71), 28.6 months (95% CI: 25.01-32.20) and 33.6 months (95% CI: 26.85-40.48), respectively. PFS and OS were statistically significant different among all three groups.

CONCLUSIONS: The predictive factors for disease control of second-line FOLFIRI chemotherapy for metastatic colorectal cancer were BMI ≥18.5 kg/m², number of metastatic sites <4, Hb ≥13 g/dl, first-line response (CR/PR/SD), PFS first-line >12 months and LVI positive. The prediction score revealed that more predictive factors could result in the optimized efficacy of chemotherapy