Prognostic Role of Pretreatment Nutritional and Inflammatory Status in Unresectable Metastatic Colorectal Cancer: Supplementary Analysis of JCOG1007.

BACKGROUND: Primary tumor resection (PTR) is not routinely recommended for asymptomatic patients with unresectable stage IV colorectal cancer, based on the results from the Japan Clinical Oncology Group (JCOG)-1007 trial, which showed no survival benefit over upfront chemotherapy. However, host-related factors such as nutritional status and systemic inflammation may impact on treatment outcomes. We conducted a supplementary analysis of JCOG1007 to evaluate whether pretreatment modified Glasgow Prognostic Score (mGPS), albumin, and C-reactive protein were associated with differential outcomes after upfront PTR. METHODS: Patients registered in JCOG1007 were stratified according to pretreatment mGPS (0, 1, 2), albumin (<3.5 vs. ≥3.5 g/dL), and C-reactive protein (≤1.0 vs. >1.0 mg/dL). Overall survival and progression-free survival (PFS) were assessed using Kaplan-Meier analysis and Cox proportional hazards models. Univariable and multivariable analyses were performed within each subgroup. RESULTS: Among 165 patients enrolled in JCOG1007, 154 patients without missing data were included for analysis. Patients with impaired host status, such as mGPS 2 and hypoalbuminemia, tended to have shorter overall survival and PFS after PTR than after chemotherapy alone, whereas no apparent differences were observed in other subgroups. In the mGPS 2 subgroup, PTR remained independently associated with worse PFS in multivariable analysis (hazard ratio 3.561; 95% confidence interval 1.005-12.621; P = 0.049), whereas a similar trend was observed in patients with hypoalbuminemia. CONCLUSIONS: Pretreatment nutritional and inflammatory status did not identify a patient population that may benefit from PTR. These findings further support avoiding routine PTR, regardless of host status.