Fig. 1From: Primary tumor resection improves prognosis of unresectable carcinomas of the transverse colon including flexures with liver metastasis: a preliminary population-based analysisDivision of the patients by the optimal cutoff points of age (A1–3), year of diagnosis (B1–3) and median household income (C1–3) produced by the X-tile software. The optimal cutoff points highlighted by the black circle (A1, B1 and C1) are shown on histograms (A2, B2 and C2) and Kaplan-Meier plots (A3, B3 and C3)Back to article page