Fig. 1.
Cohort distribution, chromosomal status classification, and its relationship to survival
a Cohort tree diagram. Two cohorts were formed for survival analyses: a test cohort comprising 206 patients with stage II–IV gastric cancer from Kanagawa Cancer Center Hospital, Yokohama, Japan, and a validation cohort comprising 748 patients with stage I–IV gastric cancer from Leeds Teaching Hospitals NHS Trust, Leeds, UK. Patients in the test cohort had locally advanced resectable gastric cancer treated by surgery alone (89) or surgery followed by adjuvant chemotherapy (117). In the validation cohort, patients with locally advanced gastric cancer received surgery and adjuvant chemotherapy (5) or surgery alone (492), and those with metastatic disease had chemotherapy alone (95) or best supportive care (156). b Bar chart showing frequency of patients with gastric cancer according to number of copy number aberrations (CNAs) determined in a preselected set of 16 genes. Chromosomal status was classified as chromosome-stable (CS; CNA score 0), chromosomal instability low (CINlow; CNA score 1 or 2) or chromosomal instability high (CINhigh). Kaplan–Meier analysis of overall survival in c test cohort and d validation cohort stratified by chromosomal status; 30 patients in the validation cohort were lost to follow-up. Survival was measured from the time of surgery, or time after diagnosis in patients who did not have surgery. c P = 0.033, d P = 0.020 (log rank test).