Fig. 4.

Spread of intraoperative tumour cell clusters as a factor associated with early metastasis

Descriptive statistics for cluster Δ end-to-baseline (S3−S0) to detect the best predictive cut-off for metastasis disease-free survival. The descriptive statistics include the first, second, and third quartiles (Q₁, Q₂, and Q₃) and the mean value ($\overline{\mathrm{x}}$) for the cluster end-to-baseline (clusters/ml). The cohort was divided into two groups (over and under equal the cut-off value) and obtained the following metrics at 3-year follow-up: i) the number of patients at risk in each group (n/n); ii) the probability of metastasis disease-free survival (probability/probability), and iii) the log-rank test P value obtained between the two groups. Kaplan–Meier curves are presented for the descriptive statistical value with the most significant metastasis disease-free survival curve separation (Q3 with a cluster Δ end-to-baseline cut-off value of 14 clusters/ml). In addition, the 12-month log-rank test P = 0.023 is also presented.