Occult neoplastic cells in the lymph node sinuses and recurrence/metastasis of stage II/Dukes' B colorectal cancer.

ABSTRACT

Lymph nodes from patients with colorectal cancer were immunohistochemically stained for cytokeratin in order to investigate the relationship between the presence of occult neoplastic cells (ONCs) and recurrence/metastasis. A total of 78 patients with stage II/Dukes' B colorectal cancer were divided into two groups. The first group consisted of 18 patients who had developed recurrence/metastasis (recurrence group) and the other one of 60 patients who had survived without recurrence (non-recurrence group). The presence of ONCs was compared between the two groups with respect to i) single cells (≥3 floating ONCs), ii) clusters of cells (≥1 floating aggregates of 2-20 ONCs), and iii) single cells + clusters. When single cells were detected, the sensitivity for recurrence was 55.6% (10/18), the positive predictive value (PPV) was 30.3% (10/33), the specificity was 61.7% (37/60, p=0.195), and the negative predictive value (NPV) was 82.2%(37/45). For the clusters, the sensitivity was 55.6% (10/18), PPV was 37% (10/27), specificity was 71.7% (43/60, p=0.033), and NPV was 84.3% (43/51). With single cells + clusters, the values were 55.6% (10/18), 43.5% (10/23), 78.3% (47/60, p=0.006), and 85.5% (47/55), respectively. These results suggest that the detection of single cells + clusters has a high specificity and NPV, and indicates a low risk of recurrence/metastasis in patients with stage II colorectal cancer.