Correlation between occult neoplastic cells in the lymph node sinuses and recurrence in patients with Dukes' C colorectal cancer.

The aim of this study was to investigate whether it was possible to select patients with Dukes' C primary colorectal cancer who had a high risk of metastasis and recurrence. Among 434 patients who underwent surgical resection of primary colorectal cancer, 115 patients (26.5%) had Dukes' C cancer. Among them, 35 patients (30.45%) suffered from metastasis/recurrence postoperatively. Thirty-two patients with recurrence for whom complete follow-up was possible (recurrence group) and 32 patients who survived for at least 5 years without recurrence (non-recurrence group) were compared by immunohistochemical staining of resected lymph nodes for cytokeratin using two antibodies (AE1/AE3 and CAM 5.2). AE1/AE3 staining was positive in 93.85% of the recurrence group versus 68.85% of the non-recurrence group (p=0.0250), while CAM 5.2 staining was positive in 84.45% vs. 53.15%, respectively (p=0.0152). The occult neoplastic cell count (mean +/- SD) in the peripheral lymph node sinuses was 6.28+/-5.17 vs. 2.38+/-3.03 (p=0.0002) in the AE1/AE3-positive patients from the recurrence and non-recurrence groups, while it was 5.13+/-4.84 vs. 1.53+/-2.37 (p=0.0003) in the CAM 5.2-positive patients in each group. Accordingly, the immunohistochemical positivity rate for both AE1/AE3 and CAM 5.2, as well as the occult neoplastic cell count, were significantly higher in the recurrence group. These results suggest that patients with Dukes' C primary colorectal cancer who have a higher risk of recurrence can be selected by immunostaining of resected lymph nodes for cytokeratin.

Correlation between occult neoplastic cells in the lymph node sinuses and recurrence in patients with curatively resected Dukes' B colorectal cancer.

This study investigated whether it is possible to detect patients who have a high risk of metastasis and recurrence after resection of stage II Dukes' B primary colorectal cancer. Among 434 patients who underwent curative resection of primary colorectal cancer, 167 (38.5%) had Dukes' B cancer. Among them, 19 patients (11.4%) suffered from postoperative metastasis or recurrence. In 17 patients with recurrence who could be followed-up completely (recurrence group) and 17 other patients who survived for at least 5 years without recurrence (non-recurrence group), immunohistochemical staining of resected lymph nodes for cytokeratin (AE1/AE3 and CAM 5.2) was performed. AE1/AE3 was positive in 76.5% and 47.1% of the patients from the recurrence and non-recurrence groups, respectively, while CAM 5.2 was positive in 52.9% and 17.6%, respectively. There were no significant differences of either AE1/AE3 or CAM 5.2 positivity between the groups. However, the occult neoplastic cell count (mean +/- SD) floating in the lymph node sinuses was significantly higher in patients from the recurrence group who were positive for AE1/AE3 or CAM 5.2 than in patients from the non-recurrence group (6.12+/-6.00 vs. 0.59+/-0.71; p=0.0019 and 3.94+/-5.06 vs. 0.29+/-0.69; p=0.0098, respectively). These results suggest that patients with Dukes' B primary colorectal cancer who have a higher risk of recurrence can be selected by immunostaining of resected lymph nodes for cytokeratin.

Selection criteria for high risk and low risk groups of recurrence and metastasis in patients with primary colorectal cancer.

Among 371 patients with primary colorectal cancer, 54 patients suffered from recurrence/metastasis (recurrence group) and 317 survived without recurrence for at least 5 years (non-recurrence group). The clinicopathological characteristics of the 2 groups were compared and occult neoplastic cells (ONCs) in the lymph node sinuses were detected by cytokeratin immunohistochemistry. There were significant differences of the following factors: venous invasion (v-) vs. (v+) for Dukes' A patients (p=0.0315); harvested lymph nodes (LN) or=15 for Dukes' B patients (p=0.0388); (v-) vs. (v+) (p=0.0059), lymphatic invasion (ly-) vs. (ly+) (p=0.0435) for Dukes' A and B patients combined; D>n vs. D=n (p=0.0033), depth of tumor invasion or=se/a2 (p=0.0329) for Dukes' C patients. When the detection of >or=3 ONCs was defined as positive, the sensitivity, specificity, PPV, and NPV were respectively 77%, 100%, 100% and 71% in Dukes' B patients, as well as 75%, 72%, 73% and 74% in Dukes' C patients. The high-risk groups for recurrence/metastasis were identified by the following criteria: (v+) and (ly+), or=se/a2, and ONCs (+) of those with >or=2 factors for Dukes' C patients (selection rate; approximately 21.2-37.5%). These factors seem to be appropriate for separating patients into high-risk and low-risk groups of colorectal cancer recurrence/metastasis.