Sensitivity to CPT-11 and platinum derivatives of stage II/Dukes' B colorectal cancer with occult neoplastic cells in lymph node sinuses

Among 13 patients with recurrent colorectal cancer (recurrence group: RG), immunohistochemical expression of Topo-1 was high in 4 patients (30.8%) and low in 9 patients (69.2%), while the non-recurrence group (N-RG) (n=8) showed high expression in 1 patient (12.5%) and low expression in 7 patients (87.5%) (NS). Regarding immunohistochemical expression of Bax/ERCC-1, high Bax/low ERCC-1 expression was observed in 6 patients (46.2%) from the RG and other patterns of expression were seen in 7 patients (53.8%), while high Bax/low ERCC-1 expression was observed in 4 patients (50.0%) from the N-RG and other patterns were found in 4 patients (50.0%) (NS). PCR analysis of Topo-1 expression revealed high expression in 9 patients (75.0%) from the RG (n=12) and low expression in 3 patients (25.0%), while the N-RG (n=8) showed high expression in all 8 patients (100.0%) and low expression in none (NS). With respect to ERCC-1, PCR analysis revealed high expression in 7 patients (58.3%) from the RG (n=12) and low expression in 5 patients (41.7%), while the N-RG (n=8) showed high expression in 1 patient (12.5%) and low expression in 7 patients (87.5%) (p<0.05). These results suggest that tumor sensitivity to CPT-11 and platinum derivatives is similar in stage II colorectal cancer patients with ONCs.