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Much recent research has been directed toward the use of monoclonal antibodies (MAb) for the inimunodetection of solid tumors. In pancreatic cancer, the results of conventional immunoscintigraphy using intact MAb remain disappointing. Clear immunoseintigrapliy with radiolabeled MAb requires a high tumor tissue/blood ratio of radioactivity and a low normal tissue/blood ratio of radioactivity. In this study, 125I‐labeled Fab fragments produced by papain digestion of MAb A7 were injected intravenously into nude mice bearing a human pancreatic cancer (HPC‐YS) xenograft previously shown to react specifically with MAb A7. The radioactivity of tumors and normal organs was subsequently measured. The tumor tissue/blood ratio of 125I‐labeled Fab fragments of MAb A7 was 1.00±0.24 and 9.68±2.54 at 2 and 24 h after injection, respectively. The tumor tissue/blood ratio of radioactivity was significantly higher than those of normal organs at 24 h after injection. Moreover, the tumor tissue/blood ratio of 125I‐labeled Fab fragments of MAb A7 was greater than that of intact MAb A7, although the 125I‐labeled Fab accumulation level was much less than that of 125I‐labeled intact MAb A7 in the tumor. When mice bearing tumors which did not react with MAb A7 were studied, 125I‐labeled Fab fragments did not specifically localize to the tumors. These results suggest that Fab fragments of MAb A7 may be suitable carriers of radionuclides for the immunodetection of human pancreatic cancer.

Background/Aim: Chemotherapy dose adjustments in colorectal cancer are usually based on body surface area (BSA). The goal of this study was to investigate patients with nutritional disorder who developed early peripheral neuropathy due to inappropriate dose adjustment of oxaliplatin. Patients and Methods: The study subjects were 88 patients with advanced or recurrent colorectal cancer who underwent chemotherapy with oxaliplatin. The psoas muscle area (PMA) was used as a nutritional index. Mild (grades 0-1, MN group) and severe (grades 2-3, SN group) peripheral neuropathy was defined using neurotoxicity criteria of Debiopharm.Results: Severe peripheral neuropathy developed in 29 patients (33.0%). The total oxaliplatin dose/PMA was significantly higher for the SN group (107.6±8.5 mg/cm 2 ) and compared with the MN group (53.8±6.0 mg/cm 2 ) in univariate (p<0.0001) and multivariate (p=0.012) analyses. Conclusion: In order to prevent peripheral neuropathy from chemotherapy for colorectal cancer, dose adjustment of oxaliplatin should be based on PMA, in addition to BSA.

In a previous study, we used a murine monoclonal antibody, A7, against human colon carcinoma as a drug-carrier to treat colorectal cancer. In the present study, we found that MAb A7 also reacted immunohistochemically with 73% of human pancreatic carcinoma cell lines, with the A7 antigen mainly being detected on the cell surface. However, the A7 antigen was found in only 9% of the spent media of these human pancreatic carcinoma cell lines by ELISA. On the other hand, the positive incidence of CA19-9, POA, ferritin, CEA, DU-PAN-2 and SLX in those spent media was 100%, 64%, 64%, 55%, 55% and 36%, respectively. These results suggest that the A7 antigen may only rarely be shed into the sera of pancreatic cancer patients, in which case MAb A7 could be a suitable drug-carrier in targeting chemotherapy for pancreatic cancer patients.