[Pilot study with the monoclonal antibody IOR-C5 as a potential agent of radioimmunoscintigraphy in colorectal cancer].
IOR C-5 is a G1 immunoglobulin type intact murine monoclonal antibody (MAb) that was developed in the Center of Molecular Immunology in Havana City, Cuba. In immunohistochemical studies, this demonstrated a significant affinity for the epithelial tissues so that it was used in a pilot clinical study to perform a radioimmunoscintigraphy of the colorectal primary tumors and their locoregional recurrences. It was labeled with 99mTc using the Schwarz method, with a > 95% performance. Planar images of the chest, abdomen and pelvis were performed at 10 minutes, 4-6 hours and 18-24 hours post-injection in the anterior and posterior projections and the SPECT was performed 4-6 hours and 18-24 hours post-injection of 1.85 GBq 99mTC. This study has aimed to verify in vivo the capacity of ior-C5 MAb to accumulate in the malignant colorectal lesions. ior-C5 accumulated in 5 out of the 7 patients who were studied and who were suffering from colorectal cancer or in whom there was suspicion of recurrence. There was a negative case of primary tumors, which was an adenocarcinoma in situ in a tubular-papillary adenoma. The second case with a negative radioimmunoscintigraphy was a true negative case.


CONCLUSIONS
It can be concluded that even though the number of patients is quite low, ior-C5 fulfilled the expectations of recognizing the epitope expressed in colorectal tumors in an in vivo human environment.
Oliva
J P
JP
Departamento de Medicina Nuclear, Instituto Nacional de Oncología y Radiobiología, (INOR), C. Habana 10400, Cuba. imagamma@infomed.sld.cu
Pimentel
G
G
Borrón
M
M
Peralta
R
R
Ortiz
R
R
Oliver
B
B
Díaz
N
N
Sánchez
I
I
Vázquez
A M
AM
Baum
R P
RP
D000230:Adenocarcinoma / Q000737:chemistry / Q000000981:diagnostic imaging*; D000236:Adenoma / Q000737:chemistry / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000818:Animals; D000910:Antibodies, Heterophile / Q000096:biosynthesis; D000911:Antibodies, Monoclonal / Q000276:immunology; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000276:immunology; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000276:immunology; D018395:CA-19-9 Antigen / Q000097:blood; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000276:immunology; D002278:Carcinoma in Situ / Q000737:chemistry / Q000000981:diagnostic imaging; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging*; D000939:Epitopes / Q000032:analysis / Q000276:immunology; D005260:Female; D006801:Humans; D018796:Immunoconjugates; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D051379:Mice; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D010865:Pilot Projects; D016719:Radioimmunodetection; D019275:Radiopharmaceuticals; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon
D000910:Antibodies, Heterophile; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen; D000939:Epitopes; D018796:Immunoconjugates; D007074:Immunoglobulin G; D019275:Radiopharmaceuticals; D013667:Technetium
Ensayo piloto con el anticuerpo monoclonal ior-C5 como agente potencial de la inmunocentelleografía del cáncer colorrectal.