Characterisation and clinical usefulness of CA130 antigen recognised by monoclonal antibodies, 130-22 and 145-9, in ovarian cancers.

A new cancer-associated antigen CA130, recognised by two monoclonal antibodies (moABs) 130-22 and 145-9, was often found to be present at high levels in the sera of patients with ovarian cancer. There was a strong correlation between CA130 and CA125 values. The epitopes recognised by moABs 130-22 and 145-9 were proved to differ from the CA125 epitope, but to exist on the molecule bearing CA125. Unlike OC125, the majority of 130-22/145-9 activity was associated with a much lower molecular mass (less than 200 kDa), indicating that a lower molecular mass immunoreactive determination may be a unique CA130 antigenic determinant within CA125 molecule. Clinical data demonstrate that, (1) elevated levels of CA130 determinant were found in the sera of 91.3% of women with epithelial ovarian cancer, (2) falling or rising levels of CA130 correlated with regression or progression of ovarian cancer in > 95% of cases, (3) normalisation of serum CA130 levels at response does not imply no microscopic residual disease, but CA130 changes during follow-up support the evaluation of recurrence and can be used as a monitoring marker in an individual patient.