The present invention provides antibodies, and antigen-binding fragments of antibodies, fusion polypeptides and analogs that preferentially bind cell-associated CA 125/O772P polypeptides relative to shed CA 125/O772P polypeptides. The present invention further provides methods of preventing, managing, treating or ameliorating one or more symptoms associated with a CA 125/O772P-related disorder. In particular, the present invention provides methods of preventing, managing, treating, or ameliorating one or more symptoms associated with a cell proliferative disorder, such as cancer, e.g., ovarian cancer. The present invention still further provides methods for diagnosing a CA 125/O772P-related disorder or predisposition to developing such a disorder, as well as methods for identifying antibodies, and antigen-binding fragments of antibodies, that preferentially bind cell-associated CA 125/O772P polypeptides relative to shed CA 125/O772P polypeptides.