CA9 and metastatic malignant neoplasm in the lymph nodes: In a further study by the Gynecological Oncology Group, the expression of CA-IX was immunohistochemically analyzed in tumor biopsies obtained from 166 women who had undergone a radical hysterectomy for stage Ia2-IIa cervical cancer that had presented with pathological findings of lymph node metastases, parametrial involvement or positive surgical margins.