Increased serum CA-125 levels in patients with lung cancer post thoracotomy.

Cancer antigen (CA)-125 is a useful tumor marker for the follow up of ovarian and lung cancer. It is a sensitive, but not specific, tumor marker. Increased serum CA-125 levels have already been described in a number of benign and malignant diseases. We report two cases of increased serum CA-125 levels status post thoracotomy for resection of an early stage lung tumor that regressed spontaneously 3 and 8 months following surgery. Serum CA-125 levels may increase after thoracotomy, unrelated to tumor recurrence. Therefore, CA-125 levels obtained postoperatively should be interpreted with caution.