Dear OncoLink "Ask the Experts,"
Both my father and paternal grandmother have had "malignant neoplasm in the appendix." I have been told that "neoplasm" rarely starts at the appendix. Is this truly a rare cancer?
Li Liu, MD, OncoLink editorial assistant, responds:
Thank you for your interest and question.
Tumors of the appendix are very rare, and represent less than 0.5% of all gastrointestinal malignancies. They usually present as an unexpected finding following an incidental appendectomy, or after an appendectomy for the clinical diagnosis of appendicitis. Hence, patients with appendiceal malignancies frequently require a second procedure for complete treatment.
There are three distinct histological types of appendiceal tumors: carcinoid, mucinous adenoarcinoma, and colonic-type adenocarcinoma. Surgical resection is the treatment of choice for the majority of patients with localized disease. More aggressive treatments, including extensive surgery, radiation therapy, and/or chemotherapy are indicated for a selected group of patients with more extensive disease (Ann Surg Oncol 1999 Dec;6(8):715-6).
One oddity of appendiceal tumors is that a second malignancy occurs commonly in these patients (15-35%). More than 50% of the second malignancies are in the gastrointestinal tract, usually the colon and rectum (Surgery 1993 May;113(5):594).