Fallopian Tube Cancer
The fallopian tube is the least common site of origin in the female genital tract for cancer. The most common histologic type of cancer, accounting for 90 percent of all malignancies of the tube, is papillary serous adenocarcinoma, but even this type is rare, with only 300 cases reported annually in the United States. The pattern of spread is similar to that seen with celomic epithelial lesions of the ovary, with dissemination throughout the peritoneal cavity perhaps the most important route of spread; hence, it is often difficult to distinguish between ovarian and fallopian tube primary tumors. Criteria have been set for lesions designated to be of fallopian tube origin: the main tumor arises from the endosalpinx and is in the tube, the histologic pattern shows a papillary pattern, a transition zone between benign and malignant epithelium must be demonstrable if the wall is involved, and the ovaries and endometrium must be either normal or less involved than the tube.
As a reflection of the propensity of tubal cancer to spread by intraperitoneal dissemination, 5-year survival rates correlate well with the degree to which the primary lesion penetrates the wall of the tube: 91 percent for intramucosal lesions, 53 percent for those with mucosal wall invasion, and 25 percent or less for lesions that penetrate the tubal serosa. The actual staging system employed, however, is a modification of the FIGO staging system for ovarian cancer.
In contradistinction to ovarian cancer, fallopian tube cancers tend to present at an earlier stage of development, with roughly 33 percent as stage I, 33 percent as stage II, and 33 percent as more advanced disease. The mainstay of therapy for patients with limited disease is surgical resection. Whether postoperative radiation therapy is of value as an adjuvant treatment in patients whose tumors have been completely resected is unclear in the absence of a randomized trial. If radiation therapy does have a role, it would seem to be in patients who have no gross disease.
Studies of chemotherapy in fallopian tube carcinoma are anecdotal. Agents noted to produce responses are the same noted to be active in celomic epithelial carcinoma of the ovary. It would seem reasonable to base the choice of systemic therapy in advanced or recurrent disease on extrapolation from data in ovarian carcinoma.