PRIMARY CYSTIC CARCINOMA
Ovarian cancer represents the second most common malignancy of the genital tract (after endometrial cancer), but is the most common fatal gynecologic cancer. The lifetime risk of developing ovarian cancer is approximately 1 in 70. Papillary serous cystadenocarcinomas make up a high proportion of most reported series of ovarian carcinomas. Roughly half of all ovarian cystic cancers occur after menopause, with an average age of 59 years, and the highest rate between 60 and 64 years. Despite this, only one-quarter to one-third of ovarian tumors in postmenopausal women are malig- nant. A family pattern is recognized in a small percentage of cases. There is an association with abnormalities of the breast cancer (BRCA1 and BRCA2) gene. Hereditary ovarian cancers are rare but usually fatal; 95% of ovarian cancers are sporadic. More than 95% of patients with ovarian cancer have no risk factor. Oral contraception, high parity, tubal ligation, hysterectomy, and breast-feeding reduce risk.
Serum testing for tumor markers, such as CA-125, lipid-associated sialic
acid, carcinoembryonic antigen, α-fetoprotein,
lactate dehydrogenase, and others should be reserved for following the progress
of patients with known malignancies and not for prognostic evaluation.
Ultrasonography, magnetic resonance imaging (MRI), and computed tomography (CT)
are helpful in evaluating patients suspected of having ovarian cancer. (The
normal postmenopausal ovary is typically 1.5 to 2 cm in size.) Asymptomatic
simple cysts of less than 5 cm diameter can generally be followed
conservatively. (Routine screening using transvaginal ultrasonography has not
been shown to be cost effective without the presence of significant risk factors
or symptoms.)
Symptoms may be vague or absent until the malignancy is well advanced.
Lower abdominal pain and progressive enlargement of the abdomen occur in the
majority of instances. Loss of weight, debilitation, anemia, anorexia, early
satiety, dyspepsia, nausea, and vomiting may be present. Local pressure or
infiltration may give rise to urinary frequency and urgency, rectal pain, and
backache. Ascites is found in about one-third of the cases. At the time of
examination, the majority of ovarian carcinomas are relatively large (15 cm),
and bilateral ovarian involvement may be expected in more than one-half of
cases. Most are diagnosed at stage III or IV. Metastatic extension may be
evident in local peritoneal implantations, omental involvement, lumbar,
abdominal and pelvic lymphadenopathy, and distant metastases to liver, lungs,
and bones. Lymphatic spread occurs in roughly 20% of tumors that appear grossly
confined to the ovary.
Ovarian cancer is a disease that requires surgical exploration and
extirpation (generally including the uterus and contralateral ovary).
Adjunctive chemotherapy (platinum-based and paclitaxel [Taxol]) or radiation
therapy is often included based on the location and stage of the disease.
As yet, there are no effective screening tools for the early detection of
primary ovarian cancer. Ultrasonog- raphy, MRI, CT, and biochemical markers
such as CA-125, which are useful for evaluating a suspicious mass or following
the progress of treatment, are not of value for mass screening. In those
suspected of having recurrent disease and other selected patients, second- look
surgery may be desirable to assess progress and discover occult disease. (When
second-look surgery is negative, the associated 5-year survival is
approximately 50%.) For those few patients at truly high risk (familial cancer
syndromes), prophylactic oophorectomy after childbearing is completed is
preferable to any attempt at prolonged surveillance with current technology.
Even this aggressive step does not preclude the development of “ovarian”
cancer; up to 10% of ovarian cancers are found in women who have had bilateral
oophorectomies.
If discovered early in the process and treated with aggressive surgical resection and adjunctive therapy, disease-free survival is possible. Survival is affected by stage, grade, cell type, and residual tumor after surgical resection. Survival (5-year) by stage: stage I, 80%; stage II, 60%; stage III, 25%; and stage IV, 15%. Serous adenocarcinoma has the poorest prognosis of the epithelial types.
