Chapter 093. Gynecologic Malignancies (Part 2)

Screening In contrast to patients who present with advanced disease, patients with early ovarian cancers (stages I and II) are commonly curable with conventional therapy. Thus, effective screening procedures would improve the cure rate in this disease. Although pelvic examination and CA-125 can occasionally detect early disease, these are relatively insensitive screening procedures. Transvaginal sonography is often used, but significant false-positive results are noted, particularly in premenopausal women. Doppler flow imaging coupled withtransvaginal ultrasound may improve accuracy and reduce the high rate of false positives. ...
Nội dung trích xuất từ tài liệu:
Chapter 093. Gynecologic Malignancies (Part 2) Chapter 093. Gynecologic Malignancies (Part 2) Screening In contrast to patients who present with advanced disease, patients withearly ovarian cancers (stages I and II) are commonly curable with conventionaltherapy. Thus, effective screening procedures would improve the cure rate in thisdisease. Although pelvic examination and CA-125 can occasionally detect earlydisease, these are relatively insensitive screening procedures. Transvaginalsonography is often used, but significant false-positive results are noted,particularly in premenopausal women. Doppler flow imaging coupled withtransvaginal ultrasound may improve accuracy and reduce the high rate of falsepositives. CA-125 has significant limitations as a screening test. Half of women withstages I and II ovarian cancer have normal CA-125 levels. Attempts have beenmade to improve the sensitivity and specificity by combinations of procedures,commonly transvaginal ultrasound and CA-125. In a screening study of 22,000women, 42 had a positive screen and 11 had ovarian cancer (seven with advanceddisease). In addition, eight women with a negative screen developed ovariancancer. Thus, the false-positive rate would lead to a large number of unnecessary(i.e., negative) laparotomies if each positive screen resulted in a surgicalexploration. In the United Kingdom, a large collaborative screening trial isunderway to prospectively compare various screening techniques with controls.Until the results of such trials are available, the National Institutes of HealthConsensus Conference recommended against screening for ovarian cancer amongthe general population without known risk factors for the disease. Although noevidence shows that screening saves lives, many physicians use annual pelvicexaminations, transvaginal ultrasound, and CA-125 to screen women with a familyhistory of ovarian cancer, Lynch type II, or breast/ovarian cancer syndrome. Proteomic technologies have been used to identify patterns of proteinsassociated with early disease. Preliminary studies identified all 50 stage I patientswith a sensitivity of 100%, a specificity of 95%, and a positive predictive value of94%. However, difficulty in consistency of replicate samples, variability of resultsfrom different spectroscopy equipment, and the tendency of the artificialintelligence algorithms to overfit the data have limited its utility. Most proteinsidentified to date have been acute phase reactants, and extensive fractionation isnecessary to identify unique cancer-specific proteins. Pathology Common epithelial tumors comprise most (85%) of the ovarian neoplasms.These may be benign (50%), malignant (33%), or tumors of low malignantpotential (16%) (i.e., tumors of borderline malignancy). Epithelial tumors of lowmalignant potential have the cytologic features of malignancy but do not invadethe ovarian stroma. More than 75% of borderline malignancies present in earlystage and generally occur in the fourth or fifth decade of life. They usually have10-year survival of 80–90%. There are five major subtypes of common epithelial tumors: serous (50%);mucinous (25%), endometrioid (15%); clear cell (5%); and Brenner tumors (1%),the latter derived from the urothelium. Benign common epithelial tumors arealmost always serous or mucinous and develop in women ages 20–60. They arefrequently large (20–30 cm), bilateral, and cystic. Malignant epithelial tumors areusually seen in women over 40. Although most ovarian tumors are epithelial, two other ovarian tumortypes, stromal and germ cell tumors, are distinct in their cell of origin, havedifferent clinical presentations and natural histories, and require differentmanagement (see below). Metastasis to the ovary can occur from breast, colon, gastric, and pancreaticcancers. The Krukenberg tumor was classically described as bilateral ovarianmasses from metastatic mucin-secreting gastrointestinal cancers. Staging and Prognostic Factors Laparotomy is the primary procedure used to establish the diagnosis andprovide accurate staging. Less-invasive studies may help define the extent ofspread, including chest x-rays, abdominal CT or MRI scans, and abdominal andpelvic sonography. Symptoms of bladder or renal dysfunction are evaluated bycystoscopy or intravenous pyelography. A careful staging laparotomy with a total abdominal hysterectomy andbilateral salpingo-oophorectomy will establish the stage and extent of disease andallow for the cytoreduction of tumor masses in patients with advanced disease.Proper laparotomy requires a vertical incision of sufficient length to ensureadequate examination of the abdominal contents. The presence, am ...