Ovarian Cancer

Ovarian cancer is the second most commonly diagnosed gynecologic malignancy, the deadliest gynecologic malignancy, and the fourth leading cause of cancer-related deaths in women in the USA. About 1 in 70 women eventually develops ovarian cancer, and 1 in 100 women dies of it. Ovarian cancer affects predominantly perimenopausal and postmenopausal women.

Etiology and Pathology

Incidence is higher in industrialized countries in which dietary fat intake is high. A history of nulliparity, infertility, late childbearing, and delayed menopause increases risk. Use of oral contraceptives significantly decreases risk.
A personal or family history of endometrial, breast, or colon cancer increases risk. Probably < 5% of ovarian cancer cases are related to an inherited autosomal dominant gene, the BRCA gene. Females with XY gonadal dysgenesis are predisposed to ovarian malignant germ cell tumors.

Ovarian tumors are the most histologically diverse group of tumors. At least 80% of malignant ovarian tumors arise from the coelomic epithelium. The most common type is serious cystadenocarcinoma, which accounts for 75% of cases of epithelial ovarian cancer. Others include mucinous, endometroid, transitional cell, Brenner, clear cell, and unclassified carcinomas. The remaining 20% of malignant ovarian tumors are germ cell and sex cord-stromal cell tumors, which are nonepithelial in origin, and metastatic carcinomas to the ovary (most commonly, breast and GI carcinomas). Germ cell tumors, which arise from the primary germ cells of the ovary, occur in young women and are uncommon in women > 30 yr. Malignant germ cell tumors include dysgerminomas, immature teratomas, endodermal sinus tumors, embryonal carcinomas, choriocarcinoma, and polyembryomas. Stromal malignancies include granulosa-theca cell tumors and Sertoli-Leydig cell tumors.

Ovarian cancer spreads by direct extension, by intraperitoneal implantation via exfoliation of cells into the peritoneal cavity, by lymphatic dissemination in the pelvis and para-aortic region, and, less commonly, hematogenously to the liver or lungs.

Symptoms, Signs, and Diagnosis

Most women (75%) present with advanced-stage disease, and most have vague, nonspecific symptoms, such as dyspepsia, bloating, early-satiety anorexia, gas pains, and backache. The most common early finding is an adnexal mass, which is often solid, irregular, and fixed. A patient may be asymptomatic until an abdominal mass is discovered during routine pelvic examination or until the disease is advanced. Occasionally, a patient presents with severe abdominal pain secondary to torsion of the ovarian mass. Late in the course, pelvic pain, anemia, cachexia, and abdominal swelling due to ovarian enlargement or accumulation of ascitic fluid usually occur. Nodular implants noted on the rectovaginal examination suggest extensive pelvic malignant disease.