Ovarian Cancer

Epidemiology and Etiology

Ovarian cancer is the leading cause of gynecologic mortality in the US, with an estimated 21,750 new cases and 13,940 deaths estimated in 2020.¹ Common risk factors include older age, early menarche, late menopause, nulliparity, infertility, endometriosis, and genetic factors including BRCA1/2 mutations and Lynch syndrome.

Pathology

The most common ovarian tumors are epithelial, GCTs, and sex cord-stromal tumors. Epithelial tumors represent 65%-70% of cases and are subdivided into serous (70%), mucinous, endometrioid, clear cell, and transitional.

Clinical Presentation

Patients with early-stage disease have nonspecific symptoms including bloating or pelvic and abdominal discomfort. In patients with more advanced disease, the symptoms often reflect the intra-abdominal spreading of the disease causing ascites, abdominal pain, and constipation.

Diagnostic Testing

Women suspected to have ovarian cancer should undergo additional evaluation including a physical examination, serum CA 125, and transvaginal ultrasound. The diagnosis is usually made through surgical resection with the exploratory laparotomy providing diagnostic, staging, and potentially therapeutic results.

Staging

The TNM and FIGO staging systems are both used in ovarian cancer. In general, FIGO stage I is similar to T1 disease, with tumor confined to the ovaries or fallopian tubes. FIGO stage II is similar to T2 disease, with tumor extending below the pelvic brim or the presence of primary peritoneal disease. FIGO stage III is similar to T3 and/or N positive disease, defined by the presence of peritoneal metastasis outside the pelvis and/or metastasis to the retroperitoneal lymph nodes. FIGO stage IV is similar to Ml disease, with metastasis beyond the peritoneal cavity and/or the retroperitoneal lymph nodes.

TREATMENT

• Since epithelial ovarian cancers disseminate predominantly through the abdominal cavity, cytoreductive surgery (also known as debulking) is the optimal initial therapy. Optimal debulking is defined by the presence of no residual tumor nodules gt;1 cm, although an R0 resection should be the therapeutic goal.

• Adjuvant therapy is defined by the surgical stage and histology. Patients with stage IA or IB disease (tumor limited to the ovaries and fallopian tubes) are usually treated with surgery alone, whereas those with stage II disease and select patients with stage IC disease (surgical spill or mal i gnant ascites) are treated with adj uvant chemotherapy (usually carboplatin plus paclitaxel). Patients with stage III or IV disease are treated with chemotherapy.

• The most commonly used systemic chemotherapy is carboplatin plus paclitaxel with or without bevacizumab. Patients with tumor relapse gt;6 months after the first-line therapy are considered platinum-sensitive and may benefit from repeating the original chemotherapy regimen. Several other chemotherapeutic agents may be considered for previously treated patients, as well as pembrolizumab in patients with MSI-high disease, PARP inhibitors, or hormonal therapy.²⁸