Overview
Epithelial ovarian cancer (EOC) is the most common type of ovarian cancer, arising from the cells that line the outer surface of the ovary. These cells are known as the *epithelium*. EOC accounts for about 90 % of all ovarian malignancies and is the fifth leading cause of cancer‑related death among women in the United States, despite representing only ~3 % of all female cancers.
Who it affects: The disease typically occurs in post‑menopausal women, with a median age at diagnosis of 63 years. However, up to 20 % of cases are diagnosed before age 50. Women with a family history of ovarian or breast cancer, especially those carrying a BRCA1 or BRCA2 mutation, are at markedly higher risk.
Prevalence: According to the CDC and American Cancer Society, an estimated 19,710 new cases of ovarian cancer will be diagnosed in the United States in 2024, and about 13,270 women are expected to die from the disease. Worldwide, the International Agency for Research on Cancer (IARC) reports approximately 313,000 new cases each year, making it the 8th most common cancer in women globally.
Symptoms
Early-stage EOC often produces vague or no symptoms, which contributes to delayed diagnosis. When symptoms do appear, they may be intermittent and easily mistaken for benign conditions. Below is a comprehensive list of potential signs, along with brief explanations:
- Abdominal bloating or swelling – fluid (ascites) or tumor growth can cause a visible distension.
- Persistent pelvic or lower‑abdominal pain – pain may be dull, cramp‑like, or sharp.
- Early satiety or feeling full quickly – pressure on the stomach reduces appetite.
- Unexplained weight loss – often due to metabolic changes and reduced intake.
- Changes in bowel habits – constipation, diarrhea, or a sensation of incomplete evacuation.
- Frequent urination or urgency – tumor pressing on the bladder.
- Back pain – especially if the tumor involves the pelvis or lower spine.
- Menstrual changes – irregular bleeding or spotting, more common in pre‑menopausal women.
- Fatigue – can stem from anemia, ascites, or the body’s response to cancer.
- General abdominal discomfort after meals – a feeling of heaviness or pressure.
Because these symptoms overlap with many benign conditions (e.g., irritable bowel syndrome, urinary infections), any persistent, unexplained change lasting more than a few weeks should prompt medical evaluation.
Causes and Risk Factors
While the exact cause of epithelial ovarian cancer remains unknown, research points to a combination of genetic, hormonal, and environmental factors.
Genetic factors
- BRCA1/BRCA2 mutations – women with these mutations have a 20‑40 % lifetime risk of ovarian cancer, compared with ~1.3 % in the general population.1
- Lynch syndrome (hereditary non‑polyposis colorectal cancer) – increases risk 5‑12‑fold.
- Family history of ovarian or breast cancer – first‑degree relatives with these cancers raise risk.
Reproductive and hormonal factors
- Nulliparity or late first pregnancy – prolonged ovulation without interruption appears to increase risk.
- Infertility treatments – some studies suggest assisted reproductive technologies may elevate risk, though data are mixed.
- Hormone replacement therapy (HRT) – especially combined estrogen‑progestin regimens used for >5 years.
Other risk contributors
- Age – risk rises sharply after menopause.
- Obesity – excess adipose tissue can raise estrogen levels.
- Endometriosis – certain subtypes (clear‑cell, endometrioid) are linked to longstanding endometriosis.
- Personal history of breast cancer – especially in BRCA mutation carriers.
There are no proven protective lifestyle factors that completely eliminate risk, but some behaviors may lower it (see the Prevention section).
Diagnosis
Because early symptoms are nonspecific, a high index of suspicion is crucial. Diagnosis typically follows a stepwise approach:
Clinical evaluation
- Detailed medical and family history.
- Physical exam focusing on pelvic and abdominal masses.
Imaging studies
- Transvaginal ultrasound (TVUS) – first‑line imaging; can identify solid versus cystic masses and assess blood flow with Doppler.
- Computed tomography (CT) scan – evaluates disease spread (stage) to lymph nodes, liver, and lungs.
- Magnetic resonance imaging (MRI) – useful for indeterminate lesions.
- PET‑CT – may be used in recurrent disease to locate metastases.
Laboratory tests
- CA‑125 – a tumor marker elevated in many ovarian cancers; useful for monitoring response but not specific enough for screening.
- HE4 – another marker that can improve diagnostic accuracy when combined with CA‑125 (Risk of Ovarian Malignancy Algorithm – ROMA).
Definitive tissue diagnosis
- Laparoscopy or laparotomy with biopsy – surgical removal of the mass provides histopathology, which classifies the tumor (serous, mucinous, endometrioid, clear cell, or transitional).
- Pathology – includes immunohistochemistry and, increasingly, molecular profiling (e.g., BRCA status, homologous recombination deficiency).
Staging
The FIGO (International Federation of Gynecology and Obstetrics) system stages disease from I (confined to ovaries) to IV (distant metastasis). Accurate staging guides treatment planning.
Treatment Options
Treatment is personalized based on stage, histology, patient’s overall health, and genetic findings.
Surgery
- Primary cytoreductive (debulking) surgery – aims to remove as much visible tumor as possible. In early-stage disease, this may be a unilateral salpingo‑oophorectomy (removal of one ovary and fallopian tube) or total hysterectomy with bilateral salpingo‑oophorectomy.
- Interval debulking – after several cycles of chemotherapy, surgery may be repeated to eliminate residual disease.
- Risk‑reducing salpingo‑oophorectomy (RRSO) – prophylactic removal of both ovaries and fallopian tubes in high‑risk women (e.g., BRCA carriers) usually performed between ages 35‑40.
Chemotherapy
- First‑line regimen – a platinum‑based drug (carboplatin) combined with a taxane (paclitaxel) given every 3 weeks for 6 cycles. This backbone is standard for most advanced cases.
- Intraperitoneal (IP) chemotherapy – delivers drugs directly into the abdominal cavity; improves survival in selected patients but carries higher toxicity.
- Maintenance therapy –
- PARP inhibitors (olaparib, niraparib, rucaparib) for tumors with BRCA mutations or homologous recombination deficiency.
- Bevacizumab (anti‑VEGF) added to chemotherapy and continued as maintenance in high‑risk disease.
Targeted & Immunotherapy
- PARP inhibitors – effective in both newly diagnosed and recurrent settings for patients with relevant genetic alterations.
- Anti‑angiogenic agents – bevacizumab reduces tumor blood supply.
- Immune checkpoint inhibitors – pembrolizumab is approved for microsatellite‑instability‑high (MSI‑H) or deficient mismatch repair (dMMR) ovarian tumors.
Radiation therapy
Rarely used as primary treatment but may be employed for palliation of painful bone metastases or localized recurrence.
Lifestyle and supportive care
- Nutrition counseling to maintain weight and protein intake.
- Physical activity as tolerated – improves fatigue and quality of life.
- Psychosocial support, counseling, and patient‑support groups.
- Fertility counseling for younger women desiring future pregnancy.
Living with Epithelial Ovarian Cancer
Managing life after diagnosis involves medical follow‑up and day‑to‑day self‑care.
Follow‑up schedule
- Every 3 months for the first 2 years, then every 6 months until year 5, and annually thereafter (per NCCN guidelines).
- Each visit typically includes physical exam, CA‑125 (if previously elevated), and imaging as indicated.
Managing side effects
- Hair loss – use gentle shampoos, consider wigs or scarves.
- Nausea – anti‑emetics (ondansetron, aprepitant) before chemo.
- Peripheral neuropathy – dose adjustments, vitamin B12, and physical therapy.
- Fatigue – prioritize sleep, short naps, and moderate exercise.
- Emotional health – counseling, mindfulness, and peer support groups (e.g., Ovarian Cancer Research Alliance).
Practical daily tips
- Keep a medication and symptom diary to share with your oncology team.
- Stay hydrated; aim for at least 8 glasses of water daily unless fluid restriction is advised.
- Eat small, frequent meals rich in protein (lean meat, legumes, dairy) to counteract early satiety.
- Plan for transportation to treatment days—ask friends, use hospital shuttles, or community ride services.
- Consider a medical alert bracelet indicating “History of ovarian cancer, on PARP inhibitor” for emergency situations.
Prevention
Although EOC cannot be completely prevented, several evidence‑based strategies can lower risk:
- Genetic counseling and testing for women with a strong family history; carriers of BRCA or Lynch mutations should discuss risk‑reducing surgery.
- Oral contraceptive use – long‑term (≥5 years) use reduces ovarian cancer risk by up to 50 % (Mayo Clinic).
- Pregnancy and breastfeeding – each full-term pregnancy and extended lactation appear protective.
- Maintain a healthy weight – BMI < 25 kg/m² is associated with lower risk.
- Avoid tobacco – smoking may increase risk for certain histologic subtypes.
- Consider tubal ligation – studies suggest a ~30 % risk reduction, possibly due to blockage of malignant cells ascending from the uterus.
Complications
If not detected early or inadequately treated, epithelial ovarian cancer can lead to serious complications:
- Ascites – fluid accumulation causing abdominal distension, discomfort, and respiratory compromise.
- Bowel obstruction – tumor encroachment causing nausea, vomiting, and inability to pass stool or gas.
- Venous thromboembolism (VTE) – ovarian cancer carries a high clotting risk; DVT or pulmonary embolism can be life‑threatening.
- Malnutrition – due to early satiety, nausea, and increased metabolic demand.
- Metastatic spread – commonly to the peritoneum, liver, lungs, and brain.
- Psychological distress – anxiety, depression, and fear of recurrence are common and may affect adherence to treatment.
When to Seek Emergency Care
Call 911 or go to the nearest emergency department immediately if you experience any of the following:
- Sudden, severe abdominal or pelvic pain that does not improve with rest.
- Rapidly increasing abdominal swelling or a feeling of pressure in the chest.
- New onset shortness of breath, especially if accompanied by chest pain.
- High fever (≥38.5 °C/101.3 °F) with chills, which may signal infection of ascitic fluid.
- Vomiting persistent for more than 24 hours, especially if you cannot keep fluids down.
- Signs of a blood clot – sudden leg swelling, pain, redness, or shortness of breath.
- Unexplained fainting or severe dizziness.
These symptoms may indicate complications such as bowel perforation, massive ascites, pulmonary embolism, or severe infection, all of which require immediate medical attention.
References
- American Cancer Society. Key Statistics for Ovarian Cancer. 2024. Link.
- Cleveland Clinic. Ovarian Cancer – Symptoms, Diagnosis, Treatment. Updated 2023. Link.
- National Comprehensive Cancer Network (NCCN). Guidelines for Ovarian Cancer, Version 2.2024.
- Mayo Clinic. Ovarian Cancer Risk Reduction. 2023. Link.
- World Health Organization. Global Cancer Observatory – Ovarian Cancer Fact Sheet. 2022.
- National Institutes of Health. PARP Inhibitors in Ovarian Cancer. 2023.
- Centers for Disease Control and Prevention. Ovarian Cancer Statistics. 2024. Link.