Ovarian Cancer – Causes, Symptoms and Treatment

What Is Ovarian Cancer?

Ovarian cancer is a malignant (cancerous) tumor that develops in the ovaries. It is the most lethal gynecological cancer in high-income countries. Because the disease rarely causes noticeable symptoms in its early stages, it is frequently not detected until it has already spread beyond the ovaries.

Ovarian cancer is classified by tissue origin. The most common form is epithelial ovarian cancer, which arises from the cells lining the outer surface of the ovary and accounts for approximately 90% of all cases. Less frequent types include germ cell tumors and sex cord-stromal tumors.

Causes and Risk Factors

The exact causes of ovarian cancer are not fully understood. Recognized risk factors include:

• Genetic mutations: Mutations in the BRCA1 and BRCA2 genes significantly increase the risk. Women carrying these mutations face a lifetime risk of 40–60% for ovarian cancer.
• Family history: Having a first-degree relative with ovarian or breast cancer raises personal risk.
• Age: Risk increases with age, particularly after menopause.
• Hormonal factors: Early onset of menstruation, late menopause, and never having been pregnant are associated with higher risk.
• Hormone replacement therapy: Long-term use may slightly increase risk.
• Obesity and certain dietary patterns are also considered contributing factors.

Symptoms

In its early stages, ovarian cancer often causes no clear symptoms. Possible signs that may indicate the disease include:

• Persistent abdominal pain or pelvic pressure
• Bloating or a noticeably enlarged abdomen (due to fluid accumulation, called ascites)
• Feeling full quickly or experiencing digestive problems
• Frequent urination
• Unexplained weight loss or gain
• Irregular menstrual bleeding

Because these symptoms are nonspecific and can occur with many other conditions, persistent complaints should always be evaluated by a gynecologist.

Diagnosis

Ovarian cancer is diagnosed using a combination of methods:

• Pelvic examination: Manual assessment of the ovaries and surrounding structures.
• Transvaginal ultrasound: Imaging to evaluate the size, shape, and internal structure of the ovaries.
• Blood test for tumor markers: Measurement of CA-125 levels in the blood. Elevated values may suggest ovarian cancer but are not specific to it.
• CT scan or MRI: Used to assess tumor extent and detect possible metastases.
• Histological confirmation: A definitive diagnosis requires tissue sampling (biopsy) and microscopic examination, usually performed during surgery.

Staging of Ovarian Cancer

Ovarian cancer is staged according to the FIGO classification (International Federation of Gynecology and Obstetrics):

• Stage I: Tumor confined to the ovaries.
• Stage II: Spread within the pelvis.
• Stage III: Spread to the abdominal cavity and/or regional lymph nodes.
• Stage IV: Distant metastases, for example to the liver or lungs.

Treatment

Treatment depends on the stage of the disease, the general health of the patient, and the histological type of the tumor. Standard treatment typically involves:

Surgery

Surgical removal of the tumor (cytoreductive surgery) is usually the first step. The goal is to remove as much tumor tissue as possible. This typically involves removal of the uterus, ovaries, fallopian tubes, and the greater omentum.

Chemotherapy

Surgery is usually followed by platinum-based chemotherapy, most commonly a combination of carboplatin and paclitaxel. This combination is considered the standard of care and is typically administered over six cycles.

Targeted Therapies

For certain patients, especially those with BRCA mutations, PARP inhibitors (e.g., olaparib) are used. These targeted drugs inhibit DNA repair mechanisms in tumor cells and can reduce the risk of recurrence.

Antiangiogenic Therapy

Bevacizumab, an antibody targeting the growth factor VEGF, can be combined with chemotherapy to inhibit the blood supply to the tumor.

Prognosis

The prognosis of ovarian cancer is strongly influenced by the stage at diagnosis. When detected at an early stage (FIGO I), five-year survival rates exceed 90%. However, since most cases are diagnosed at an advanced stage (FIGO III or IV), the overall five-year survival rate is approximately 40–50%. Regular gynecological check-ups therefore play an important role in early detection.

Prevention and Genetic Counseling

There is currently no established general screening program for ovarian cancer. Women with an elevated familial risk or a confirmed BRCA mutation are strongly advised to seek genetic counseling. In some cases, prophylactic removal of the ovaries and fallopian tubes (prophylactic salpingo-oophorectomy) may be considered as a preventive measure.

References

1. Leitlinienprogramm Onkologie (German Cancer Society): S3 Guideline for the Diagnosis, Therapy and Follow-up of Malignant Ovarian Tumors, Version 5.1, 2023. AWMF Registration No. 032/035OL.
2. World Health Organization (WHO): Classification of Tumours of Female Reproductive Organs. IARC Press, Lyon, 2020.
3. Ledermann J et al.: Newly diagnosed and relapsed epithelial ovarian carcinoma: ESMO Clinical Practice Guidelines. Annals of Oncology, 2013; 24 (Suppl 6): vi24-vi32.