Ovarian Cancer (Stromal)

Ovarian cancer is a type of carcinoma that causes one or more tumours to develop in the ovaries. The ovaries are a pair of small, walnut shaped organs that are responsible for the release of eggs (ovum) during the female reproductive cycle. In general, ovarian cancers are broadly classified into one of three categories depending on the type of cells they develop from – epithelial, germ-cell or stromal-cell.

Stromal-cell ovarian cancer is a rare subtype of this disease that originate in stromal cells. In the ovaries, these cells are connective tissue cells that also produce the female sex hormones oestrogen (has various roles in the body, including maintaining puberty and strengthening bones) and progesterone (regulates menstruation and supports pregnancy).

Stromal-cell ovarian cancers are generally diagnosed in women between the ages of 40-60, however, it can affect almost anyone with ovaries – including women, teenagers, transgender men, non-binary individuals, and intersex people – at any age.

Types of Stromal Ovarian Cancers

There are two primary types of stromal ovarian tumours, which are categorised by the hormones that are produced.

Granulosa Cell Tumours

Granulosa cell tumours (GCTs) are the most common subtype of stromal ovarian tumours. They are rare carcinomas (cancer arising from cells in tissues that line organs), and they are known to produce the female hormone, oestrogen. For more information on GCTs, please refer to the Granulosa Tumours of the Ovary page in our knowledgebase.

Sertoli-Leydig Cell Tumours

Sertoli-Leydig cell tumours are rare ovarian cancer that produces male hormones, such as testosterone. These tumours originate in Sertoli and Leydig cells, which act as support cells. While these cells are generally found in male reproductive organs, they can also be found in the ovaries. People with this type of tumour may develop secondary male characteristics, such as facial hair growth or a deepened voice, which is known as a process called masculinisation or virilisation. Sertoli-Leydig cell tumours are usually slow-growing, and generally have a good prognosis.

Treatment

If an ovarian cancer is detected, it will be staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.

Ovarian cancers can be staged using the Federation of Gynecology and Obstetrics (FIGO) system from stage I to IV.

  • Stage I: cancer cells are confined to one or both ovaries only. This stage is also known as early-stage cancer.
  • Stage II: cancer cells have grown deeper into nearby organs in the pelvis, such as the uterus, fallopian tubes, bladder and/or bowel. This is also known as localised cancer.
  • Stage III: the cancer has become larger and has spread beyond the pelvis into the lining of the abdomen (peritoneum). Lymph nodes are also often affected. This is also known as advanced or metastatic cancer.
  • Stage IV: the cancer has spread to more distant organs, such as the lungs or the liver. This is also known as advanced or metastatic cancer.

Cancers can also be graded based on the rate of growth and how likely they are to spread:

  • Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
  • Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
  • Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.

Once your tumour has been staged and graded, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. In particular, they may look for mutations in the hereditary breast cancer genes (BRCA1 and BRCA2), which can cause an increased risk in developing ovarian cancer. They will then discuss the most appropriate treatment option for you.

Treatment is dependent on several factors, including fertility, type, stage of disease and overall health.

Treatment options for the stromal sub-type may include:

  • Surgery, potentially including:
    • Hysterectomy.
    • Bilateral salpingo-oophorectomy.
    • Unilateral salpingo-oophorectomy.
    • Lymphadenectomy.
    • Removal of other organs (only required in some cases where the cancer has spread beyond the pelvis).
  • Chemotherapy.
  • Targeted therapy.
  • Clinical trials.
  • Palliative care.

For more information on the treatment options, please refer to the Rare Cancers Australia Treatment Options page.

Ovarian Cancer Treatment and Fertility

Treatment for ovarian cancer may make it difficult to become pregnant. If fertility is important to you, discuss your options with your doctor and a fertility specialist prior to the commencement of treatment.

Risk factors

While the cause of ovarian cancer remains unknown, the following factors may increase your risk of developing the disease:

  • Having a family history of ovarian, breast, uterine and/or bowel cancer.
  • A mutation in the BRCA1, BRCA2 and/or DICER1 genes.
  • Having Lynch syndrome.
  • Having certain medical conditions such as endometriosis.
  • Use of hormone replacement therapy (HRT).
  • Having a history of tobacco smoking.
  • Being obese.
  • Reproductive history, including:
    • Women who have never had children.
    • Women who have had assisted reproduction.
    • Women who have had children over the age of 35.
  • Having early puberty.
  • Having late menopause.
  • Having Ashkenazi Jewish ancestry.

Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.

Symptoms

Early-stage stromal ovarian cancers may be asymptomatic. As the cancer progresses, some of the following symptoms may appear:

  • Abdominal bloating/swelling.
  • Abdominal/pelvic pain and/or pressure.
  • Changes in appetite, such as feeling full quickly or not feeling hungry.
  • Urinary changes, such as changes in frequency and urgency.
  • Changes in bowel habits, such as constipation and diarrhoea.
  • Unexplained weight loss or weight gain.
  • Unexplained fatigue.
  • Indigestion and/or heartburn.
  • Changes in menstrual periods, such as irregular periods, unusual vaginal bleeding, or vaginal bleeding post menopause.
  • Pain during sex.
  • Development of male secondary sex characteristics, such as:
    • Deeper voice.
    • Enlarged clitoris.
    • Facial hair growth.
    • Loss in breast size.
    • Loss of menstrual periods.

Not everyone with the symptoms above will have cancer, but see your GP if you are concerned.

Diagnosis/diagnosing

If your doctor suspects you have ovarian cancer, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment:

  • Pelvic examination.
  • Imaging tests, potentially including:
    • Pelvic ultrasound.
    • Transvaginal ultrasound.
    • CT (computed tomography) scan.
    • PET (positron emission tomography) scan.
  • Blood tests.
  • Biopsy.

References

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