Ovarian Neuroendocrine Tumours

Ovarian neuroendocrine tumours (NETs), also known as ovarian carcinoid tumours, are a very rare type of neuroendocrine tumour that develops 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.

Neuroendocrine cancers are a complex group of tumours that develop in the neuroendocrine system, which is responsible for regulating important bodily functions such as heart rate, blood pressure and metabolism. They most commonly develop in the gastro-intestinal tract, pancreas, and the lungs; however, they can develop anywhere in the body. These tumours develop from neuroendocrine cells, which are responsible for receiving signals from the nervous system and producing hormones and peptides (small proteins) in response.

Ovarian NETs are most common in post-menopausal women who are over 50 years old, however it can affect anyone with ovaries – including pre-menopausal women, teenagers, transgender men, non-binary individuals, and intersex people – at any age.

Treatment

If an ovarian NET is detected, it will be staged and graded based on size, metastasis, and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.

FIGO Staging System

Gynaecological cancers, such as ovarian NETs, can be staged using the Federation of Gynaecology 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.

TNM Staging System

The TNM system can also be used to classify an ovarian NET. The TNM system is comprised of:

  • T (tumour) indicates the size and depth of the tumour.
  • N (node) indicates whether the cancer has spread to nearby lymph nodes.
  • M (metastasis) indicates whether the cancer has spread to other parts of the body.

This system can also be used in combination with a numerical value, from stage 0-IV:

  • Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
  • Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
  • Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
  • Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
  • Stage IV: the cancer has spread to other tissues and organs in the body. 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. They will then discuss the most appropriate treatment option for you.

Treatment Options

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

Treatment options for ovarian NETs may include:

  • Surgery, potentially including:
    • Hysterectomy.
    • Bilateral salpingo-oophorectomy.
    • Unilateral salpingo-oophorectomy.
    • Anterior pelvic exenteration.
    • Posterior pelvic exenteration.
    • Total pelvic exenteration.
  • Somatostatin analogues (SSAs).
  • Chemotherapy.
  • Radiation therapy, potentially including brachytherapy.
  • Targeted therapy.
  • Clinical trials.
  • Palliative care.

 Ovarian Neuroendocrine Tumour Treatment and Fertility

Treatment for ovarian NETs 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

Because of how rare ovarian NETs are, there has been little research done into the risk factors of this disease.

Symptoms

Some patients with ovarian NETs will appear asymptomatic in the early stages of disease. As the tumour 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 intercourse.
  • Bleeding after intercourse.
  • Carcinoid syndrome (rare), which carries its own set of symptoms:
    • Facial flushing (usually red or purple in the face, neck, and/or upper chest).
    • Diarrhoea.
    • Wheezing.
    • Abdominal pain.
    • Carcinoid heart disease (plaques on the heart muscle caused by excess hormone production).
    • Faecal urgency.
    • Fatigue.
    • Skin changes, such as red or purple spots on the face, neck, and/or upper chest.
  • Paraneoplastic syndromes (rare).
  • Hypercalcaemia (rare).

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

Diagnosis

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

  • Physical examination.
  • Pelvic examination.
  • Imaging tests, potentially including:
    • Pelvic ultrasound.
    • Transvaginal ultrasound.
    • MRI (magnetic resonance imaging).
    • CT (computed tomography) scan.
    • PET (positron emission tomography) scan.
  • Blood tests.
  • Exploratory surgery, such as a diagnostic laparoscopy.
  • Biopsy.

References

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