Cure Our Ovarian Cancer NZ is Aotearoa’s Ovarian Cancer Charity. We are committed to improving the outcomes for people affected by ovarian cancer.

This page gives information about malignant ovarian germ cell tumours (MOGCT). It describes what MOGCT is, how it is diagnosed and gives information about the treatments. It is designed to supplement our more comprehensive ovarian cancer information.

Ovarian germ cell cancers

Germ cells are embryonic cells that develop into sperm in males and eggs in females. Tumours that arise from germ cells may be benign (non-cancerous) or malignant (cancer). Most types of germ cell tumours are not cancerous.

Germ cell tumours that are cancerous are referred to as Malignant Ovarian Germ Cell Tumours (MOGCT).

Approximately 1.5% to 5% of all ovarian cancers are MOGCT. They are more common in younger age. MOGCT accounts for 70% of ovarian cancer diagnosed in people between the ages of 10 and 30 years old.

MOGCT grow very rapidly. Despite this early diagnosis is common because the tumour can grow very large before it spreads. Some types also secrete hormones which can cause additional symptoms. Most people are diagnosed at stage 1A (when the tumour is contained within one ovary).

Even when the cancer has spread, in contrast to many types of ovarian cancer, MOGCT treatment is often curative.

Types of germ cell tumours

The different types of ovarian germ cell tumours are called subtypes. Subtypes of ovarian germ cell tumours are (commonest to rarest): teratoma, dysgerminoma, yolk sac tumour, mixed germ cell tumour, embryonal carcinoma, non-gestational choriocarcinoma and polyembryoma. The last three are very rare.

What are the symptoms of germ cell tumours?

The vast majority people visit their doctor with abdominal pain and an abdominal mass.

Pain can be due to the size and/or rupture and/or torsion (twisting) of the mass, and/or ascites (fluid) in the abdomen.

Tumours which secrete human chorionic gonadotropin (HCG) may cause early puberty or atypical vaginal bleeding and can cause a false positive pregnancy test result.

Other symptoms such as: eating less and feeling fuller, needing to pee more often or urgently, a change in bowel habits, painful intercourse, indigestion, unexplained weight change and fatigue are also possible.

How are malignant germ cell ovarian tumours diagnosed?

If a doctor suspects ovarian cancer is a possibility they may order a CA-125 blood test and an ultrasound. Less commonly other imaging such as a computerised topography (CT) or magnetic resonance imaging (MRI) scan may be used. CA-125 is not a specific marker for MOGCT, so it may be normal. CA-125 is not typically used in children and adolescents.

Additional blood tests may be ordered because many germ cell tumours can produce abnormal levels of other proteins (tumour markers) that can be measured in the bloodstream.

The below table illustrates the tumour markers which can be raised with each germ cell tumour.

Lists tumour markers for dysgerminomas, yolk sack tumours, embryonal carcinomas, polyembryoma, non-gestational choriocarcinoma, immature teratoma, Mixed OGCT, gonadoblastoma

* mature teratoma (dermoid cysts are non-cancerous but in rare cases (1%) portions of the tumour can develop into cancer
† gonadoblastomas are a non-invasive tumour with malignant potential (i.e. sometimes develop into cancer)

[LDH = lactate dehydrogenase; HCG = human chorionic gonadoptropin; AFP = alpha fetoprotein; estrogens (i.e. estradiol, E2); A = androgens]

(Reference: Society of Gynecologic Oncology – Malignant Germ Cell Tumours – What Should You Know)

Like all ovarian cancers, a conclusive diagnosis can only be made by histology. This is when a specialised doctor called a pathologist examines tumour cells under a microscope. The cells can be taken from a biopsy, or more commonly from tissue obtained when the ovary is removed by surgery.

How are malignant ovarian germ cell tumours treated?


The goal of surgery is to confirm the diagnosis, determine the spread (staging); and help treat the cancer by removing all visible cancer growth. Fertility preserving surgery (where one, rather than both ovaries, are removed) may be possible.

The extent of surgery will be individualized to the type of tumour, extend of disease and age of the patient. Generally speaking adults will have more extensive surgery than children.

Surgery usually occurs before chemotherapy, but if the cancer is extremely advanced (stage III-IV), doctors may consider starting chemotherapy prior to surgery. This is called neoadjuvant treatment. This can help preserve fertility and reduce the complexity of surgery.


Ovarian germ cell cancers are highly sensitive to platinum-based chemotherapy, and treatment is often curative.

Chemotherapy is routinely offered to most people as the outcome is better than with surgery alone (except stage IA, grade 1 immature teratoma, and stage IA and IB dysgerminoma where the outcome is excellent with just surgery). For children, chemotherapy may be recommended less frequently for certain stages and subtypes, but this remains controversial.

The most commonly prescribed chemotherapy is bleomycin, etoposide and cisplatin (BEP). It is also used in testicular cancer. Sometimes carboplatin is used instead of cisplatin in younger people. This is being evaluated in AGCT1531. Usually 3-4 cycles are prescribed.

Special considerations:

Breastfeeding is not recommended during chemotherapy and pregnancy must be avoided during and for up to two years after treatment. Sexually active people should ask their doctor or nurse about effective contraception before starting treatment.


Tumours with microsatellite instability and a high mutational burden may also respond to immunotherapy such as pembrolizumab. This is not funded in New Zealand.


In extremely rare circumstances radiotherapy may be considered for a patient with dysgerminoma who cannot have chemotherapy. Other MOGCT are not sensitive to radiotherapy.

Monitoring and side effects while on treatment

During treatment frequent blood tests and imaging will take place. In addition side effects will be closely monitored. Side effects from treatment vary person to person. It is important to discuss any side effects you are experiencing with your cancer care team.

Special considerations

Lung problems can develop after BEP chemotherapy with high doses of oxygen (such as during a general anaesthetic, oxygen therapy and scuba diving). Some people choose to wear a medical alert. If you need surgery in the future – tell the doctor you have had bleomycin. If you want to go scuba diving, you’ll need additional tests after a year to check whether it is safe for you.

For further information on side effects visit:

Macmillan – BEP
Cancer Research UK – BEP 

Follow-up after chemotherapy

Recurrence is uncommon. Most recurrences happen within two years (75% in first year). Because of this, people will be monitored very closely for the first two years with a combination of specialist visits, blood tests (for tumour markers) and imaging (Chest x-ray and ultrasound, or CT or MRI or PET).

Effect of treatment on fertility

When fertility sparing surgery is used, most people will regain their periods and fertility within a year of completing chemotherapy. Three percent of people experience premature menopause.

If someone experiences menopause from surgery or chemotherapy and wants to have children, other pathways may be possible. These include egg donation, surrogacy and adoption. In New Zealand government funding may be available for fertility treatment if IVF or an egg donor and/or surrogate is needed due to cancer related infertility.

Survival rates:

Survival rates correlated with the stage (spread) at diagnosis, and levels of tumour markers hCG and AFP.

Five-year survival rates for ovarian germ cell cancers are:

  •  Stage 1A – 1C 100%
  •  Stage II 85%
  •  Stage III 79%
  •  Stage IV 71%

Approximately 5 in 6 people with MOGCT will experience cure.

Navigating a new normal

Side effects from treatment and the mental challenge of cancer and its effects can impact life during and after treatment. The end of treatment, doesn’t mean that life is back to normal.

Everyone’s coping mechanism is different. It is really helpful to have a supportive team around you at home – and to keep a check on your physical and emotional care needs. Be open with your GP and cancer care team about any struggles you may be having.

Online support groups (such as Facebook) can also be useful to learn what has helped others with Germ Cell cancer. Many people find a psychologist helpful for processing and mental resilience. Mindfulness and yoga can also be helpful for mental health.

What if the cancer comes back?

Even if MOGCT recurs, treatment can sometimes be curative. Treatment for recurrence usually consists of further surgery and/or chemotherapy.

Clinical Trials

A clinical trial is a type of research involving human participants. Clinical trials can offer new or different treatment options for people with ovarian cancer, and help doctors make better decisions for people in the future. Medications in a clinical trial are provided at no cost. There may be unknown benefits and unique risks to participating in a clinical trial. An oncologist or gynae-oncologist can advise if there are any clinical trials which people may be eligible for.

There are, as of January 2022, two clinical trials specifically for malignant ovarian germ cell tumours currently recruiting in New Zealand.

The first is an international study called Active Surveillance, Bleomycin, Carboplatin, Etoposide, or Cisplatin in Treating Pediatric and Adult Patients With Germ Cell Tumours (NCT03067181/AGCT1531). It is a Phase III clinical trial comparing outcomes with different dosing regimens and combinations of chemotherapy; and surveillance (in specific low-risk patients); in newly diagnosed Germ Cell Tumours. It is available in Auckland and Christchurch.

The second is an international trial called A Randomised Phase 3 Trial of Accelerated Versus Standard BEP Chemotherapy for Patients With Intermediate and Poor-risk Metastatic Germ Cell Tumours (ANZUP P3BEP). It is investigating outcomes with different dosing regimens. This study is for people 11 years to 45 years with newly diagnosed germ cell tumours that are considered intermediate or poor risk. Prior chemotherapy is accepted in limited circumstances. It is available in Auckland, Palmerston North, Christchurch and Dunedin.

Further information:

Stories of New Zealanders with Germ Cell Ovarian Cancer

Content has been reviewed by NZ gynaecological, medical and paediatric oncologists. Information is provided for general use and not a substitute for professional medical advice.

Published November 18th 2022