Long-Term Survival Rates For Ovarian Germ Cell Tumours

Introduction

Definition of ovarian germ cell tumours:

Ovarian germ cell tumours (OGCT) are cancerous cells that form in the germ cells of the ovaries.1 This can also be referred to as a malignant tumour, which is defined as an abnormality in cell division that leads to cancer. These types of tumours can occur in assigned females at birth (AFAB). Typically, they occur in teenagers and young women but can affect older women too.1 The term ovarian germ cell tumours almost acts as an umbrella term for the different subtypes. These subtypes include dysgerminoma, mature teratoma, immature ovarian teratoma and endodermal sinus tumours.2 Common characteristics of OGCT include pelvic pain, swelling of the abdomen, vaginal bleeding, and changes in eating and bowel habits.²

Importance of understanding survival rates:

To start, what is a survival rate, and what does it mean? A survival rate is a percentage that indicates the number of people who survive different forms of cancer. Usually, this is represented as a five-year survival rate (%). However, some statistics provide further information. For example, the disease-free survival rate represents the percentage of people with no cancer after treatment. Also, the progression-free survival rate shows the number of people without recurrent cancer who are stable.⁵ Considering all these factors is crucial to understand your prognosis and devise a treatment plan accordingly.

Incidence and staging

Key Definitions:

Incidence - This is the measure of new cancers in the population each year. This is represented as new cases per 100,000 people.⁴ 

Staging - A system used to describe different cancers and their progression.⁵

Prevalence of ovarian germ cell tumours

• OGCT accounts for 2.6% of all ovarian cancers.⁶
• In England, 2.34/1,000,000 AFAB had OGCT, and there were approximately 75-110 new cases each year between 1979-2003.⁶
• The most common type of OGCT is ovarian dysgerminoma, accounting for 32.8-37.5% of all cases.⁶

Overview of the staging process

There are two commonly used scales. Most people are familiar with stages 0-4, where the higher the number, the more severe the cancer is.⁵ The other scale is the TNM staging system. This scale is used to provide more detail about the characteristics of the cancer in comparison to the other scales.⁵

Survival rates

Overall survival rates

Overall, OGCT has a high five-year survival rate. However, the specific numbers depend on how far the cancer has spread, as seen below.⁷

Localised (tumours that have not spread outside the ovaries) ~97%

Regional (tumours have spread to nearby areas) ~94%

Distant (tumours have spread to other parts of the body far away from the point of origin) ~71%

Combined average ~92%.⁷

Factors influencing survival

Although survival rates are a good start when looking into a diagnosis, survival is influenced by many things. These include:⁸

• Type of cancer
• Stage of cancer at diagnosis
• Early detection of cancer (the use of screening programmes)
• Family history and genetics
• Available treatment options
• Diet and nutrition
• Exercise and physical activity
• Weight
• Previous diagnosis
• Medical history

All of the above are factors linked to influencing survival. However, they do this in different ways. Factors directly associated with cancer have the biggest influence, but other factors, such as having a healthy diet and being active, are also suggested to improve the survival of some types of cancers.⁸

Data on long-term survival rates

Most data for survival rates is broken down into types of cancer. Below the table shows the survival rates in England for a range of cancers.⁹ Blue - Assigned male at birth (AMAB) only and Red - Assigned female at birth (AFAB) only.

For further information regarding more specific statistics for each cancer, visit Public Health England Cancer Survival.⁹

Treatment and outcomes

Treatment options

Although specific treatment plans will vary from person to person and will also depend on the stage of the cancer, many of the same methods will be used. Firstly, observations take place to assess and monitor cancer without treatment.¹ Following this, chemotherapy, radiation therapy, combinational therapies, and surgery may be suggested as well as a recommendation to take part in a clinical trial, as this is often the best option.¹ Taking part in a clinical trial can open doors to new treatment opportunities such as high-dose chemotherapy with a bone marrow transplant.¹ However, specifically for OGCT, surgery is the most common option with the best outcomes.¹⁰ For further information about OGCT surgery, visit the National Cancer Institute website.¹

Success rates

The success rate of treatment depends on what type of cancer and what stage of treatment started. However, below are some examples of the positive effects of chemotherapy for certain cancers to give you an idea of how effective chemotherapy can be. Chemotherapy is commonly used to treat breast cancer, and when diagnosed at stage one, survival is estimated to be nearly 100%. However, like other cancers, this survival rate decreases when diagnosed at a later stage, even when treated with chemotherapy.¹¹

Another treatment route, like surgery, is often suggested for colorectal cancers when treating stages one and two; then chemotherapy is introduced at stages three and four. The survival rate decreases from 64% at stage three to 12% at stage four.¹¹

Radiation therapy is another common treatment method and is used to treat most thyroid cancers. Specifically, a radioactive iodine treatment is used. This type of treatment is a form of internal radiotherapy.¹² This type of treatment is also highly successful and is recorded to have a nearly 100% survival rate when treating stages 1-3 and only decreases to 71% when treating stage four.¹¹

Role of surgery, chemotherapy, and radiation

The role of surgery, chemotherapy, and radiation is the same. Overall the aim is to kill cancer cells and prevent them from reoccurring and these treatments do that just in different ways.

Chemotherapy - This is a common treatment for cancer that uses different drugs to kill cancer cells. Can be given orally or intravenously.

Radiation - Radiation therapy can be internal or external. External radiation uses X-rays or protons outside the body to kill cancerous cells, whereas internal radiation is done inside the body. This is called brachytherapy. Another form of internal radiation uses treatment such as radioactive iodine to target cancer cells.

Surgery - Surgery is used to remove the cancerous cells.

Follow-up and recurrence

Importance of surveillance

Surveillance is important in monitoring many aspects of cancer prevalence. Surveillance can be used to monitor a patient's cancer without treatment, to monitor a patient's condition after treatment, and to gather information about a variety of cancers. One of the main purposes is to help identify any early signs of the cancer reoccurring, especially for those people at higher risk of developing cancer. This is important because the earlier cancer is detected, the higher the survival rate, and treatments will be more effective.

Signs of recurrence

Recurrence is when cancer returns after previous treatment. There is no specific timeframe in which cancer may return; it may even be months or years later when it develops again, so it is always best to look out for any possible signs of recurrence.¹³ Although recurrence can happen with most types of cancer, some are more common. People who previously had ovarian cancer, metastatic melanoma, and types of non-Hodgkin lymphoma are more likely to develop recurring cancer.¹³ 

Below is a list of common symptoms associated with recurrent cancer. It is important to note that these are not definite signs of recurring cancer. However, if you notice any of these symptoms and you have a history of cancer, it is best to seek further advice from a doctor or healthcare provider.¹³

• Appearance of lumps
• Unexplained weight loss
• Fever
• Blood in feces
• Unusual bleeding 
• Pain
• Nausea and vomiting
• Difficulty swallowing
• Bruising

It is also important to look out for any similar symptoms that you experienced during any previous cancers, as this can be a good personal indicator and may help you diagnose the cancer earlier.¹³

Managing and treating recurrence

The best way to manage recurrence is to identify it as early as possible, as this gives the best chances of treatment being effective and survival rates increase. Once recurrent cancer is diagnosed, a healthcare professional will be able to put a treatment plan in place. Usually, this involves repeating your previous first-line treatment, performing surgery to remove new tumours, or trying a new treatment. A new treatment could mean a new combinational therapy that wasn't used previously, or there may be a new treatment that is available to you that was developed after your previous diagnosis. For example, new immunotherapies.¹³ 

Also, other important factors influence the direction of a treatment plan for recurrent cancer. Two of the most important are how soon the cancer returned and where the cancer is relative to the previous cancer’s location. Typically, if cancer returns quite soon after the first, it is more difficult to treat. Also, if it is distant from the previous cancer, it is more difficult to treat compared to a local cancer.¹³ Dealing with recurrent cancer can be challenging, but there are options like considering palliative care available, and they will be able to provide any additional support you may need during this time.¹³

Summary

Ovarian germ cell tumours predominantly affect AFAB teenagers but can also affect older women. OGCT is a form of ovarian cancer but only accounts for 2.6% of all cases. Furthermore, there are different types of OGCT, the most common of which is dysgerminoma, which accounts for 32.8-37.5%. The classification of OGCT is done through staging. Stages 0-4 represent the severity of the cases, where four is the most severe. The TNM staging system is also used to provide more information about the cancer's location and type. OGCT has a very high combined average survival rate of 92%. Although this number is very high, there are lots of affecting factors that can increase and decrease this rate. This includes the stage at diagnosis, family history, and lifestyle habits. The most common treatment for OGCT is surgery. However, other theories, such as observation, chemotherapy, and radiation theory, may also be used. These approaches are often very effective and have a high success rate. Although these treatments are often successful, ovarian cancer is known to be a reoccurring cancer. Therefore, it is important to look out for any signs of cancer returning and seek advice from a professional as soon as possible. Treating recurrent cancer is difficult, but catching it early is the best way to increase the likelihood of success.