We’ve been working in oncology for a while and know that information on genomics and cancer can be hard to find. Here we answer some of the common questions we’ve heard and where we can, we point you to some useful resources.
This page is here to help oncologists who may want to know more about ordering genomic testing for cancer. Bookmark it to keep it handy.
Please note: This is general information and not intended to replace advice from a cancer genetics expert.
- How is genomics used in oncology?
- Is genomics useful for all types of cancer?
- When should I consider ordering a genomic test for my patient?
- What sample types do I need for genomic testing?
- How do I order a genomic test?
- What do I need to discuss with my patient when ordering a genomic test?
- Things to consider about genomic testing in oncology
- Where can I find support and resources?
How is genomics used in oncology?
Genomic testing can be very useful in diagnosing the exact type of cancer a patient might have. It can also be used to guide day-to day patient management in clinical settings.
Genomics can provide information about:
- the specific type of cancer and how it will affect the patient
- how the cancer and/or individual might respond to drugs
- which drugs may or may not work, and why
The UK’s Genomics Education Programme explores the use of genomics in oncology in detail.
Is genomics useful for all types of cancer?
Genomics can be more useful for certain tumour types. Sometimes, more research on specific tumour types is available. Other times, there are more targeted therapies accessible for certain types of cancer. Generally, the more common the cancer is, the more is known about its genome. This includes cancers of the bowel, lung, prostate and breast.
For cancers that are less common, broad genomic sequencing – like whole genome sequencing – can still provide useful information and help guide care based on what is known.
This table describes which cancer subtypes are currently recognised for Medicare funded genomic testing:
| Cancer subtype | Testing | MBS Item Number |
|---|---|---|
| Ovarian, fallopian, peritoneal | Homologous recombination deficiency (HRD) status; And BRCA1, BRCA2 status | Item 73307 |
| Non-Small Cell Lung Cancer | Variants in at least EGFR, BRAF, KRAS and MET exon 14 The fusion status of at least ALK, ROS1, RET, NTRK1, NTRK2 and NTRK3 | Item 73437 |
| Melanoma | BRAF V600E | Item 73336 |
| Colorectal Cancer | RAS | Item 73338 |
| Gastric/ Gastro-oesophageal junction | HER2 | Item 73342 |
| Breast Cancer | HER2 | Item 73332 |
| Ovarian Cancer | BRCA1/BRCA2 Germline | Item 73295 |
When should I consider ordering a genomic test for my patient?
It’s becoming increasingly useful to order a genomic test at the very start of a patient’s treatment plan. Having the most amount of information available can help, even within curative settings.
While you may not be able to use all the information immediately, genomic testing can help you think two steps ahead – a bit like playing chess. However, it’s never too late to order a genomic test. Even if it hasn’t been done up front, it can help guide further lines of treatment. The table below lists things you should consider when ordering a genomic test for your patient.
What sample types do I need for genomic testing?
Most of the time, genomic testing doesn’t require a separate sample to be biopsied. Genomic sequencing can be done on the surgical or biopsy sample a patient may already have on file.
The current gold standard of testing involves a tissue sample, while circulating tumour DNA (ctDNA) testing is often used as a complementary method. A ctDNA test relies on a simple blood sample. It’s used as an alternative when it is not feasible to get a new tissue sample from a patient due without undue risk or harm.
This information sheet explains ctDNA testing in a easy-to-understand way for patients.
How do I order a genomic test in Victoria?
The path for ordering a genomic test for cancer is not as straightforward as genomic testing for inherited conditions. Most cancer hospitals, centres and departments will have a pre-existing relationship with a preferred laboratory. Reaching out to your affiliated laboratory is the best place to get started.
It’s also important to make sure you’re ordering the right test for your patient, and for the answers you’re looking for. Speaking to your pathologist can help you make the right decision.
Each of the major public hospitals that provide cancer care are linked to pathology services and would be happy to be contacted for more information. The Peter MacCallum Cancer Centre has its own public pathology department, as well as a private laboratory. Both services offer clinical genomic testing for cancer.
You will also need informed consent from your patient or their guardian.
Read more:
eviQ in NSW has a guide for health professionals ordering genetic testing
What do I need to discuss with my patient when ordering a genomic test?
While genomic testing for cancer usually focuses on tumour DNA and not inherited DNA, there is the potential of finding a germline mutation. This can do more than give patients a point-in-time answer to a specific question: it can have implications for their blood relatives or future decisions about having children; and it can show unexpected family relationships. In addition, genomic data can be stored, reanalysed in the future, and shared with other laboratories.
For these reasons, it is vital that patients understand the meaning and implications of a genomic test, and provide documented consent before the test can be undertaken. If a germline mutation is found, the patient should be referred to a familial cancer centre, which can provide more information and support for the patient and their family.
It’s also important to make sure patients have reasonable expectations of the test. Because genomic sequencing is so complex, it takes a long time to return results. Walking patients through the genomic testing process can help alleviate concern. Patients should also know that depending on the quality of a sample, tests might fail and need to be redone. This is especially relevant when a patient is paying for the cost of the testing out of pocket.
It's important to note that while genomic testing may provide useful information, but it might not always. Make sure your patient has reasonable expectations of the types of answers genomics can provide.
Some useful resources on informed consenting for genomic testing:
Things to consider about genomic testing in oncology
| Question | Considerations |
|---|---|
| What’s the clinical goal? | Assessing clinically approved biomarker-informed treatment options Assessing all biomarker-informed treatment options Identifying all variants that could be contributing Investigating family cancer variants |
| What’s the clinical context? | The cancer type The timing of testing The stage of disease Performance status |
| What previous testing has been done? | What are the results and methods from any previous genomic and/or biomarker testing? Do these indicate additional testing will be beneficial? |
| What are the patient motivations? | Discuss benefits, limitations and expectations for testing with your patient Are they open to off-label therapies or clinical trials? |
| What about logistics and costs? | What tissue is available for testing? Is the quality good enough? Will there be out-of-pocket costs for the patient? |
Where can I find support and resources?
Jumping onto your local Molecular Tumour Board can be an incredibly useful starting point. It can be overwhelming at first, but these meetings are a great way to get familiar with genomics.
If you want to dip into formalised education, there are a number of genomics education opportunities available. The University of Melbourne offers a micro-credential on
Using Genomic Data for Personalised Care. The VCCC Alliance also offers a number of genomics-focused webinars, symposia and presentations.
If you’re after clinical resources, NSW Health has developed a number of cancer genetics-focused treatment protocols, available on eviQ. The Memorial Sloan Kettering Cancer Centre maintains a precision oncology knowledge base called OncoKB. The Garvan Institute of Medical Research maintains a similar, Australian-based knowledge base called Topograph.info.