Oncotype DX and Mammaprint tests are becoming recognized and popular for helping make breast cancer treatment decisions, but what about tests for other cancers? Similar genomic tests are now available for prostate and colon cancer. Let’s break out these well-kept secrets and see what they can do – and get them used!
Oncotype DX for prostate cancer
Oncotype DX for prostate cancer can be used to predict the aggressiveness of prostate cancer. The test does this by measuring the activity of multiple key genes and biological pathways.
The test helps you make treatment decisions by assessing whether your cancer is low risk and likely to be contained within the prostate or whether it is high risk and more likely to grow and spread. The test is performed using a tissue sample that is saved from your biopsy, so no further surgery/biopsy is necessary (the hospital automatically saves these samples.) Armed with the Oncotype test results, you and your doctor can choose the most appropriate treatment option for you. If you are low risk, you might not need further treatment and can just be carefully monitored, using what is called “active surveillance”. I like to use this active surveillance time as an opportunity to add some lifestyle changes – thus moving you from active surveillance to empowered “proactive surveillance.” If the Oncotype test results indicate the cancer is high risk, you might need further surgery, or radiation, or other treatment.
Eligibility for the Oncotype DX prostate test is:
- PSA score less than 20
- Tumor stage T1 or T2
- Gleason score of 6 or less, or a score of 7 (3+4) with fewer than four positive cores
- Biopsy sample within the last six months
Knowing your Oncotype score is important when making treatment decisions because, with the exception of (pro)active surveillance, prostate cancer treatment options can cause serious and long-term urinary, bowel, and sexual issues. If it’s appropriate to do so, choosing (pro)active surveillance allows for close monitoring of the status of your disease and avoids unnecessary treatments and their side effects.
As with all decisions, take the time to choose what is right for you. There is rarely any huge rush to make a decision. Discuss test results with your doctor and family, and take them into consideration when deciding what feels right to you – but make your decision based on your beliefs and wishes and feelings – not only the test results.
The Oncotype DX prostate test is available in the US and might be covered by insurance. The test is also available in the UK via the NHS or through private insurance.
Oncotype DX & Coloprint for colon cancer
Oncotype DX colon cancer and Coloprint (from the same company as Mammaprint for breast cancer) offer genomic tests for early stage colon cancer. The tests are performed on a tumor sample taken during surgery. The tests look at the likelihood of recurrence and thus can evaluate whether chemotherapy is warranted or not.
Here is a simplified comparison of the two tests:
Interpretation of test results is more involved than just the simplified version in the table above and depends on many factors, including T scores for stage 2 colon cancer. The Oncotype DX test also looks at MMR, which is a DNA mismatch repair (MMR) system within the cell for correcting errors in DNA. Knowing the MMR status of your tumor – either MMR-D (deficient) or MMR-P (proficient) – is also helpful in planning treatment since both stage II/2, and III/3 colon cancer patients with MMR-D have a lower risk of recurrence than tumors with MMR-P.
These tests are important because surgery alone typically cures up to 80% of stage 2 colon cancer patients, so there is no need for chemo and its accompanying side effects in those patients. These tests help to identify whether you will benefit from chemo or whether it isn’t needed. Today, approximately 30-50% of stage 2 patients receive chemo – many of whom gain no benefit. Rather than enduring chemo and the side effects it brings, these tests could help people make an informed decision not to have chemo treatment and start making lifestyle changes to boost their odds of remaining cancer free.
Additionally, with stage 3 colon cancer, the standard chemo regimen after surgery sometimes includes oxaliplatin in addition to other chemo drugs. However, oxaliplatin benefits only a small percentage of patients and is associated with significant side effects such as nerve damage. The oncoscore from the Oncotype Dx Colon test helps determine if oxaliplatin is worth the risk.
At a time when you might well have fear, anxiety, and indecision, these tests can add a level of reassurance to your decision making. They don’t make the decision easy – but they can make it easier and better informed, so they are worth considering and discussing with your oncologist.
Again, these tests might be covered by your insurance in the US (check the websites below for more information) and are available in the UK via the NHS or through private insurance.
Neither of these tests are as well known as the tests for breast cancer, so you might need to send one or more of the following links to your oncologist so that they can evaluate the tests for themselves before you discuss the topic with them. And of course, you can read through both the “patient” and the “oncologist” information too, so you are well informed and can see the validation studies that have been performed.
I’d love to hear from you if you have used any of these tests, and how they helped. Please tell us in the comments section.