Genes govern the way cells behave, the way they grow and how they respond to a treatment. A genomic test called the Oncotype DX test is used to evaluate the functions of genes dictating the cancer cells activity.
This Oncotype DX test can be employed in two ways. It can be used to assess the recurrence risk of estrogen-receptor-positive, early stage cancer in women. Also it may help assess after a breast cancer surgery the benefit of chemotherapy. This genomic test secondly can be put to use to evaluate the recurrence risk of DCIS and/or development of new invasive cancer. Post DCIS if the radiation therapy can be of much help can also be assessed from this test.
This test is very helpful in assessing the prognosis in various situations. Like on combination with other aspects of cancer, the results of the Oncotype DX testcan be used to make a fact based decision on the use of chemotherapy for treatment of early-stage hormone-receptor-positive breast cancer or radiation therapy to treat DCIS.
This test may be successfully done to give accurate results in women who have recently been diagnosed with stage I or II invasive breast cancer and in women having estrogen-receptor-positive cancer. Oncotype DX test gives good results also in cases where no cancer is detected in the lymph nodes (lymph node-negative breast cancer). This test contributes significantly in making informed decisions about chemotherapy.
There is a reduced recurrence risk for most of the early-stage (stage I or II), estrogen-receptor-positive breast cancers which are lymph node negative breast cancers. To reduce the recurrence risk once these have been surgically treated hormonal therapies such as an aromatase inhibitor or tamoxifen are prescribed. In such cases the application of chemotherapy is a doubtful risk and Oncotype DX test results can contribute in helping the doctor make an informed decision.
For women detected and diagnosed with DCIS or who are having lumpectomy for DCIS removal are also good candidates for the Oncotype DX test. In non – invasive breast cancer DCIS is the most common and is surgically treated with lumpectomy. Lumpectomy is usually followed by hormonal therapy for hormone receptor positive breast cancers. In some cases radiation therapy is also advised but there is an uncertainty in who would benefit from radiation therapy.
An Oncotype DX test helps the doctor in such cases to make an informed decision on the requirement of radiation therapy.
This test evaluates the functions of genes dictating the cancer cells activity. And how these genes are influencing the cancer to multiply and grow. A genomic test is not same as a genetic test. In a genetic test mutations are evaluated which may be inherited through generations.
This test analyses activities of 21 genes associated with cancer cell growth in a breast cancer tissue sample. A study of these genes can give the doctor information on the recurrence risk of the cancer. Also it help in prognosis of a early stage invasive breast cancer being treated by chemotherapy and prognosis of DCIS being treated by radiation therapy.
Thus this test has both the qualities of prognostic and a predictive test.
The result of this Oncotype DX test gives the tissue a “Recurrence Score”. This score ranges from a number between 0 and 100 for both early-stage breast cancer and/or DCIS. If the test results assign the tested tissue a Recurrence Score lower than 18, it means that the chances of the cancer coming back are quite low. In such a condition, the benefit of giving chemotherapy to early-stage breast cancer or radiation therapy for DCIS is not likely to be much, thus the risks of side effects is also not much. A recurrence Score between 18 and 31 would mean that there is an intermediate risk of the breast cancer (DCIS or early stage invasive breast cancer) recurrence. And there is an uncertainty in the benefits of chemotherapy for early-stage breast cancer or radiation therapy for DCIS and corresponding risks of side effects. Lastly, a recurrence Score greater than 31clearly implies that there is a high recurrence risk for the cancer or DCIS. Thus chemotherapy/radiation therapy will benefit the patient largely with the benefits outweighing the risks of side effects for early-stage breast cancer or radiation therapy for DCIS.