Ki67 is not a protein. It is the rate of growth. The lower the better. My oncologist told me cancer grows at an average rate of 20%, and he considers chemo at 50%.
It really doesn’t help with treatment options, it is more a prognostic factor. Some places don’t test for it because determine treatment.
I was diagnosed with TNBC, stage 1, ki-67 85% in 2018. Had chemo, surgery and radiation. Currently no evidence of cancer.

The Ki-67 test and the Oncotype Dx test are both used in breast cancer to help determine prognosis and guide treatment decisions, but they differ significantly in their approach and application. Ki-67 is a protein marker that indicates the rate of cell proliferation within a tumor, measured through immunohistochemistry on a tissue sample. It is a relatively simple and cost-effective test that can be performed in most pathology laboratories. A high Ki-67 level suggests a more aggressive tumor with a higher likelihood of recurrence. In contrast, the Oncotype Dx test is a complex, commercially available genomic assay that analyzes the expression of 21 specific genes within a tumor tissue sample. This analysis generates a recurrence score (RS) that predicts the risk of cancer recurrence and the potential benefit of adding chemotherapy to endocrine therapy. The Oncotype Dx test is more expensive and requires specialized processing, often being sent to a central laboratory in the United States. While Ki-67 provides a single biomarker value, the Oncotype Dx test offers a comprehensive assessment of tumor biology by integrating multiple genetic factors. The correlation between Ki-67 levels and Oncotype Dx recurrence scores has been studied, with some research indicating a positive correlation, suggesting Ki-67 could serve as a more accessible surrogate marker in resource-limited settings
1. However, the relationship is not perfect, and the two tests are not interchangeable due to differences in methodology and the complexity of tumor biology
2. The choice between them often depends on availability, cost, and the need for a more detailed prognostic assessment.

The first time I was diagnosed with breast cancer they did the oncotype test, but the second time they used the Ki-67 test. I asked them if they planned to also do the oncotype test for the second cancer but was told it wasn't needed since they had already done the Ki-67 test and it was my second time with breast cancer.

At UCLA they use the Ki-67 proliferation index test, not the Oncotype Dx test.

Welcome to our team!