I would order an Oncotype DX assay for both of these 40-year-old patients. Because I believe that the Oncotype results give me additional information on hormone-driven breast cancer and allow me to have a more informed discussion with the patient, I order the test for all of my patients.

I would order the Oncotype DX assay for the 40-year-old patient with a 0.8-cm tumor or a 3.0-cm tumor. For the smaller T1b tumor, I feel less strongly about having to order the test and I would factor in the patient’s preferences. The patient with the 3.0-cm, node-negative tumor is not that different from the patients studied in the NSABP-B-20 trial, and I’m comfortable ordering the Oncotype DX assay in this setting.

I would order the Oncotype DX assay for both of these patients.

For the 40-year-old with a 0.8-cm tumor, I would definitely order the Oncotype DX assay. For the 40-year-old with a 3-cm tumor, I have to admit it would be a more difficult decision for me. I would probably order the test, but I would have a discussion with the patient.

For the 40-year-old with a 0.8-cm tumor, I probably would not order the Oncotype DX assay unless it was a high-grade tumor. Conversely, unless it were a low-grade tumor, I would not order the Oncotype DX assay for the patient with the 3-cm tumor. For most of these patients I would go ahead and administer chemotherapy.

I probably would not order the Oncotype DX assay for the patient with the 0.8-cm node-negative tumor, but I would absolutely order it for the patient with the 3.0-cm tumor.

We have few credible data about the prognoses of patients with subcentimeter tumors, and this is likely due to the fact that these patients were excluded from the majority of trials. There certainly is a point where a small tumor size results in such a low risk of distant disease, irrespective of the aggressiveness of the biology, and I wouldn’t be recommending any more aggressive therapy. For me it is certainly less than 0.5 centimeters. Between 0.5 and 1.0 centimeters is honestly a bit of a gray area for me, so I would be walking into that 40-year-old’s room with the plan to recommend hormone therapy alone and not be recommending Oncotype.

The decision whether to order the Oncotype DX assay or not in both of these scenarios for me would depend on the tumor biology. I would want to know the biology because 8 millimeters of cancer is 800 million cells. That’s a lot of cells that can metastasize if they have bad biology. Because I’d be happy to administer chemotherapy if it appeared as if she had highly proliferative breast cancer, I wouldn’t order the Recurrence Score if the biology didn’t look favorable.

For the patient with the 0.8-cm tumor, the decision would be dependent on grade in terms of ordering the Oncotype DX assay. If this were a low-grade tumor, I would not order Oncotype. If it were a high-grade tumor, I would definitely consider Oncotype, because sometimes these scores are high. For a patient who has a 3-cm node-negative tumor, I would generally order an Oncotype DX assay.

The factors that influence whether I order an Oncotype DX assay are size of tumor, age of patient, grade of tumor and the interest of the patient in considering chemotherapy as part of the treatment when the potential benefits, based on the Recurrence Score, are understood.