Low Onco Score but Node Positive - Chemo?

I have no idea but sure do understand your confusion. It doesn't seem to make sense at all. Many prayers that you will find the answers you need to move forward

Hi DZF60:

Do you have a copy of your node-positive (N1-3) Oncotype report? You should insist on receiving a copy for your review and records.

Regarding whether to add chemotherapy in any particular case, I think this is a question that requires the expertise of a medical oncologist familiar with the details of the specific case. A second opinion may also be very helpful.

A medical oncologist should be able to explain the meaning of your Recurrence Score ("RS") to you, and provide a recommendation in light of all relevant clinicopathologic features and the RS result. They should also be able to provide a clear explanation of the study results (and any associated caveats) featured in your report, and how they are viewed in clinical practice today (in light of any additional available evidence re the test that is applicable to your situation).

In node-NEGATIVE (N0) patients, the clinical data shown in the Oncotype report that compares outcomes in those receiving endocrine therapy alone (Tam) versus endocrine therapy plus chemotherapy (Tam + Chemo) are as you would expect: the Tam + Chemo curve is lower across all scores, and the curves converge as Recurrence Score approaches zero.

The data in the node-positive (1-3N+) report is from a different clinical validation study (the SWOG 8814 study) that was performed in node-positive patients (using different clinical endpoints, as explained in the notes above the graph), and the curves actually cross each other just above the cut-point between Low and Intermediate risk groups.

Node-Positive (1-3 N+) Sample Report for Recurrence Score of 6:

Keep in mind that the 5-year risk shown in the node-positive report is an average (with Confidence Intervals ("CI")) and is based on the results of a validation study that compared outcomes from a group of patients who received Tam with a group of patients who received Tam + Chemo.

In this Sample Node-Positive (1-3 N+) Report, with a Recurrence Score of 6, for Tam Alone, the average "5-Yr Risk of Recurrence or Mortality after 5 Year of Tam" measured was 8% (95% CI: 4% - 15%) and with Tam + Chemo the average risk was 11% (95% CI: 7% - 17%), oddly higher, but note that the Confidence Intervals ("CI") overlap. Check your printed report for the averages and confidence intervals associated with your Recurrence Score.

In light of the large and overlapping confidence intervals, what does this mean about the average recurrence risks and what is the clinical significance, if any, to those with "Low risk" scores who receive a recommendation for chemotherapy? What have other subsequent studies shown about Recurrence Risk in patients like me?

You need a trained medical oncologist to advise you regarding such questions to be sure you receive accurate information from a person with appropriate training, familiarity with the test, and all relevant studies available that may affect understanding of its import.

To the extent that it may help you frame your follow-up questions, I provided my layperson thoughts about the cross-over and some information from the study publication in another thread:

https://community.breastcancer.org/forum/105/topics/812929?page=35#post_4784284

Please note that I am a layperson with no medical training. I never received an Oncotype test, and I never received related medical advice. There may be errors in fact or understanding in this and the linked post.

All information should be confirmed with an expert professional medical oncologist to ensure receipt of accurate, current, case-specific expert professional advice.

BarredOwl

Hi DZF60:

I would add that the reliability of this type of test depends on the scope of "clinical validation" and the type of patients included in the studies that show prognostic ability, as well as the quality of the studies and strength of the data. In turn, the scope of validation is generally reflected in "eligibility" requirements for the test and in what clinical consensus guidelines say about in whom it should be used.

The commercial provider of the test lists the eligibility requirements here, as up to 3 positive nodes:

Formal Eligibility: http://breast-cancer.oncotypedx.com/en-US/Professional-Invasive/OncotypeDXBreastCancerAssay/PatientEligibility

In some patients with lymph node involvement, radiation is used instead of further axillary dissection. That approach appears to have benefit in terms of reduced morbidity, such as reducing the risk of lymphedema. However, when this approach is used, the actual number of positive nodes is not known. Accordingly, "eligibility" for the test is not clear.

Moreover, if the actual number of positive nodes was 4 or more, then the associated recurrence risk with Tam alone (or with added chemotherapy) would be higher than shown in your Node-positive (1-3 N+ report). They have looked at that. See for example, Figure 6A-6B of Albain (2010):

https://www.researchgate.net/publication/40683006_Prognostic_and_predictive_value_of_the_21-gene_recurrence_score_assay_in_postmenopausal_women_with_node-positive_oestrogen-receptor-positive_breast_cancer_on_chemotherapy_A_retrospective_analysis_of_a

With 4 or more positive nodes, the NCCN guidelines (Version 2.2016) do not include use of the test, and instead recommend added chemotherapy.

As usual, please confirm all information above with your treatment team.

BarredOwl

DZF- Did you have a PET scan? When my case went to the tumor board, that was what they recommended. Another imperfect test, I know........ No new nodes or anything else showed up for me.