In another prospective data collection effort by the largest health maintenance organization in Israel, we found similar outcomes in that the Recurrence Score result correlated with the risk of distant recurrence at 5 years.4 This study found that 98% of patients with low Recurrence Score results under 18 avoided chemotherapy, yet less than 1% of these patients had any distant recurrence after 5 years.

Even patients with Recurrence Score results up to 25 did very well with hormone therapy alone. The rate of distant recurrence was 1.4% at 5 years in the group of patients with a Recurrence Score result between 11 and 25 who avoided chemotherapy. Over 80% of all patients tested in both the United States and Israel registries had Recurrence Score results up to 25, and most of these patients avoided chemotherapy and had excellent outcomes. 

Continue Reading

In addition to these prognostic outcomes from real world studies, our validation evidence for predicting chemotherapy benefit, which includes the NSABP B20 study for node-negative patients and the SWOG 8814 study for node-positive patients, indicate that patients with low Recurrence Score derive no benefit from chemotherapy.5,6

These were  compelling studies because they gave physicians and patients over the years more confidence that not only did patients with low Recurrence Scores have low risks, chemotherapy simply did not offer these patients any further benefits. 

Let’s take the other extreme. If a patient’s Recurrence Score is 31 or higher they are at higher risk of recurrence according to every validation study we have performed. In addition, the NSABP B20 study would tell us that these patients have a very large benefit from chemotherapy when compared with receiving hormone therapy alone. The margin of benefit is a reduction of risk by 75%.

It’s good to know that of all patients who have been tested, fewer than 10% of patients have a high Recurrence Score result of 31 or greater. Our registry data indicates that sometimes these high Recurrence Score results can be found in patients who might otherwise present with what appear to be average clinical risks based on their pathology reports. It’s important to identify these patients to treat appropriately with chemotherapy. 

Regarding Recurrence Score results between 26 and 30, you might call this an intermediate-high risk group. In the TAILORx trial, which we are all awaiting the complete results of, all such patients were assigned to receive chemotherapy.( Identifier: NCT00310180). It is true that these patients are at a higher level of risk than the lower intermediate-risk patients, and there’s more uncertainty as to their chemotherapy benefit. I think it’s safe to say that most of these patients today will receive chemotherapy. The SEER and the Israeli registry data suggest that about 55% to 60% of these patients received chemotherapy.

As you can see, the Recurrence Score result is a continuum; the higher the score, the higher the risk, and the higher of likelihood of chemotherapy benefit. So you really get 2 different endpoints, 2 different pieces of information from a Recurrence Score test.