Do you still recommend SBRT for oligometastatic and oligoprogressive breast cancer after the abstracts of the BR002 and CURB, respectively?

"Absence of evidence is not evidence of absence."

The negative trials have put a damper on enthusiasm for these patients. This is interesting in light of past training and thinking where breast cancer patients with solitary or few metastases were thought to be emblematic of those that we could potentially cure. The data from the studies is the data we have, at least prospectively. The board answer has to be "no treat, unless symptomatic, and then treat for palliation".

My evolving approach is s...

For patients with asymptomatic oligoprogressive/oligometastatic breast cancer and without any high-risk lesions that can potentially cause significant morbidities in the future, I do not routinely treat them with SBRT now given the negative findings of CURB and NRG BR002 (although I cannot emphasize enough that these are two completely different trials with different patient populations). I would highly consider treating them on institutional protocols/trials if they exist. For patients who are ...

As with many cases, treatment should be individualized and multidisciplinary. If the medical oncologist is about to start systemic therapy or switch to the next line therapy, then I would not offer SBRT and would monitor for response on systemic therapy. Exceptions are for palliative RT for bone mets in good PS patients where we have level 1 evidence that SBRT in single fx (Nguyen et al., PMID 31021390) or 2fxs (for spine, Sahgal et al., PMID 34126044) is superior. Another recent exception is bo...

Metastatic breast cancer patients are such a diverse population overall and not all clinical scenarios may have been captured in the BR002 and CURB trial. While acknowledging that metastatic breast cancer is a systemic disease, I think there is still a role of SBRT in select cases and a number of retrospective institutional experiences do show good outcomes. For example, we do see on occasion, a patient with a single denovo metastatic deposit on a vertebral body, after discussion in Tumor board,...

It is always a challenge when the question is asked as broadly as this one in the absence of clear prospective clinical trial data. Our answers are often best tempered with nuance. In doing so, we might seem "wishy washy" but it truly reflects the dynamic state of our knowledge and practice. Dr. @Dr. First Last correctly noted above that "absence of evidence is not evidence of absence" and he is correct. All you have to do is look at any of the oligometastatic trials including our own [Phase II ...

BR002 results definitely cause me to hesitate. On the other hand, I have encountered quite a few breast cancer patients who developed 1-2 metastases (usually bone) and were treated with SBRT and are now >5 years NED. Maybe a deeper dive into patterns of failure in BR002 will allow us to understand who to treat or not to treat in this setting.

I am a community physician. I would first like to see an analysis of the CURB and BR002 trial for signals. I would also like to see a retrospective review with the following considerations

1. Stratify patients based on the recent proposal for De-novo metastatic breast cancer (Plichta et al., PMID 36944149) and the OLIGO-BC1 database for metachronous disease. (Imoto et al., PMID 36689066).
2. For the remaining groups, use the ESRO/EORTC classification system (Guckenberger et al., PMID 31908301).
3. Consid...