Is there a rationale for treating medically inoperable stage I-III breast cancer patients with RT alone?

We treated stage III patients with "radical radiotherapy" with or without chemotherapy when I was a resident in the early 1980s, since they were considered SURGICALLY inoperable then. However, very high doses were needed (75-80 Gy to the primary using external beam followed by interstitial implants) to achieve local-regional failure rates of "only" about 20-30%. Cosmetic results were poor. Once chemotherapy was shown to be able to shrink cancers, they became "operable" and the surgeons started d...

There are two situations I consider RT (without surgery) in these situations:

1. Palliation - if the mass begins to grow and involves skin or deep chest wall, we can offer palliative dose RT.
2. Borderline operable cases - in these scenarios, we often start with systemic therapy. If still borderline, we consider RT (with concurrent xeloda) to try for downstaging and potential surgery.

For inoperable patients or those who refuse surgery, there are multiple case series that report reasonable results with radiotherapy +/- systemic therapy without surgery. Meaningful definitive local control can be achieved. Higher doses are better, but not always feasible for large tumor volumes. Anecdotally, I have achieved durable local control in some elderly patients, most commonly hypofractionated due to poorer PS using either 3 Gy per fraction, or the 6.5 Gy per fraction scheme from Instit...

There is a cohort of patients, medically inoperable due to multiple comorbidities and hence not systemic therapy candidates too, we have been offering SBRT with good outcomes, off trial.

There is an in-house trial too at Sunnybrook, breast SBRT trial (dose escalation/toxicity endpoints) from which we offer RT only for most patients.