Thriving not surviving.
Top Line: While we await phase 3 data on the efficacy of ablative radiation for oligomets across various histologies, we can all lean on some common sense.
The Study: As the downside of ablative versus more conventional radiation techniques on safe targets is resource utilization, translating to higher cost to insurance companies, it remains good public health policy to reserve these treatments with better long term outcomes for patients with better chances of long term survival. Here’s a retrospective look at outcomes among 82 women receiving ablative radiation for all extracranial breast cancer oligomets at MSKCC between 2008-2018. Perhaps most telling is the median survival time of 82 months, or 6 years 10 months, or a long time. At a median follow-up of just over 4 years, 82% maintained local control at the irradiated site. What’s more, 8 of 10 women experiencing further progression progressed at fewer than five sites. Another look back at 120 women again receiving ablative radiation for all extracranial mets (not just oligo) at a Toronto center between 2011-2017 has similar trends. In contrast to the prior study, median follow-up was only 15 months. Here the authors’ focus was the separation in survival curves based on indication of treatment. Survival at one year 91% when ablative radiation was delivered for new oligomets, 79% for oligoprogression, and 64% (still not so bad) for dominant disease only.
TBL: Large retrospective data consistently draws more of a chronic, not rapidly fatal, disease picture for metastatic breast cancer, particularly when all sites are amenable to ablative radiation. | Wijetunga, Cancer Med 2021 & Tan, Radiother Oncol 2021