Pavlos Msaouel, Associate Professor of Genitourinary Medical Oncology at MD Anderson Cancer Center, shared on LinkedIn:
“How should metastasis-directed radiation be incorporated into the treatment of SMARCB1-deficient renal medullary carcinoma?
Our new study in European Urology Oncology, with Shlok Mohanty and Chad Tang, provides clinical evidence to inform that question.
We retrospectively evaluated 24 patients treated at MD Anderson: 16 with oligometastatic disease, seven with oligoprogression, and one receiving adjuvant radiation after resection of metastatic disease:
Title: High Radiographic Response Rates After Metastasis-directed Radiation Therapy in SMARCB1-deficient Renal Medullary Carcinoma
Authors: Shlok Mohanty, Pavlos Msaouel, Chad Tang
The principal findings were:
- Estimated median overall survival of 36.9 months from radiation initiation, with a 95% confidence interval of 19.7 months to an upper limit not reached.
- Patient-level radiographic responses in 82% of 22 evaluable patients, including 50% complete responses, using RECIST-informed assessment of irradiated lesions.
- Patient-level local control of 91.3% at one year and 84.3% at two years.
- Median progression-free survival of 5.4 months, with progression predominantly at distant sites.
Median survival exceeding three years following radiation therapy initiation deserves recognition in RMC.
Although these were highly selected patients receiving multimodal care, their outcomes represent a clinically meaningful experience.
The retrospective design and absence of a comparison group prevent attribution of that survival to radiation.
The biological rationale also warrants investigation.
SMARCB1 loss can impair DNA damage repair and may increase radiosensitivity.
Complete responses in six of 17 lesions treated with moderate-dose radiation support studying dose requirements specifically in RMC.
The next studies should prospectively evaluate patient selection, dose and fractionation, and integration with systemic therapy, while measuring toxicity, quality of life, and disease control beyond the irradiated sites.”
Other articles about renal medullary carcinoma on OncoDaily.