Evaluating the effectiveness and safety of stereotactic ablative body radiotherapy in advanced cancer

This study investigated the effectiveness and safety of stereotactic ablative radiation therapy (SABR) in the treatment of patients with oligometastatic (few metastases) cancer. The data showed that the use of SABR in these patients was associated with high overall survival and low toxicity.

Oligometastatic cancer (OMC) is cancer that has spread away from the original (primary) organ and has formed a small number of new tumors in one or 2 different organs. Treatments for OMC involve systemic (whole-body) treatments such as chemotherapy. However, systemic therapies also increase the risk of side effects to healthy organs and tissues.

Stereotactic ablative radiation therapy (SABR) is a type of radiotherapy (RT). It uses a high dose of radiation and targets a specific area from different angles. SABR has been shown to improve survival without cancer worsening and to delay the need for systemic therapies in patients with advanced cancer. However, whether SABR is effective and safe in patients with OMC is not known.

This study involved 1422 patients with OMC. Patients had prostate, colorectal, breast, lung, kidney cancer, or melanoma as their primary tumor. 75.6% of all patients had one metastasis only. All patients received 3-8 SABR treatments. The average follow-up time was 13 months.

The overall survival rate was 92.3% at 1 year and 79.2% at 2 years. The average time until the disease worsened was longer than 2 years. 72.3% of patients did not have cancer grow or spread after 2 years. After 1 year, 84% were alive without any metastases. This rate was 52% at 2 years.

There were no treatment-related deaths and the most common side effects were tiredness, cough, and an increase in liver enzymes.

This study concluded that SABR resulted in high rates of overall survival with low levels of toxicities in patients with OMC.

This study had a short follow-up period. A longer follow-up period is necessary to evaluate the long-term effectiveness and safety of SABR for OMC.