A federally funded phase III trial provides additional information regarding a long-standing discussion about the impact of adjuvant whole brain radiation therapy (WBRT) on cognitive function.

Patients with 1-3 small brain metastases who received radiosurgery followed by WBRT were more likely to experience cognitive decline than those who received radiosurgery alone.

Furthermore, WBRT did not significantly extend patient survival, though it did help control growth of brain metastases.

Up to 650,000 patients newly diagnosed with cancer in the United States every year will develop brain metastases.

At least 200,000 of these patients will receive WBRT at some point in the course of their disease (i.e., as adjuvant, salvage, or end-stage therapy).¹

Patients with limited metastases often receive radiosurgery, a type of radiotherapy that aims beams very precisely at the area of the brain tumour.

Brain metastases are removed by conventional surgery in only a select minority of patients.

“We used to offer whole brain radiation early on, but we now know that the toxicities of this therapy are worse for the patient than cancer growth or recurrences in the brain,” said senior study author Jan C. Buckner, MD, a professor of oncology at Mayo Clinic in Rochester, USA.

“We expect that practice will shift to reserve the use of whole brain radiation therapy for salvage treatment and end-stage palliative care.”

In the study, 213 patients were randomly assigned to receive radiosurgery or radiosurgery followed by WBRT.

All patients had 1-3 brain small brain metastases (up to 3 cm in width).

At three months, more patients experienced cognitive decline in the WBRT group (92%) than in the radiosurgery group (64%).

Specifically, patients who received WBRT had a greater decline in immediate recall (30% vs. 8%), delayed recall (51% vs. 20%), and verbal communication (19% vs. 2%).

The analysis of quality of life data from this study has not yet been completed.

The difference in overall survival was not statistically significant between the two treatment groups.

According to the authors, the findings of this study have broad implications for oncology practice, as brain metastases are a common complication in cancer care.

Melanoma and cancers of the lung, breast and colon spread to the brain especially often.

Patients with bladder, kidney and gynaecologic cancers can also develop brain metastases.

Dr Buckner remarked that while adjuvant WBRT continues to be an option for patients with resected (surgically removed) brain metastases, the ongoing NCCTG/Alliance trial comparing WBRT to stereotactic radiosurgery to the surgical cavity in patients with resected brain metastasis will eventually determine which treatment approach is better.

Reference

1. Rapp SR, Case LD, Peiffer A, et al. Donepezil for irradiated brain tumor Survivors: A Phase III randomized placebo-controlled clinical trial, J Clin Oncol 33:1653-1659, 2015.

Source: ASCO

Watch the interview or press conference for more.