A Phase III study conducted by the European Organisation for Research and Treatment of Cancer (EORTC) has shown that giving combination chemotherapy after standard radiation therapy delayed tumour growth and extended the lives of patients with anaplastic oligodendroglial tumours, a form of brain cancer.

A sub-analysis of the study showed the survival benefit of combination chemotherapy-radiation treatment may be limited to patients whose tumours contained specific deletions of genetic material in chromosomes 1 and 19 (1p/19q co-deletions).

"From this trial, it’s clear that combining chemotherapy and radiation can significantly improve survival for certain patients," explained lead author Martin Van Den Bent, MD, Professor of Neuro-Oncology at Erasmus MC – Daniel den Hoed Cancer Center in Rotterdam, The Netherlands.

"Not only do we now have a better treatment – we also have a genetic marker that can help us determine which patients will benefit, allowing us to personalise treatment for this challenging disease."

The 368 patients enrolled in this study had newly diagnosed, previously untreated anaplastic oligodendroglial tumours. They were randomly assigned to receive either radiation therapy alone or radiation followed by six cycles of chemotherapy with the drugs procarbazine, CCNU and vincristine, a regimen known as PCV.

Currently, most patients with the disease are treated with either chemotherapy or radiation, but not both.

Progression-free survival was 24.3 months in the radiation/PCV group and 13.2 months in the radiation-only group. Overall survival was 42.3 months in the radiation/PCV group and 30.6 months in the radiation-only group.

When examined by genetic subtype, researchers found that the benefit of PCV and radiation was restricted to a subset of 80 patients known to have 1p/19q co-deletions. For these patients, treatment with radiation/PCV reduced their risk of dying by 44 percent, compared with patients who received radiation alone.

Median overall survival was 9 years among patients with such deletions who received radiation alone, but this endpoint has not yet been reached in the radiation/PCV group after follow-up of almost 12 years. Among 236 patients without these co- deletions, overall survival was not statistically different between the treatment groups (25 months for the radiation/PCV group versus 22 months for radiation alone).

This study complements similar research also presented at the Annual Meeting and conducted by North American investigators. That Phase III study (Abstract #2008b) also found that giving both PCV and radiation therapy (with chemotherapy preceding radiation) improved survival for oligodendroglial tumour patients with 1p/19q co- deletions, compared with radiation alone, but not for patients without these deletions. 

Source: ASCO