化学療法と放射線療法の併用は一部の脳腫瘍患者の寿命を延長する（Abstract # 2）

化学‐放射線療法の併用は退形成性乏突起膠腫、特に染色体突然変異を有する者の生存期間を延長する

Combined chemo-radiation extends survival in patients with anaplastic oligodendroglial tumors, particularly those with chromosomal mutations

European Organization for Research and Treatment of Cancer（EORTC）が施行し2012年ASCO学会で発表された第3相試験の結果、脳腫瘍の一種である退形成性乏突起膠腫患者に標準的な放射線治療を行った後に化学療法を併用することにより、腫瘍の成長が遅延し寿命が延長したことが示された。このスタディに登録された患者368人は新たに診断された未治療の退形成性乏突起膠腫を有していた。患者は放射線療法単独または放射線療法の後にPCVとして知られるプロカルバジン、CCNUおよびビンクリスチンを用いた化学療法を6サイクル併用する群に無作為に割り付けられた。今日、この疾患のほとんどの患者が化学療法かまたは放射線療法により治療され、併用療法はなされていない。無増悪生存期間は放射線/PCV療法群で24.3か月であり、放射線療法単独群では13.2か月であった。全生存期間は放射線/PCV療法群で42.3か月であり放射線療法単独群では30.6か月であった。遺伝子サブタイプによる調査を行ったところ、PCVと放射線療法の有益性は1p/19q共欠失を有することが判明しているサブセットの80人に限定された。これらの患者においては放射線/PCV療法により放射線療法単独を受けた患者と比較し、死亡リスクが44%低下した。

A Phase III study conducted by the European Organization for Research and Treatment of Cancer (EORTC) and presented at ASCO's 2012 annual meeting has shown that giving combination chemotherapy after standard radiation therapy delayed tumor growth and extended the lives of patients with anaplastic oligodendroglial tumors, 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 tumors 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, M.D., 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 personalize treatment for this challenging disease."

The 368 patients enrolled in this study had newly diagnosed, previously untreated anaplastic oligodendroglial tumors. 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 tumor patients with 1p/19q co-deletions, compared with radiation alone, but not for patients without these deletions.