In their Wisdom by C.P. Snow

Through the late summer Dr Pemberton was receiving regular reports about Hillmorton. They came from his contact at the hospital where Hillmorton had been first examined, for, contrary to his prediction to Sedgwick and his own wishes, that was where he had been moved. He hadn't been able to argue much, he was only fitfully coherent or capable of a continued effort of will.

The disease, after the lull in the spring, had gone faster than Pemberton had expected. As he listened to the reports, he thought that it was unlikely to take long now. He followed the progress exactly as he had followed the progress of others in this condition. He had seen it all before. There were one or two curiosities. The brain tumour had grown with untypical speed. Pemberton's nearest approach to feeling was the reflection that for himself, he would prefer another way of dying.