The recent launch of a revolutionary prostate cancer vaccine, custom-made for each individual patient, marks an exciting advance in medical science. It also highlights some of the hardest problems in the effort to contain health care costs.

How much can we afford to spend for each new, new thing? And how much should taxpayers pay to provide a few additional months of life for someone who is terminally ill?

Provenge is the first cancer vaccine to win FDA approval. It enlists key cells in a patient's own immune system to target and destroy tumor cells. Such personalized drugs are a promising new frontier, and Provenge is great news for the 2 million American men with prostate cancer, a disease that kills more than 27,000 each year.

But Provenge costs $93,000 per patient. And in clinical trials, including some on Long Island, it extended survival by just 4.1 months compared with traditional therapies. The Dendreon Corp. will defray the cost for people who can't afford its new drug. But company officials project that about 75 percent of those who want it will be eligible for Medicare.

As additional personalized drugs and more advanced treatments become available, tough questions about the cost of end-of-life care will have to be confronted. Scary talk of fictitious "death panels" made the issue untouchable during the recent health care debate. But we can't duck it for long. hN