Cancer: Promising but Scarce

Of all the drugs that physicians now use to treat various forms of cancer, by far the most promising is the enzyme "L"-asparaginase. It is the first that has been found to deprive some types of cancer cells of a substance that they cannot make but must have.

This substance is the amino acid, "L"-asparagine. Normal cells also use it, and can apparently make it themselves.

So, unfortunately, can certain cancer cells, which explains why asparaginase cannot be effective against all kinds of cancer. But it has the enormous ad vantage that whereas other anticancer drugs may damage normal cells as...