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New Cancer Cure -- Hype Or
Hope?
Media outlets throughout the United States were trumpeting the
news of a new "cure" for cancer last May, following a New York Times article
that discussed cancer research taking place at Children's Hospital in Boston.
That article, and news stories that followed, left many readers with the
impression that a cure for cancer was just around the corner—a promise
that sounded, and may well be, too good to be true.
In November 1997, Dr. Judah Folkman and his colleagues at
Children's Hospital reported that two proteins that occur naturally in the
body—angiostatin and endostatin—caused tumors to shrink in mice. The
compounds work by inhibiting the blood supply to the tumor—a novel
approach to cancer treatment that has excited many cancer researchers. At least
11 other compounds also inhibit the blood supply to tumors in mice, and are
currently being tested in humans. If effective in humans, these proteins and
molecules could play an important role in eliminating certain types of tumors.
Unfortunately, throughout the history of cancer research, many
promising drugs that totally eliminated cancer in mice failed miserably when
tested on human subjects. According to researchers at the National Cancer
Institute (NCI), mice metabolize drugs differently than humans. Moreover, tests
on mice often involve tumors that were transplanted into mice rather than
tumors that occur naturally. Transplanted tumors have a different biology than
naturally occurring tumors and are often not accurate predictors of what will
happen in natural human cancers.
To overcome this problem, major research effort is under way to
find better animal models for naturally occurring human cancers, say NCI
officials. For example, researchers can now alter mouse genes and introduce the
same mutations into mice that occur in human cancer. These mutant mice develop
specific cancers and pass a susceptibility of developing certain cancers onto
their offspring, just as do humans. Researchers hope these new animal models
will better predict how new treatments will affect humans. In the meantime,
researchers are keeping their fingers crossed that anti-cancer drugs now being
tested will be as effective in humans as they were in mice. |
