Research offers
hopeful news to women whose breast cancers are typically
more difficult to treat: Modern chemotherapy means more of
them will survive than previously thought.
The latest
findings offer more evidence that a tumor's "personality
characteristics" are more important than size and how much
the cancer has spread. Often the key is whether the
tumor is fueled by the hormone estrogen. Increasingly,
doctors are considering that when recommending
treatment. About two thirds of breast cancer patients have
hormone-fueled tumors. Typically such cancers are
treated with tamoxifen and other groundbreaking
hormone-blocking drugs, which have fewer side effects.
These women sometimes get chemotherapy too, although the new
study suggests many of them will do just as well
without it.
But that still
leaves about 70,000 U.S. women diagnosed each year with
nonhormonal cancer.
The new study
found that advances in conventional intravenous
chemotherapy give many of those patients almost as good a
chance at survival as women with estrogen-fueled
tumors.
While tamoxifen
"changed the landscape" for estrogen-fueled tumors,
"the playing field has now been leveled somewhat" because
nonhormonal cancers respond so well to modern chemo, said
lead author Donald Berry, a biostatistician at M.D.
Anderson Cancer Center.
The research
supports updated guidelines released in December by the
National Comprehensive Cancer Network, a group of leading
cancer treatment centers. They recommend that
treatment be based partly on the tumor's hormone
status.
"Breast cancer
isn't one disease, and one size won't fit all," said
Eric Winer, a study coauthor and director of the breast
oncology center at Dana-Farber Cancer Institute in
Boston.
The study appears
in Wednesday's Journal of the American Medical
Association along with an unrelated report from the
government's landmark research into hormone pills.
That study shows
that unlike estrogen-progestin pills, estrogen-only
pills don't increase older women's risks for breast cancer.
The new results, based on an updated analysis, echo
findings from a report two years ago that showed
estrogen pills linked to a higher risk of strokes, but
not breast cancer.
The research on
tumors and treatment is an analysis of 20 years of data
from three studies involving 6,644 patients whose disease
had spread to lymph nodes. Modern chemotherapy
improved five-year cancer-free survival rates by
almost 23% in women with nonhormonal cancer, versus just 7%
in women with estrogen-fueled disease.
The latest
chemotherapy regimen studied--three drugs including
Taxol and infusions every other week for 16
weeks--reduced the risk of recurrence and death
in patients with nonhormonal disease by more than 50%,
compared with older, lower-dose, and less-frequent
regimens.
The results
reveal "just how big an effect the new chemotherapy is
having" on women with estrogen-negative cancer and likely
will instill more optimism about these women's
prognosis, said Debbie Saslow, director of breast and
gynecologic cancer for the American Cancer Society.
The estrogen
pills study involved 10,739 postmenopausal volunteers in the
Women's Health Initiative. It found that the pills increase
older women's risks of abnormal mammograms just as
pills containing estrogen and progestin do. That's
because hormones can make breast tissue denser and
harder to interpret on mammograms. That often results in
repeat mammograms to clarify the initial images, a
process that can be costly and anxiety-provoking.
Wyeth's Eileen
Helzner called the results reassuring but said women
should discuss their individual risks with their doctors
before deciding whether to take hormones at menopause.
(AP)