GAINESVILLE,
Fla. – Cancer that has spread
from the site of an original tumor to other places in the body is often viewed
as a death sentence. But if there are just a few of those secondary tumors,
called metastases, some patients have a good chance of survival if treated with
a type of radiation that precisely targets small tumors, researchers at the
University of Florida and the University of Rochester report online and in an
upcoming print edition of the International Journal of Radiation Oncology,
Biology, Physics.

“The dogma is that this type of disease is incurable and
that if theres a metastatic tumor in one organ, then others must be present
throughout the body,” said investigator Paul Okunieff, M.D., director of the UF
Shands Cancer Center and chairman of the UF College of Medicines department of
radiation oncology. “Its considered an all-or-none phenomenon, but the fact is
this view is probably not correct. We need to think about metastasis like we
think about the primary tumor: determine how much it has spread, then decide
whether its treatable based on existing technology.”

Nearly 1.6 million Americans were diagnosed with cancer last
year, and nearly 600,000 died from the disease, according to the National
Cancer Institute. Experts estimate that up to 90 percent of those deaths were
from metastases.

The researchers studied 121 patients who had five or fewer
tumors that spread from areas such as the breast, colon or lung, to up to three
additional organs. Tumors were treated with a one- to two-week radiation course
strong enough to kill them and prevent their recurrence while sparing healthy
tissue. In about 20 percent of the patients, who were enrolled from 2001 to
2006, long-term follow up revealed that the treated tumors did not return, nor
did new ones pop up elsewhere. Very few regrowths occurred among patients who
made it to three years.

Breast cancer patients fared even better, with one-third of
patients being free of tumor regrowth after three years. Six years after
treatment, almost half of breast cancer patients in the study were still alive
– five times the survival rate for people with forms of metastatic cancer other
than breast cancer. In addition, for more than one-third of breast cancer
patients, the cancer did not become widespread after six years, whereas only
one-eighth of people with other forms of metastatic cancer did not see their
cancer spread. In general, survival was greatest among patients whose secondary
tumors were relatively small and responded well to chemotherapy or hormone
treatment given before radiation.

“Our results suggest that patients with metastases that are
limited in number and extent should be considered for potentially curative
radiotherapy, said investigator Michael Milano, M.D., Ph.D., an associate
professor of radiation oncology at the University of Rochester. “Further
studies are needed to ascertain which patients are most likely to benefit,
either through prolonged survival or, perhaps, a cure. We need a better
understanding of the biology of cancer, and what makes one persons cancer
behave so differently from anothers.”

Some patients in the study had recurrence of a small number
of tumors, and retreatment with targeted radiation controlled their disease.

The researchers call for further investigation into the most
appropriate types of treatment for cancer that has spread to limited areas, and
the types of cancers most likely to respond.

“Given the promising results of precisely targeted radiation
in controlling the spread of disease, easing pain and even unexpectedly
extending patient survival – as weve seen in our own clinical experience and
in the published literature – we must pursue research that advances our
understanding of the mechanisms at work,” said Raymond B. Wynn, M.D., executive
director for stereotactic radiosurgery at the University of Pittsburgh Medical
Center Cancer Center, and a clinical professor of radiation oncology at
University of Pittsburgh School of Medicine. “Fortunately, we are more than
halfway there.”

UF&Shands, The University of Florida Academic Health
Center, is the most comprehensive in the Southeast. It comprises the colleges
of Dentistry, Public Health and Health Professions, Medicine, Nursing, Pharmacy
and Veterinary Medicine, and an academic campus in Jacksonville that offers graduate education
programs in dentistry, medicine, nursing and pharmacy. Patient care activities,
under the banner UF&Shands, are provided through teaching hospitals and a
network of clinics in Gainesville and Jacksonville. The Academic Health
Center also has a statewide presence
through satellite medical, dental and nursing clinics staffed by UF health
professionals; and affiliations with community-based health-care facilities
stretching from Hialeah and Miami to the Florida Panhandle.