Radiation therapy plus treatment to
raise the temperature of a tumor is more effective than radiation alone in
treating pelvic cancers, particularly cervical cancer, according to new study
findings.
Preventing tumors of the bladder, cervix and rectum from spreading is
difficult, according to Dr. Jacoba van der Zee and colleagues at the Academic
Medical Centre in Amsterdam, the Netherlands. But a treatment called
hyperthermia, which involves raising the temperature of a tumor to 40 to 45
degrees Celsius (104 to 113 degrees Fahrenheit), has been shown to be an
effective way to kill cells, they report in the April 1st issue of The Lancet.
One of the study's authors, Dr. Gerard C. van Rhoon, told Reuters Health
that keeping tumors from spreading may lead to better survival. "Therefore, it
is necessary to increase the effectiveness of the conventional local treatment,
here radiotherapy, by the addition of hyperthermia," he noted.
From 1990 to 1996, 358 patients with bladder, cervical or rectal cancer were
randomly assigned to be treated with radiation alone or in combination with
hyperthermia. Once a week for 5 weeks, patients in the hyperthermia group
received the additional treatment 1 to 4 hours after radiation. Each
hyperthermia session lasted about 90 minutes.
Overall, the combination therapy was more effective at keeping tumors in
check than radiation alone, the researchers report. Thirty-nine percent of the
tumors treated with radiation alone disappeared completely, compared with 55% of
the tumors treated with radiation and hyperthermia.
Even though there were not any statistically significant differences in the
effects of treatment on the three types of cancer, people with cervical cancer
appeared to benefit the most from hyperthermia. Eighty-three percent of cervical
tumors treated with both radiation and hyperthermia disappeared after treatment,
compared with just 57% of those not treated with hyperthermia.
In addition, hyperthermia appeared to improve survival, especially for
patients with cervical cancer. "For the patients with advanced cervical cancer,
we have found that hyperthermia increases the 3-year overall survival rate by
24%," van Rhoon told Reuters Health. People with bladder cancer who underwent
hyperthermia also were more likely to survive than those treated with just
radiation, although the benefits were not as dramatic as they were for cervical
cancer.
Hyperthermia did not cause any major side effects, but some patients said
that the probe inserted to heat the tumor was uncomfortable and some did
experience minor burns.
The researchers conclude that radiation plus hyperthermia should be the
treatment of choice for some types of cervical cancer, but there is not enough
evidence yet to recommend it for tumors of the bladder and rectum.
