Partial Breast Radiation - long

J · medicine forum addict Joined: 07 May 2005 Posts: 93

<http://www.cancer.org/docroot/NWS/content/NWS_2_1x_Study_to_Test_Partial_Breast_Radiation.asp>

Study to Test Partial Breast Radiation
Will Compare to Whole Breast Radiation
Article date: 2005/03/21

A new clinical trial of partial breast radiation is set to begin.
Researchers hope it will answer some important questions about this
alternative way of delivering radiation therapy to women who have had
breast tumors removed.

The Phase 3 study is run by the National Surgical Adjuvant Breast and
Bowel Project (NSABP) and the Radiation Therapy Oncology Group (RTOG), and
sponsored by the National Cancer Institute. It will include 3,000 women
with early stage breast cancer who have had a breast-conserving therapy
called lumpectomy.

The women will be randomly assigned (like flipping a coin) into one of two
groups. Half of them will be assigned to receive whole breast radiation,
the standard treatment after lumpectomy, while the others will be assigned
to partial breast radiation. Their patients will be followed for about 10
years to find out if partial breast radiation is just as safe and
effective as whole breast radiation.

"We'd like to think they'd be equivalent, based on early information that
we have, but this is why we conduct a trial," said Thomas Julian, MD, one
of the NSABP protocol officers for the study and associate director of the
Breast Care Center at Allegheny General Hospital in Pittsburgh.

He presented information about the trial Friday at the annual meeting of
the American Society of Breast Surgeons. The study protocol is identified
as NSABP B-39/RTOG 0413.
RESOURCES:

Learn more about the trial and how to register from the National Cancer
Institute
Long-Term Data Needed

Whole breast radiation therapy is usually given after a lumpectomy to kill
any stray cancer cells that might remain in the breast. Studies have shown
that the treatment can reduce the rate of local recurrences and improve
long-term survival. Whole breast radiation can be inconvenient, usually
requiring clinic visits 5 days a week for 5 to 7 weeks.

Partial breast radiation delivers the treatment only to the tumor site and
to a small area of surrounding tissue. It has been used in various forms
for about a decade, and has recently grown in popularity. Some women
prefer it to whole breast radiation because it takes much less time to
complete treatment (1 or 2 weeks). But there are no large studies showing
that partial breast radiation is as effective as whole breast radiation.

Some doctors worry that limiting the field of radiation might allow some
stray cancer cells in other parts of the breast to survive -- and possibly
grow into another tumor later. There has also been opposition from doctors
who worry the technique will cause too much scarring in the breast, making
it harder to detect any recurrence of cancer.

Several small studies suggest women who get partial breast radiation fare
just as well as women who get whole breast radiation; both groups have
similar rates of recurrence. But those studies tracked the women for only
a few years. There have been no large, long-term studies to see if the
outcomes remain the same 10 or more years down the road.

"This is an important study," said Len Lichtenfeld, MD, deputy chief
medical officer for the American Cancer Society. "There has been a
substantial interest in the last few years in reducing either the amount
of radiation, the length of radiation therapy, or the amount of breast
that has to be radiated. This trial will help find out whether every woman
really needs to have whole breast radiation, and that's important."
Who Is a Good Candidate?

It should also help determine which women would be best suited to partial
breast radiation.

Previous trials, Julian explained, included only highly-selected patients
-- women with small tumors, no lymph node involvement (or minimal lymph
node involvement), and cleanly removed tumors that left no suspicious
tissue behind. Most of the studies were also conducted in women over age
45.

That was a precaution taken because breast cancer tends to be more
aggressive in younger women, said Frank Vicini, MD, a radiation oncologist
at William Beaumont Hospital in Royal Oak, Mich. He conducted many of the
early trials of partial breast radiation and is lead protocol chair for
this new study.

"If you're going to try a new technique, you try it in patients who have a
better prognosis," he said. "We've been doing that for many years and
we've had good results. As more data accumulate, we're seeing age probably
isn't a risk factor."

The current study will include women 18 and older.
Three Types of Partial Radiation Studied

The study will compare whole breast radiation to three different types of
partial breast radiation: multi-catheter brachytherapy, balloon catheter
brachytherapy (MammoSite), and 3-D conformal external beam radiation.
After talking with their doctors, the women who are selected for partial
breast radiation will choose one of these treatments, and will receive it
twice a day for a total of 5 days. Each treatment will deliver the same
amount of radiation.

In multicatheter brachytherapy, doctors insert hollow tubes (usually
15-20) into the tumor site. Radioactive pellets are then inserted into the
tubes. They are left in the breast for a few minutes, then taken out
again. The tubes themselves remain in place for the length of the
treatment, which is 1 to 2 weeks.

Balloon catheter brachytherapy is a similar technique, but it uses only
one tube with a balloon at the end. The balloon is inserted into the
breast and inflated with salt water to fill the cavity left by the removal
of the tumor. The radiation pellet is inserted into the center of the
balloon for a few minutes at a time. This is done over the course of 1 to
2 weeks.

The final technique, 3-D conformal external beam radiation, is similar to
traditional radiotherapy for breast cancer in that the radiation is
delivered from outside the breast. But instead of hitting the whole
breast, the beams are targeted to hit only the tumor site and a small
portion of surrounding tissue.
Quality of Life Also Investigated

Another thing the researchers hope to learn from the study is whether
partial breast radiation can improve a woman's quality of life.

It may be more convenient for women who live far from a radiation facility
because it cuts their treatment time sharply.

The researchers will also compare the cosmetic results of the different
radiation types and side effects like fatigue.

Vicini said women who are interested in receiving partial breast radiation
should consider joining the study. And Julian said women should only get
partial breast radiation in the context of a clinical trial.

"A woman should understand the complexity of this," he said. "Less is not
necessarily better, and it may or may not be as good. But the only way to
really know is to conduct this randomized Phase 3 trial." <snip>

There's obvious positives, but what's the downsides?
Potentially resurgeries/delays/need for full radiation therapy later?
J

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