Jenny Speicher, Medical Tribune News Service
The chances of breast cancer recurrence were reduced from 31 to
13 percent among women with noninvasive cancer who had radiation
following tumor removal, according to an eight-year update of a
national research trial.
The researchers also found that a condition in the original
tumor, called comedo necrosis, can be a significant predictor of
cancer recurrence, although no characteristics were found that
could predict whether the recurrence would be invasive or not.
The women studied had what's known as intraductal carcinoma,
also called ductal carcinoma in situ (DCIS), a stage of the disease
in which the cancer has not metastasized, or spread beyond the
primary site. Each woman underwent the surgical procedure
lumpectomy, in which only the tumor and some surrounding breast
tissue is removed. Currently most cases of DCIS are treated with
lumpectomy, although radiation treatment following the surgery
varies. Radiation kills both healthy and cancerous cells; it can
cause painful swelling and damage the heart and lung.
In the study, the women with ``moderate or marked comedo
necrosis'' -- a condition in which cells in the duct die -- an
eight-year recurrence rate of 40 percent could be predicted. But
among those treated with radiation, the recurrence rate was only 14
percent. Women who had ``absent or slight comedo necrosis'' had a
recurrence rate of 23 percent; in those treated with radiation, it
was 13 percent. Recurrence was defined as the return of cancer to
the same breast where it originated.
Cancer recurrence overall was 22 percent among the 623 women
studied in the trial. In about 40 percent of the recurring cases,
the cancer was invasive
The good news is that despite the high levels of invasive
disease when the cancer recurred, there was a high survival rate,
said the lead author of the study, Dr. Edwin R. Fisher, in an
interview.
Just 1.6 percent of the women overall died within the eight
years studied.
As breast cancer awareness and treatment have improved,
detection of earlier-stage disease -- such as DCIS -- has increased,
along with survival rates. Although most DCIS cases are treated
with lumpectomy, if cancer returns, sometimes a mastectomy -- in
which the whole breast is removed -- must be performed.
What we have in those cases is a ``cosmetic failure, not a
treatment failure,'' said Fisher, who again referred to the high
survival rates. Fisher is with the NSABP Pathology Center in
Pittsburgh.
The research trial, named Protocol B-17 of the National Surgical
Adjuvant Breast and Bowel Project (NSABP), is expected to last at
least 20 years. The current findings are reported in the Aug. 1
issue of Cancer, a journal of the American Cancer Society.
Fisher and colleagues emphasized in the report that there is no
information in the research ``to support the need for mastectomy
among patients with DCIS, at least among those who exhibit the
characteristics of the women who comprised this cohort.''
In an editorial in the same issue of the journal, Dr. Monica
Morrow stated that the findings will be useful in helping women and
their physicians decide on the best course of treatment. ``The
study does provide valuable data to assist the individual woman
with DCIS in selecting a treatment that meets her personal
definition of an acceptable level of risk,'' said Morrow, who is at
the Department of Surgery, Lynn Sage Breast Center, Northwestern
University Medical School, Chicago.
Morrow wrote that the B-17 trial has been subject to criticism,
mainly because the evaluation techniques for DCIS have changed
since the participants were first chosen for the study. She also
commented on how the study found no differences in recurrence based
on ``margin status,'' a reference to where and if cancer cells are
found in the tissue removed from around a tumor. The authors
reported that the result could be attributed to the predominance of
early recurrence in their study. But Morrow suspects it had more to
do with inaccurate margin-assessment techniques used in the trial.
In spite of these limitations, Morrow wrote, ``the NSABP B-17
database represents the largest group of prospectively evaluated,
randomized patients undergoing uniform treatment.'' The results of
the trial's updated analysis ``are particularly welcome,'' she
wrote, considering the vacuum in knowledge needed to distinguish
between high and low risk DCIS.
