FORT LAUDERDALE, FlaThe National Comprehensive Cancer Center (NCCN)
Practice Guidelines for Breast Cancer have been updated to reflect
the results of new trials demonstrating the effectiveness of
tamoxifen (Nolvadex) as a risk reduction agent for women treated for
The updated guidelines also include new recommendations in other
areas, which will be described in an upcoming issue of ONI. Robert W.
Carlson, MD, professor of medicine, Stanford University, presented
the findings on tamoxifen at the NCCNs Fifth Annual Conference.
For patients who have been treated for ductal carcinoma in situ
(DCIS) with breast-conserving surgery and radiation therapy, the
guidelines urge clinicians to strongly consider the use
of tamoxifen, 20 mg/d for 5 years, as adjuvant treatment. The
previous version of the guidelines simply said to consider
tamoxifen for prevention in this setting.
The new recommendation is based on the National Surgical Adjuvant
Breast and Bowel Project (NSABP) B-24 randomized trial, which found a
reduction in risk in this setting in women who received tamoxifen. At
5 years, tamoxifen users had about a 5% absolute reduction in the
risk of developing breast cancer, compared with placebo, and
that translated into about a 37% relative risk reduction, Dr.
Reductions in both invasive and noninvasive breast cancers were
observed, but no survival advantage for tamoxifen has yet been demonstrated.
In DCIS patients treated with excision alone, high-level evidence is
lacking for the use of tamoxifen, but, Dr. Carlson said, there was a
uniform consensus within the breast cancer panel to make the
recommendation that it be strongly considered based on
For DCIS patients treated with mastectomy, the recommendation to
strongly consider tamoxifen for contralateral risk reduction lacked a
uniform consensus. Panel members agreed that you could use it
or not use it in this setting. Practice patterns differ, Dr.
For women with lobular carcinoma in situ (LCIS), the NSABP Breast
Cancer Prevention Trial showed that tamoxifen reduces breast cancer
risk in both breasts. Thus, for women with LCIS who are being
observed, the guidelines advise counseling regarding use of
tamoxifen for risk reduction.
The guidelines on adjuvant therapy for stage I, IIA, and IIB invasive
breast cancer now include a new column on risk reduction.
One should consider tamoxifen for contralateral breast cancer
risk reduction if tamoxifen was not given as an adjuvant
therapy, Dr. Carlson said. We have high level evidence
from multiple trials that tamoxifen will reduce the contralateral
risk. We dont say that it should be used but, rather, that one
should consider its use, because the magnitude of benefit is
relatively modest, and cost effectiveness analysis to my knowledge
has not yet been done.
For certain subsets of patients treated for stage I, IIA, or IIB
disease, previous guidelines had recommended the optional use of
tamoxifen for systemic adjuvant therapy. This has now been replaced
with the unequivocal recommendation for its use (with or without
chemotherapy) in node-positive patients with stage I, IIA, or IIB
disease (1 to 3 cm) who are hormone-receptor positive and in those
with node-negative, hormone-receptor positive stage IIA or IIB
disease (with adjuvant chemotherapy).