NEW YORK (Reuters Health) Mar 09 - After lumpectomy and radiation for ductal carcinoma in situ (DCIS), tamoxifen lowers the risk of invasive breast cancer -- but only in women with estrogen receptor (ER)-positive disease, new data show.
"No ipsilateral benefit was observed in ER-negative disease, emphasizing that tamoxifen must bind to functional ER to exert its beneficial effect on pre-existing residual tumor cells," the authors write in their report, published online March 5th in the Journal of Clinical Oncology.
Dr. D. Craig Allred, of Washington University School of Medicine in St. Louis, Missouri, and colleagues explain that the National Surgical Adjuvant Breast and Bowel Project B-24 trial -- which showed adjuvant tamoxifen reduces subsequent ipsilateral and contralateral breast cancers after standard therapy for DCIS -- was begun before hormone receptor status was routinely evaluated in DCIS.
The current study is an analysis of outcomes in 732 of the participants in that trial for whom receptor status could be determined retrospectively. Tumors were estrogen receptor-positive in 76% and progesterone receptor-positive in 66%, the report indicates.
Compared to placebo treatment, adjuvant tamoxifen in cases of estrogen receptor-positive DCIS was associated with a significant reduction in risk of ipsilateral breast cancer at 10 years (hazard ratio 0.49; p<0.001), the investigators found. The ipsilateral effect in ER-negative DCIS was not significant (HR 1.06; p=0.87).
Adjuvant tamoxifen had a protective effect against the development of contralateral breast cancer regardless of hormone receptor status, the analysis showed.
Factoring in progesterone receptor status generally did not change the predictive value of estrogen receptor status alone, the authors note.
In general, however, "adjuvant tamoxifen should be considered for patients with DCIS," Dr. Allred and colleagues conclude,
The author of an editorial, Dr. Monica Morrow of Memorial Sloan-Kettering Cancer Center, New York, sums up the results, saying, "This study allows us to refine our definition of the subgroup of women with DCIS most likely to have a favorable risk/benefit ratio with tamoxifen treatment -- namely, premenopausal women with two breasts at risk and ER-positive DCIS."
However, she adds, "At this point, NSABP B-24 is an old trial, and other options are available to postmenopausal women with DCIS who wish to minimize their risk of future breast cancer events."
One of those, she points out, is exemestane (Aromasin), which she calls "a viable alternative to tamoxifen for the postmenopausal woman with DCIS."
SOURCE: http://bit.ly/xt0WdN
J Clin Oncol 2012.
2 σχόλια:
Sorry, I do not speak Greek, but I want to thank you for having this blog with so much information. I was diagnosed with DCIS and had a lumpectomy. Now, the doctor wants me to have radiotherapy. I am really worried about the long-term effects of radiation treatments to the heart, lungs, arteries, etc., 10, 20 years after radiation treatments. There seems to be so much confusion about what medical professionals have determined about DCIS and how to treat it, and whether it is a cancer or a precancer, and what the real risks are that it will return again later as an invasive cancer.
Great blog all the best
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