MIAMI BEACH, Fla--Radiation therapy may not be necessary after the removal of ductal carcinoma in situ (DCIS), Gordon F. Schwartz, MD, said at the 14th International Breast Cancer Conference. In his experience, only 3% of DCIS patients who received breast-conserving surgery alone later experienced invasive breast cancer.
MIAMI BEACH, Fla--Radiation therapy may not be necessary after the removalof ductal carcinoma in situ (DCIS), Gordon F. Schwartz, MD, said at the14th International Breast Cancer Conference. In his experience, only 3%of DCIS patients who received breast-conserving surgery alone later experiencedinvasive breast cancer.
Although his data lack the rigorous scientific standard of a randomized,clinical trial, Dr. Schwartz, professor of surgery, Jefferson Medical College,Philadelphia, believes that his findings still offer encouragement for"the very motivated patient who wants to conserve her breast and doesnot want to undergo radiation."
The study included 194 breast procedures to eliminate DCIS. After fiveyears of surveillance, cancer returned in 28 women (14.4%), but almostall of the recurrences (23) were also DCIS.
In addition, most of the DCIS recurrences showed up within three yearsof the first treatment, suggesting, he said, that they might really havebeen part of the original tumor that was left behind in the first surgery.
More than 180,000 cases of breast cancer will be diagnosed this year,and one fourth--45,000--will be DCIS. At one time, the treatment of choicefor DCIS was mastectomy, but, more recently, surgeons have been using breast-conservinglumpectomy. Treatment of DCIS has been controversial, Dr. Schwartz said,"because we do not know the natural history of DCIS."
Mammography has led to the earlier detection of nonpalpable, subclinicalDCIS, Dr. Schwartz said. Concurrently, the inevitable progression of DCISto invasive carcinoma has been questioned, and the traditional use of mastectomyhas been challenged for these minute areas of disease.
In his presentation, Dr. Schwartz asked, rhetorically, "Is it reasonableto treat these subclinical areas of malignant cells, which have not yetdemonstrated the ability to invade or metastasize--the definition of DCIS--bylocal excision alone without requiring attention to the whole breast oraxilla?" He believes that such an approach is reasonable in carefullyselected patients. The women in the Jefferson College study were selectedby the surgical team after considering various risk factors.
Dr. Schwartz noted that many surgeons and oncologists seem more concernedwith the morphology or architecture of the DCIS in making a decision aboutfurther treatment than in the biology of the cancer.
He believes that more important information to quantify parameters ofaggressiveness--proliferation markers, steroid receptors, and the like--shouldbe collected on all patients with DCIS to see if other, more precise, predictorsof recurrence can be identified.
The ultimate objective, he reiterated, is to identify subsets of patientswith subclinical DCIS who are unlikely to suffer recurrence of diseaseafter local excision alone, sparing them from either mastectomy or irradiation.