BOSTON -- Young women with DCIS, a common form of early breast cancer that arises in and is confined to the mammary ducts, are presumed more likely to have recurrences than older women with the same diagnosis. But a new study from Fox Chase Cancer Center rebuffs this conventional thinking.
"There are discrepancies among past studies that looked at the outcomes of very young women with DCIS treated with radiation, but many suggested a less favorable outcome than for older women," explains Aruna Turaka, MD, a fellow in the Department of Radiation Oncology at Fox Chase. "Because each of these studies reflects diverse factors, including how the cancer was managed by the surgeons and radiation oncologists, we wanted to look at our institution's experience in treating DCIS in this population."
Ductal carcinoma in situ, or DCIS, is generally treated with breast-conserving surgery (lumpectomy) and radiation. At Fox Chase, surgeons will commonly re-excise the tumor site until the pathologists and surgeons have "clear margins," or find no sign of cancer around where the tumor was removed. General radiation guidelines dictate that the entire affected breast be irradiated. At Fox Chase, additional radiation also is delivered to the site where the cancer was removed. This is called a "boost."
For this study, physicians examined the records of 440 patients with DCIS treated from 1978 to 2007 at Fox Chase. Of these, 24 patients were 40 years old or younger. Patients with invasive disease or more than one area involved in the breast were excluded. Re-excision to obtain wider clear margins was used in 62 percent of all patients, and even more often - 75 percent - in patients 40 or younger.
All women received whole-breast radiotherapy and 95 percent also received a radiation boost. Data analyzed included method of presentation, patient and DCIS characteristics, and surgical and adjuvant treatment. The median follow-up was 6.8 years (range 0.2-24) and the median age was 56.5 years. The results of the study were presented today at the 50th annual meeting of the American Society for Therapeutic Radiology and Oncology.
"We didn't find a significant difference in recurrence rates based on age," explains Turaka. "Our study suggests that when treating DCIS with breast-conserving surgery and radiation, very young age plays a smaller role as a contributor to local recurrence than previously suggested."
Local recurrence for all women was 7 percent at 10 years and 8 percent at 15 years. At 15 years, the recurrence rate was 10 percent in patients 40 or younger, 7 percent in those ages 41-54, 11 percent in those ages 55-69, and 4 percent in those 70 and older. The different recurrence rates were not statistically significantly.
Turaka notes, "These results are specific to one institution. The reasons for the low rates of recurrence in young women could be related to the careful patient selection and a high utilization of surgical re-excision and a radiation boost."