Choice of treatment, choice of surgeon, and surgical margin (a measure of whether the cancer was completely removed) all appear to affect the risk of disease recurrence among women with ductal carcinoma in situ (DCIS) of the breast. These findings were reported in the Journal of the National Cancer Institute.
Ductal carcinoma in situ refers to a condition in which abnormal cells are found within a breast duct but have not spread outside of the duct to other tissues in the breast. It is most commonly detected by screening mammography. If not treated, some cases of DCIS may progress to invasive breast cancer.
Treatment for DCIS tends to vary. Options include lumpectomy with or without radiation therapy or mastectomy. Data comparing outcomes of different treatment options, as well as how individual outcomes vary by surgeon, have previously been limited.
To compare outcomes of different treatments for DCIS, researchers reviewed the medical records of 994 women who had been diagnosed with DCIS between 1985 and 2000. They evaluated treatment (surgery and radiation therapy), margin status, and the role of surgeons and how these factors affect outcomes. The margin refers to the edges of the tissue that is removed surgically. If cancer cells are found at or near the margin (positive margin), it’s possible that the cancer was not completely removed.
- Type of treatment had a significant impact on recurrence risk at five years. Mastectomy was associated with the lowest risk of recurrence, followed by breast-conserving surgery with radiation therapy. Women who received breast-conserving surgery without radiation therapy had the highest risk of recurrence.
- Margin status was also significantly associated with disease-free survival, with negative margins linked with improved disease-free survival.
- Disease-free survival also varied by surgeon. Choice of surgeon appeared to account for 15-30% of the variability in outcome.
These findings indicate that treatment type, margin status, and choice of surgeon are important predictors of long-term disease-free survival in DCIS. Recurrence risk is lowest for women with negative surgical margins and for women who are treated with mastectomy or the combination of breast-conserving surgery and radiation therapy.
Reference: Dick AW, Sorbero MS, Ahrendt GM, et al. Comparative effectiveness of ductal carcinoma in situ management and the roles of margins and surgeons. Journal of the National Cancer Institute [early online publication]. January 3, 2011.