Initial Treatment of Ductal Carcinoma in Situ May Affect Subsequent Treatment of Tumor Recurrences After Surgery
The use of radiotherapy for the index ductal carcinoma in situ (DCIS) may affect subsequent treatment of tumor recurrences and complications after breast-conserving surgery, reported Greenberg et al in the Annals of Surgical Oncology. Based on the results of this retrospective cohort study, the long-term clinical implications of initial treatment decisions for women with DCIS warrant serious consideration.
Although the optimal therapeutic strategy for women with DCIS remains unclear, treatment centers on local tumor control to prevent progression to invasive disease, with its risk of metastases. Randomized clinical trials have shown that radiotherapy after breast-conserving surgery reduces the risk of a second ipsilateral event by 50% to 60%.
However, with no survival benefits confirmed with the use of radiotherapy and an association with complications (potentially limiting wound healing and complicating treatment choices after tumor recurrence), there is a lack of consensus on the role of radiotherapy in this setting. In fact, the optimal type of radiotherapy, whether it be standard external-beam radiation or newer options such as hypofractionation, partial-breast irradiation, and brachytherapy, remains debatable as well.
Study Details
To shed more light on the consequences of treatment decisions for index DCIS, Greenberg et al conducted a retrospective cohort study of 270 patients from two data sources: the National Comprehensive Cancer Network (NCCN) Oncology Outcomes Database and the Cancer Research Network (CRN). A total of 88 patients were from academic NCCN centers, and 182 patients were from community-based integrated health-care delivery systems of the CRN. After undergoing breast-conserving surgery for index DCIS, all of these patients experienced a tumor recurrence (either DCIS or invasive cancer).
In addition to assembling demographic, clinical, and treatment data at the time of the index diagnosis for patients in both cohorts, the investigators collected information on the treatments performed at the time of tumor recurrence (mastectomy alone, breast-conserving surgery, or mastectomy with reconstruction). Furthermore, they assessed whether subsequent surgical complications (such as incision and drainage, wound evacuation, and flap debridement) were affected by the use of radiotherapy for the index tumor.
Surgical Complications More Likely in Irradiated Patients
Approximately 40% of patients in both cohorts had mastectomy alone at the time of tumor recurrence. The choice of treatment for the remaining 60% of patients in both cohorts varied. For example, repeat breast-conserving surgery was performed in 39% (71 patients) of the CRN cohort, compared with only 16% (14 patients) in the NCCN cohort. Mastectomy with reconstruction was performed in 18% (32 patients) in the CRN cohort, compared with 44% (39 patients) in the NCCN cohort.
The investigators also reported that patients who received radiotherapy for their index DCIS were significantly less likely to undergo repeat breast-conserving surgery than patients who did not receive radiotherapy (NCCN: 6.6% vs 37%; P = .001; CRN: 20% vs 48%; P = .0004). Furthermore, those who had radiotherapy for their index DCIS were more likely to experience surgical complications after treatment of their tumor recurrence than were those who did not have radiotherapy (NCCN, 15% vs 4%; CRN, 40% vs 25%; P = .09), although this difference in the NCCN cohort did not reach statistical significance (P = .17).
Clinical Implications
These study results indicate that the use of radiotherapy for index DCIS may have a substantial impact on surgical decision-making and perhaps influence the likelihood of surgical complications at the time of treatment of tumor recurrence. The investigators acknowledged the possible benefits of adjuvant radiotherapy after breast-conserving surgery for DCIS in reducing the risk of local tumor recurrence but noted the lack of a confirmed survival advantage. In closing, they cautioned that the use of radiotherapy may limit surgical options for treatment of subsequent local tumor recurrence and added that the long-term sequelae of these treatments warrant serious consideration.
“Determining the optimal approach to the treatment of [DCIS] has important implications, not only for individual patients but also for the American healthcare system,” the investigators remarked.
Caprice C. Greenberg, MD, MPH, of the University of Wisconsin Hospitals and Clinics, Madison, is the corresponding author of the article in the Annals of Surgical Oncology.
This study was supported by the Agency for Healthcare Research and Quality, the U.S. Department of Health and Human Services, and by grants from the National Cancer Institute. The investigators reported no potential conflicts of interest.
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