RTOG 9804: a prospective randomized trial for good-risk ductal carcinoma in situ comparing radiotherapy with observation.

Abstract

PURPOSE:

The Radiation Therapy Oncology Group 9804 study identified good-risk patients with ductal carcinoma in situ (DCIS), a breast cancer diagnosis found frequently in mammographically detected cancers, to test the benefit of radiotherapy (RT) after breast-conserving surgery compared with observation.

PATIENTS AND METHODS:

This prospective randomized trial (1998 to 2006) in women with mammographically detected low- or intermediate-grade DCIS, measuring less than 2.5 cm with margins ≥ 3 mm, compared RT with observation after surgery. The study was designed for 1,790 patients but was closed early because of lower than projected accrual. Six hundred thirty-six patients from the United States and Canada were entered; tamoxifen use (62%) was optional. Ipsilateral local failure (LF) was the primary end point; LF and contralateral failure were estimated using cumulative incidence, and overall and disease-free survival were estimated using the Kaplan-Meier method.

RESULTS:

Median follow-up time was 7.17 years (range, 0.01 to 11.33 years). Two LFs occurred in the RT arm, and 19 occurred in the observation arm. At 7 years, the LF rate was 0.9% (95% CI, 0.0% to 2.2%) in the RT arm versus 6.7% (95% CI, 3.2% to 9.6%) in the observation arm (hazard ratio, 0.11; 95% CI, 0.03 to 0.47; P < .001). Grade 1 to 2 acute toxicities occurred in 30% and 76% of patients in the observation and RT arms, respectively; grade 3 or 4 toxicities occurred in 4.0% and 4.2% of patients, respectively. Late RT toxicity was grade 1 in 30%, grade 2 in 4.6%, and grade 3 in 0.7% of patients.

CONCLUSION:

In this good-risk subset of patients with DCIS, with a median follow-up of 7 years, the LF rate was low with observation but was decreased significantly with the addition of RT. Longer follow-up is planned because the timeline for LF in this setting seems protracted.

• Authors: Beryl McCormick, Kathryn Winter, Clifford Hudis, Henry Mark Kuerer, Eileen Rakovitch, Barbara L Smith, Nour Sneige, Jennifer Moughan, Amit Shah, Isabelle Germain, Alan C Hartford, Afshin Rashtian, Eleanor M Walker, Albert Yuen, Eric A Strom, Jeannette L Wilcox, Laura A Vallow, William Small Jr, Anthony T Pu, Kevin Kerlin, Julia White
• Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology (J Clin Oncol) Vol. 33 Issue 7 Pg. 709-15 (Mar 01 2015) ISSN: 1527-7755 [Electronic] United States
• PMID: 25605856 (Publication Type: Clinical Trial, Phase III, Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, N.I.H., Extramural)
• Copyright: © 2015 by American Society of Clinical Oncology.

Topics

• Adult
• Aged
• Breast Neoplasms (diagnostic imaging, pathology, prevention & control, radiotherapy, surgery)
• Canada
• Carcinoma, Intraductal, Noninfiltrating (diagnostic imaging, radiotherapy, surgery)
• Disease Management
• Disease-Free Survival
• Female
• Humans
• Kaplan-Meier Estimate
• Mammography
• Mastectomy, Segmental
• Middle Aged
• Neoplasm Recurrence, Local (prevention & control)
• Odds Ratio
• Prospective Studies
• Radiotherapy, Adjuvant
• Risk Assessment
• Treatment Outcome
• United States
• Watchful Waiting