Declining recurrence among ductal carcinoma in situ patients treated with breast-conserving surgery in the community setting

IntroductionRandomized trials indicate that adjuvant radiotherapy plus tamoxifen decrease the 5-year risk of recurrence among ductal carcinoma in situ (DCIS) patients treated with breast-conserving surgery (BCS) from about 20% to 8%. The aims of this study were to examine the use and impact of these therapies on risk of recurrence among DCIS patients diagnosed and treated in the community setting.

Methods: We identified 2995 patients diagnosed with DCIS between 1990 and 2001 and treated with BCS at three large health plans.

Medical charts were reviewed to confirm diagnosis and treatment and to obtain information on subsequent breast cancers. On a subset of patients, slides from the index DCIS were reviewed for histopathologic features.

Cumulative incidence curves were generated and Cox regression was used to examine changes in 5-year risk of recurrence across diagnosis years, with and without adjusting for trends in use of adjuvant therapies.

Results: Use of radiotherapy increased from 25.8% in 1990-1991 to 61.3% in 2000-2001; tamoxifen increased from 2.3% to 34.4%. A total of 245 patients had a local recurrence within 5 years of their index DCIS.

The 5-year risk of any local recurrence decreased from 14.3% (95% confidence interval (CI) 9.8-18.7) for patients diagnosed in 1990-91 to 7.7% (95% CI 5.5-9.9) for patients diagnosed in 1998-99; invasive recurrence decreased from 7.0% (95% CI 3.8-10.3) to 3.1% (95% CI 1.7-4.6). In Cox models, the association between diagnosis year and risk of recurrence was modestly attenuated after accounting for use of adjuvant therapy.

Between 1990-1991 and 2000-2001, the proportion of patients with tumors with high nuclear grade decreased from 46% to 32% (P=0.03) and those with involved surgical margins dropped from 15% to 0% (P=0.03).

Conclusions: The marked increase in the 1990s in the use of adjuvant therapy for DCIS patients treated with BCS in the community setting only partially explains the 50% decline in risk of recurrence risk. Changes in pathology factors have likely also contributed to this decline.

Author: Laurel HabelNinah AchacosoReina HaqueLarissa NekhlyudovSuzanne FletcherStuart SchnittLaura CollinsAnn GeigerBalaram PuligandlaLuana ActonCharles Quesenberry
Credits/Source: Breast Cancer Research 2009, 11:R85

Published on: 2009-11-18

Copyright by the authors listed above - made available via BioMedCentral (Open Access). Please make sure to read our disclaimer prior to contacting 7thSpace Interactive. To contact our editors, visit our online helpdesk. If you wish submit your own press release, click here.

Comments Page 0 of 0

There are currently 0 comments to display.

+ Add New Comment

Custom Search