Ductal carcinoma in situ--the influence of the radiotherapy boost on local control.

Local recurrence (LR) of ductal carcinoma in situ (DCIS) is reduced by whole-breast irradiation after breast-conserving surgery (BCS). However, the benefit of adding a radiotherapy boost to the surgical cavity for DCIS is unclear. We sought to determine the impact of the boost on LR in patients with DCIS treated at the McGill University Health Centre. A total of 220 consecutive cases of DCIS treated with BCS and radiotherapy between January 2000 and December 2006 were reviewed. Of the patients, 36% received a radiotherapy boost to the surgical cavity. Median follow-up was 46 months for the boost and no-boost groups. Kaplan-Meier survival analyses and Cox regression analyses were performed. Compared with the no-boost group, patients in the boost group more frequently had positive and <0.1-cm margins (48% vs. 8%) (p < 0.0001) and more frequently were in higher-risk categories as defined by the Van Nuys Prognostic (VNP) index (p = 0.006). Despite being at higher risk for LR, none (0/79) of the patients who received a boost experienced LR, whereas 8 of 141 patients who did not receive a boost experienced an in-breast LR (log-rank p = 0.03). Univariate analysis of prognostic factors (age, tumor size, margin status, histological grade, necrosis, and VNP risk category) revealed only the presence of necrosis to significantly correlate with LR (log-rank p = 0.003). The whole-breast irradiation dose and fractionation schedule did not affect LR rate. Our results suggest that the use of a radiotherapy boost improves local control in DCIS and may outweigh the poor prognostic effect of necrosis.

Wong P ，Lambert C ，Agnihotram RV ，David M ，Duclos M ，Freeman CR ... -  《-》

Role of radiotherapy boost in women with ductal carcinoma in situ: a single-center experience in a series of 389 patients.

The use of adjuvant radiotherapy in ductal carcinoma in situ is accepted by most radiation oncologists worldwide; the role of a boost on the tumor bed is however more controversial. We reviewed our Institute experience in DCIS treatment, focusing on main prognostic factors and impact of radiation boost on local relapse. A total of 389 patients treated between 1990 and 2007 were retrospectively analyzed. All patients received adjuvant radiotherapy after breast-conserving surgery for a median dose of 50 Gy; 190 patients (48.8%) received and additional radiation boost on the tumor bed. At a mean follow up of 7.7 years, we recorded 26 local recurrence (6.7%). Concerning local relapse-free survival, at Cox regression univariate analyses <1 mm surgical margins (p < 0.0001) and young age (p = 0.01) emerged as significant unfavorable prognostic factors. At multivariate analysis Cox regression model, surgical margins (p < 0.001) and radiation boost (p = 0.014) resulted as the significant independent predictors of recurrence. Our experience showed the negative prognostic impact of surgical margins <1 mm and the protective role of radiation boost on LR rate. Anyway, results from ongoing prospective Phase III studies are strongly necessary to better identify high-risk DCIS patients.

Meattini I ，Livi L ，Franceschini D ，Saieva C ，Meacci F ，Marrazzo L ，Bendinelli B ，Scotti V ，De Luca Cardillo C ，Nori J ，Sanchez L ，Orzalesi L ，Bonomo P ，Greto D ，Bucciolini M ，Bianchi S ，Biti G ... -  《-》

Improved outcomes of breast-conserving therapy for patients with ductal carcinoma in situ.

Patients treated for ductal carcinoma in situ (DCIS) with breast-conserving surgery (BCS) and radiation therapy (RT) at our center from 1976 to 1990 had a 15% actuarial 10-year local recurrence (LR) rate. Since then, improved mammographic and pathologic evaluation and greater attention to achieving negative margins may have resulted in a lower risk of LR. In addition, clinical implications of hormone receptor and HER-2 status in DCIS remain unclear. We sought to determine the following: LR rates with this more modern approach; the relation between LR and HER-2 status; and clinical and pathologic factors associated with HER-2(+) DCIS. We studied 246 consecutive patients who underwent BCS and RT for DCIS from 2001 to 2007. Of the patients, 96 (39%) were Grade III and the median number of involved tissue blocks was 3. Half underwent re-excision and 222 (90%) had negative margins (>2 mm). All received whole-breast RT (40-52 Gy) and 99% (244) received a tumor bed boost (8-18 Gy). Routine estrogen receptor (ER), progesterone receptor (PR), and HER-2 immunohistochemistry was instituted in 2003. With median follow-up of 58 months, there were no LRs. Seven patients (3%) developed contralateral breast cancer (4 invasive and 3 in situ). Among 163 patients with immunohistochemistry, 124 were ER/PR(+)HER-2(-), 27 were ER/PR(+)HER-2(+), 6 were ER(-)/PR(-)HER-2(+), and 6 were ER(-)/PR(-)HER-2(-). On univariable analysis, HER-2(+)was significantly associated with Grade III, ER(-)/PR(-), central necrosis, comedo subtype, more extensive DCIS, and postmenopausal status. On multivariable analysis, Grade III and postmenopausal status remained significantly associated with HER-2(+). In an era of mammographically identified DCIS, larger excisions, widely negative margins and the use of a tumor bed boost, we observed no LR regardless of ER/PR/HER-2 status. Factors associated with HER-2(+)DCIS included more extensive DCIS, Grade III, ER(-)/PR(-), central necrosis, comedo subtype, and postmenopausal status. Further follow-up and additional studies are required to confirm these results.

Halasz LM ，Sreedhara M ，Chen YH ，Bellon JR ，Punglia RS ，Wong JS ，Harris JR ，Brock JE ... -  《-》

Defining negative margins in DCIS patients treated with breast conservation therapy: The University of Chicago experience.

Sahoo S ，Recant WM ，Jaskowiak N ，Tong L ，Heimann R ... -  《Breast Journal》

Factors associated with local recurrence and cause-specific survival in patients with ductal carcinoma in situ of the breast treated with breast-conserving therapy or mastectomy.

Vargas C ，Kestin L ，Go N ，Krauss D ，Chen P ，Goldstein N ，Martinez A ，Vicini FA ... -  《INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS》