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


METHODS
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.


RESULTS
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(+).


CONCLUSIONS
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.
Harvard Radiation Oncology Program, Boston, MA, USA.
Lia M
LM
Halasz
Meera
M
Sreedhara
Yu-Hui
YH
Chen
Jennifer R
JR
Bellon
Rinaa S
RS
Punglia
Julia S
JS
Wong
Jay R
JR
Harris
Jane E
JE
Brock
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000737:chemistry / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D009364:Neoplasm Recurrence, Local; D011879:Radiotherapy Dosage; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D012086:Reoperation / Q000379:methods; D016896:Treatment Outcome
D009363:Neoplasm Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone