Poster lunch (ID 46) Poster display session

127P - Treatment outcomes after post-operative radiotherapy in triple-negative breast cancer: Multi-institutional retrospective study (KROG 17-05) (ID 523)

Presentation Number
127P
Lecture Time
12:15 - 12:15
Speakers
  • Jin Hee Kim (Daegu, Korea, Republic of)
Session Name
Poster lunch (ID 46)
Location
Exhibition area, MARITIM Hotel Berlin, Berlin, Germany
Date
03.05.2019
Time
12:15 - 13:00

Abstract

Background

Triple-negative breast cancer (TNBC) shows different clinical course from ER-positive cancers. We designed multi-institutional retrospective study to analyze treatment outcomes after post-operative radiotherapy in TNBC.

Methods

We retrospectively reviewed 699 TNBC patients with post-operative radiation therapy from 6 institutions between 2008 and 2010. Median age was 49 (range, 24-80) and neoadjuvant chemotherapy was administered in 130 patients (18.6%). Breast conserving surgery was done in 634 (90.7%) and invasive ductal carcinoma was reported in 611 (87.4%). Two hundred and twenty five patients (36.5%) were stage I, 305 (43.6%) in II, and 67 (9.6%) in III. Lymphatic invasion (LI) was reported in 240 patients (34.3%) and extracapsular extension (ECE) was in 49 (7.0%). Patients were irradiated 45-50.4Gy with 25-28 fractions to the breast or chest wall followed by tumor bed boost with 10-16Gy with 5-8 fractions. Simultaneously, additional radiation fields were irradiated to supraclavicular or internal mammary lymph nodal areas. Adjuvant chemotherapy was done in 596 (85.3%).

Results

In median 94 months (range, 7-192) after treatments, 594 patients (85.0%) were no evidence of disease, 31 patients (5.0%) with alive with disease, 3 patients (0.4%) with died due to other causes, and 67 (9.6%) death from the breast cancer. Local recurrence was reported in 33 patients (4.7%), and regional failure was in 31 patients (4.4%), respectively. Distant metastasis was in 78 patients (11.2%). 5-year OS was 91.4%, 5-year LRRFS was 92.3%, 5-year DMFS was 89.4%, 5-year DFS was 85.2%, and 5-year CSS was 91.8%. On univariate analysis, age, clinical/pathologic T stages, clinical/pathologic N stages, histologic grade, LI, and ECE were related to survival rates. On multivariate analysis, younger age (≤50), clinical/pathologic stages, and ECE were also related to the survival outcomes.

Conclusions

We could verify several prognostic factors including age, stage, and ECE related survival outcomes after post-operative radiation therapy in TNBC. Distant metastasis was also more common than loco-regional failures. Further detailed analysis, including more patients scheduled for enrolment, would be necessary.

Legal entity responsible for the study

Jin Hee Kim.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.

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