2686 - Relationship of Immediate Breast Reconstruction and the Development of Lymphedema in Breast Cancer Patients with Radiotherapy

S. W. Hong¹, K. Kim², and I. A. Kim²; ¹Seoul National University Hospital, Seoul, Korea, Republic of (South), ²Department of Radiation Oncology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea, Republic of (South)

Purpose/Objective(s): Upper extremity lymphedema, a common complication following breast cancer treatments, often poses management challenges with limited knowledge of prevention. While several factors are well known for their contribution, recent studies have also suggested the potential association of immediate breast reconstruction with lower incidence. Given the inconclusive results, we explored the impact of immediate reconstruction on lymphedema incidence in breast cancer patients who underwent a mastectomy and radiotherapy. Materials/

Methods: Our study included 471 breast cancer patients who underwent a mastectomy with subsequent radiotherapy from 2012 to 2020, and clinical data were retrospectively collected. Of these, 229 underwent immediate breast reconstruction, whereas 242 did not. Upper extremity lymphedema events were defined and graded on a scale of 0 to 3, following the International Society of Lymphology (ISL) staging system. We utilized univariate and multivariate Cox regression models to identify associated factors.

Results: After a median follow-up period of 49 months, 121 patients developed upper extremity lymphedema. Regarding the stage 2 or 3 lymphedema events (n=91), patients who underwent axillary lymph node dissection (ALND) were more likely to develop the event (3-year actuarial rate 16.6% vs. 4.9%; p<0.001), while the immediate breast reconstruction was linked to a lower incidence (3-year actuarial rate 8.5% vs. 18.1%; p<0.001) in univariate Cox analysis. This pattern persisted in the multivariate Cox analysis (p=0.038 and 0.018) and was still observable when including stage 1 lymphedema, although the impact of immediate reconstruction was less pronounced(3-year actuarial rate 12.5% vs. 20.7%; p=0.092).




Conclusion: In terms of the factors that are related to the upper extremity lymphedema events in postmastectomy breast cancer patients, the lymph node dissection method was found to be the most significant. Besides, immediate breast reconstruction is also noteworthy for its association with a lower incidence of lymphedema in these patients. Validation is needed to confirm this finding in future studies.

	Lymphedema with grade =2		Lymphedema with grade =1
	HR (95% CI)	P	HR (95% CI)	P
BMI at surgery, kg/m2 (continuous)	1.026 ( 0.97 - 1.08 )	0.355	1.047 ( 1 - 1.1 )	0.067
Taxane-based chemotherapy	2.109 ( 0.86 - 5.15 )	0.101	1.855 ( 0.85 - 4.04 )	0.120
ALND (yes vs SLNB only)	2.775 ( 1.06 - 7.29 )	0.038	4.202 ( 1.65 - 10.67 )	0.003
Radiotherapy technique (IMRT vs 3D)	1.434 ( 0.92 - 2.25 )	0.115	1.355 ( 0.91 - 2.01 )	0.130
RNI (axilla level I-II included or not)	1.035 ( 0.35 - 3.02 )	0.950	1.061 ( 0.4 - 2.78 )	0.905
Immediate reconstruction	0.570 ( 0.36 - 0.91 )	0.018	0.710 ( 0.48 - 1.06 )	0.092
ALND, axillary lymph node dissection; SLNB, selective lymph node biopsy; RNI, Regional lymph node irradiation