The Risk of Subclinical Breast Cancer-Related Lymphedema by the Extent of Axillary Surgery and Regional Node Irradiation: A Randomized Controlled Trial

John Boyages,Frank A Vicini,Chirag Shah,Louise A Koelmeyer,Jerrod A Nelms,Sheila H Ridner

doi:10.1016/j.ijrobp.2020.10.024

Abstract

To compare the risk of subclinical breast cancer-related lymphedema (sBCRL) using bioimpedance spectroscopy (BIS) or tape measure (TM) by the extent of axillary surgery and regional nodal irradiation (RNI). Patients were randomized to surveillance with TM or BIS. A BIS ≥6.5 L-Dex units or TM volume change ≥5 and <10% above presurgical baselines "triggered" sBCRL. The incidence of sBCRL by sentinel node biopsy or axillary lymph node dissection (ALND) with or without RNI was examined for 484 patients. Radiation was categorized as "limited RNI" (axilla level I/II only) or "extensive RNI" (axilla level III or supraclavicular fossa with or without level I/II). At a median follow-up of 20.5 months, 109 of 498 patients (21.9%) triggered sBCRL (BIS 13.5% vs TM 25.6%; P <.001). In patients not receiving RNI, BIS triggered 12.9% of patients undergoing SNB and 25.0% undergoing ALND (P = .18). Extensive RNI significantly increased triggering with BIS versus no RNI after sentinel node biopsy (SNB; 33.3% vs 12.9%; P = .03) but not ALND (30.8% vs 25.0%; P = .69). Triggering by TM was greater than 25% for most subgroups and was inferior to BIS in discriminating the risk of sBCRL by utilization of RNI or axillary surgery. The lower triggering rates with BIS and its better discrimination of the risk of sBCRL by receipt and type of RNI compared with TM support its use for posttreatment surveillance to detect sBCRL and to initiate early intervention. The risk of sBCRL increased with more extensive axillary treatment. Patients having ALND or extensive RNI require close surveillance for BCRL. Longer follow-up is required to determine rates of progression to clinical lymphedema.

Highlights

In the modern era of breast cancer treatment, there is an increasing trend to “de-escalate” axillary management to avoid the morbidity of an axillary lymph node dissection (ALND)
But mostly unanswered, question is how to balance the extent of treatment to the axilla, which has a small effect on breast cancer mortality to the higher risk of breast cancererelated lymphedema (BCRL)
The crude incidence of triggering for potential subclinical BCRL (sBCRL) detected by either screening technique was 30.8% for patients who underwent ALND versus 19.2% for patients undergoing sentinel node biopsy (SNB) (P Z .01)

Summary

Introduction

In the modern era of breast cancer treatment, there is an increasing trend to “de-escalate” axillary management to avoid the morbidity of an axillary lymph node dissection (ALND). The dilemma is that more aggressive treatment to the regional nodes is associated with higher rates and earlier onset of breast cancererelated lymphedema (BCRL).[1] Less aggressive treatments, are potentially associated with higher rates of locoregional recurrence and breast cancer mortality. It is unclear why some patients develop BCRL and others do not. But mostly unanswered, question is how to balance the extent of treatment to the axilla, which has a small effect on breast cancer mortality to the higher risk of BCRL. A question arises as to whether long-term metaanalysis data applies to patients treated today with more effective systemic treatments, such as taxanes[4] and trastuzumab, likely means that it is probably safe to omit postmastectomy radiation for some patients with early nodal disease and limit the extent of radiation for others.[5,6,7]

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Discussion

Conclusion