Lymphedema after complete axillary node dissection for melanoma: assessment using a new, objective definition

Abstract

Objectives: The objectives of this study were to define appropriate criteria for assessing the presence of lymphedema, and to report the prevalence and risk factors for development of upper limb lymphedema after level I-III axillary dissection for melanoma.

Summary background data: The lack of a consistent and reliable objective definition for lymphedema remains a significant barrier to appreciating its prevalence after axillary dissection for melanoma (or breast carcinoma).

Methods: Lymphedema was assessed in 107 patients (82 male, 25 female) who had previously undergone complete level I-III axillary dissection. Of the 107 patients, 17 had also received postoperative axillary radiotherapy. Arm volume was measured using a water displacement technique. Change in volume of the arm on the side of the dissection was referenced to the volume of the other (control) arm. Volume measurements were corrected for the effect of handedness using corrections derived from a control group. Classification and regression tree (CART) analysis was used to determine a threshold fractional arm volume increase above which volume changes were considered to indicate lymphedema.

Results: Based on the CART analysis results, lymphedema was defined as an increase in arm volume greater than 16% of the volume of the control arm. Using this definition, lymphedema prevalence for patients in the present study was 10% after complete level I-III axillary dissection for melanoma and 53% after additional axillary radiotherapy. Radiotherapy and wound complications were independent risk factors for the development of lymphedema.

Conclusions: A suggested objective definition for arm lymphedema after axillary dissection is an arm volume increase of greater than 16% of the volume of the control arm.

FIGURE 1. Reference points for arm volume and circumference measurements were marked with the elbow at a right angle and the shoulder in the anatomic position. MP, midpoint between the lateral epicondyle of the humerus and the acromion of the shoulder; C-15, 15 cm above the lateral epicondyle of the humerus; F-MP, midpoint between the tip of the ulnar styloid process and the lateral epicondyle of the humerus; C-10, 10 cm below the lateral epicondyle of the humerus.

FIGURE 2. Classification tree for arm volume measured at MP. An arm volume increase of >15.7% the volume of the control arm was determined by CART analysis to provide the optimal point of discrimination, allowing patients to be partitioned into 2 groups (A and B) on the basis of arm volume measurements. Group A contains as many as possible patients who experienced larger arm volume increases and who actually noticed this themselves, and group B contains as many as possible patients who experienced smaller arm volume increases (if at all) and who did not notice any volume change themselves. Of 106 patients (MP volume measurements were unavailable from 1 patient), 48 perceived an increase in arm volume. When these patients were partitioned, group A contained 18 patients with arm volume increases above 15.7%, 17 of these patients perceiving a volume increase, whereas group B contained 88 patients with volume increases less than 15.7%, 57 of these patients not perceiving any volume change.

FIGURE 3. Chronic lymphedema of the right upper limb in a 53-year-old man 6 years after level I–III axillary dissection and postoperative radiotherapy for metastatic melanoma.