The Pittsburgh Trunk Lymphedema Staging System (PTLSS) - a validated staging system for the description of breast cancer-associated trunk lymphedema.

Background: Neither anatomic nor functional descriptions exist of trunk/breast lymphedema following breast cancer treatment. Indocyanine green (ICG)-lymphangiography has been shown to characterize lymph channel dysfunction seen in lymphedema. We propose using ICG-lymphangiography to evaluate trunk and breast lymphedema following breast cancer surgery to characterize the regions affected via a novel, validated staging system.

Methods: Patients undergoing revisional breast surgery with suspicion of upper extremity lymphedema between December 2014 and March 2020 were offered lymphangiography. The breast and lateral/anterior trunks were visualized and blindly evaluated using Koshima's patterns of dermal backflow. Patients were then staged. A linear-weighted Cohen's kappa statistic was calculated comparing each rated area and stage assignment.

Results: Fifty-two sides (29 patients) were included. Eight sides underwent no treatment and were considered controls. No lymphedema was identified within this cohort. One patient (two sides) had no transit of ICG. Seventy-six percent of the non-controls had dermal backflow. This was seen in 67% of anterior trunks, 50% of lateral trunks, 50% of inframammary folds (IMFs), 43% of inferior breasts, and 5% of superior breasts. Cohen's kappa for area agreement was 0.4117 ± 0.0535. Stage 0 was seen in 31 (±7)% of sides; stage 1: 21 (±1)%; stage 2: 22 (±5)%; stage 3: 18 (±4)%; stage 4: 5 (±1)%; and stage 5: 4 (±0). Cohen's kappa for staging was 0.8109 ± 0.0868.

Conclusion: Following breast cancer surgery, lymphedema occurs throughout the trunk and breast. Severe dysfunction appears to be located around the inferior-lateral aspect of the breast and chest wall. Furthermore, the Pittsburgh Trunk Lymphedema Staging System is a validated measure of trunk and breast lymphedema.