INT participants will be asked to perform self-measurements of arm circumference at five points along the arm at home every three months. Additional measurements can be performed if the participants experience signs of BCRL. Participants will report the self-measurements in cm and mm in an online questionnaire, or over the phone to a physiotherapist navigator, along with reporting sign and symptoms of BCRL.

The CON group will follow the usual post-operative care. CON participants will be prompted every 6 months by an online questionnaire to report if they have been diagnosed with BCRL and if so, month of initiation of treatment.

A participant with an increase from pre-surgery in total arm volume of ≥6% by self-measurement, or symptoms of BCRL ≥2 NRS will receive an assessment by a lymphedema therapist. At this appointment, participants will receive a physical examination of the arm along with a BIS measurement. A participant is considered having subclinical BCRL if an increase in lymphedema index (L-DEX) ≥7 from pre-surgery measured by BIS is identified. A fitted compression garment and gauntlet is then provided, free of charge, for daily wear 10 hours/day for four weeks along with a recommendation to use the arm for daily activities and maintain regular physical activity. Following the four-week compression period, participants will be re-measured using BIS to evaluate response. Participants who do not respond to compression will receive CDT delivered by the lymphedema therapist.

A binary outcome (y/n) defined as BIS ≥10 from pre-surgery or outside normal range ±10

INT group: The time (weeks) from surgery to first elevated L-DEX score which triggers immediate treatment along with time (weeks) to resolution of BCRL from diagnosis. For CON: time from surgery to BCRL diagnosis, time from diagnosis to BCRL treatment, and time from initiation to termination of treatment