Post-breast cancer lymphedema: incidence increases from 12 to 30 to 60 months.

Breast cancer survivors are at life-time risk of developing lymphedema (LE). Quantification of LE has been problematic as the criteria used to identify lymphedema use various methods to assess changes in the volume of the affected limb. In part because of difficulties and variability in measurement and diagnosis, the reported incidence of LE varies greatly among women treated with surgery and radiation for breast cancer. The goal of this research was to describe the trends for LE occurrence over three points in time (12, 30, and 60 months) among breast cancer survivors using four diagnostic criteria based on three measurement techniques. Participants were enrolled following diagnosis of breast cancer but before surgery. Baseline limb volume and symptom assessment data were obtained. Participants were followed every 3 months for 12 months, then every 6 months thereafter for a total of 60 months. Limb volume changes (LVC) in both limbs were measured using three techniques: objectively by (a) circumferences at 4 cm intervals and (b) perometry and subjectively by (c) symptom experience via interview. Four diagnostic criteria for LE most often reported in the literature were used: (i) 2 cm circumferential change; (ii) 200 mL perometry LVC; (iii) 10% perometry LVC; and (iv) signs and symptoms (SS) report of limb heaviness and swelling, either 'now' or 'in the past year' (diagnostic criteria i-iii define increases/differences in limb volume from baseline and/or between the affected and non-affected limb). Standard survival analysis methods were applied to identify when the criteria corresponding to LE were met. Trends in LE occurrence are reported for preliminary analysis of data from 236 participants collected at 6-, 12-, 18-, 24-, 30-, and 60-months post-op. At 60 months post-treatment, LE incidence using the four criteria ranged from 43% to 94%, with 2 cm associated with the highest frequency for lymphedema occurrence and SS the lowest. Sixty-month trends are compared to earlier trends at 12- and 30-months, per criterion. These preliminary findings provide additional evidence that breast cancer survivors are at risk for developing LE beyond the first year following treatment. Cases of lymphedema continue to emerge through 60-months post-breast cancer surgery. This 60-month analysis supports the previous 12- and 30-month analyses in finding the 2 cm criteria to be the most liberal definition of LE. The self-report of heaviness and swelling, along with 10% LVC, represent the most conservative definitions (41% and 45%, respectively). Furthermore, the variety of criteria used to identify LE, along with the absence of baseline (pre-treatment) measurements, likely contribute to the wide range of LE incidence rates reported in the literature.