Preoperative inter-arm differences and normative-based thresholds for lymphedema in Chinese breast cancer patients: Insights from a large cohort study.

Objective: Early detection and diagnosis of lymphedema are crucial for effective treatment and prevention of its progression. Normative-based diagnostic thresholds can enhance diagnostic accuracy in the absence of preoperative measurements. This study aimed to investigate preoperative inter-arm differences and the associated factors, as well as to determine normative-based thresholds for lymphedema in Chinese breast cancer patients.

Methods: This study utilized baseline data from a large cohort of Chinese breast cancer patients. Bilateral arm circumferences were measured at the wrist and at 10 cm intervals proximally up to 40 cm. Arm volumes were calculated using the truncated cone formula. Paired test, repeated measures analysis of variance, and regression analysis were performed.

Results: A total of 1707 breast cancer patients were included. Paired tests showed that the dominant arm circumferences and volumes were significantly larger than those of the nondominant arm ( < 0.001). Regression analysis and repeated measures analysis of variance revealed that hand dominance was the influencing factor of inter-arm differences ( < 0.05). Normative-based thresholds determined by two standard deviations above the mean inter-arm volume ratio were 1.057 for the dominant arm and 1.079 for the nondominant arm.

Conclusions: The absolute and relative normative-based thresholds for Chinese breast cancer patients differed slightly from the commonly used diagnostic criteria and those reported in Western populations and among Chinese healthy women. The normal variability and asymmetry associated with arm dominance underscore the importance of preoperative baseline assessments. Implementing normative-based diagnostic thresholds can facilitate more accurate lymphedema diagnosis when preoperative measurements are unavailable.

Trial Registration: Registration No. ChiCTR2200057083.