The Characteristics of Pain Tolerance in Patients Who Underwent Unilateral Breast Cancer Surgery: The Effect of Handedness and Surgical Site to Assess the Potential Musculoskeletal Symptoms and Function.

Background: Breast cancer survivors (BCS) usually experience musculoskeletal pain and strength imbalance between surgical and nonsurgical sites.

Material And Methods: This study aimed to assess the effect of handedness and surgical site on pain tolerance and upper extremity strength in BCS. A total of 96 female BCS (Mean age and BMI: 51.06 ± 9.36 years and 27.77 ± 3.75 kg/m) were included in this study. BCS were categorized as "DoS" or "NoS" whether they had surgery on their dominant or nondominant site, respectively. Socio-demographic data, upper extremity strength, pain tolerance, and pain-related function measurements were performed by simple form, manual muscle tester, pain algometer, and Disabilities of Arm, Shoulder, and Hand's (DASH) pain subscale, respectively.

Results: Pain tolerances were significantly lower in upper trapezius muscle region in the surgical site (t = -4,263, P < .001 and t = -2138, P = 0.037) while in the deltoid tuberosity, pain tolerance was significantly higher in surgical site (t = 2633, P = 0.011). Mean differences in strength in shoulder flexion and abduction were significantly lower in the DoS group compared to the NoS group (z = -3.166, P = .002 and z = -2.131, P = .033, respectively), whereas the pain subscale was significantly higher in the DoS (P = .013).

Conclusion: Pain tolerance decreased in the upper trapezius muscle region on the surgical site irrespective of the handedness. However, in deltoid tuberosity, the effect of handedness was remarkable. Exercise programs should focus to establish a strength balance in nondominant surgery BCS since strength imbalance might be more prominent to affect them to take part in activities in daily living.