Pain sensitivity and shoulder function among breast cancer survivors compared to matched controls: a case-control...

Area of Science:

• Oncology
• Pain Medicine
• Rehabilitation Science

Background:

• Persistent pain and impaired shoulder function are common after breast cancer treatment (BCS).
• The long-term impact on shoulder function and pain sensitivity in survivors beyond 1.5 years post-treatment remains unclear compared to healthy individuals.

Purpose of the Study:

• To compare pressure pain thresholds (PPTs), maximal isokinetic muscle strength (MIMS), and active range of motion (ROM) in female BCS with persistent pain (≥1.5 years post-treatment) against pain-free matched controls (CON).
• To investigate movement-evoked pain (MEP) during MIMS assessment in BCS survivors.

Main Methods:

• Assessed PPTs at 18 locations using a pressure algometer.
• Measured active ROM with a universal goniometer and MIMS with an isokinetic dynamometer.
• Quantified MEP intensity using a numeric rating scale.

Main Results:

• BCS survivors exhibited significantly lower PPTs across all locations compared to CON.
• Significant reductions in MIMS (shoulder extension/flexion, adduction) and active ROM (flexion, horizontal extension, abduction, external rotation) were observed in BCS survivors.
• BCS survivors reported significantly higher MEP, which negatively correlated with PPTs.

Conclusions:

• Female breast cancer survivors with persistent pain ≥1.5 years post-treatment demonstrate widespread reductions in PPTs and specific deficits in shoulder MIMS and active ROM.
• The presence of MEP during physical assessment suggests central sensitization in these survivors.
• Individualized rehabilitation strategies may be beneficial for BCS survivors experiencing persistent pain and functional deficits.