Patient-Reported Outcomes-Secondary Analysis of the SCORE-2 Trial Comparing 4 Gy × 5 to 3 Gy × 10 for Metastatic Epidural Spinal Cord Compression

Abstract

Purpose: To compare 4 Gy × 5 (1 week) to 3 Gy × 10 (2 weeks) in relieving pain and distress in patients with metastatic epidural spinal cord compression (MESCC).

Methods and materials: The randomized SCORE-2 trial compared 4 Gy × 5 (n = 101) to 3 Gy × 10 (n = 102) for MESCC. In this additional analysis, these regimens were compared for their effect in relieving pain and distress. Distress was evaluated with the distress-thermometer (0 = no distress, 10 = extreme distress) and pain on a linear scale (0 = no pain, 10 = worst pain). Relief of distress was defined as decrease of ≥2 points; complete and partial pain relief were defined as achieving a score of 0 points and a decrease ≥2 points, respectively, without increase of analgesic use. This prospective secondary analysis of the SCORE-2 trial aimed to show that 4 Gy × 5 was not inferior to 3 Gy × 10 regarding distress and pain relief. Analyses were performed using the unconditional test of noninferiority for binomial differences based on restricted maximum likelihood estimates (noninferiority margin: -20%). Evaluations were performed before, directly after, and 1, 3, and 6 months after radiation therapy. (ClinicalTrials.gov: NCT02189473).

Results: At baseline, median distress scores were 8 (2-10) points in the 4 Gy × 5 group and 8 (2-10) points in the 3 Gy × 10 group. At 1 month, distress relief rates were 58.1% (43/74) and 62.7% (47/75) (difference: -4.6%; 95% confidence interval, -20.0% to +11.1%; P = .025). At baseline, median pain scores were 7 (2-10) and 7 (2-10) points, respectively. At 1 month, complete pain relief rates were 23.5% (16/68) versus 20.0% (14/70) (difference, +3.5%; 95% confidence interval, -10.4% to +17.5%; P < .001), and overall pain relief rates were 52.9% (36/68) versus 57.1% (40/70) (difference, -4.2%; 95% confidence interval, -20.5% to +12.3%; P = .029). Distress and pain relief rates after 4 Gy × 5 were largely comparable to 3 Gy × 10 at all time points. Associated 95% confidence intervals did not point toward any relevant differences.

Conclusions: In patients with MESCC and poor to intermediate survival prognoses, 4 Gy × 5 appeared noninferior to 3 Gy × 10 regarding pain and distress relief.