Psoas muscle area is not representative of total skeletal muscle area in the assessment of sarcopenia in ovarian cancer

Abstract

BackgroundComputed tomography measurements of total skeletal muscle area can detect changes and predict overall survival (OS) in patients with advanced ovarian cancer. This study investigates whether assessment of psoas muscle area reflects total muscle area and can be used to assess sarcopenia in ovarian cancer patients.MethodsOvarian cancer patients (n = 150) treated with induction chemotherapy and interval debulking were enrolled retrospectively in this longitudinal study. Muscle was measured cross sectionally with computed tomography in three ways: (i) software quantification of total skeletal muscle area (SMA); (ii) software quantification of psoas muscle area (PA); and (iii) manual measurement of length and width of the psoas muscle to derive the psoas surface area (PLW). Pearson correlation between the different methods was studied. Patients were divided into two groups based on the extent of change in muscle area, and agreement was measured with kappa coefficients. Cox‐regression was used to test predictors for OS.ResultsCorrelation between SMA and both psoas muscle area measurements was poor (r = 0.52 and 0.39 for PA and PLW, respectively). After categorizing patients into muscle loss or gain, kappa agreement was also poor for all comparisons (all κ < 0.40). In regression analysis, SMA loss was predictive of poor OS (hazard ratio 1.698 (95%CI 1.038–2.778), P = 0.035). No relationship with OS was seen for PA or PLW loss.ConclusionsChange in psoas muscle area is not representative of total muscle area change and should not be used to substitute total skeletal muscle to predict survival in patients with ovarian cancer.

Screening for low muscularity in colorectal cancer patients: a valid, clinic‐friendly approach that predicts mortality

“…Rutten et al . found that while their linear method took very little time to implement (<1 min per scan), there was a poor correlation between the psoas linear area (length × width) and the total cross‐sectional area ( r  = 0.39) among 150 ovarian cancer patients and no associations with psoas linear area and survival 25. By contrast, Jones et al .…”

“…While smaller studies have taken linear measures of the psoas among colorectal26 and ovarian cancer25 patients, ours is the largest study to use the technique developed by Avrutin et al . to take linear measures of multiple muscle groups (the psoas and paraspinal) among colorectal cancer patients.…”

“…Two recent studies among cancer patients have evaluated abbreviated methods for assessing skeletal muscle using digital rulers; both have focused on the psoas muscle alone, without quantifying the paraspinal muscle groups as done here 25, 47. The psoas represents only 10% of the total cross‐sectional muscle area measurable at L3 and may be an inadequate marker of whole body muscle in cancer patients 47.…”

“…Meanwhile, Rutten et al . included ovarian cancer patients likely to have advanced tumour spread and reduced performance status 25. The psoas is a hip flexor muscle indicative of physical fitness; it could be that while the psoas has limited utility in older ovarian cancer patients with advanced illness, the psoas alone is sufficient to represent total cross‐sectional area and predict cancer survival in a younger, more mobile populations of non‐metastatic patients.…”

“…Abbreviated methods to screen for low muscle from routine CT imaging have been proposed in intensive care and trauma populations,24 and to a limited extent in cancer patients, where results have been mixed 25, 26. One recently proposed method27 allows the user to quickly assess patient muscularity using the combined area of the psoas and paraspinal muscles computed from linear measurements that take <2 min per patient.…”