Impact of low skeletal muscle mass in oropharyngeal cancer patients treated with radical chemo-radiotherapy: A mono-institutional experience

Abstract

Aims: Low skeletal muscle mass index (SMI) has recently emerged as an independent prognostic factor in oncological patients and it is linked with poor survival and higher treatment toxicity. The present study aims to determine the possible impact of low SMI on survival and acute toxicity in oropharyngeal patients. Methods: Seventy-six patients with locally advanced oropharyngeal squamous cell carcinoma (stage III-IVC) were treated in our institution with Helical TomoTherapy® (HT - Accuray, Maddison, WI, USA) between 2005 and 2021. All patients received concomitant platinum-based chemotherapy (CT) (at least 200 mg/m2). The SMI was determined using the calculation of cross-sectional area at C3. Twenty patients (26%) presented pre-treatment low SMI, according to Chargi definitions. Results: All patients concluded the treatment. Thirteen patients with low SMI (65%) and 22 patients with normal SMI (39%) presented acute toxicity greater than or equal to grade 3, but this difference was not statistically significant (p-value = 0.25). Overall survival was analyzed in 65 patients, excluding those who finished CT-RT less than six months before the analysis. Overall survival was significantly lower in low SMI versus normal SMI patients (p-value = 0.035). Same difference was observed in N0-N2a patients, suggesting an important role of SMI also in lower nodal burden and putatively better prognosis. Conclusions: Although the results are limited to a small population, our case series has the advantage to be very homogeneous in patients and treatment characteristics. In our setting, SMI demonstrated a crucial impact on overall survival. Further investigation with larger samples is necessary to confirm our results to improve patient outcomes.

Response to Deantoni et al.

“…And second, Deantoni et al reported that the survival analysis of 65 patients (47 normal SMI and 18 low SMI), those with a follow-up period of over six months, revealed that the median OS was significantly longer in normal SMI (46.2 vs 40.3 months, HR 0.27, 95% CI 0.08-0.92, p-value 0.035) compared to low SMI group. 1 Similar significant disparities were also seen in patients with a lower nodal burden (N0-N2a) and a supposedly more favorable prognosis (median 46 vs 43 months, HR 0.17, 95% CI 0.04-0.79, p-value 0.02). However, upon close analysis of Figures 1 and 2, it is evident that both the low and normal SMI groups failed to achieve the sufficient number of deaths (⩾50%) required to calculate median OS times for each group.…”

“…We commend Deantoni et al 1 for their effort to determine whether low skeletal muscle mass index (SMI) has any impact on the survival and acute toxicity outcomes of 76 stage III-IVC oropharyngeal squamous cell carcinoma (OPSCC) patients treated with Helical TomoTherapy® and concurrent platinum-based chemotherapy. In this study, 20 patients (26%) had low pretreatment SMI according to Chargi definitions, determined by measuring the cross-sectional area at C3 vertebra level.…”