From simple body mass index to lifesaving action: Linking low muscle mass, late diagnosis, and survival in chemoradiotherapy-treated esophageal cancer

Abstract

In the challenging landscape of esophageal squamous cell carcinoma (ESCC), where late diagnosis often brings progressive dysphagia, feeding difficulties, and chronic caloric-protein deficits that accelerate muscle wasting even before treatment begins, Xiao et al offer a compelling insight in the World Journal of Clinical Oncology. Their retrospective analysis of 360 patients undergoing definitive chemoradiotherapy reveals that baseline body mass index (BMI) is a powerful, readily available predictor of low muscle mass (LMM). Each additional BMI unit is linked to roughly a 39% lower odds of LMM (odds ratio: 0.613; 95%CI: 0.531-0.707), with a clear inflection point around 21.5 kg/m² marking heightened risk below this threshold. What truly stands out is the synergistic prognostic impact: Patients burdened by both low BMI and LMM face the bleakest outlook, with a median overall survival of only 17 months. This underscores that LMM is far more than a nutritional byproduct — it acts as an independent driver of poorer treatment tolerance, heightened toxicities, and reduced survival in locally advanced ESCC. These observations open a practical window for action in everyday oncology practice. A simple BMI measurement at diagnosis can serve as an immediate, zero-cost alert to prompt detailed body composition evaluation (ideally via pretreatment computed tomography) and swift multidisciplinary intervention. Early nutritional reinforcement — through hypercaloric, high-protein oral nutritional supplements (ONS) delivering ≥ 1.5-2.0 g protein/kg ideal body weight daily — has been shown in dedicated trials to preserve weight, BMI, albumin, and prealbumin levels while attenuating radiation esophagitis, myelosuppression, and other toxicities during radiotherapy or chemoradiotherapy in ESCC patients. Meta-analyses further support that high-protein ONS reduces complications and aids lean mass maintenance in high-sarcopenia-risk cancers such as esophageal cancer. When oral intake falters due to tumor-related dysphagia, enteral routes become essential, complemented by individualized dietitian guidance and frequent reassessments. Adding supervised resistance training (2-3 sessions/week) where performance status allows provides a vital non-nutritional countermeasure against sarcopenia progression. By viewing BMI and LMM not merely as prognostic signals but as modifiable targets, we can shift toward more proactive, personalized supportive care — potentially transforming outcomes in one of oncology’s most demanding diseases.

Key Words: Esophageal squamous cell carcinoma; Body mass index; Low muscle mass; Chemoradiotherapy; Sarcopenia; Nutritional intervention; Survival

Core Tip: In the challenging landscape of esophageal squamous cell carcinoma (ESCC), where late diagnosis often brings progressive dysphagia, feeding difficulties, and chronic caloric-protein deficits that accelerate muscle wasting even before treatment begins, Xiao et al offer a compelling insight. Baseline body mass index emerges as a simple yet potent predictor of low muscle mass in ESCC patients facing chemoradiotherapy, highlighting opportunities for early nutritional and exercise interventions to mitigate poor survival outcomes.

This editorial refers to “Body mass index predicts low muscle mass in esophageal squamous cell carcinoma patients undergoing chemoradiotherapy” by Xiao et al, 2026; https://dx.doi.org/10.5306/wjco.v17.i4.116601.

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INTRODUCTION

Esophageal squamous cell carcinoma (ESCC) remains a global challenge, with approximately 511000 new cases and 445000 deaths in 2022, concentrated mainly in East Asia due to tobacco, alcohol, and dietary risk factors[1]. Late diagnosis leads to advanced stages, where definitive chemoradiotherapy is the standard of care for unresectable disease[2]. Treatment often exacerbates dysphagia, toxicities, and cachexia, resulting in high rates of malnutrition and sarcopenia[3].

Sarcopenia, defined as progressive and generalized loss of skeletal muscle mass and strength, independently predicts higher treatment toxicities, lower treatment tolerance, and poorer survival in ESCC[4-6]. Recent meta-analyses confirm that sarcopenia is associated with worse overall survival in patients receiving definitive chemoradiotherapy[7,8]. The gold standard for assessment is computed tomography (CT)-derived skeletal muscle index at the L3 level, although alternatives such as bioelectrical impedance analysis, ultrasound, or handgrip strength are also used[9-11]. Interventions based on high-protein nutrition and resistance exercise have shown promise in preserving muscle mass and mitigating complications[12,13].

Xiao et al’s analysis positions baseline body mass index (BMI) as a practical predictor of low muscle mass (LMM)[14], supporting the implementation of early supportive strategies in this aggressive disease.

ASSESSING SKELETAL MUSCLE MASS IN ONCOLOGY: FROM CT GOLD STANDARD TO MULTIMODAL ALTERNATIVES

In the recent issue of World Journal of Clinical Oncology, Xiao et al[14] used CT at the L3 level (SliceOmatic software) to calculate the skeletal muscle index, defining low muscle mass with Asian-validated cutoffs[14]. This approach aligns with the European Working Group on Sarcopenia in Older People (EWGSOP2) guidelines and takes advantage of routine staging CT scans[9].

Alternatives include bioelectrical impedance analysis, dual-energy X-ray absorptiometry, ultrasound, and handgrip strength for initial screening[10,11,15]. A tiered approach improves accessibility and allows longitudinal monitoring.

Unraveling confounding in the BMI-LMM-survival relationship: Mediator or marker? Critical appraisal of study design

Xiao et al[14] excluded patients who did not complete treatment, which may introduce survivor bias, since sarcopenic patients are more likely to drop out due to toxicities[4,5]. Treatment heterogeneity was adjusted for in the models, although intention-to-treat analyses would strengthen generalizability.

Patients with low BMI presented more advanced T and N stages, supporting the notion that low muscle mass is partly driven by the tumor itself (through dysphagia, systemic inflammation, and catabolism)[16]. Multivariable adjustments confirmed an independent inverse association between BMI and LMM. Nevertheless, residual confounding cannot be fully ruled out in this retrospective design. Future studies with mediation analyses and longitudinal assessment of muscle dynamics would help clarify the mediating role of LMM[17].

From prognosis to action: Practical interventions targeting low BMI and muscle mass in ESCC

A BMI below 21.5 kg/m² should flag immediate action[14]. Early initiation of high-protein oral nutritional supplements (ONS) providing ≥ 1.5-2.0 g protein/kg ideal body weight per day is recommended. Randomized controlled trials have demonstrated that such supplementation preserves BMI, albumin, and prealbumin levels while reducing severe esophagitis, myelosuppression, and improving treatment completion rates[18,19]. When oral intake is insufficient due to tumor-related dysphagia, escalation to enteral nutrition via nasogastric tube or percutaneous endoscopic gastrostomy is essential. Weekly monitoring with the Patient-Generated Subjective Global Assessment allows tailored adjustments[20].

Supervised resistance training (2-3 sessions per week targeting major muscle groups at 60%-80% of one-repetition maximum) can help preserve or increase lean mass and improve physical performance, fatigue, and quality of life[21-23]. Prehabilitation programs combining exercise and nutrition have shown additional benefits in attenuating muscle loss[24,25]. American Society of Clinical Oncology guidelines endorse multimodal prehabilitation approaches[2].

A stepwise pathway (BMI screening → risk stratification → dietitian referral → ONS/enteral nutrition ± exercise → frequent reassessment) is resource-efficient and patient-centered (Figure 1). The current evidence supporting early intervention is summarized in Table 1.

Figure 1 Practical stepwise algorithm for screening and multimodal intervention based on baseline body mass index in patients with locally advanced esophageal squamous cell carcinoma receiving chemoradiotherapy. The pathway emphasizes early nutritional support and resistance exercise to mitigate sarcopenia and improve treatment outcomes. BMI: Body mass index; ESCC: Esophageal squamous cell carcinoma; LMM: Low muscle mass; PEG: Percutaneous endoscopic gastrostomy; NG tube: Nasogastric tube.

Table 1 Selected key evidence on the prognostic impact of low muscle mass/sarcopenia and the benefit of multimodal interventions in patients with esophageal squamous cell carcinoma undergoing chemoradiotherapy.

Ref.	Study type	Main findings	Clinical implication
Xiao et al[14], 2026	Retrospective cohort study (n = 360)	Baseline BMI is a strong predictor of low muscle mass (OR: 0.613 per unit); BMI < 21.5 kg/m2 + LMM associated with median OS of 17 months	Simple BMI measurement at diagnosis can serve as a zero-cost screening tool
Fang et al[6], 2023	Systematic review and meta-analysis	Sarcopenia significantly associated with worse overall survival in esophageal cancer	Sarcopenia is an independent prognostic factor
Jogiat et al[7], 2022	Systematic review and meta-analysis	Sarcopenia reduces overall survival in unresectable ESCC treated with chemoradiotherapy (HR: 1.51)	Routine screening for sarcopenia is warranted
Yang et al[18], 2023/Qiu et al[19], 2020	RCTs/prospective trials	High-protein ONS preserves weight, BMI, albumin and reduces grade ≥ 3 esophagitis and myelosuppression	Early nutritional support improves treatment tolerance
Halliday et al[24], 2024/Sugimura et al[25], 2025	Prehabilitation studies	Multimodal prehabilitation (nutrition + resistance exercise) attenuates muscle loss during neoadjuvant or definitive therapy	Combined nutritional and exercise interventions are promising
Vongcharoenpol et al[26], 2025	Prospective cohort	Sarcopenia after concurrent chemoradiotherapy is common and associated with poor outcomes	Need for proactive muscle-preserving strategies

BMI: Body mass index; LMM: Low muscle mass; OS: Overall survival; ONS: Oral nutritional supplements; HR: Hazard ratio; RCT: Randomized controlled trial; ESCC: Esophageal squamous cell carcinoma; OR: Odds ratio.

CONCLUSION

Xiao et al[14] highlight that baseline BMI is a simple, independent predictor of low muscle mass in patients with ESCC undergoing chemoradiotherapy. This finding flags the need for early body composition assessment[9-11,15]. Despite limitations such as completer bias and treatment heterogeneity, the strong prognostic role of low muscle mass persists after stage adjustment[4-8,26].

High-protein ONS and enteral nutrition help preserve nutritional status and reduce toxicities[12,18,19], while resistance exercise and prehabilitation counter muscle loss[21-25]. These modifiable factors should be integrated proactively into clinical practice to improve treatment tolerance and patient outcomes. Future randomized controlled trials are needed to evaluate the impact of multimodal interventions on survival and to validate BMI and muscle mass thresholds across different populations[27-30].