Sarcopenia as a determinant of chemotherapy toxicity and time to tumor progression in metastatic breast cancer patients receiving capecitabine treatment

Progressive resistance training and cancer testis (PROTRACT) - efficacy of resistance training on muscle function, morphology and inflammatory profile in testicular cancer patients undergoing chemotherapy: design of a randomized controlled trial

Background

Standard treatment for patients with disseminated germ cell tumors is combination chemotherapy with bleomycin, etoposide and cisplatin (BEP). This treatment is highly effective, but the majority of patients experience severe adverse effects during treatment and are at risk of developing considerable long-term morbidity, including second malignant neoplasms, cardiovascular disease, and pulmonary toxicity. One neglected side effect is the significant muscular fatigue mentioned by many patients with testicular cancer both during and after treatment. Very limited information exists concerning the patho-physiological effects of antineoplastic agents on skeletal muscle. The primary aim of this study is to investigate the effects of BEP-treatment on the skeletal musculature in testicular cancer patients, and to examine whether the expected treatment-induced muscular deterioration can be attenuated or even reversed by high intensity progressive resistance training (HIPRT).

Design/Methods

The PROTRACT study is a randomized controlled trial in 30 testicular cancer patients undergoing three cycles of BEP chemotherapy. Participants will be randomized to either a 9-week HIPRT program (STR) initiated at the onset of treatment, or to standard care (UNT). 15 healthy matched control subjects (CON) will complete the same HIPRT program. All participants will take part in 3 assessment rounds (baseline, 9 wks, 21 wks) including muscle biopsies, maximum muscle strength tests, whole body DXA scan and blood samples. Primary outcome: mean fiber area and fiber type composition measured by histochemical analyses, satellite cells and levels of protein and mRNA expression of intracellular mediators of protein turnover. Secondary outcomes: maximum muscle strength and muscle power measured by maximum voluntary contraction and leg-extensor-power tests, body composition assessed by DXA scan, and systemic inflammation analyzed by circulating inflammatory markers, lipid and glucose metabolism in blood samples. Health related Quality of Life (QoL) will be assessed by validated questionnaires (EORTC QLQ-C30, SF-36).

Discussion

This study investigates the muscular effects of antineoplastic agents in testicular cancer patients, and furthermore evaluates whether HIPRT has a positive influence on side effects related to chemotherapy. A more extensive knowledge of the interaction between cytotoxic-induced physiological impairment and exercise-induced improvement is imperative for the future development of optimal rehabilitation programs for cancer patients.

Trial Registration

Current Controlled Trials ISRCTN32132990.

Sarcopenia negatively impacts short-term outcomes in patients undergoing hepatic resection for colorectal liver metastasis

BACKGROUND

As indications for liver resection expand, objective measures to assess the risk of peri-operative morbidity are needed. The impact of sarcopenia on patients undergoing liver resection for colorectal liver metastasis (CRLM) was investigated.

METHODS

Sarcopenia was assessed in 259 patients undergoing liver resection for CRLM by measuring total psoas area (TPA) on computed tomography (CT). The impact of sarcopenia was assessed after controlling for clinicopathological factors using multivariate modelling.

RESULTS

Median patient age was 58 years and most patients (60%) were male. Forty-one (16%) patients had sarcopenia (TPA ≤ 500 mm(2) /m(2) ). Post-operatively, 60 patients had a complication for an overall morbidity of 23%; 26 patients (10%) had a major complication (Clavien grade ≥3). The presence of sarcopenia was strongly associated with an increased risk of major post-operative complications [odds ratio (OR) 3.33; P= 0.008]. Patients with sarcopenia had longer hospital stays (6.6 vs. 5.4 days; P= 0.03) and a higher chance of an extended intensive care unit (ICU) stay (>2 days; P= 0.004). On multivariate analysis, sarcopenia remained independently associated with an increased risk of post-operative complications (OR 3.12; P= 0.02). Sarcopenia was not significantly associated with recurrence-free [hazard ratio (HR) = 1.07] or overall (HR = 1.05) survival (both P > 0.05).

CONCLUSIONS

Sarcopenia impacts short-, but not long-term outcomes after resection of CRLM. While patients with sarcopenia are at an increased risk of post-operative morbidity and longer hospital stay, long-term survival is not impacted by the presence of sarcopenia.

Proteolysis in illness-associated skeletal muscle atrophy: from pathways to networks

Improvements in health in the past decades have resulted in increased numbers of the elderly in both developed and developing regions of the world. Advances in therapy have also increased the prevalence of patients with chronic and degenerative diseases. Muscle wasting, a feature of most chronic diseases, is prominent in the elderly and contributes to both morbidity and mortality. A major research goal has been to identify the proteolytic system(s) that is responsible for the degradation of proteins that occurs in muscle atrophy. Findings over the past 20 years have clearly confirmed an important role of the ubiquitin proteasome system in mediating muscle proteolysis, particularly that of myofibrillar proteins. However, recent observations have provided evidence that autophagy, calpains and caspases also contribute to the turnover of muscle proteins in catabolic states, and furthermore, that these diverse proteolytic systems interact with each other at various levels. Importantly, a number of intracellular signaling pathways such as the IGF1/AKT, myostatin/Smad, PGC1, cytokine/NFκB, and AMPK pathways are now known to interact and can regulate some of these proteolytic systems in a coordinated manner. A number of loss of function studies have identified promising therapeutic approaches to the prevention and treatment of wasting. However, additional biomarkers and other approaches to improve early identification of patients who would benefit from such treatment need to be developed. The current data suggests a network of interacting proteolytic and signaling pathways in muscle. Future studies are needed to improve understanding of the nature and control of these interactions and how they work to preserve muscle function under various states of growth and atrophy.

Muscle wasting in cancer cachexia: clinical implications, diagnosis, and emerging treatment strategies

Cancer cachexia is a complex metabolic condition characterized by loss of skeletal muscle. Common clinical manifestations include muscle wasting, anemia, reduced caloric intake, and altered immune function, which contribute to increased disability, fatigue, diminished quality of life, and reduced survival. The prevalence of cachexia and the impact of this disorder on the patient and family underscore the need for effective management strategies. Dietary supplementation and appetite stimulation alone are inadequate to reverse the underlying metabolic abnormalities of cancer cachexia and have limited long-term impact on patient quality of life and survival. Therapies that can increase muscle mass and physical performance may be a promising option; however, there are currently no drugs approved for the prevention or treatment of cancer cachexia. Several agents are in clinical development, including anabolic agents, such as selective androgen receptor modulators and drugs targeting inflammatory cytokines that promote skeletal muscle catabolism.

Cancer cachexia therapy: a key weapon in the fight against cancer

PURPOSE OF REVIEW

Cachexia affects millions of cancer patients around the world. Though its causes are poorly understood, its devastating impact on the patient and their loved ones underscore the urgency of this unmet medical need. Recent research efforts suggest multiple body systems are dysregulated in cachexia, not only increasing the challenge in effectively treating the disease but also expanding the opportunities for intervention.

RECENT FINDINGS

Agents as diverse as anti-inflammatory monoclonal antibodies and novel anabolic small molecules are under clinical evaluation for their ability to prevent and treat wasting. The therapies evaluated to date range in their ability to improve appetite, mitigate weight loss and reverse undesirable changes in body composition and physical function.

SUMMARY

An increased understanding of cancer cachexia, both mechanistically and its impact on cancer patients' struggle with their disease, has resulted in diverse therapeutic concepts. Recent clinical efforts demonstrate progress with novel therapies but fall short of effectively treating most cachectic patients and highlight a clear need for further research. Given the inherent heterogeneity of cancer patients and the significant impact of muscle wasting on morbidity and mortality, continued research efforts are critical in developing effective therapies to prevent and treat cancer cachexia.

Two faces of drug therapy in cancer: drug-related lean tissue loss and its adverse consequences to survival and toxicity

PURPOSE OF REVIEW

A common feature of cancer patients is loss of lean tissue, specifically skeletal muscle, which may be the result of the tumor or a side-effect of chemotherapy or other drugs. Lean tissue loss in turn has important adverse implications for toxicity of antineoplastic therapy and, hence, cancer prognosis.

RECENT FINDINGS

Contemporary cancer populations have heterogeneous proportions of lean tissue, regardless of body weight. Wasting of lean tissue during the cancer trajectory has been associated with tumor progression. Lean tissue depletion is an independent predictor of severe toxicity in patients treated with chemotherapeutic agents of diverse classes. Patients with lean tissue depletion behave as if overdosed and have toxicity of sufficient magnitude to require dose reductions, treatment delays or definitive termination of treatment. Muscle loss may occur due to a specific effect of a chemotherapy agent (i.e. sorafenib), androgen suppression therapy or other drugs (i.e. statins such as atorvastatin).

SUMMARY

Lean tissue wasting occurs due to cancer progression and may be exacerbated by several drug classes. This loss of lean tissue is not proportional to changes in body weight and is prognostic of enhanced treatment toxicity and reduced survival.

Definition and classification of cancer cachexia: an international consensus

To develop a framework for the definition and classification of cancer cachexia a panel of experts participated in a formal consensus process, including focus groups and two Delphi rounds. Cancer cachexia was defined as a multifactorial syndrome defined by an ongoing loss of skeletal muscle mass (with or without loss of fat mass) that cannot be fully reversed by conventional nutritional support and leads to progressive functional impairment. Its pathophysiology is characterised by a negative protein and energy balance driven by a variable combination of reduced food intake and abnormal metabolism. The agreed diagnostic criterion for cachexia was weight loss greater than 5%, or weight loss greater than 2% in individuals already showing depletion according to current bodyweight and height (body-mass index [BMI] <20 kg/m(2)) or skeletal muscle mass (sarcopenia). An agreement was made that the cachexia syndrome can develop progressively through various stages--precachexia to cachexia to refractory cachexia. Severity can be classified according to degree of depletion of energy stores and body protein (BMI) in combination with degree of ongoing weight loss. Assessment for classification and clinical management should include the following domains: anorexia or reduced food intake, catabolic drive, muscle mass and strength, functional and psychosocial impairment. Consensus exists on a framework for the definition and classification of cancer cachexia. After validation, this should aid clinical trial design, development of practice guidelines, and, eventually, routine clinical management.

Peak oxygen consumption and long-term all-cause mortality in nonsmall cell lung cancer

BACKGROUND

Identifying strong markers of prognosis is critical to optimize treatment and survival outcomes in patients with nonsmall cell lung cancer (NSCLC). The authors investigated the prognostic significance of preoperative cardiorespiratory fitness (peak oxygen consumption [VO(2peak)]) among operable candidates with NSCLC.

METHODS

By using a prospective design, 398 patients with potentially resectable NSCLC enrolled in Cancer and Leukemia Group B 9238 were recruited between 1993 and 1998. Participants performed a cardiopulmonary exercise test to assess VO(2peak) and were observed until death or June 2008. Cox proportional models were used to estimate the risk of all-cause mortality according to cardiorespiratory fitness category defined by VO(2peak) tertiles (<0.96 of 0.96-1.29/>1.29 L/min⁻¹) with adjustment for age, sex, and performance status.

RESULTS

Median follow-up was 30.8 months; 294 deaths were reported during this period. Compared with patients achieving a VO(2peak) <0.96 L/min⁻¹, the adjusted hazard ratio (HR) for all-cause mortality was 0.64 (95% confidence interval [CI], 0.46-0.88) for a VO(2peak) of 0.96 to 1.29 L/min⁻¹, and 0.56 (95% CI, 0.39-0.80) for a VO(2peak) of >1.29 L/min⁻¹) (P(trend) = .0037). The corresponding HRs for resected patients were 0.66 (95% CI, 0.46-0.95) and 0.59 (95% CI, 0.40-0.89) relative to the lowest VO(2peak) category (P(trend) = .0247), respectively. For nonresected patients, the HRs were 0.78 (95% CI, 0.34-1.79) and 0.39 (95% CI, 0.16-0.94) relative to the lowest category (P(trend) = .0278).

CONCLUSIONS

VO(2peak) is a strong independent predictor of survival in NSCLC that may complement traditional markers of prognosis to improve risk stratification and prognostication.

Models of accelerated sarcopenia: critical pieces for solving the puzzle of age-related muscle atrophy

Sarcopenia, the age-related loss of skeletal muscle mass, is a significant public health concern that continues to grow in relevance as the population ages. Certain conditions have the strong potential to coincide with sarcopenia to accelerate the progression of muscle atrophy in older adults. Among these conditions are co-morbid diseases common to older individuals such as cancer, kidney disease, diabetes, and peripheral artery disease. Furthermore, behaviors such as poor nutrition and physical inactivity are well-known to contribute to sarcopenia development. However, we argue that these behaviors are not inherent to the development of sarcopenia but rather accelerate its progression. In the present review, we discuss how these factors affect systemic and cellular mechanisms that contribute to skeletal muscle atrophy. In addition, we describe gaps in the literature concerning the role of these factors in accelerating sarcopenia progression. Elucidating biochemical pathways related to accelerated muscle atrophy may allow for improved discovery of therapeutic treatments related to sarcopenia.

Skeletal muscle depletion is associated with reduced plasma (n-3) fatty acids in non-small cell lung cancer patients

Upwards of 50% of newly diagnosed advanced lung cancer patients have severe muscle wasting (sarcopenia). Supplementation with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in advanced cancer has been shown to attenuate lean tissue wasting. However, the relationship between muscle mass and plasma (n-3) fatty acids in the absence of supplementation is unclear. We aimed to determine how plasma phospholipid (n-3) fatty acids relate to sarcopenia and change in muscle mass in non-small cell lung cancer patients receiving chemotherapy. Computed tomography images were used to measure muscle mass. Patients were classified as sarcopenic or nonsarcopenic based on sex-specific cutpoints. Change in muscle mass during chemotherapy (2.5 mo) was calculated and patients were divided into quartiles based on the rate of muscle loss or gain. Patients with sarcopenia had lower plasma EPA (16.7 +/- 2.1 micromol/L vs. 31.6 +/- 4.4 micromol/L; P = 0.001), DHA (36.6 +/- 4.0 micromol/L vs. 55.3 +/- 4.0 micromol/L; P = 0.003), and Sigma(n-3) fatty acids (63.6 +/- 5.6 micromol/L vs. 95.0 +/- 7.7 micromol/L; P = 0.002) than nonsarcopenic patients. Patients with maximal muscle loss (mean - 3.5 kg) had lower plasma EPA (12.2 +/- 3.3 micromol/L vs. 35.0 +/- 7.1 micromol/L; P = 0.03), DHA (26.9 +/- 8.7 micromol/L vs. 59.6 +/- 5.3 micromol/L; P = 0.01), and Sigma(n-3) fatty acids (57.8 +/- 13.5 micromol/L vs. 104.6 +/- 11.1 micromol/L; P = 0.005) compared with patients who were gaining muscle (mean +1 kg). Plasma (n-3) fatty acids are depleted in cancer patients with sarcopenia, which may contribute to accelerated rates of muscle loss.

Changes in functional performance measures in adults undergoing chemoradiation for primary malignant glioma: a feasibility study

PURPOSE

To investigate the feasibility of longitudinal assessment of functional performance measures in newly diagnosed postsurgical malignant glioma patients.

METHODS

Patients with histologically confirmed, clinically stable, postsurgical, and previously untreated high-grade glioma (HGG) or low-grade glioma (LGG) were studied. Using a prospective design, all participants performed a cardiopulmonary exercise test with expired gas analysis to assess cardiorespiratory function (VO(2peak)) immediately following surgical resection (mean, 10 days). Additional functional outcomes were skeletal muscle cross-sectional area (CSA) via magnetic resonance imaging, isokinetic muscle strength (isokinetic dynamometry), and body composition (air displacement plethysmography). Quality of life (QOL) was assessed by the Functional Assessment of Cancer Therapy-Brain scale. All study assessments were repeated at 6 and 24 weeks following surgery.

RESULTS

Thirty-five patients (HGG, n = 25; LGG, n = 10) completed baseline assessments. Of these, 20 HGG (80%) and nine LGG (90%) and 15 HGG (60%) and nine LGG (90%) patients completed study assessments at 6 weeks and 24 weeks, respectively. Intention-to-treat analyses indicated several significant time-by-group interactions, with favorable improvements in functional and QOL endpoints from baseline to 24 weeks in the LGG cohort and unfavorable changes in the HGG cohort. Per-protocol analyses including participants assessed at all three study timepoints indicated significant improvements in VO(2peak) and fatigue from baseline to 24 weeks in the HGG cohort; peak workload, body composition, and muscle strength improved from baseline to 6 weeks (all p-values < .05).

CONCLUSIONS

Longitudinal quantitative functional assessments are safe and feasible among select patients undergoing chemoradiation for primary malignant glioma. Large prospective studies investigating the clinical importance of these measures appear warranted.

The diversity of nutritional status in cancer: new insights

OBJECTIVE

Nutritional status in cancer has been mostly biased toward undernutrition, an issue now in dispute. We aimed to characterize nutrition status, to analyze associations between nutritional and clinical/cancer-related variables, and to quantify the relative weights of nutritional and cancer-related features.

METHODS

The cross-sectional study included 450 nonselected cancer patients (ages 18-95 years) at referral for radiotherapy. Nutritional status assessment included recent weight changes, body mass index (BMI) categorized by World Health Organization's age/sex criteria, and Patient-Generated Subjective Global Assessment (PG-SGA; validated/specific for oncology).

RESULTS

BMI identified 63% as >or=25 kg/m(2) (43% overweight, 20% obese) and 4% as undernourished. PG-SGA identified 29% as undernourished and 71% as well nourished. Crossing both methods, among the 319 (71%) well-nourished patients according to PG-SGA, 75% were overweight/obese and only 25% were well nourished according to BMI. Concordance between BMI and PG-SGA was evaluated and consistency was confirmed. More aggressive/advanced stage cancers were more prevalent in deficient and excessive nutritional status: in 83% (n = 235/282) of overweight/obese patients by BMI and in 85% (n = 111/131) of undernourished patients by PG-SGA. Results required adjustment for diagnoses: greater histological aggressiveness was found in overweight/obese prostate and breast cancer; undernutrition was associated with aggressive lung, colorectal, head-neck, stomach, and esophageal cancers (p < .005). Estimates of effect size revealed that overweight/obesity was associated with advanced stage (24%), aggressive breast (10%), and prostate (9%) cancers, whereas undernutrition was associated with more aggressive lung (6%), colorectal (6%), and head-neck (6%) cancers; in both instances, age and longer disease duration were of significance.

CONCLUSION

Undernutrition and overweight/obesity have distinct implications and bear a negative prognosis in cancer. This study provides novel data on the prevalence of overweight/obesity and undernutrition in cancer patients and their potential role in cancer histological behavior.

Body composition in patients with non-small cell lung cancer: a contemporary view of cancer cachexia with the use of computed tomography image analysis

BACKGROUND

The prominent clinical feature of cachexia has traditionally been understood to be weight loss; however, in recognition of the potential for divergent behavior of muscle and adipose tissue, cachexia was recently defined as loss of muscle with or without loss of fat mass. Detailed assessments are required to verify body composition in patients with cancer cachexia.

DESIGN

We adopted a population-based approach to study body composition in patients with cancer, with the use of diagnostic computed tomography images acquired for cancer diagnosis and follow-up. A prospective cohort of 441 patients with non-small cell lung cancer, who were referred consecutively to a regional medical oncology service in Alberta, Canada, was evaluated.

RESULTS

At referral (median time to death: 265 d), mean body mass index (BMI; in kg/m(2)) was 24.9, with 47.4% of patients being overweight or obese. Only 7.5% overall were underweight as conventionally understood (BMI < 18.5). Analysis of computed tomography images showed extremely high heterogeneity of muscle mass within all strata of BMI. The overall prevalence of severe muscle depletion (sarcopenia) was 46.8% and was present in patients in all BMI categories. A much higher proportion of men (61%) than women (31%) met the criteria for sarcopenia.

CONCLUSIONS

Wasting of skeletal muscle is a prominent feature of patients with lung cancer, despite normal or heavy body weights. The significance of muscle wasting in normal-weight, overweight, and obese patients as a nutritional risk factor, as a prognostic factor, and as a predictor of cancer treatment toxicity is discussed in this article.

A diet containing whey protein, free glutamine, and transforming growth factor-beta ameliorates nutritional outcome and intestinal mucositis during repeated chemotherapeutic challenges in rats

Anticancer chemotherapy often induces side effects such as mucositis. Recent data suggest that a diet, Clinutren Protect (CP), containing whey proteins, glutamine, and transforming growth factor-beta (TGFbeta)-rich casein limits intestinal mucositis and improves recovery after a single methotrexate (MTX) challenge in rats. Chemotherapy consists of alternating periods of treatment and rest. Thus, our study evaluated the effects of CP on nutritional outcome and intestinal mucositis in rats receiving repeated chemotherapeutic challenges. Thirty-six Sprague-Dawley rats received 3 cycles of MTX at 8-d intervals. Rats had free access to CP or control diet (Co) from 7 d before the first MTX injection until the end of the experiment at d 27. In Co, whey proteins and TGFbeta-rich casein were replaced by TGFbeta-free casein. L-Glutamine was replaced by L-alanine. Body composition was assessed by dual energy X-ray absorptiometry. Before MTX challenges, food intake and body weight were similar in both groups but became higher during MTX challenges in CP (P < 0.05). Fat mass decreased similarly in both groups. In contrast, the decrease of fat free mass between d -1 and d 27 was less pronounced in the CP group (-9.5 g) than in the Co group (-57.2 g) (P < 0.05). The intestinal damage score was lower in the CP group (0.6 +/- 0.3 vs. 2.1 +/- 0.6; P < 0.05). Fecal IgA increased over time in the CP group (P < 0.05) but not in the Co group. A diet containing whey proteins, glutamine, and TGFbeta improves nutritional outcome by limiting the reduction of fat free mass and reduces intestinal mucositis during repeated chemotherapeutic challenges in rats.

An exploratory study of body composition as a determinant of epirubicin pharmacokinetics and toxicity

PURPOSE

Although body composition has emerged as an important predictor of drug efficacy and toxicity, explanations for this association are unclear. Our goal was to investigate relationships between lean body mass (LBM), liver size/function and epirubicin pharmacokinetics (PK) and toxicity.

METHODS

Data from a clinical study (n = 24) of patients with breast cancer receiving adjuvant intravenous FE(100)C chemotherapy were used to examine relationships between LBM, liver size, and epirubicin clearance. Muscle tissue and liver mass were measured by analysis of computerized tomography cross-sectional images, and an extrapolation of muscle mass to total LBM compartment was employed. Population PK analysis of epirubicin was undertaken to test effects of body composition on epirubicin clearance and area under the curve (AUC).

RESULTS

Estimated LBM was extremely variable in this cohort ranging from 32.9 to 67.3 kg. LBM was associated with neutrophil nadir (r = 0.5, P = 0.023), and mean LBM was lower for patients presenting with toxicity compared to those where toxicity was absent (41.6 vs. 56.2 kg, P = 0.002); 33% of variance in clearance was explained by LBM and aspartate aminotransferase (AST). Liver mass was not related to epirubicin clearance likely due to larger livers presenting with larger fat content, but liver attenuation (degree of fat infiltration) and AST were associated with AUC.

CONCLUSION

To our knowledge, this is the first study to examine relationships between LBM, liver mass/function and epirubicin PK and toxicity. This exploratory work investigates the notion of organs and tissues having distinctive contributions to the distribution and metabolism of antineoplastic drugs.

Association of Skeletal Muscle Wasting With Treatment With Sorafenib in Patients With Advanced Renal Cell Carcinoma: Results From a Placebo-Controlled Study

Purpose

Effects of specific antineoplastic therapies on progression of cancer-associated wasting remain uncharacterized. We selected a targeted therapy, sorafenib, because of its reported association with weight loss.

Patients and Methods

Patients with metastatic renal cell cancer (RCC) who were resistant to standard therapy (N = 80) received sorafenib 400 mg twice daily or placebo in a randomized, double-blinded clinical trial. Computed tomography image analysis, which has high precision and specificity for evaluation of specific muscles and adipose tissues, was used to define change in total skeletal muscle and adipose tissue.

Results

At inclusion, 51% of patients were overweight or obese (ie, body mass index [BMI] > 25 kg/m2). Only 5% were underweight. Advanced muscle wasting (ie, sarcopenia) was present in 72% of patients with BMI less than 25 and in 34% of those with a BMI greater than 25. Patients received placebo for an average of 6 months and received sorafenib for 1 year. Patients in the placebo group had stable body weight during 6 months (0.8 kg ± 0.7 kg), with no significant alteration of muscle or fat. Patients who received sorafenib lost 2.1 kg ± 0.6 kg (P < .01) in 6 months and lost 4.2 kg ± 0.7 kg (P < .01) by 1 year. Sorafenib-treated patients lost skeletal muscle progressively at 6 months (decrease of 4.9%; P < .01) and 12 months (decrease of 8.0%; P < .01).

Conclusion

Sarcopenia is prevalent in patients with metastatic RCC and is an occult condition in patients with normal or high BMI. Muscle loss is specifically exacerbated by sorafenib, consistent with the evidence for a role of kinases in regulating muscle mass. Muscle loss is a sorafenib adverse effect that may relate to asthenia, fatigue, and physical disability.

Low body mass index and sarcopenia associated with dose-limiting toxicity of sorafenib in patients with renal cell carcinoma

BACKGROUND

Patients with severe depletion of skeletal muscle (sarcopenia) are prone to dose-limiting toxicity (DLT) during fluoropyrimidine therapy. We hypothesized that sarcopenia may also predict toxicity of targeted therapy drugs.

MATERIALS AND METHODS

Metastatic renal cell cancer (RCC) patients (n = 55) received sorafenib 400 mg b.i.d. Weight, height and skeletal muscle cross-sectional area at the third lumbar vertebra were measured by computed tomography (CT). Toxicity was assessed.

RESULTS

DLT occurred in 22% of patients overall, of which three-quarters were dose reductions to 400 mg and the remainder entailed termination of treatment. DLT was most common (41%) in sarcopenic patients whose body mass index (BMI) was <25 kg/m(2) and least common (13%) in patients who were not sarcopenic and/or overweight or obese (P = 0.03). Toxicity was especially prevalent in sarcopenic male patients with BMI < 25, with 71% of men with these characteristics being unable to continue treatment at 800 mg/day. By contrast, only 5% of male patients whose muscle index was above the cut-off for sarcopenia and only 11% of male patients whose BMI was >25 experienced a DLT.

CONCLUSION

BMI < 25 kg/m(2) with diminished muscle mass is a significant predictor of toxicity in metastatic RCC patients treated with sorafenib.

Muscle atrophy in cancer: a role for nutrition and exercise

Developing successful antineoplastic therapies has been a primary focus of cancer research, whereas less attention has been directed at body composition and metabolism in cancer patients. Here, we examine the metabolic implications of muscle atrophy in cancer as well as the potential factors that contribute to muscle atrophy, including energy imbalance, hormone perturbations, and inflammation. The role of nutrition and exercise interventions in maintaining muscle mass during the cancer trajectory is examined.

An integrative view of obesity

Obesity is the result of the accumulation of excess body fat and not simply excess weight that can be muscle or fat. Adipocytes function in the adaptation to starvation, in exercise energetics, and in the immune defense against pathogens. Sustained positive energy balance results in excessive accumulation of adipocytes, which, in the abdomen, leads to chronic inflammation. Although informative studies have been performed with cultured adipocytes, an integrative approach to the regulation of abdominal adipose tissue involves feedback from autocrine and paracrine effectors secreted by adipocytes, the immune system, and blood flow through adipose tissue. Numerous adipokines, chemokines, and cytokines feed back to other bodily systems to regulate both energy balance and immune function. Studies of the interactions of the gastrointestinal tract and the central nervous system, as well as psychophysiological considerations of reward circuitry in the central nervous system, have shown a general adaptation to starvation that is opposed to those strategies being proposed for the prevention and treatment of obesity, ie, food restriction and increased physical activity. The obesogenic environment of highly palatable foods with hidden fats and sugars can promote metabolic syndrome and obesity, whereas fruit and vegetables with antiinflammatory phytochemicals can counteract metabolic syndrome. Therefore, a plant-based diet and the seamless integration of increased physical activity and social support to alter modern diets and lifestyles hold out the greatest hope for the solution of the obesity epidemic. Both public health and medical nutrition approaches can benefit from this integrative view of obesity.