Sarcopenia as Prognostic Factor in Lung Cancer Patients: A Systematic Review and Meta-analysis

Abstract

Background/Aim: Sarcopenia describes the loss of skeletal muscle mass. While this condition is associated with a high mortality in cancer patients, its influence on survival is still underestimated. Patients and Methods: A systematic review for articles was performed using the PubMed database, Cochrane Library, Biomed Central, Science Direct and by manual search. We used data of overall survival in sarcopenic patients for assessing the death risk. We extracted hazard ratio estimates from univariate and multivariate Cox proportional hazards models for meta-analysis. Results: A total of 15 studies were eligible for meta-analysis including a total of 2,521 lung cancer patients. Univariate meta-analysis revealed a twofold increased death risk in sarcopenic patients; multivariate meta-analysis yielded a significant, threefold elevated risk of death. This higher mortality is independent of tumour stage. Conclusion: Muscle loss is an independent risk factor for increased death risk in lung cancer patients independent of cancer stage. This argues for implementing screening for sarcopenia into cancer care. Sarcopenia describes the age-related loss of muscle mass and strength starting during the fourth to fifth decade of life. It is defined as a muscle mass of at least two standard deviations below the mean muscle mass found in young healthy adults (1-3). While often reported in the elderly, loss of muscle mass does also manifest in patients suffering from a chronical disease like congestive heart failure, chronical obstructive pulmonary disease, chronical renal failure or cancer. Muscle loss has a relevant impact on survival, especially in the latter group. The prevalence of sarcopenia in cancer patients depends on cancer entity, which is why a prevalence of 16% is described in breast cancer patients, whereas 71% of lung cancer patients under palliative therapy suffer from sarcopenia (4-6). Muscle wasting is an unfavourable prognostic factor for cancer specific survival of rectum, liver, oesophagus, stomach or kidney cancer patients (1, 7). If muscle mass is maintained or increased, patients show a longer overall survival (5). Sarcopenia may be caused by several different factors; cancer, chemotherapy or locoregional impairment caused by surgery or radiation therapy, comorbidities, malnutrition or physical inactivity (8). Sarcopenia itself is also a risk factor for an increase in chemotoxicity and a decrease in therapy response (1). Physical activity prevents muscle wasting; a small pilot study showed that smartphones are a good tool to implement personalized physical activity programs and to increase physical activity of patients (9, 10). Sarcopenia is assessed by using Dual-energy X-ray absorptiometry scan (DEXA), bioelectrical impedance analysis (BIA) or computed tomography (2). Especially computed tomography is used routinely for investigations 4603 This article is freely accessible online.

Sarcopenia and mortality in cancer: A meta-analysis

“…The subgroup analyses in our meta-analysis according to cancer type yielded results largely consistent results with previous meta-analyses. Previous literature have identified significant associations in patients with lung cancer [ 10 ], head and neck cancer [ 11 , 18 ], GI cancer [ 9 , 19 , 20 ], liver cancer [ 9 , 21 , 22 ], pancreatic cancer [ 23 ], and urinary tract cancer [ 24 ], with largely consistent effect sized identified in the current meta-analysis. However, other recently published meta-analyses by Zhang et al [ 25 ], Ubachs et al [ 26 ], and Jia et al [ 27 ] have identified a significant association between sarcopenia and survival in breast cancer, ovarian cancer, and hematological malignancies, respectively, contrary to insignificant association identified in the current meta-analysis.…”

“…Previous meta-analyses have suggested that sarcopenia is associated with a higher mortality in cancer patients [ [9] , [10] , [11] ]. However, these meta-analyses focussed on certain type(s) of cancer, and whether these results could be generalized to a wider spectrum of cancer types remains uncertain.…”

Sarcopenia as A Predictor of Mortality Among the Critically Ill in an Intensive Care Unit: A Systematic Review and Meta-Analysis

“…Our subgroup results found that when considering the reasons for admission, critically ill patients with sarcopenia have an increased risk of mortality, profoundly con rming that sarcopenia could be a prognostic factor in critical illness. Our ndings are in line with previous research, which has found that older adults with sarcopenia are at increased risk of mortality in other settings, such as the community 36 , nursing homes 43 , or in an oncology setting [44][45][46] . According to published studies, the main reason explaining the relationship between sarcopenia and mortality is lower muscle mass, which has been con rmed as a strong predictor for an increased risk of death 31,47 .…”

Sarcopenia and mortality in different clinical conditions: A meta-analysis

“…Previous meta-analyses evaluated the impact of lean mass on mortality in a particular population, such as people awaiting liver transplantation [ 7 , 8 ], or people with liver cirrhosis [ 10 ], tumors [ [11] , [12] , [13] , [14] ], and post-operation [ [15] , [16] , [17] , [18] , [19] ]. Some studies included less validated methods, such as phase angle [ 14 ] and mid-arm muscle [ 8 ] in the meta-analysis. The risk estimates identified in these studies were largely consistent with the estimated identified in the subgroup analysis of the present meta-analysis.…”