LAUSR

Dear editors, This letter is about the work of Oflazoğlu et al. entitled “Prevalence and related factors of sarcopenia in newly diagnosed cancer patients,” which was recently published [1]. In this study, the researchers screened newly diagnosed cancer patients for the presence of sarcopenia, as well as the possible factors contributing to its development. For the diagnosis and classification of sarcopenia, they used the diagnostic criteria proposed by the European Working Group on Sarcopenia in Older People (EWGSOP), which was published in 2010 [2]. It is a widely accepted set of criteria that uses various methods to assess muscle strength, muscle mass, and physical performance to classify patients in the context of sarcopenia. Recently, the diagnostic criteria proposed by EWGSOP were revised [3]. The new version of the criteria includes a different approach, using a stepwise method to screen the patients at risk first, and then assess the patients at risk for muscle mass using relevant methods (bioimpedance analysis, imaging, circumferential measurements, etc.), musle strength, and physical performance using functional test such as gait speed, like its predecessor. The main difference lies in this altered stepwise approach, as well as newly defined cut-off values for the tests mentioned. Moreover, these criteria do not always give the cut-off values for the target population. Thus, they usually require calibration to be used more accurately in patients over different parts of the world [4]. As the researchers gather data from different populations, it is naturally expected for these cut-off values to change over time. Although this study was sent for approval in 2019 and finally published in 2020, it used the older diagnostic criteria to classify the newly diagnosed cancer patients for sarcopenia. Moreover, the revised criteria are also cited in the text as a reference. While it is hard for the researchers to conduct new analyses after completion most of the time since these analyses require new data from the patients that was not obtained, it is actually not valid for this case. It is possible to use the existent data for the application of the new criteria, and conduct the same analyses once again to show whether they still apply for the new classification. While the researchers evaluated the patients for possible contributing factors in sarcopenia, there are some crucial details that should be known in a study. Comorbidities, the numbers and the properties of the drugs that are used, and presence of a surgical operation or physical activity levels can affect the presence or the severity of sarcopenia [5, 6]. However, these details are lacking in patient characteristics or exclusion criteria. While the researchers preferred using the Eastern Cooperative Oncology Group (ECOG) performance status to assess physical performance, it would be preferable to use a test that actually measures the performance itself, such as 4-m gait test, which can easily be accomplished in the clinical settings [7]. Assessment of sarcopenia in cancer patients, who are usually in a severe catabolic state [8], is an important aspect of the cancer treatment and rehabilitation. We were excited to read their work about sarcopenia in oncology patients, as well as the risk factors. This study emphasizes the importance of vigilance for sarcopenia in this patient population, and we would like to thank the researchers for that.