Systematic Review Highlights Lack Of Focus On Sarcopenia In Lung Cancer

Researchers conduct a systematic review of sarcopenia in patients with lung cancer

medwireNews: More research is needed into sarcopenia, as a potentially modifiable factor influencing lung cancer outcomes, say the authors of a systematic review.

Lead study author Jemima Collins, from Cardiff University, UK, and team say that early palliative care has been shown to increase survival, as well as quality of life, highlighting “the importance of supportive measures in a poor-prognosis population receiving active oncological intervention”.

They say: “As such, focusing research on the identification and management of sarcopenia in patients with lung cancer may prove to be a tolerable and cost-effective adjunct to the current lung cancer care.”

However, their systematic review highlights the lack of focus on sarcopenia in lung cancer patients to date. The researchers focused on lung cancer, because of the previously demonstrated impact of sarcopenia on these patients with an already poor prognosis. Many of the 35 studies reviewed identified sarcopenia in patients with cachexia, yet none of them prospectively assessed the impact of sarcopenia on cancer outcomes.

The studies measured muscle mass in a variety of ways, including appendicular skeletal muscle mass, smooth muscle area at the levels of specific vertebrae and mid-upper arm circumference, and used different cut-offs for sarcopenia. In addition, they defined sarcopenia based purely on muscle mass measurements, despite the non-linear relationship between muscle mass and strength.

This makes it hard to draw direct comparisons between studies, and demonstrates the need for a “standardised definition of cancer-related sarcopenia which can be used clinically and in the research setting”, write the team in BMJ Open.

The review also shows the complex but as yet unclear pathophysiological mechanisms of muscle mass loss. The findings suggest the involvement of inflammatory pathways, but provide little evidence for abnormal protein metabolism, despite this being implicated with sarcopenia. The study results also suggest that the mechanisms of muscle loss may vary according to cancer stage and cachexia phase.

The unclear pathophysiology was related in the conflicting findings of the nine studies that evaluated interventions for sarcopenia.

Nutritional supplementation had a variable effect, and the two studies assessing the effects of ATP infusions had contradictory findings. However, the researchers note that just one study appeared statistically robust.

“Strikingly, our review has demonstrated that, to date, there has not been due attention to the concept of sarcopenia as a distinct, if overlapping syndrome, [in cachexia],” say Jemima Collins and colleagues.

Reference

Collins J, Noble S, Chester J, et al. The assessment and impact of sarcopenia in lung cancer: a systematic literature review. BMJ Open. 2014 Jan 2;4(1):e003697. doi: 10.1136/bmjopen-2013-003697.

medwireNews (www.medwireNews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2014