Malignant pleural mesothelioma (MPM) is an incurable cancer that develops primarily as a result of exposure to asbestos. MPM is distinctly different from advanced lung cancer given the longer median survival of 9–12 months, localized nature of the disease and lack of clarity surrounding cause of death. Standard treatment for MPM is chemotherapy, which offers a modest survival benefit. Given the palliative nature of management of MPM, optimizing and maintaining daily physical activity and quality of life are primary goals of treatment. As weight loss has been identified as an independent predictor of poor survival in people with MPM, body composition and nutritional status could be integral to optimal supportive care for those with MPM.
In cancer populations, reduced muscle mass and malnutrition are conditions with a complicated etiology that could be impacted by dietary intake as well as systemic inflammation. Weight loss can occur in those with adequate energy intakes, suggesting that factors beyond dietary intake influence weight loss. Inflammatory cytokines and many other molecules have been associated with the pathobiology of low muscle mass and malnutrition in cancer patients. Knowledge regarding dietary intake and inflammatory profile is therefore essential for guiding the development of interventions to address low muscle mass and malnutrition in MPM.
The study was a cross-sectional analysis of the baseline data collected from two prospective studies. The studies were (1) a longitudinal observational study of nutritional status and body composition and participants were followed until death or for up to 18 months and (2) a 6-week progressive resistance exercise intervention.
Weight and height, measured with participants dressed in light clothing with shoes removed, were used to calculate the body mass index (BMI). Participants were classified as underweight, normal weight, overweight or obese based on World Health Organization (WHO) BMI criteria.
Body composition was assessed using whole body dual-energy X-ray absorptiometry (DXA) scans. Participants with low skeletal muscle mass were categorized as pre-sarcopenic, consistent with the European Working Group on Sarcopenia in Older People diagnosis criteria.
Nutritional status was assessed using the Patient-generated Subjective Global Assessment (PG-SGA). Participants were categorized with a global rating of A— well nourished, B— suspected malnutrition/malnutrition, or C— severe malnutrition. Malnutrition was defined as a rating of B or C on the PG-SGA. As the PG-SGA categories of B and C both represent participants with malnutrition, the two categories were amalgamated for statistical analysis.
Dietary intake was measured prospectively, using an estimated food record over three consecutive days. Written and verbal instructions were provided to participants, explaining how to complete the food record and accurately estimate portion sizes using household measures (e.g., measuring cups and spoons). Returned food records were visually inspected by the researchers and incomplete details were clarified with participants. The food records were then analyzed using Foodworks 8 software. Intake variables were calculated per day and averaged across three days for each participant.
Sixty-one participants enrolled in the study. Participants were predominantly male (79%), with a median age of 69 years, and were enrolled a median 2 months from diagnosis. Forty-three (71%) participants had the epithelioid subtype of MPM and 56 (92%) participants had an ECOG performance status of 0– 1. On average patients were overweight (median BMI was 25.8 kg/m2 ): no participants were underweight, 41% were in the normal weight range, 44% were overweight, and 15% were obese.
Fifty-three participants completed a DXA scan. Of those, 28 (54%) had pre-sarcopenia. All participants completed the PG-SGA, of those 23 (38%) participants were classified as malnourished. Half (54%) of the participants with pre-sarcopenia were malnourished.
This result is particularly striking because none of the participants were underweight, the large majority had a good performance status and were early in their diagnosis. Consistent with population trends, a high proportion of cancer patients are overweight or obese. These results highlight that pre-sarcopenia and malnutrition are common in MPM patients where clinicians might not expect, for example, newly diagnosed, overweight and obese patients of a good performance status.
Overall energy and protein intake did not differ between nutritional status or body composition groups. High rates of reported nutrition supplement consumption amongst malnourished participants suggest that participants may have already made changes to their diet to address malnutrition. These results indicate malnourished patients with MPM can meet their recommended energy and protein intake with nutrition support.
Despite good performance status and a normal or high BMI, participants with MPM had high rates of presarcopenia and malnutrition. Both pre-sarcopenia and malnutrition were associated with negative outcomes for participants. For the first time, we report that presarcopenia was associated with lower activity levels whilst malnutrition was associated with poorer quality of life. Interventions that aim to address reduced muscle mass and weight loss, should be tested in MPM to assess their impact on activity levels and quality of life.
Source: Jeffery E, et al. Body composition and nutritional status in malignant pleural mesothelioma: implications for activity levels and quality of life. European Journal of Clinical Nutrition volume 73, pages1412–1421 (2019).