One in four lung cancer patients is malnourished and this can impact on their prognosis and response to cancer therapies. This issue is addressed in a review recently published in Clinical Lung Cancer, which examines the prevalence of malnutrition in lung cancer patients, the impact of body composition and weight loss on survival, and the effectiveness of different nutritional interventions.
«Lung cancer ‒ explains Professor Emilio Bria, Head of the Thoraco-Pulmonary Neoplasms Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS and Associate Professor of Oncology at Università Cattolica, Rome campus – is the most frequent cancer in the world (over 2 million cases in 2018) which causes 18% of all cancer deaths. Many of these patients also have a significant degree of malnutrition that is usually not diagnosed and therefore not treated. But this is a major problem, which can affect the success of cancer treatment and patient survival».
«It is important to always investigate the presence of signs of malnutrition in cancer patients - says Professor Maria Cristina Mele, Head of the Nutrition and advanced Cancer Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS and Aggregate Professor of Applied Dietary Techniques at Università Cattolica, Rome campus – in order to intervene promptly according to international guidelines. Malnutrition can develop because the patient eats or assimilates less, due to metabolic alterations, but also due to chemotherapy-induced toxicity, which leads to loss of muscle mass and systemic inflammation syndrome. It is essential that oncologists understand the consequences and impact of good nutritional status or malnutrition on cancer treatment because a malnourished patient, regardless of therapy, survives less».
How Malnutrition Is Diagnosed
We start with a pre-screening of malnutrition by simply asking the patient: “how many kilos have you lost in the last 6 months? Are you eating less than usual?” and then move on to screening questionnaires (NRS 2002, MUST), which can be completed in a few minutes and identify patients at risk of malnutrition, who should be referred to the specialist.
After working on this basic screening, we acquire further elements by using the examinations already carried out for oncological staging (e.g. abdominal CT scan) – therefore without introducing new items of expenditure ‒ for example by calculating the amount of active muscle mass of the patient. «Studies show ‒ explains Professor Mele – that if muscle mass is reduced, the patient risks a more complex oncological pathway that will sooner become more complex and make treatment less effective. It must be assumed that every cancer patient, even if not fundamentally malnourished, will become so during his or her course of therapy. The most important parameter to be assessed in predicting response to surgery and systemic cancer therapies is the reduction in muscle mass, which correlates with survival».
How to Intervene to Correct Malnutrition
Professor Mele says: «The clinical nutrition doctor has to take care of the patient before the chemotherapy starts, by 'pre-qualifying' the patient, as before surgery. The patient is then followed throughout his or her chemotherapy, with a personalised diet, supported by medical foods to ensure protein and energy intake. There is a great deal of activity in the oncology field on the part of manufacturers to make these special medical foods more palatable. ‘Neutral’ flavours are preferred, because during chemotherapy there is a devastating taste alteration; these products also need to be very concentrated in terms of energy and protein to keep the volume down. Foods for special medical purposes allow us, together with the food tolerated by the patient, to supplement his/her energy, protein and lipid quota. The way forward - continues Professor Mele - is ultra-personalisation, so that patients feel welcomed even on such an important aspect as nutrition, enabling them to sit down at the table and eat at least three times a day».
Why It Is Important to Feed Cancer Patients Well
«The immune system works well if it is constantly supplied with specific nutrients – explains Professor Mele ‒ otherwise it is as if we were sending an army into battle without providing them with warm food, blankets and ammunition. A tired soldier is unable to use even the most powerful weapons. This is what happens to the immune system when it lacks energy, proteins, amino acids, trace elements (zinc) and vitamins (especially D, A, C and B), which enable it to produce the weapons capable of destroying all invaders, from bacteria to transforming cells. For good immunonutrition of cancer patients, products enriched with arginine, nucleotides and omega-3 are preferable, due to their ability to modulate the proinflammatory cascade».
The gut microbiota also needs certain nutrients and constituents from food to maintain immunomodulation. «Food has a dramatic impact on the immune system. When patients are not re-nourished early by natural means after an operation (we too often forget that we are food that has to transit through the intestine), they may suffer from bacterial translocation, because the non-nourished intestine becomes more permeable to bacteria and this facilitates the development of infections, such as enterobacterial pneumonia. So, feeding properly also means modulating the microbiota and preventing this huge mass of ‘bad’ bacteria from reaching areas of the body where they can cause serious infections». says Professor Mele.
Maintaining an adequate nutritional status must therefore be a priority objective of cancer treatment because it allows the oncologist to use all lines of chemotherapy and radiotherapy. Early nutritional screening is strongly recommended and patients at risk of malnutrition should be referred immediately to a clinical nutritionist for further diagnosis and treatment. The clinical nutritionist should then take part in tumour boards to suggest personalised nutritional support to patients with cancer, starting with accurate counselling and ending with the prescription of a personalised diet, accompanied by foods for special medical purposes.