Supplemental Parenteral Nutrition in Patients with Cancer

Short abstract

This letter to the editor remarks on the recent article by Bouleuc et al. on parenteral nutrition for patients with advanced cancer cachexia.

I read with interest the excellent paper by Bouleuc et al. [1], and I congratulate the authors for this extremely difficult randomized control trial and for the well‐balanced discussion of their results, which I agree with.

To understand these findings and to better define the potential role of parenteral nutrition (PN) in patients with cancer, two considerations are needed.

Looking at the current literature [2], as well as to the original aim of PN in patients with cancer [3], the main role of supplemental parenteral nutrition (SPN) should be “permissive” toward an intensive oncologic therapy, which a malnourished or hypophagic patient could not well tolerate because of an excessive gastrointestinal toxicity. This was not the case in this study, in which less than half the patients were on chemotherapy, a treatment that was also delivered without apparent problems to the controls. Hence, this study, although clearly showing no benefit of SPN on quality of life (QoL) in this patient population, does not answer the question “does a malnourished/hypophagic patient undergoing an intensive oncologic therapy get an oncologic benefit from SPN?” The message that SPN does not improve QoL is relevant even if it would be unlikely to expect that just doubling the protein‐calorie intake might translate in the improvement of the patient status. In fact, especially when survival is short (only 2.6 months, contrary to the expectations of the researchers), the general status of the patients is characterized by a myriad of negative poorly controlled impact factors beside malnutrition. A better comprehension of the results would have been possible by expressing the protein‐calorie intake of the controls by kilogram of bodyweight.

A completely different issue is the potential impact of total parenteral nutrition (TPN) on survival: the rationale for a benefit is delaying the final outcome which would occur in less than 1–2 months in patients undergoing a total macronutrient deprivation [4]. Such benefit can be expected provided the patients’ general status is not too compromised and tumor spread is limited. Survival prognostic scores are available in the literature [5, 6]. This study, however, did not address this issue because the patients maintained the capability of oral food intake. A small quasirandomized study [7] in severely malnourished aphagic patients has recently shown that TPN can almost triple the length of survival as compared with simple hydration even if the absolute values of survival were very modest in this population. Nevertheless, it would support the potential of TPN when the indication is correct.

I think the message of this paper is clear and relevant, but it should not divert the oncologist's attention from the above‐mentioned potential roles of PN in patients with cancer as reported in the ESPEN guidelines [8]. Misuse of PN is common in the clinical practice, perhaps because the full competence of this approach is at crossroads between oncologists and nutritionists, without fully belonging to any of them. This study well demonstrates the limits of this approach when the indications are not in line with the recommendations of the scientific societies.

Disclosures

The author indicated no financial relationships.