Pharmaconutrition administration on outcomes of elective oncological surgery for gastrointestinal malignancies: is timing everything?-a review of published meta-analyses until the end of 2016

Methodological quality of research on perioperative immunomodulatory supplementation in oncological gastrointestinal tract surgery: a meta-research protocol

INTRODUCTION

One of the topics that show differences of opinion in the scientific field of nutrition is the recommendation by clinical practice guidelines (CPGs) of an immunomodulatory diet with arginine, nucleotides and omega-3 for individuals diagnosed with cancer undergoing major surgery. The quality of the recommendations is directly related to credibility, transparency and rigour in their development, but also to the quality of the studies published and available for inclusion in the recommendation, such as systematic reviews (SRs) and randomised clinical trials. The aim of this study is to evaluate the methodological quality of the recommendation of perioperative immunomodulatory supplementation for individuals with gastrointestinal and head and neck cancer, the CPGs, and the studies that support the recommendations.

METHODS AND ANALYSIS

We will conduct a systematic search for CPGs. Recommendations for nutritional supplementation with immunomodulatory substrates for individuals undergoing major oncological surgery will be analysed using the Appraisal of Guidelines Research and Evaluation-Recommendations Excellence tool. CPGs will be analysed using the Appraisal of Guidelines Research and Evaluation II tool. The SRs cited in the recommendations will be analysed using the A Measurement Tool to Assess Systematic Reviews II tool and additional questions regarding heterogeneity in reviews. The clinical trials cited in the SRs and in the guideline recommendations (when applicable) will be analysed according to questions regarding heterogeneity in trials. The results will be presented in tables or charts using descriptive analyses.

ETHICS AND DISSEMINATION

The results of this study will be disseminated through relevant conferences and peer-reviewed journals.

PROTOCOL REGISTRATION NUMBER

10.17605/OSF.IO/X2GYT.

Pharmaconutrition: Which substrates?

With the term "pharmaconutrition" or "immunonutrition" is intended the use of specific nutritional substrates having the ability of modulating specific mechanisms involved in several immune and inflammatory pathways. To achieve these goals, these substrates have to be administered with over physiologic dose. Glutamine and omega-3 polyunsaturated fatty acids, used as single substrate, did not show clear clinical advantages on solid endpoints such as postoperative complications. Despite several multiple substrate enteral feeds are available on the market, very few of them have been tested in randomized clinical trial to prove efficacy. The most extensive investigated formulation is a combination of arginine, omega-3 fatty acids, ribonucleic acid with or without glutamine. Several meta-analyses of randomized clinical trials have been conducted to compare the effects of enteral immunonutrition with control diets on post-surgical morbidity. The results consistently showed that the use of enteral multiple substrate formulas significantly reduced infectious complications and duration of hospitalization. In a more contemporary view, pharmaconutrition should be tested more accurately in the contest of enhanced recovery programs, during neoadjuvant chemotherapy, and in the prehabilitation setting.

Long-term outcomes after perioperative treatment with omega-3 fatty acid supplements in colorectal cancer

Background

This study aimed to evaluate the effect of perioperative supplementation with omega‐3 fatty acids (n‐3 FA) on perioperative outcomes and survival in patients undergoing colorectal cancer surgery.

Methods

Patients scheduled for elective resection of colorectal cancer between 2007 and 2010 were randomized to either an n‐3 FA‐enriched oral nutrition supplement (ONS) twice daily or a standard ONS (control) for 7 days before and after surgery. Outcome measures, including postoperative complications, 3‐year cumulative incidence of local or metastatic colorectal cancer recurrence and 5‐year overall survival, were compared between the groups.

Results

Of 148 patients enrolled in the study, 125 (65 patients receiving n‐3 FA‐enriched ONS and 60 receiving standard ONS) were analysed. There were no differences in postoperative complications after surgery (P = 0·544). The risk of disease recurrence at 3 years was similar (relative risk 1·66, 95 per cent c.i. 0·65 to 4·26).The 5‐year survival rate of patients treated with n‐3 FA was 69·2 (95 per cent c.i. 56·5 to 78·9) per cent, compared with 81·7 (69·3 to 89·4) per cent in the control group (P = 0·193). After adjustment for age, stage of disease and adjuvant chemotherapy, n‐3 FA was associated with higher mortality compared with controls (hazard ratio 1·73, 95 per cent c.i. 1·06 to 2·83; P = 0·029). The interaction between n‐3 FA and adjuvant chemotherapy was not statistically significant.

Conclusion

Perioperative supplementation with n‐3 FA did not confer a survival benefit in patients undergoing colorectal cancer surgery. n‐3 FA did not benefit the subgroup of patients treated with adjuvant chemotherapy or decrease the risk of disease recurrence.