Jan06.html

University of Virginia Nutrition Support
E-Journal Club
January 2006

Greetings,

We have been getting back “in stride” now that the hectic Holiday and Post-holiday schedule is behind us.  We are busy preparing for Clinical Nutrition Week in Dallas next month – Joe will be presenting our data on pancreatitis patients in a scientific session and as well as a clinical poster presentation.  Please stop by our poster and say hello if you will be at Nutrition Week.  We are also preparing to launch a new page to our traineeship website with tips and clinical pearls, and we will be listing some journal articles that we found interesting, but have not formally critiqued.

 

January Citation:  

Rabinovitch, Grant, Berkey, et al. Impact of nutrition support on treatment outcome in patients with locally advanced head and neck squamous cell cancer treated with definitive radiotherapy: a secondary analysis of RTOG trial 90-03 .   Head and Neck 2005 Nov. 14.

 

Summary: 

This study is a   reevaluation of data from a previous study “The Radiation Therapy Oncology Group prospective randomized trial” that evaluated for host toxicity and cancer outcomes in patients with advanced squamous cell head and neck cancer treated with four different radiotherapy fractionation schedules.   Data was collected prospectively on nutrition support (NS) at baseline (BNS), during treatment (TNS), and at follow up after XRT.  When the secondary evaluation was done, all patients from all of the original treatment arms were grouped together and analyzed according to the need for, and timing of, nutrition support. A recursive partition analysis (RPT) was done to identify subgroups with distinct results on survival and locoregional control.

  • 1113 pts enrolled, 1073 analyzed for outcome (1991-1997)
  • (28 “found ineligible”, 5 refused protocol Tx, 7 died)
  • Definition of BNS: 50% of pts used only oral liquid supplements, 27% used only enteral tube feeding, 16% used oral and enteral supplementation, 6% used parenteral nutrition.
  • Pt characteristics: majority were middle-aged men, w/ stage III or IV oropharyngeal CA. 86% of all patients receive some form of “nutrition support” during therapy (TNS).

 

Major Results reported by authors:

For patients who received BNS as compared to those who did not:

  • Significantly more likely to have poorer Karnofsy performance status (KPS), higher primary tumor classification, more extensive regional lymph node involvement; greater overall cancer stage (by American joint committee on Cancer staging-AJCC), and a greater incidence of anemia.
  • Significantly greater weight loss in the 6 mo preceding treatment than those who did not receive BNS.
  • Significantly more patients w grade 3 or 4 dysphagia before treatment initiation than those w grade 1 or 2 dysphagia. (more likely to receive BNS and TNS)
  • Significantly less weight loss after treatment.
  • A trend to lower incidence of grade 3 or 4 mucositis after treatment.

 

For patients who received BNS as compared to those who received TNS or no NS:

  • Significantly less 5-year locoregional control rate than those who received either TNS, or no NS (no significant difference between TNS and no NS).
  • Significantly poorer 5-year actuarial overall survival (TNS inferior to no NS in only one treatment arm).
  • Parenteral nutrition was associated with a more negative effect on locoregional failure and death than did oral and enteral nutrition.

 

Authors Conclusions:

Patients who received BNS had less weight loss and lower incidence of grade 3-4 mucositis at treatment completion.   These pts completed Tx in the same time frame as did those who did not receive NS, despite poorer Karnofsky performance status and greater tumor burden.

BNS was significantly associated with worse locoregional control of cancer and overall survival.

 

Evaluation:

This was not a randomized, or blinded study.   Although the data on nutrition was collected prospectively, this was an observational study with all of the inherent selection bias in any retrospective or observational study.  This selection bias is evident by the fact that those patients who received nutrition support before therapy (BNS) had a host of factors associated with poor outcome. The authors attempted to control for the substantially worse prognostic factors seen in those patients who received BNS with recursive partitioning analysis, but the simple matter is that it is not possible to control for all factors short of randomizing a large number of patients.  Unfortunately the language of the discussion section seems to imply a causal association in sections “the effects of oral and enteral nutrition…”.  However, the final conclusions of the authors are quite clear that the associations reported should be used only to generate hypothesis, and to justify future randomized studies.

 

Highlighting the limitations of this should not be taken that nutrition is a panacea either – the hypothesis that providing nutrition support to oncology patients may have negative effects is a critical question, and these observational studies provide the necessary groundwork to justify prospective investigation.

 

Take home message:  

This study showed that the patients with worse prognostic factors and malnutrition tended to received nutrition support prior to radiotherapy, and they have the worst outcomes.   This study did not address what would happen if the sickest patients did not receive nutrition support, nor did it address if a certain level, different timing, or type of nutrition support would allow a different outcome.  Randomized studies that address these questions are needed.

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Other News:

Check out the latest Practical Gastroenterology article at:www.uvadigestivehealth.org. Scroll down to GI Nutrition on the far left column and click on link, then scroll down to box with links within the nutrition site
Nutrition Articles in Practical Gastroenterology is in the left column.

  • Makola, D. Elemental and Semi-Elemental Formulas: Are they superior to polymeric formulas?  Practical Gastroenterology 2005;XXIX(12):59.

 

Joe Krenitsky MS, RD
Carol Parrish RD, MS

PS – Please feel free to forward this on to friends and colleagues.