What is the clinical definition of failure to thrive (FTT) in an oncology patient?

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From the Guidelines

Failure to thrive in an oncology patient is clinically defined as a progressive decline in physical, functional, and nutritional status, characterized by unintentional weight loss of 5% or more of body weight over 6 months, decreased muscle mass, declining performance status, and reduced mobility, as provisionally defined by the international Delphi consensus in 2011 1. This definition is crucial for early identification and management of failure to thrive, which often represents a complex interplay between the direct effects of cancer, treatment side effects, and psychological factors. Key characteristics of failure to thrive in oncology patients include:

  • Unintentional weight loss, generally 5% or more of body weight over 6 months
  • Decreased muscle mass (sarcopenia)
  • Declining performance status
  • Reduced mobility
  • Increasing fatigue
  • Diminished ability to perform activities of daily living The diagnosis of failure to thrive requires a comprehensive assessment, including:
  • Weight trends
  • Nutritional intake evaluation
  • Functional status measurement using scales like ECOG or Karnofsky
  • Exclusion of reversible causes Management of failure to thrive typically involves a multidisciplinary approach, targeting:
  • Nutritional support
  • Symptom control
  • Physical therapy
  • Psychological support As noted in the ASCO guideline on the management of cancer cachexia, early identification and management of failure to thrive are crucial, as it often indicates poor prognosis and may signal the need to discuss goals of care and possibly transition to palliative approaches if progressive despite interventions 1.

From the Research

Definition of Failure to Thrive (FTT)

  • Failure to thrive (FTT) is a complex syndrome of nutritional failure and functional decline 2
  • It is characterized by a combination of factors, including weight loss, malnutrition, and decreased functional capacity 3, 2
  • In oncology patients, FTT can be caused by various factors, including cancer cachexia, malnutrition, and treatment-related side effects 3, 4, 5

Clinical Characteristics of FTT

  • Weight loss of more than 5% of body weight in 12 months or less in the presence of chronic disease, such as cancer 3
  • Loss of muscle mass with or without loss of fat mass 3
  • Decreased appetite and food intake 4, 5
  • Malnutrition and decreased nutritional status 3, 2, 5
  • Decreased functional capacity and increased risk of morbidity and mortality 2, 5

Diagnosis and Assessment of FTT

  • Assessment of nutritional status and functional capacity 3, 2
  • Evaluation of weight loss and changes in body composition 3, 2
  • Laboratory tests, such as prealbumin and serum leptin levels, to assess nutritional status 6
  • Clinical evaluation of appetite, food intake, and overall health status 4, 5, 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Nutrition challenges of cancer cachexia.

JPEN. Journal of parenteral and enteral nutrition, 2021

Research

Treatment of unintentional weight loss in patients with cancer.

Nutrition in clinical practice : official publication of the American Society for Parenteral and Enteral Nutrition, 2005

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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