PHILADELPHIAOver the last 20 years, nutritional assessments in
oncology have evolved from just assessing a patients
nutritional status to using the information to improve outcome. The
latest assessment tool is the scored Patient Generated Subjective
Global Assessment (PG-SGA) developed by Faith Ottery, MD, PhD,
president of the Society for Nutritional Oncology Adjuvant Therapy.
The PG-SGA was discussed at a session of the 5th Annual Congress of
the Society for Nutritional Oncology Adjuvant Therapy.
Even though this is called a subjective global assessment, it
has great reliability, said Suzanne Kasenic, RD, an oncology
dietitian at Temple University Cancer Center, Philadelphia. Ms.
Kasenic worked with Dr. Ottery to develop the point system by which
the PG-SGA is scored.
The PG-SGA is the latest step in an evolution that began in the 1980s
when Detsky and Baker first showed that the results of clinical
assessment of nutritional status correlated with results of
assessments using laboratory tests and anthropometric measures, and
that the major factor clinicians use to determine overall nutritional
status is loss of subcutaneous tissue, muscle, and weight.
The first SGA was developed and published by the University of
Toronto in 1987. Dr. Otterys PG-SGA includes a numeric score
for triage of medical nutrition therapy and a global assessment
The total numeric score is derived from information supplied by the
patient and the clinician. Patients enter information on a form about
their weight, dietary intake, the nutritional impact of their
symptoms, and their functioning. The clinician supplies information
about the patients disease and its metabolic and physical
score is keyed to broad categories of nutritional triage
recommendations, which include patient and family education and
symptom management, including pharmacologic intervention and
appropriate nutrient intervention (food, nutritional supplements,
enteral or parenteral nutrition).
The clinicians global assessment of nutritional status is based
on the history and a physical examination, and is assigned a letter,
from A (well nourished) to C (severely
malnourished) (see Table, left).
The global assessment is a broader assessment that takes a
longer view and is reflective of what happens with a patient over a
longer period of time, Ms. Kasenic said. It connotes a
physiological state. So if the patient is assigned an A
classification, were saying that the person is probably in an
anabolic state, whereas if they are labeled C, the understanding is
that it is a catabolic state. The total numeric score gives more of a
snapshot, a freeze-frame of where that patient is at a particular time.
Interventions are tied to the numeric score, not to the global score,
Ms. Kasenic stressed. The idea is that, hopefully, in
intervening in reaction to patients numeric scores, you will
eventually change their global rating and begin to move them in the
direction we want them to go.
Using the PG-SGA in Clinical Trials
Ms. Kasenic said that the scoring also makes it possible to relate
the PG-SGA rating to scales that are already recognized in clinical
practice such as performance scales and toxicity scales.
We would like to see nutrition begin to be incorporated into
clinical trials, into protocols that are funded by the NCI, she
said. With those protocols, there are always toxicity scales
that tell the oncologists at what point they must reduce the dosage
of the drug or stop the study or intervene in some wayand we
would like to see nutrition be a stronger part of the scales. There
is already a toxicity scale for weight loss in these studies.