Growth Factors Help Combat Neutropenia in the Elderly

Growth Factors Help Combat Neutropenia in the Elderly

ORLANDO—Febrile neutropenia, the bane of older patients receiving chemotherapy,

may be preventable, or at least greatly reduced, when growth factors are used in

the first cycle to stimulate the recovery of neutrophils in the bone marrow.

So says an initial report from a pioneering study of 701 elderly cancer patients that

was presented at the annual meeting of the American Society of Clinical Oncology.

“This is the largest prospective study focusing on chemotherapy side effects in

the elderly—of which febrile neutropenia is the worst, with its frequent hospitalizations,

heavy antibiotics use, and dose delays or reductions in potentially curative

chemotherapy,” notes coinvestigator Ludovico Balducci, MD, of the University

of South Florida College of Medicine, and head, Senior Oncology Program, H. Lee

MoffittCancer Center, Tampa. “Febrile neutropenia is the most common

presentation of infection in patients receiving chemotherapy,” he emphasizes.

Although most cancer diagnoses are made in those aged >65 years, randomized,

controlled studies involving this age-group are scarce, adds coinvestigator William B.

Ershler, MD, of the National Institute on Aging, and director, Institute for Advanced

Studies in Aging, Washington, DC. “Older patients are underrepresented in

clinical trials; they also are undertreated in the community due largely to fear of side

effects—notably febrile neutropenia, which can at times be fatal,” Dr Ershler

points out. “The paradox is, if you cut or delay the chemotherapy dosage, you

relieve side effects in the short-term but jeopardize cure in the long-term.”

Thus, this study documents the feasibility of conducting controlled clinical trials

in the community setting involving basically healthy older cancer patients receiving

chemotherapy. “It shows us that with growth factor support, their ability to benefit

from full-dose, on-time, myelosup pressive chemotherapy is as good as a youngerperson’s,” he said. This is a far cry from the view that age cutoffs are necessary in clinical trials. This

nationwide study was conducted by the Geriatric Oncology Consortium and included

701 patients with lung, breast, or ovarian cancer who were randomized to receive the

growth factor pegfilgrastim (Neulasta), starting either in the first chemotherapy cycle (n

= 349) or, at the physician’s discretion, in later cycles (n = 352).

A 60% decrease in the incidence of febrile neutropenia was seen across all

cycles in patients receiving pegfilgrastim starting in the first cycle compared with

those receiving it later. Regardless of which chemotherapy regimens

were used or type of tumor, all patients “showed a favorable outcome with

the primary prophylaxis,” Dr Ershler said. “The study also showed a 50% decrease in

chemotherapy dose reductions in patients receiving pegfilgrastim starting in cycle 1

compared with the others.” “‘Physician discretion’ can include waiting

until the patient has developed an alarmingly low white blood cell count,” he

told IMWR.