Diagnostic imaging in stage IV cancer on the rise

Aug 6 2012

By Ingrid Grasmo

Diagnostic imaging in elderly patients with stage IV cancer has increased significantly in recent years, while its use among those with early-stage disease has decreased, suggest study findings.

Using the Surveillance, Epidemiology, and End Results Medicare database, Caprice Greenberg (University of Wisconsin Hospitals and Clinics, Madison, USA) and colleagues identified claims for computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and nuclear medicine (NM) among 100,594 elderly patients diagnosed with stage IV breast, colorectal, lung, or prostate cancer between 1995 and 2006.

Findings were compared with trends in imaging use among 192,429 early-stage (I and II) patients with the same tumor types over the period.

The team also studied imaging rates among a recent-care group of 55,253 patients diagnosed with stage IV cancer between 2002 and 2006.

The researchers found that the proportion of stage IV cancer patients imaged at least once during the course of their disease increased significantly by 4.6% between 1995 and 2006.

By contrast, the proportion of early-stage patients undergoing imaging decreased by 2.5% over the study period.

Among the recent-care group, 95.9% of patients underwent at least one high-cost imaging procedure, with a mean 9.79 scans per patient and 1.38 scans per patient per month of survival. During continuing care, 75.3% of patients were scanned, receiving a scan every 6 weeks.

The most commonly performed high-cost imaging procedure was CT (93.7%), followed by NM (56.9%), MRI (46.4%), and PET (27.5%) among this recent-care group.

"Diagnostic imaging is used frequently in patients with stage IV disease, and its use increased more rapidly over the decade of study than that in patients with early-stage disease," conclude Greenberg et al in the Journal of the National Cancer Institute.

In an accompanying editorial, Robin Yabroff and Joan Warren from the National Cancer Institute in Bethesda, Maryland, USA, say: "Physicians tend to overestimate survival for terminally ill cancer patients, which may influence their treatment and related imaging recommendations.

"Development of practice guidelines for advanced imaging in patients with stage IV disease, with explicit statements about the state of evidence will be critical, particularly for care outside of the window surrounding patient diagnosis."

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