BY ROBERT H. CARLSON
While diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma in adults, the optimal way to follow these patients after therapy has been relatively unclear. A new study, though, now shows that routine CT scans post-therapy are of little value and that the vast majority of relapses occur outside of planned follow-up visits and are detected by symptoms, laboratory abnormalities, or physical examination.
The study was discussed during an American Society of Clinical Oncology news conference held before the Annual Meeting.
The data (Abstract 8504), showing that surveillance suffices for the vast majority of these patients, mirror observations made in other common malignancies, said ASCO President-Elect Clifford A. Hudis, MD, Chief of the Breast Cancer Medicine Service and Attending Physician at Memorial Sloan-Kettering Cancer Center, commenting during the news conference.
“The oncology community has already begun to reevaluate the utility of advanced imaging scans and some aspects of surveillance in the routine follow-up of patients with certain cancers. This study is one case in which the benefits of such scans do not appear to outweigh their potential burdens on patients, in terms of anxiety, physical risks, or financial costs.”
CT scans are currently called for in surveillance guidelines at no more than every six months for two years after completion of treatment, explained the lead study author, Carrie A. Thompson, MD, a hematologist at the Mayo Clinic. But in this study, only 1.5 percent of patients (8 of 537) in remission had a relapse detected solely through a scheduled imaging scan.
The study was part of a large, prospective, multi-institutional cohort of newly diagnosed DLBCL patients from the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER).
Patients were followed for events including relapse, re-treatment, and death with events verified by medical records.
The 644 patients, who were enrolled in the study from 2002 to 2009, had a median age of 63 (range of 18 to 92). Median follow-up was 59 months (range of 8 to 116). All patients had been treated with anthracycline-based immunochemotherapy, with initial and post-treatment management determined by the treating physician, Thompson said.
Out of 537 patients who had observation only after therapy, 109 (20%) relapsed and 41 died from other causes, she reported. A total of 42 percent of relapses were in the first 12 months following diagnosis, 27 percent were between 12 and 24 months, and 31 percent after more than 24 months.
Among the 109 patients who had disease relapse, 62 percent (62/100, nine unknown) presented to their physician earlier than a planned follow-up visit due to symptoms. At the time of relapse, 68 percent were symptomatic, 42 percent had abnormal physical exam, 55 percent had elevated LDH, and 87 percent had one or more of these features.
Of the 38 patients with relapse detected at a planned visit, 26 had clinical features of relapse and 12 asymptomatic patients had relapse detected solely by planned surveillance scan. And four of those 12 had relapse of low-grade or other subtype.
That left only eight of 537 patients (1.5%) whose relapse was detected by surveillance CT scans.
“Scans theoretically increase the risk of a second cancer, and can also increase patient anxiety and lead to biopsies that may not be necessary,” Thompson said. Even so, she added, the decision of whether to do surveillance scans and how often should be tailored to each individual patient.