Routine surveillance with computed tomography scans add little to the surveillance of patients in remission from diffuse large B-cell lymphoma, a large epidemiologic study shows.
Planned CT scans detected diffuse large B-cell lymphoma (DLBCL) relapse prior to clinical symptoms or signs in only 8 of the 537 (1.5%) patients who entered post-treatment surveillance.
The vast majority (62%) of relapses were detected by patients who contacted their provider because of symptoms before their planned visit, according to lead author Dr. Carrie A. Thompson, a hematologist at Mayo Clinic, Rochester, Minn.
Dr. Carrie A. Thompson
"The take-home point is that the majority of relapses occur outside of planned follow-up visits and are accompanied by symptoms, exam or lab abnormalities," she said. "In this study, scheduled scans added little to patients who had none of the above."
She noted that DLBCL patients in remission in the United States undergo a median of 2.5 CT or positron emission tomography scans per year during surveillance, according to a recent study (Leuk. Lymphoma 2012;53:1113-6). Moreover, only 4.2% of patients in the series received no imaging.
DLBCL is the most common form of non-Hodgkin lymphoma, with about 20,000 new cases diagnosed each year in the United States. It is an aggressive lymphoma, but is potentially curable with chemotherapy. Post-treatment surveillance is necessary, but the optimal strategy is unclear, she explained at a press briefing highlighting studies at the upcoming American Society of Clinical Oncology (ASCO) meeting.
The National Comprehensive Cancer Network recommends that patients be evaluated every 3-6 months for 5 years, with a CT scan no more often than every 6 months for the first 2 years after treatment completion, and then as clinically indicated.
The investigators enrolled 644 patients with biopsy-proven DLBCL treated with anthracycline-based chemotherapy in the University of Iowa/Mayo Clinic SPORE (Specialized Programs of Research Excellence) Molecular Epidemiology Resource, a prospective cohort of newly diagnosed lymphoma patients. Their median age was 63 years (range 18-92), 54% were men, and median follow-up was 59 months (range 8-116). Overall disease management and follow-up was at the discretion of their hematologist/oncologist.
Of the 537 patients who entered surveillance, 109 (20%) relapsed. Medical records were available in 100 patients.
Of the 38 patients with relapse detected at a planned visit, 26 had an abnormal physical exam and/or labs, Dr. Thompson said. The remaining 12 patients were asymptomatic, and their relapses were detected solely by CT scan. "It is noteworthy that four of these relapses turned out to be another form of lymphoma, not diffuse B-cell lymphoma," she added.
Although the data show that scans detected relapses in a minority of patients, it is too early to say definitively how many scans are needed or how often they should be done, Dr. Thompson told reporters.
"I think it’s very interesting, it’s very provocative, but what I would like to see is a randomized study to determine just what the best surveillance strategy is in this disease," she said. "Is it scheduled scans, as we currently do, or clinically directed scans, where we only do a scan when a patient has new symptoms or abnormal findings on clinical exam or laboratory findings?"
Incoming ASCO president Clifford Hudis, chief of the breast cancer medicine service at Memorial Sloan-Kettering Cancer Center in New York, observed that the low 1.5% rate of CT-detected relapse mirrors what has been observed in other common malignancies.
"These findings will help physicians develop guidelines for following patients who are in remission from DLBCL and will spare patients from the costs and excessive radiation exposure of unnecessary CT scans, not to mention the impact of false-positive findings on such scans," Dr. Hudis said.
Dr. Thomson reported having no financial disclosures.