Use of Surveillance CT Scans to Detect DLBCL Relapse

Diffuse large B-cell lymphoma (DLBCL) is both an aggressive lymphoma and the most common form of lymphoma, accounting for 30% of non-Hodgkin lymphoma cases. It is potentially curable with a combination of chemotherapy and targeted immunotherapy with rituximab (Rituxan). Up to one-third of patients relapse following remission. Relapsed DLBCL can be treated with stem-cell transplantation and high-dose chemotherapy, so strategies to catch relapses early are important. The optimal approach to achieve timely detection of relapses is not clear, though some strategies are outlined in the National Comprehensive Cancer Network (NCCN) guidelines.

Currently, DLBCL patients typically get two to three CT scans per year, to monitor for possible relapse. Optimized use of surveillance scans is important because of the risk of secondary malignancies that they pose, and because scans can lead to patient anxiety and unnecessary biopsies.

A study by investigators from the Mayo Clinic, Rochester, Minnesota; the University of Iowa Hospitals and Clinics, Iowa City; and Centre Lon Brard, Lyon, France, assessed 684 patients with newly diagnosed biopsy-proven DLBCL treated with immunochemotherapy, who were enrolled in the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource, a prospective cohort of newly diagnosed lymphoma patients, from 2002 to 2009. They had received both initial and post-treatment management per treating physician.

The goal of the study was to determine how relapses were detected over time. The investigators reviewed medical records for patients with events for clinical details at relapse and relationship to planned follow-up visits and surveillance scans. The median follow-up period was 59 months. A total of 537 patients (median age 63 years, 54% men) entered post-treatment surveillance, and 109 (20%) relapsed. A total of 62% of relapses were detected by patients (due to symptoms) prior to a planned visit, while 36% of relapses were detected during a planned visit. Regarding the value of scans to detect relapse, scans detected DLBCL relapse prior to observation of clinical signs/symptoms in only 8 of 537 patients (1.5%).

The take-home message is that the majority of relapses in patients with DLBCL occurred outside of regularly scheduled visits. Therefore, the investigators emphasized, it is important to educate patients to be more alert to signs and symptoms of relapse, which include enlarged lymph nodes, night sweats, unexplained fever, and unintentional weight loss. Also, said lead investigator Carrie Thompson, MD, a hematologist at the Mayo Clinic, “the decision of whether to do surveillance scans and how often should be tailored to each individual patient.” In discussing the study in a pre-ASCO press briefing, she commented, “I want to see a randomized study to see if clinically directed [by patient symptoms] scans would work better for patients than scheduled scans.”