A large study reports that the vast majority of diffuse large B cell lymphoma (DLBCL) relapses are detected based on symptoms, abnormal blood tests or abnormal findings on physical exam, suggesting that CT scans, which are currently a routine part of follow-up, may be unnecessary. Researchers found that just 1.5 percent of patients in remission had a relapse that was detected solely through a scheduled imaging scan. These findings will help physicians develop guidelines for following patients in remission for DLBCL and spare patients from the excess radiation exposure and costs associated with unnecessary CT scans.

Current surveillance guidelines for DLBCL recommend CT scans no more than every six months for two years after the completion of treatment, and as clinically indicated thereafter. Generally, patients also receive physical exams and blood tests during follow-up. However, optimal surveillance strategies have been unclear.

“Scans expose patients to radiation and that theoretically increases the risk of a second cancer. Surveillance scans can also increase patient anxiety and lead to biopsies that may not be necessary,” said lead study author Carrie A. Thompson, MD, a hematologist at Mayo Clinic, Rochester, Minn. “While our study shows that the majority of relapses are detected by patient symptoms, the decision of whether to do surveillance scans and how often should be tailored to each individual patient.”

Researchers assessed post-treatment outcomes (relapse, re-treatment and death) in 644 patients enrolled in a prospective, multi-institutional cohort of patients with newly diagnosed DLBCL. All patients had received initial treatment with standard anthracycline based immune-chemotherapy.

During a median follow-up period of 59 months, 109 out of 537 patients (20 percent) who entered post-treatment follow-up experienced a relapse. Overall, at the time of relapse 68 percent of patients had symptoms, 42 percent had an abnormal finding on physical exam, and 55 percent had abnormalities in blood tests. Planned surveillance scans detected relapses in only 8 out of 537 (1.5 percent) of patients before clinical signs appeared.

Given that so many relapses are accompanied by symptoms, patients should be vigilant about reporting symptoms between scheduled visits, Dr. Thompson said. Some signs of a possible relapse in DLBCL include enlarged lymph nodes, night sweats, unexplained fever, and unintentional weight loss.

DLBCL is the most common form of lymphoma, accounting for 30 percent of non-Hodgkin lymphoma cases. The disease is aggressive but potentially curable with a combination of chemotherapy and targeted immunotherapy (rituximab). However, up to a third of patients experience a relapse after achieving remission. Relapsed DLBCL is often treated with stem cell transplantation and high-dose chemotherapy.