Limited Benefit of Routine Clinical Follow‐Up for Relapse Detection in Diffuse Large B‐Cell Lymphoma Patients in Complete Remission Following First‐Line Treatment

ABSTRACT Despite advances in treatment, approximately 15% of patients with diffuse large B‐cell lymphoma (DLBCL) who achieve complete remission (CR) after first‐line therapy will experience a relapse. However, there is no consensus on the optimal follow‐up strategies for detecting relapse after achieving CR. This population‐based study, based on the Danish Lymphoma Registry (LYFO), identified a total of 1634 patients diagnosed with DLBCL between 2010 and 2017, including 105 patients who achieved CR following first‐line R‐CHOP‐like therapy and subsequently relapsed. The median follow‐up time was 6 years (range 3–8 years). Most cases of relapse were symptomatic (83%), with B symptoms and peripheral lymphadenopathy being the most common. Asymptomatic relapses were identified through physical examination (1%), blood tests (3%), or imaging findings (13%). The proportion of relapses identified outside routine visits was 70%. Only 5% of scheduled routine visits led to a relapse diagnosis, whereas 74% of unscheduled visits initiated by the patient outside routine follow‐up resulted in relapse detection. Our findings highlight that systematic, scheduled monitoring of patients in remission after first‐line treatment contributes only modestly to the early detection of disease recurrence. Future studies should explore alternative methods of relapse surveillance rather than relying solely on pre‐scheduled clinical follow‐up.