title: Clinical significance of the WHO grades of follicular lymphoma in a population-based cohort of 505 patients with long follow-up times.
abstract: The prognostic value of grading follicular lymphoma has been debated since the 1980s. There is consensus that World Health Organization (WHO) grades 1 and 2 are indolent, but not whether grades 3A or 3B are aggressive. We retrospectively reviewed the follicular lymphoma diagnoses according to the 2008 WHO classification in all diagnostic specimens from a population-based cohort of 505 patients with a median follow-up time of 10·0years (range, 4·6-16·0). After excluding 43 patients with concomitant diffuse large B-cell lymphoma, 345 remained with grade 1-2, 94 with grade 3A, and 23 with grade 3B follicular lymphoma. Grades 1-2 and 3A seemed equally indolent, with indistinguishable clinical courses, even in patients receiving anthracyclines. Compared with grades 1-3A and independently of clinical factors, grade 3B correlated with higher mortality (P=0·008), but outcome was improved after upfront anthracycline-containing therapy (P=0·015). In contrast to grade 1-3A patients, grade 3B patients experienced no relapses or deaths beyond 5years of follow-up. Furthermore, patients with grade 3B were predominantly male and seldom presented with bone-marrow involvement. We conclude that follicular lymphoma grade 1-3A is indolent and incurable with conventional therapy. Grade 3B appears to be an aggressive but curable disease.
authors: Division of Haematology, Department of Medicine at Huddinge, Karolinska Institutet, Stockholm, Sweden. bjorn.wahlin@karolinska.se
authors: Björn E
authors: BE
authors: Wahlin
authors: Olav E
authors: OE
authors: Yri
authors: Eva
authors: E
authors: Kimby
authors: Harald
authors: H
authors: Holte
authors: Jan
authors: J
authors: Delabie
authors: Erlend B
authors: EB
authors: Smeland
authors: Christer
authors: C
authors: Sundström
authors: Birger
authors: B
authors: Christensson
authors: Birgitta
authors: B
authors: Sander
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008224:Lymphoma, Follicular / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011379:Prognosis; D014944:World Health Organization