BACKGROUND: The definition of primary extranodal non-Hodgkin's lymphoma (NHL) is a controversial issue, especially in patients where both nodal and extranodal sites are involved. PATIENTS AND METHODS: The impact of different definitions of primary extranodal NHL on incidence and prognosis is explored using data from a population-based NHL registry. RESULTS: Using liberal criteria, 389 (34%) cases were classified as primary extranodal NHL. Overall survival (OS) rates of nodal and extranodal NHL patients defined this way were comparable; however, extranodal NHL patients had a better disease-free survival (DFS). When strict criteria were applied, 231 cases (20%) were classified as primary extranodal NHL. OS and DFS rates of extranodal NHL patients defined this way were superior to nodal NHL patients; however, the difference in OS was reversed after correction for differences in International Prognostic Index and malignancy grade. CONCLUSION: This study illustrates the selection bias that is introduced when a strict definition of primary extranodal NHL, that excludes cases with disseminated disease, is used. Patients with primary extranodal NHL were found to have a superior DFS, irrespective of which definition of primary extranodal NHL was used.
BACKGROUND: The definition of primary extranodal non-Hodgkin's lymphoma (NHL) is a controversial issue, especially in patients where both nodal and extranodal sites are involved. PATIENTS AND METHODS: The impact of different definitions of primary extranodal NHL on incidence and prognosis is explored using data from a population-based NHL registry. RESULTS: Using liberal criteria, 389 (34%) cases were classified as primary extranodal NHL. Overall survival (OS) rates of nodal and extranodal NHL patients defined this way were comparable; however, extranodal NHL patients had a better disease-free survival (DFS). When strict criteria were applied, 231 cases (20%) were classified as primary extranodal NHL. OS and DFS rates of extranodal NHL patients defined this way were superior to nodal NHL patients; however, the difference in OS was reversed after correction for differences in International Prognostic Index and malignancy grade. CONCLUSION: This study illustrates the selection bias that is introduced when a strict definition of primary extranodal NHL, that excludes cases with disseminated disease, is used. Patients with primary extranodal NHL were found to have a superior DFS, irrespective of which definition of primary extranodal NHL was used.
Authors: Ann D King; Benjamin King Hong Law; Wai Kiu Tang; Frankie Kwok Fai Mo; Radha Raghupathy; Kunwar S Bhatia; Kenny I K Lei Journal: Eur Arch Otorhinolaryngol Date: 2016-10-13 Impact factor: 2.503
Authors: J P Gleeson; G B Woods; G A Watson; J Ryan; E Doyle; F Quinn; J C O'Keane; J A McCaffrey Journal: Ir J Med Sci Date: 2017-05-03 Impact factor: 1.568
Authors: C Fernández-Rodríguez; B Bellosillo; M García-García; B Sánchez-González; E Gimeno; M C Vela; S Serrano; C Besses; A Salar Journal: Leukemia Date: 2014-06-06 Impact factor: 11.528