Splenic involvement (A) and prior exposure to chemotherapy (B) correlated to freedom from transformation to DLBCL in patients with NLPHL (222 patients). The rates of 40-year freedom from transformation were 87% when there was no splenic involvement (black solid line, A) vs 21% when the spleen was involved (dotted gray line, A) and 87% if radiation therapy was used as a single modality (black solid line, B) compared with 77% in patients treated with prior chemotherapy or chemoradiation combination (dotted gray line, B). Splenic involvement was diagnosed based on pathology or imaging studies.