Clinical characteristics of non-Hodgkin's lymphoma as a second primary tumor: a population-based survey

Data from 29,845 patients with lymphomas, 981 of whom had lymphoma as a second primary tumor, registered in the Surveillance Epidemiology and End Results (SEER) program in the U.S.A. between 1973 and 1986 were analyzed. The characteristics of the 274 patients with lymphoma as a second tumor who had received chemotherapy and/or radiotherapy for their primary tumor (SEP PT) were compared with 675 patients with second primary lymphomas who had no prior treatment (SEP NT) and with patients with single lymphomas (SIP). Patients with SEP PT disease had a significantly higher percentage of intermediate and high-grade tumors (80%) compared to those with SEP NT or SIP tumors (73% and 72%, respectively). The survival of all patients with SIP tumors did not differ from those with SEP tumors, but the median survival of those with SEP PT disease was shorter than for SEP NT disease. This was most probably due to the high percentage of intermediate and high-grade lymphomas in the SEP PT group. This was statistically significant in the group treated by combined chemotherapy and radiotherapy but not in those treated by a single modality alone. These findings relating to a worse prognosis in patients with SEP PT lymphoma are in line with our previous observations of a poor survival in patients with other multiple primary tumors.