Primary mediastinal lymphoma: A multicenter study by the ielsg

In a retrospective study coordinated by the IELSG, data from 426 patients with primary mediastinal lymphoma (PML) treated in 27 centers of 4 European countries were collected and analyzed, 40% of them were males and 60% females, with a median age of 34 yrs (range: 13-87) and a performance status 2 in 66 (15%) cases. Abnormal LDH and systemic symptoms occurred in 279 (65%) and 182 (43%) patients, respectively. The mediastinal involvement was bulky in more than 80% of the patients and nearly 60% of all cases presented in stage II. The patients had been typically treated according to three different chemotherapy scheme groups, that is MACOP-B, CHOP or high dose sequential chemotherapy (HDS), mostly followed by radiation therapy (XRT). The chemotherapy regimen choice was generally influenced by the single institution policy rather than prognostic factors such as the IPI score. Overall, 277 patients were treated with MACOPB like regimens, 105 with CHOP-like ones and 44 with HDS or ABMT. No substantial differences were found among the three different therapeutic options as of CR (round 50%) and overall response rates (between 80% and 90%). However, additional XRT was differently able to lift the CR rate achieved with chemotherapy, as it moved from 51 % to 79% in the MACOP-B-, from 49% to 61% in the CHOP- and from 53% to 75% in the HDS-treated: patients. No relapses were recorded in the last group, compared with 12% and 23% of the patients who had achieved a CR following MACOP-B or CHOP treatment, respectively. The overall median duration of the first CR was 47 months. At a median follow up of 65 months, the 17-year-projected overall and progression-free survival are 70% and 80%, respectively, with a statistically significant advantage for HDS- or MACOPB-treated paitients, compared to those who received CHOP chemotherapy. The overall survival was significantly influenced by the patients' IPI score. In conclusion, and with the obvious limitations of a retrospective study, the analysis of a large number of patients diagnosed and treated in a number of independent European centers seems to indicate that: 1 ) PML is an aggressive but generally highly curable variety of NHL; 2) X RT is almost always needed after completion of chemotherapy; 3) The use of intensive chemotherapy regimens may improve the outcome, but this has to be confirmed by controlled clinical trials.