[Efficacy of conservative treatment of gastric lymphosarcoma]

To compare efficacy and toxicity of conservative therapy (different programs of polychemotherapy) of gastric lymphosarcoma conducted for the last 10 years in Hematological Research Center of the Russian Academy of Medical Sciences.

The study included 63 patients (40 females and 23 males aged 14 to 78 years, mean age 49 years) with primary diagnosis of gastric lymphosarcoma (GL). Of them, 56 (89%) patients had diffuse large B-cell lymphosarcoma (DLBCL) and 7 (11%) had gastric Berkitt's lymphoma (BL). Only detection of t(8;14) with rearrangement of c-myc gene provided accurate diagnosis of gastric BL. By the treatment DLBCL patients were divided into two groups: 44 patients of group 1 received polychemotherapy (PCT) according to CHOP scheme or in combination with radiotherapy and surgical treatment; 12 patients of group 2 were treated according to modified program mNHL-BFM-90, without surgical or radiation treatment. Of 7 patients with gastric BL 5 patients received treatment according to a modified program mNHL-BFM-90 and 2 patients were given CHOP because of DLBCL misdiagnosis without cytogenetic detection of t(8;14).

Overall survival in group 1 was 73% in mean follow-up 61 months. The survival depended only on initial factors of poor prognosis (PPF): tumor size over 10 cm, Ann-Arbor stage higher than IE, B-symptoms, elevated level of LDH. Overall survival of 18 gastric DLBCL patients without PPF reached 94%, of 26 patients with PPF - 60%. Lethality due to side effects was 4% (2 patients), primary resistance was 14% (6 patients), recurrence arose in 9% (4 patients). Overall survival in group 2 was 100% in mean remission duration 18 months, was unrelated to PPF (10 of 12 patients) but correlated with high toxicity. 5 BL patients treated with a modified mNHL-BFM-90 program achieved remission (a mean follow-up at present is 1 to 50 months, mean 24 months). 2 BL patients treated with CHOP died for a year.

Gastric lymphosarcomas are sensitive to chemotherapy, thereby PCT only is effective in most patients. PPF in gastric DLBCL were responsible for poor outcome in 40% patients in CHOP treatment. The modified program mNHL-BFM-90 can produce up to 100% complete long-term remissions in therapy of gastric lymphosarcoma in adults both in BL and DLBCL patients. A cytogenetic examination of c-myc gene rearrangement is obligatory before initiation of PCT of gastric lymphosarcoma.