CNS-directed therapy appears more effective for synDLBCL

Controlling CNS disease is “paramount” in treating diffuse large B-cell lymphoma with synchronous CNS and systemic disease (synDLBCL), according to researchers.

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In a retrospective study, the CNS was the most common site of relapse in patients with synDLBCL, and patients had better outcomes when they received CNS-directed therapy.

The 2-year progression-free survival rate was 50% in patients who received CNS-intensive therapy and 31% in those who received CNS-conservative therapy. The 2-year overall survival rate was 54% and 44%, respectively.

Dr. Joel C. Wight, of Austin Health in Heidelberg, Australia, and colleagues conducted this study and recounted their findings in the British Journal of Haematology.

The researchers retrospectively analyzed 80 patients with synDLBCL treated at 10 centers in Australia and the United Kingdom. Patients had DLBCL not otherwise specified (n = 67); high-grade B-cell lymphoma, including double-hit lymphoma (n = 12); or T-cell histiocyte-rich DLBCL (n = 1).

At baseline, all patients were treatment-naive, they had a median age of 64 years (range, 18-87 years), and 68% were male. Seventy percent of patients had high-risk disease according to the CNS International Prognostic Index (IPI), and 96% had non-CNS extranodal disease. The median number of extranodal sites outside the CNS was 2 (range, 0 to more than 10).

Patients were divided into those who received CNS-intensive therapy (n = 38) and those given CNS-conservative therapy (n = 42). The CNS-conservative group was significantly older (P less than .001), significantly more likely to have high-risk disease according to the National Comprehensive Cancer Network IPI (P = .009) or CNS IPI (P = .01) and significantly more likely to have leptomeningeal disease only (P less than .001).

Treatment

CNS-intensive therapy was defined as any established multiagent IV chemotherapy regimen with two or more CNS-penetrating drugs and cytarabine, with or without intrathecal chemotherapy and/or radiotherapy.

CNS-conservative therapy was defined as one or fewer IV CNS-penetrating chemotherapy agents in induction, with or without intrathecal chemotherapy and/or radiotherapy.

Systemic induction in the CNS-intensive group consisted of R-HyperCVAD (rituximab, hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with IV methotrexate and cytarabine) in 66% of patients and R-CODOX-M/IVAC (rituximab, hyperfractionated cyclophosphamide, vincristine, doxorubicin, methotrexate/ifosfamide, etoposide, cytarabine) in 24% of patients.

The most common systemic induction regimens in the CNS-conservative group were R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone) or CHOP-like regimens, given to 83% of patients.

CNS-directed IV therapy was given to 100% of the CNS-intensive group and 60% of the CNS-conservative group. This consisted of IV methotrexate plus cytarabine (97%) or MATRix (methotrexate, cytarabine, and thiotepa; 3%) in the CNS-intensive group and high-dose methotrexate in the conservative group.

Intrathecal chemotherapy was given to 97% of the CNS-intensive group and 60% of the CNS-conservative group. CNS-directed radiation was given to 32% and 19%, respectively.

Thirteen patients in the CNS-intensive group and one in the CNS-conservative group underwent autologous transplant as consolidation.

Outcomes

Dose reductions were more frequent in the CNS-conservative group than in the CNS-intensive group, at 48% and 18% (P = .009), as was early cessation of chemotherapy, at 52% and 18% (P = .002). Rates of treatment-related mortality were similar, at 13% in the CNS-intensive group and 12% in the CNS-conservative group.