A Retrospective Analysis of the Efficacy of Low-Dose Metronomic Cyclophosphamide for Treatment in Patients with Low Grade Non-Hodgkin Lymphoma

Background

Low-dose metronomic cyclophosphamide chemotherapy is an emerging strategy offering a potentially less toxic yet effective treatment modality. We evaluated the efficacy and safety of low-dose metronomic cyclophosphamide in patients with low grade non-Hodgkin lymphoma (NHL) by retrospectively reviewing the data.

Method

The patients received oral cyclophosphamide (50 mg per day) and/or oral methotrexate (2.5 mg twice weekly) until disease progression or unacceptable toxicity was noted.

Results

Of the 36 patients, 17 (47.2%) were male, median age was 66.4 years (range, 37-91 years), and subtypes of NHL were mucosa associated lymphoid tissue lymphoma (55.6%), small lymphocytic lymphoma (13.9%), follicular lymphoma (11.1%), mantle cell lymphoma (8.3%), nodal marginal zone lymphoma (4.5%), splenic marginal zone lymphoma (2.8%), and lymphoplasmacytic lymphoma (2.8%). The stage I, II, III, IV were 38.9%, 13.9%, 11.1%, 36.1%, respectively and 55.6% of patients received this regimen as the first-line treatment, mainly due to frailty, refusal to standard chemotherapy.

The overall best response rate (ORR) was 73.5% (12 complete responses, CRs and 13 partial responses, PRs), with 29.1 months of the median duration of response and the disease control rate was 88.2%. The median treatment duration was 8.8 months (range, 0.1-38.4 months); the median progression-free survival (PFS) was 43.5 months, and the median overall survival (OS) was not yet reached. Especially, the ORR in patients who were treated with metronomic cyclophosphamide as the first line treatment and as more than the second line treatment were 78.9% (10 CRs, 5 PRs) and 66.6% (2 CRs, 9 PRs), respectively. The median PFS were not reached in the first line cyclophosphamide treatment group and 26.5 months (range, 5.7-47.2 months) in the other group (p=0.110), and similarly, the median OS were not reached and 64.4 months (0-135.7 months) (p=0.058), respectively.

The regimen was generally well tolerated, with small numbers of grade 3-4 toxicities; neutropenia (2%), anemia (3%), thrombocytopenia (3%), fatigue (4%), and anorexia (1%).

Conclusion

We concluded that low-dose metronomic cyclophosphamide represents efficacious and well-tolerated treatment for low-grade NHL patients.