Reducing time between salvage chemotherapy cycles in relapsed or refractory Hodgkin lymphoma

This study determined whether a faster course of salvage chemotherapy reduced tumor volume in patients with relapsed or refractory Hodgkin lymphoma. The authors concluded that shorter intervals between SC cycles was safe and effective.

Hodgkin lymphoma is considered to be a highly curable form of cancer. Some patients, however, either do not respond to treatment (refractory disease) or relapse soon afterwards. These patients are less likely to be cured. High-dose chemotherapy (HDC) followed by stem cell (immature blood cells) transplantation can improve outcomes. Salvage chemotherapy (SC) is a second course of chemotherapy given before HDC to shrink tumor size. HDC tends to be more effective if there was a response to SC.

The intensity of the SC dose has also been shown to improve outcomes. Shortening the intervals between chemotherapy cycles can increase the intensity of the dose. Granulocyte colony stimulating factor (G-CSF) is a treatment that may be used to stimulate the bone marrow to produce stem cells. G-CSF treatment can help to shorten the intervals between chemotherapy cycles. It is not clear whether shortening the time between the cycles is a safe and effective treatment for relapsed or refractory Hodgkin lymphoma.

This study determined whether reducing the time between SC cycles was safe or effective. 

This study included 102 patients. 84% had relapsed disease. 16% had refractory disease. All had received chemotherapy previously. Patients were treated with two cycles of DHAP (dexamethasone, cisplatin, cytarabine) salvage therapy. They were also treated with G-CSF. Patients with partial or complete remission after DHAP received high-dose chemotherapy. Eight patients had blood stem cells collected after their first DHAP cycle. This was to evaluate the number of stem cells available after treatment. 

89% of patients responded to the DHAP. 21% had a complete remission and 68% had a partial remission. 91-93% of relapsed-disease patients responded. 65% of refractory-disease patients responded. Those with refractory disease and/or stage-III or stage-IV disease were less likely to respond. 

43% of patients experienced low levels of white blood cells. 48% experienced low levels of platelets (blood cells involved in clotting). There were no severe infections or treatment-related deaths. The stem-cells multiplied to an average level of 6.1 million units per kilogram.

The longer-term effects need to be examined.