Which low-intensity chemotherapy is most effective for patients with classical Hodgkin lymphoma receiving stem cell transplantation?

This study compared the effectiveness of three low-intensity chemotherapy combinations to treat patients with classical Hodgkin lymphoma (HL) following stem cell transplantation (SCT). There were no significant differences between the three chemotherapy types in terms of patients’ survival and relapse.

Following initial treatment for HL, some patients see a return of the cancer (relapse), while others do not respond to treatment (refractory). Patients with relapsed or refractory HL often undergo stem cell transplantation (SCT) with chemotherapy. 

Some patients experience severe side effects from chemotherapy and require reduced doses, or chemotherapy drugs that are not as harsh. Several different chemotherapy drugs are used for these patients, including fludarabine (Fludara), busulfan (Busulfex), melphalan (Alkeran), and cyclophosphamide (Cytoxan).  It is unclear if any combinations are more effective for patients than others.

Data from 492 patients with relapsed or refractory HL was examined. Patients received SCT different chemotherapy combinations. 102 patients received fludarabine/busulfan (Flu/Bu). 318 patients received fludarabine/melphalan (Flu/Mel). 72 patients received fludarabine/cyclophosphamide (Flu/Cy). Patients were followed for 3 to 121 months.

After 4 years, patients had a 62% chance of survival in the Flu/Bu group, 59% in the Flu/Mel group, and 55% in the Flu/Cy group. Within the first 11 months, patients in the Flu/Cy group had a 72% higher chance of survival compared to Flu/Bu. However, after 11 months, patients in the Flu/Cy group were 2.46 times less likely to survive than those in the Flu/Bu group.

After 4 years, patients had a 29% chance of survival without cancer worsening in the Flu/Bu group, 37% in the Flu/Mel group, and 25% in the Flu/Cy group. After 4 years, patients in the Flu/Bu group had a 57% risk of relapse or cancer worsening compared to 47% in the Flu/Mel group and 65% in the Flu/Cy group. 

After 1 year, 50% of the Flu/Bu group, 49% of the Flu/Mel group, and 43% of the Flu/Cy group had developed graft versus host disease (GVHD). GVHD is a complication of SCT when the transplanted cells attack the patient's body.  

The authors concluded that Flu/Bu, Flu/Mel, and Flu/Cy are similarly effective alongside SCT for the treatment of patients with relapsed or refractory HL.

This study used data from medical records meaning that not all information was available. Also, there were unequal numbers of patients in each group. It is possible this caused some bias.