Long-term outcomes of radioimmunotherapy in patients with follicular lymphoma

This study investigated the long-term outcomes of radioimmunotherapy following first-line (primary) R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) in previously untreated patients with advanced-stage follicular lymphoma (FL). This study concluded that this treatment approach is effective and well-tolerated in these patients.

One of the main goals in the management of FL is to increase long-term survival. Relapse (cancer recurrence) is the main cause of treatment failure in patients with FL. New treatment options that get rid of remaining disease after first-line treatment, are needed. This type of treatment is called consolidation treatment.

Radioimmunotherapy is one possible consolidation treatment. It uses immunotherapy drugs that release radiation directly on the tumor. Previous studies have shown that 60 – 80% of patients with previously untreated FL respond to this treatment. The long-term outcomes of these patients after radioimmunotherapy remains under investigation.

This study involved 30 patients with previously untreated FL. All patients received first-line R-CHOP chemoimmunotherapy followed by radioimmunotherapy with ibritumomab tiuxetan (Zevalin). Patients were followed-up for an average of 8.5 years.

After R-CHOP, 40% of patients achieved a complete response (disappearance of all signs of cancer). After radioimmunotherapy, this rate was 76.6%. 16.7% of patients achieved a partial response (tumor shrinkage). 30% of patients experienced a relapse.

5-year overall survival (patients still alive 5 years later; OS) was 90%. 5-year progression-free survival (patients still alive a 5 years later without disease progression; PFS) was 70%. At 8 years, these rates were 80% (PFS) and 66% (OS). Patients who achieved a complete response after treatment had a significantly higher 5-year OS (91%) and PFS (82%) compared to patients who did not (86%, OS; 28%, PFS).

This study concluded that first-line R-CHOP followed by ibritumomab tiuxetan is effective and well-tolerated in patients with advanced FL, including those with high-risk disease.

The patient population in this study was quite small. Larger studies are needed to confirm these results.