ECOG 1484 (DLBCL Consolidation RT)

Background

Phase III RCT (ECOG 1484). 352 patients with limited-stage (stage I–II) aggressive non-Hodgkin lymphoma (predominantly DLBCL) who achieved CR after 8 cycles of CHOP chemotherapy. Randomized to observation vs consolidation involved-field radiotherapy (IFRT). Pre-rituximab era.

Interventions and follow up

Arm A: Consolidation IFRT 30 Gy (n=172)
Arm B: Observation (no further treatment) (n=180)
Primary endpoint: Disease-free survival (DFS)
mFollow up: ~6 year

Results

6-yr DFS: 73% (IFRT) vs 58% (observation), P=.05
6-yr OS: 73% (IFRT) vs 70% (observation) — not statistically significant

Adverse events

Main adverse events: Acute: mild to moderate RT-related effects (fatigue, esophagitis, skin reactions based on field location). Late: second malignancy and cardiac/pulmonary toxicity potential with mediastinal RT (not specifically quantified at this follow-up).

Conclusions

Consolidation IFRT after CR with CHOP improved DFS but not OS in limited-stage aggressive NHL in the pre-rituximab era. The DFS benefit reflects improved local tumor control with RT.

Key Limitations

Key Limitations: Pre-rituximab era — 8 cycles CHOP is not the modern standard (R-CHOP × 6 now standard). Adding rituximab has significantly improved outcomes, changing the risk-benefit calculation for consolidation RT. OS not significantly improved. The DFS benefit was modest (p=0.05). Modern practice uses R-CHOP × 6 ± consolidation RT for bulky disease.

Clinical Context

ECOG 1484 established the concept of consolidation RT after chemotherapy CR for limited-stage DLBCL. The MDACC series (Phan JCO 2010) extended this to the rituximab era with excellent outcomes. Current practice: R-CHOP × 3–4 + ISRT 30–36 Gy for limited-stage DLBCL (NCCN preferred), with R-CHOP × 6 alone as an option for selected non-bulky patients.

References

References: Horning SJ et al, JCO 2004 (ECOG 1484)