Abbreviated 8-week chemotherapy (CT) plus involved node radiotherapy (INRT) for nonbulky stage I-II Hodgkin lymphoma: Preliminary results of the Stanford G5 Study.

Abstract

8064 Background: Combined modality therapy is the standard of care for non-bulky Stage I-II HL. Currently, brief CT +30 Gy involved field (IF) radiotherapy (RT) is associated with a high cure rate. To further limit treatment risk, we tested brief CT (Stanford V–C x 8 weeks) + 20 Gy INRT (G5 study). Methods: Pts with stage I-IIA supra-diaphragmatic non-bulky disease (mediastinal mass ratio <1/3 and no disease >10 cm) were eligible. Stanford V-C (cyclophosphamide substituted for nitrogen mustard) was administered x 8 weeks. G-CSF was permitted for gr ≥3 neutropenia. Two wks after completion of CT, pts received INRT (20 Gy) to initially involved nodes with 1-1.5 cm margins axially and 2-5 cm cephalo-caudad. All pts were treated and followed at Stanford. Endpoints were toxicity and efficacy (PFS and OS). Results: 43 pts (16% stage I and 84% stage II) were accrued with median age 31 yrs (19-66). 20 pts (47%) were “unfavorable” according to German Hodgkin Study Group (GHSG) criteria: >2 nodal sites (n=20) or elevated ESR (≥ 50 mm/hr) (n=3). G-CSF was required in 60% of pts due to gr 3 (n=10) or 4 (n=16) neutropenia. Other gr 3 toxicities reported: fever (n=1), pain (n=3), acute pulmonary embolism (n=1) and epigastric pain (n=2). At median follow-up of 4.8 yrs (0.8-9.6), the overall PFS and OS are 94.6% and 100%, respectively. For pts with unfavorable risk factors the PFS and OS are 88.5% and 100%, respectively. Therapy failed in 2 pts considered “unfavorable” by GHSG criteria with >2 nodal sites. The mean time to relapse was 23 mths (16-30). One pt failed in RT field and the second in-field and distant. Both were salvaged with secondary therapy and stem cell support. No bleomycin lung toxicity or radiation pneumonitis have been noted and to date there have been no second malignancies, AML or cardiac events. Conclusions: The G5 regimen (8 wks Stanford V-C and 20 Gy INRT) has excellent results with minimal toxicity in pts with non-bulky stage I-II HL, including those defined as “unfavorable” by the GHSG criteria. The outcome is comparable to studies using more intense CT and IFRT. Longer follow up is required to assess the impact of this reduced intensity approach on CT and RT related late effects.