Predictors of Local Recurrence in Patients With Advanced-Stage Diffuse Large B-Cell Lymphoma (DLBCL) Treated With Rituximab-Based Chemotherapy Alone: Guiding Decisions for Consolidative Radiation Therapy

Volume 90  Number 1S  Supplement 2014 Purpose/Objective(s): Outcomes of patients with diffuse large B-cell lymphoma (DLBCL) can significantly differ according to the primary site of presentation. The purpose of this study was to investigate the influence of primary bone presentation on both event free (EFS) and overall survival (OS). Materials/Methods: The records of over 1000 patients (pts) with pathologically proven DLBCL were reviewed and the appropriate institutional review board approval was obtained. We identified 103 pts with primary bone DLBCL treated consecutively from 1988-2013. The medical records were reviewed for clinical, pathologic, and treatment characteristics. Survival outcomes were calculated using the KaplanMeier method with factors affecting survival determined by the log-rank test. Results: The median age was 55 years (range 16-87) and 65 (63%) were men. The most common site of presentation was in the long bones in 43 pts (42%). This was followed by 15 (15%) in the vertebral body, 13 (13%) in the pelvic bones, 8 (8%) in the skull/mandible, and 3 (3%) in the ribs/ sternum. Twenty-one pts (20%) had multiple bony sites of involvement. Prognostic factors had the following distribution: 58 pts (56%) were stage I/II and 45 (44%) were stage III/IV; 51 pts (50%) had an IPI score of 0 or 1, 28 pts (27%) with a IPI score of 2, and 16 pts (16%) had IPI scores of 3, 4, or 5. The majority of patients (55, 53%) received 6-8 cycles of R-CHOP and 6 pts (6%) received 4 or fewer cycles of R-CHOP. Twenty-five pts (24%) were treated prior to the era of Rituximab. Three pts received 4-6 cycles of R-EPOCH and the remaining 14 pts received non-CHOP chemotherapy. Radiation therapy (RT) was given to 69 pts (67%) with 82% of stage I/II pts treated with RT and 49% of stage III/IV treated with RT. The median dose of RT was 39.6 Gy (range 24.5-50 Gy). After a median follow-up of 82 months (range 2-304), the 5-year EFS and OS was 80% and 82%, respectively. On univariate analysis, stage, IPI score, and the type of chemotherapy significantly affected both EFS and OS. The addition of RT as a consolidation significantly improved OS with a 5-year OS of 88% vs 72% (RT vs no RT, p Z 0.04). Radiation also significantly improved 5-year EFS with 86% vs 69% (RT vs no RT, p Z 0.03). Compared to our institutional outcomes for DLBCL as a whole, pts with primary bone DLBCL had better outcomes with a 5-year EFS of 91% (stage I/II) and 67% (stage III/IV) compared to 81% (stage I/II) and 60% (stage III/IV), respectively. Conclusions: Pts with primary bone lymphoma treated with standard chemotherapy of R-CHOP followed by radiation therapy have an excellent outcome with even better results than DLBCL as a whole. The addition of radiation was associated with a statistically significant improvement in both EFS and OS. Author Disclosure: R. Tao: None. F. Shihadeh: None. C.C. Pinnix: None. I. Arzu: None. V. Reed: None. Y. Oki: None. J. Westin: None. L. Fayad: None. L. Medeiros: None. A. Rodriguez: None. B. Dabaja: None.

143 Predictors of Local Recurrence in Patients With Advanced-Stage Diffuse Large B-Cell Lymphoma (DLBCL) Treated With RituximabBased Chemotherapy Alone: Guiding Decisions for Consolidative Radiation Therapy N. Jegadeesh,1 N. Esiashvili,2 Z. Shi,2 C. Flowers,2 Y. Liu,2 and M. Khan2; 1 Emory University, Atlanta, GA, 2Winship Cancer Institute, Emory University, Atlanta, GA Purpose/Objective(s): The role of consolidative radiation therapy (RT) for DLBCL in the era of rituximab and [18F] fluorodeoxyglucose-positron emission tomography (PET) scan is not well defined. This is especially true for stage III or IV disease. Although there is new evidence that some patients with disease > 7.5 cm may benefit, the exact patient selection criteria are not well established. The investigators sought to identify a group of patients who experienced a high local failure rate after receiving

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rituximab-based chemotherapy alone and hence may benefit from the addition of consolidative RT. Materials/Methods: The records of 211 histologically confirmed stage III and IV DLBCL patients treated between August 1999 and January 2012 were reviewed. Of these patients, 80 had a complete response to systemic therapy including rituximab and also received no initial RT. Kaplan-Meier log rank test and Cox proportional hazards regression were performed with local recurrence (LR) as the primary outcome variable. LR was defined as local failure at one of the original presenting sites as the first site of recurrence. Results: Median age of patients at diagnosis was 59 years (21-81). Median follow-up time was 46 months (21-81). Forty-two percent of patients had stage III (n Z 34) and 58% with stage IV disease (n Z 46). Thirty-five percent experienced LR (n Z 28). In Kaplan-Meier analysis, five year LR free survival for patients with > 5 cm lesions was 43.2% versus 81.7% for patients with  5cm lesions (log-rank p Z 0.016). On multivariable analysis, tumor > 5 cm (HR Z 5.8, p Z 0.017) and International Prognostic Index (IPI)  2 (HR Z 3.0, p Z 0.079) were associated with an increased risk of LR. Analysis of the subgroup of patients with  5 cm tumors revealed that an SUV  18 on initial PET/CT predicted for a higher rate of LR. Five year LR free survival was 100% in SUV < 18 versus 61.0% in SUV 18 (p Z 0.039). Conclusions: Advanced stage DLBCL patients with either initial disease > 5 cm,  5 cm but with baseline PET SUV  18, or IPI  2 appear to be at an increased risk for LR as first site of failure. These patients may benefit from consolidative RT following chemoimmunotherapy. While it is unclear to what extent control of local disease may have on systemic failure, prospective studies to better define the benefits of RT in this high-risk population are warranted. Author Disclosure: N. Jegadeesh: A. Employee; Winship Cancer Institute, Emory University. N. Esiashvili: A. Employee; Winship Cancer Institute, Emory University. Z. Shi: A. Employee; Winship Cancer Institute, Emory University. C. Flowers: A. Employee; Winship Cancer Institute, Emory University. Y. Liu: A. Employee; Winship Cancer Institute, Emory University. M. Khan: A. Employee; Winship Cancer Institute, Emory University.

144 Nodular Lymphocyte Predominant Hodgkin Lymphoma (NLPHL): Management in the Modern Era M. King, S. Donaldson, M. Link, R. Advani, and R. Hoppe; Stanford Cancer Center, Stanford, CA Purpose/Objective(s): To analyze treatment outcomes for NLPHL at a single institution during the past 15 years. Materials/Methods: We conducted an IRB-approved retrospective review of 45 patients (pts) with newly diagnosed NLPHL who were treated at our institution between 1996-2011. All pathology was centrally reviewed, and confirmed by IHC. We analyzed effects of age (21), stage (limited vs advanced), radiation treatment (RT) (yes vs no), and treatment response (complete response [CR] vs < CR), on progression free survival (PFS) using univariate Cox regression analysis. We also evaluated the effects of relapse and transformation to large cell lymphoma (LCT) on overall survival (OS). Results: Median follow-up was 6.6 yrs. Thirteen pts were younger than 21 years at diagnosis. Limited disease: Twenty-nine9 pts had limited (stage III) disease, and treatments included RT alone (N Z 9), chemoradiation therapy (CRT) on a pediatric protocol (9), rituximab monotherapy +/maintenance (Rmab) on a trial (10), and observation without treatment (OBS) (1). Pts treated with RT or CRT received limited-field RT (involved or slightly extended field), and RT doses ranged from 10 Gy to 44.6 Gy. Pts treated with CRT, received VAMP (vincristine, doxorubicin, methotrexate, prednisone) (7) or Stanford V (doxorubicin, vinblastine, mechorethamine, vincristine, bleomycin, etoposide, prednisone) (2). Seven of 29 pts relapsed