Single-Cell RNA Analysis Reveals Cell-Intrinsic Functions of CAR T Cells Correlating with Response in a Phase II Study of Lymphoma Patients.

PURPOSE: Although CD19 chimeric antigen receptor T cells (CAR-T) therapy has shown remarkable success in B-cell malignancies, a substantial fraction of patients do not obtain a long-term clinical response. This could be influenced by the quality of the individual CAR-T infusion product. To shed some light on this, clinical outcome was correlated to characteristics of CAR-T infusion products. PATIENTS AND METHODS: In this phase II study, patients with B-cell lymphoma (n = 23) or leukemia (n = 1) received one or two infusions of third-generation CD19-directed CAR-Ts (2 × 108/m2). The clinical trial was registered at clinicaltrials.gov: NCT03068416. We investigated the transcriptional profile of individual CD19 CAR-T infusion products using targeted single-cell RNA sequencing and multicolor flow cytometry. RESULTS: Two CAR-T infusions were not better than one in the settings used in this study. As for the CAR-T infusion products, we found that effector-like CD8+CAR-Ts with a high polyfunctionality, high cytotoxic and cytokine production profile, and low dysfunctional signature were associated with clinical response. An extended ex vivo expansion time during CAR-T manufacturing negatively influenced the proportion of effector CD8+CAR-Ts in the infusion product. CONCLUSIONS: We identified cell-intrinsic characteristics of effector CD8+CAR-Ts correlating with response that could be used as an indicator for clinical outcome. The results in the study also serve as a guide to CAR-T manufacturing practices.

Preoperative accelerated radiotherapy combined with chemotherapy in a defined cohort of patients with high risk soft tissue sarcoma: a Scandinavian Sarcoma Group study.

BACKGROUND: We recently reported outcomes from a Scandinavian Sarcoma Group adjuvant study (SSG XX group A) conducted on localized and operable high risk soft tissue sarcoma (STS) of the extremities and trunk wall. SSG XX, group B, comprised of patients in a defined cohort with locally advanced STS considered at high risk for intralesional surgery. These patients received preoperative accelerated radiotherapy, together with neoadjuvant and adjuvant chemotherapy. Herein we report the results of this group B. METHODS: Twenty patients with high-grade, locally advanced and deep STS located in lower extremities (n = 12), upper extremities (5) or trunk wall (3) were included. The median age was 59 years and 14 patients were males. The treatment regimen consisted of 6 cycles of doxorubicin (60 mg/m2) and ifosfamide (6 g/m2), with three cycles given neoadjuvantly, and preoperative radiotherapy (1, 8 Gyx2/daily to 36 Gy) between cycles 2 and 3. After a repeated MRI surgery was then conducted, and the remaining 3 chemotherapy cycles were given postoperatively at 3 weeks intervals. Survival data, local control, toxicity of chemotherapy and postoperative complications are presented. RESULTS: Median follow-up time for metastasis-free survival (MFS) was 2.8 years (range 0.3-10.4). The 5-year MFS was 49.5% (95% confidence interval [CI] 31.7-77.4). The median follow-up time was 5.4 years (range 0.3-10.4) for overall survival (OS). The 5-year OS was 64.0% (95% CI 45.8-89.4). The median tumour size was 13 cm, with undifferentiated pleomorphic sarcoma (n = 10) and synovial sarcoma (n = 6) diagnosed most frequently. All patients completed surgery. Resection margins were R0 in 19 patients and R1 in 1 patient. No patients had evidence of disease progression preoperatively. Three patients experienced a local recurrence, in 2 after lung metastases had already been diagnosed. Eleven patients (55%) had postoperative wound problems (temporary in 8 and persistent in 3). CONCLUSIONS: Preoperative chemotherapy and radiotherapy were associated with temporary wound-healing problems. Survival outcomes, local control and toxicities were deemed satisfactory when considering the locally advanced sarcoma disease status at primary diagnosis. Trial registration This study was registered at ClinicalTrials.gov Identifier NCT00790244 and with European Union Drug Regulating Authorities Clinical Trials No. EUDRACT 2007-001152-39.

The simplified follicular lymphoma PRIMA-prognostic index is useful in patients with first-line chemo-free rituximab-based therapy.

Follicular lymphoma (FL) is a heterogeneous disease; therefore, reliable prognostic tools are needed to plan treatment strategies. The FL International Prognostic Index (FLIPI) was developed before the rituximab era, while the PRIMA-PI was built on rituximab chemotherapy. Our objective was to evaluate these two prognostic tools in a cohort of 291 patients with FL treated in two prospective randomised Nordic Lymphoma Group trials with rituximab ± interferon. All patients had symptomatic/progressive disease and were previously untreated. The PRIMA-PI was prognostic for both time to treatment failure (TTF) and overall survival (OS) (log-rank P = 0·003 and P < 0·001, respectively). The PRIMA-PI high-risk identified a small group of patients with a very short TTF and OS compared to the low-risk group, with a hazard ratio (HR) of 1·90 (95% confidence interval [CI] 1·30-2·78, P = 0·001) and HR of 3·19 (95% CI 1·75-5·83, P < 0·001), respectively. The FLIPI risk groups were prognostic only for OS (log-rank P = 0·018). The simplified PRIMA-PI was valid in our FL cohort with first-line rituximab-containing chemo-free therapy and shows an improved risk stratification compared to the FLIPI, especially in patients aged >60 years. Patients in the PRIMA-PI high-risk group should be considered for alternative therapies.

Short regimen of rituximab plus lenalidomide in follicular lymphoma patients in need of first-line therapy.

The SAKK 35/10 phase 2 trial, developed by the Swiss Group for Clinical Cancer Research and the Nordic Lymphoma Group, compared the activity of rituximab vs rituximab plus lenalidomide in untreated follicular lymphoma patients in need of systemic therapy. Patients were randomized to rituximab (375 mg/m2 IV on day 1 of weeks 1-4 and repeated during weeks 12-15 in responding patients) or rituximab (same schedule) in combination with lenalidomide (15 mg orally daily for 18 weeks). Primary end point was complete response (CR)/unconfirmed CR (CRu) rate at 6 months. In total, 77 patients were allocated to rituximab monotherapy and 77 to the combination (47% poor-risk Follicular Lymphoma International Prognostic Index score in each arm). A significantly higher CR/CRu rate at 6 months was documented in the combination arm by the investigators (36%; 95% confidence interval [CI], 26%-48% vs 25%; 95% CI, 16%-36%) and confirmed by an independent response review of computed tomography scans only (61%; 95% CI, 49%-72% vs 36%; 95% CI, 26%-48%). After a median follow-up of 4 years, significantly higher 30-month CR/CRu rates and longer progression-free survival (PFS) and time to next treatment (TTNT) were observed for the combination. Overall survival (OS) rates were similar in both arms (≥90%). Toxicity grade ≥3 was more common in the combination arm (56% vs 22% of patients), mainly represented by neutropenia (23% vs 7%). Addition of lenalidomide to rituximab significantly improved CR/CRu rates, PFS, and TTNT, with expected higher, but manageable toxicity. The excellent OS in both arms suggests that chemotherapy-free strategies should be further explored. This trial was registered at www.clinicaltrials.gov as #NCT01307605.

Chemotherapy-Free Initial Treatment of Advanced Indolent Lymphoma Has Durable Effect With Low Toxicity: Results From Two Nordic Lymphoma Group Trials With More Than 10 Years of Follow-Up.

PURPOSE: For indolent lymphoma, the optimal timing, sequence, and choice of therapeutic regimens remain a matter of debate. In two Nordic Lymphoma Group randomized trials, symptomatic or clearly progressing patients were treated first line with a rituximab-containing regimen without chemotherapy. The purpose of this study was to assess long-term survival, risk of transformation, and need of new therapies. METHODS: Data were collected at cross-sectional follow-up for 321 patients with indolent lymphoma (84% with follicular lymphomas [FL]) included in one of two Nordic Lymphoma Group trials (accrual 1998 to 1999 and 2002 to 2008). All patients received first-line therapy with one or two cycles of four weekly infusions of rituximab 375 mg/m2, and 148 were randomly allocated to the addition of interferon alfa-2a. Follow-up data were retrieved from initial trial databases and medical records on repeated clinical evaluations. RESULTS: At the end of follow-up, 73% of patients were alive, with a median follow-up after random assignment of 10.6 years. Among all, 36% (38% with FL) had never needed chemotherapy. For patients with FL who required new therapy within 24 months because of early disease progression, the 10-year survival rate was 59% versus 81% for those with longer remission. Interferon was not shown to improve long-term outcome. Transformation was diagnosed in 20% of all patients (2.4% per person-year) and in 18% with FL. An additional malignancy was found in 12%. CONCLUSION: Approximately one third of patients with symptomatic indolent lymphoma (30% with FL, 23% without FL) did not need new therapy in the long term after first-line rituximab without chemotherapy. In the entire cohort, 10-year survival was excellent with no major safety issues, which suggests that chemotherapy can be delayed safely in the majority of patients.

A Phase I/IIa Trial Using CD19-Targeted Third-Generation CAR T Cells for Lymphoma and Leukemia.

PURPOSE: The chimeric antigen receptor (CAR) T-cell therapy has been effective for patients with CD19+ B-cell malignancies. Most studies have investigated the second-generation CARs with either CD28 or 4-1BB costimulatory domains in the CAR receptor. Here, we describe the first clinical phase I/IIa trial using third-generation CAR T cells targeting CD19 to evaluate safety and efficacy. PATIENTS AND METHODS: Fifteen patients with B-cell lymphoma or leukemia were treated with CAR T cells. The patients with lymphoma received chemotherapy during CAR manufacture and 11 of 15 were given low-dose cyclophosphamide and fludarabine conditioning prior to CAR infusion. Peripheral blood was sampled before and at multiple time points after CAR infusion to evaluate the persistence of CAR T cells and for immune profiling, using quantitative PCR, flow cytometry, and a proteomic array. RESULTS: Treatment with third-generation CAR T cells was generally safe with 4 patients requiring hospitalization due to adverse reactions. Six of the 15 patients had initial complete responses [4/11 lymphoma and 2/4 acute lymphoblastic leukemia (ALL)], and 3 of the patients with lymphoma were in remission at 3 months. Two patients are still alive. Best predictor of response was a good immune status prior to CAR infusion with high IL12, DC-Lamp, Fas ligand, and TRAIL. Responding patients had low monocytic myeloid-derived suppressor cells (MDSCs; CD14+CD33+HLA-DR-) and low levels of IL6, IL8, NAP3, sPDL1, and sPDL2. CONCLUSIONS: Third-generation CARs may be efficient in patients with advanced B-cell lymphoproliferative malignancy with only modest toxicity. Immune profiling pre- and posttreatment can be used to find response biomarkers.

Adjuvant chemotherapy and postoperative radiotherapy in high-risk soft tissue sarcoma patients defined by biological risk factors-A Scandinavian Sarcoma Group study (SSG XX).

PURPOSE: To investigate the outcome following adjuvant doxorubicin and ifosfamide in a prospective non-randomised study based on a soft tissue sarcoma (STS) patient subgroup defined by specific morphological characteristics previously shown to be at a high-risk of metastatic relapse. The expected 5-year cumulative incidence of metastases in patients with this risk profile has previously been reported to be about 50% without adjuvant chemotherapy. METHODS: High-risk STS was defined as high-grade morphology (according to the Fédération Nationale des Centres de Lutte Contre le Cancer [FNCLCC] grade II-III) and either vascular invasion or at least two of the following criteria: tumour size ≥8.0 cm, infiltrative growth and necrosis. Six cycles of doxorubicin (60 mg/m2) and ifosfamide (6 g/m2) were given. Postoperative accelerated radiotherapy was applied and scheduled between cycles 3 and 4. RESULTS: For the 150 eligible patients, median follow-up time for metastases-free survival was 3.9 years (range 0.2-8.7). Five-year metastases-free survival (MFS) was 70.4% (95% confidence interval [CI]: 63.1-78.4) with a local recurrence rate of 14.0% (95% CI: 7.8-20.2). For overall survival (OS), the median follow-up time was 4.4 years (range: 0.2-8.7). The five-year OS was 76.1% (95% CI: 68.8-84.2). Tumour size, deep location and reduced dose intensity (<80%) had a negative impact on survival. Toxicity was moderate with no treatment-related death. CONCLUSIONS: A benefit of adjuvant chemotherapy, compared to similar historical control groups, was demonstrated in STS patients with defined poor prognostic factors. Vascular invasion, tumour size, growth pattern and necrosis may identify patients in need of adjuvant chemotherapy.

Valproate in combination with rituximab and CHOP as first-line therapy in diffuse large B-cell lymphoma (VALFRID).

The aims of the present study were to establish the maximally tolerated dose (MTD) of the histone deacetylase inhibitor valproate together with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) in patients with diffuse large B-cell lymphoma (DLBCL). A phase 1 dose escalation study of valproate together with R-CHOP followed by a dose expansion study using the established MTD of valproate was performed. MTD of valproate together with R-CHOP was established at 60 mg/kg per day, as higher doses resulted in auditory adverse events (AEs). In the study population, 2-year progression-free survival was 84.7% (95% confidence interval [CI], 73.2%-98%). The 2-year overall survival (OS) was 96.8% (n = 31; 95% CI, 90.8%-100%). These data were compared with 2 risk-factor matched populations of R-CHOP-treated patients from the Swedish Lymphoma Registry (cohort A, n = 330 and B, n = 165). As compared with the matched cohorts, we observed a statistically significant (P = .034 and 0.028, respectively) beneficial effect of the addition of valproate to R-CHOP on the OS in the studied population. In conclusion, addition of valproate to R-CHOP is a feasible strategy in first-line treatment of DLBCL. The proposed phase 2 dose is 60 mg/kg per day together with prednisone. Auditory AEs were unexpected and warrant close monitoring. Our findings suggest that drugs that target histone deacetylation may add benefit and are tolerable when combined with standard R-CHOP in DLBCL. The phase 1 trial was registered at www.clinicaltrials.gov as #NCT01622439.

KIT signaling is dispensable for human mast cell progenitor development.

Human hematopoietic progenitors are generally assumed to require stem cell factor (SCF) and KIT signaling during differentiation for the formation of mast cells. Imatinib treatment, which inhibits KIT signaling, depletes mast cells in vivo. Furthermore, the absence of SCF or imatinib treatment prevents progenitors from developing into mast cells in vitro. However, these observations do not mean that mast cell progenitors require SCF and KIT signaling throughout differentiation. Here, we demonstrate that circulating mast cell progenitors are present in patients undergoing imatinib treatment. In addition, we show that mast cell progenitors from peripheral blood survive, mature, and proliferate without SCF and KIT signaling in vitro. Contrary to the prevailing consensus, our results show that SCF and KIT signaling are dispensable for early mast cell development.

Population-based experience on primary central nervous system lymphoma 2000-2012: the incidence is increasing.

BACKGROUND: Primary central nervous system lymphomas (PCNSL) are rare lymphomas with a poor prognosis. Recently, an increased incidence has been reported. The present study is a population-based study of all patients with PCNSL in the Uppsala/Örebro region of middle Sweden. PATIENTS AND METHODS: All patients diagnosed with a PCNSL at Uppsala University Hospital 2000-2012 were identified. Altogether, 96 patients (50 women and 46 men) were included. The median age at diagnosis was 66 years (17-95). RESULTS: There was a statistically significant increase in age-standardized incidence during the study period, 30 patients were diagnosed in the first half and 66 in the second half of the period. No patient had an HIV-infection. Two patients had undergone kidney transplantation and were treated with immunosuppressive drugs. A high proportion of the patients, 29%, had a history of an autoimmune or inflammatory disease. The prognosis was poor with a median survival of only four months. In the 70 (73%) patients treated with curative intention the median survival was 12 months. Patients treated with high-dose methotrexate, radiotherapy and/or temozolomide appeared to have a better survival. There was no improvement in survival during the study period or after the introduction of rituximab. There also was no difference in any of the analyzed variables that could explain the increased incidence. CONCLUSION: In this population-based study we could confirm the previously described increased incidence of PCNSL. The prognosis remains poor despite the inclusion of treatment with rituximab during the study period. A high proportion of the patients had a history of an autoimmune or inflammatory disease not previously described but there was no increase during the study period.

Randomized, Double-Blind, Phase III Trial of Enzastaurin Versus Placebo in Patients Achieving Remission After First-Line Therapy for High-Risk Diffuse Large B-Cell Lymphoma.

PURPOSE: To compare disease-free survival (DFS) after maintenance therapy with the selective protein kinase C ß (PKCß) inhibitor, enzastaurin, versus placebo in patients with diffuse large B-cell lymphoma (DLBCL) in complete remission and with a high risk of relapse after first-line therapy. PATIENTS AND METHODS: This multicenter, phase III, randomized, double-blind, placebo-controlled trial enrolled patients who were at high risk of recurrence after rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Patients (N = 758) with stage II bulky or stage III to IV DLBCL, three or more International Prognostic Index risk factors at diagnosis, and a complete response or unconfirmed complete response after 6 to 8 cycles of R-CHOP were assigned 2:1 to receive oral enzastaurin 500 mg daily or placebo for 3 years or until disease progression or unacceptable toxicity. Primary end point was DFS 3 years after the last patient entered treatment. Correlative analyses of biomarkers, including cell of origin by immunohistochemistry and PKCß expression, with efficacy outcomes were exploratory objectives. RESULTS: After a median follow-up of 48 months, DFS hazard ratio for enzastaurin versus placebo was 0.92 (95% CI, 0.689 to 1.216; two-sided log-rank P = .541; 4-year DFS, 70% v 71%, respectively). Independent of treatment, no significant associations were observed between PKCß protein expression or cell of origin and DFS or overall survival. CONCLUSION: Enzastaurin did not significantly improve DFS in patients with high-risk DLBCL after achieving complete response to R-CHOP. Achievement of a complete response may have abrogated the prognostic significance of cell of origin by immunohistochemistry.

Malignancies in transplanted patients: Multidisciplinary evaluation and switch to mTOR inhibitors after kidney transplantation - experiences from a prospective, clinical, observational study.

Background Solid organ transplant recipients are at increased risk of developing malignancies. The objective of this prospective, observational, one-armed study was to study the feasibility to add a mammalian target of rapamycin (mTOR) inhibitor to the immunosuppressive regimen in transplanted patients with post-transplant malignancies. During the trial the need to improve identification of post-transplant malignancies and to reassure adequate oncological treatment of these patients became evident. Multidisciplinary team (MDT) evaluation of oncological and immunosuppressive treatments was implemented for all patients with malignancies after renal or combined renal and pancreas transplantation because of the trial. Material and methods At Uppsala University Hospital, Sweden, a MDT consisting of transplant surgeons, nephrologists, oncologists and dermatologists evaluated 120 renal or combined renal and pancreas-transplanted recipients diagnosed with malignancies from September 2006 to July 2012. To identify all malignancies, the population was linked to the Regional Tumor Registry (RTR). We recorded to which extent a switch to mTOR inhibitors was possible and how often the originally planned oncological managements were adjusted. All patients were followed for three years. (ClinicalTrials.gov: NCT02241564). Results In 76 of 120 patients (63%) a switch to mTOR inhibitors was possible. Immunosuppression was interrupted in seven patients (6%), reduced in three patients (2%) and remained unchanged in 34 of 120 patients (28%). Identification of post-transplant malignancies increased significantly after linkage to RTR (p = 0.015). The initially recommended oncological treatment was adjusted in 23 of 44 patients (52%) with solid or hematological malignancies; 36 of these patients (82%) were treated according to national guidelines. Conclusion In two thirds of the patients the immunosuppressive treatment could be changed to an mTOR inhibitor with anti-tumor effects in transplanted patients with post-transplant malignancies. The use of regional tumor registers considerably improved the identification of patients with post-transplant malignancies indicating that post-transplant malignancies might be timely underreported in transplant registers.

First-in-human, phase I/IIa clinical study of the peptidase potentiated alkylator melflufen administered every three weeks to patients with advanced solid tumor malignancies.

PURPOSE: Melflufen (melphalan flufenamide, previously designated J1) is an optimized and targeted derivative of melphalan, hydrolyzed by aminopeptidases overexpressed in tumor cells resulting in selective release and trapping of melphalan, and enhanced activity in preclinical models. METHODS: This was a prospective, single-armed, open-label, first-in-human, dose-finding phase I/IIa study in 45 adult patients with advanced and progressive solid tumors without standard treatment options. Most common tumor types were ovarian carcinoma (n = 20) and non-small-cell lung cancer (NSCLC, n = 11). RESULTS: In the dose-escalating phase I part of the study, seven patients were treated with increasing fixed doses of melflufen (25-130 mg) Q3W. In the subsequent phase IIa part, 38 patients received in total 115 cycles of therapy at doses of 30-75 mg. No dose-limiting toxicities (DLTs) were observed at 25 and 50 mg; at higher doses DLTs were reversible neutropenias and thrombocytopenias, particularly evident in heavily pretreated patients, and the recommended phase II dose (RPTD) was set to 50 mg. Response Evaluation Criteria In Solid Tumors (RECIST) evaluation after 3 cycles of therapy (27 patients) showed partial response in one (ovarian cancer), and stable disease in 18 patients. One NSCLC patient received nine cycles of melflufen and progressed after 7 months of therapy. CONCLUSIONS: In conclusion, melflufen can safely be given to cancer patients, and the toxicity profile was as expected for alkylating agents; RPTD is 50 mg Q3W. Reversible and manageable bone marrow suppression was identified as a DLT. Clinical activity is suggested in ovarian cancer, but modest activity in treatment of refractory NSCLC.

Two courses of four weekly infusions of rituximab with or without interferon-α2a: final results from a randomized phase III study in symptomatic indolent B-cell lymphomas.

Patients with advanced CD20 + indolent lymphoma, requiring therapy, were randomized to rituximab (four weekly infusions of 375 mg/m(2)) or to rituximab combined with 5 weeks of interferon-α2a (IFN-α2a) (3-4.5 MIU daily) as priming. Responding patients were eligible for a second cycle with the same allocated treatment. In total, 156 patients were randomized to rituximab and 157 to rituximab + IFN-α2a. In the intention-to treat (ITT) population, 244 patients (78%) responded to cycle 1. After a second cycle the complete remission/complete remission unconfirmed (CR/CRu) rate was 41% with the combination versus 24% with monotherapy (p = 0.005). The median time to treatment failure (primary endpoint) in ITT patients was 28 vs. 21.5 months, respectively (p = 0.302). After a long median follow-up (61 months), 33% (42% of patients responding to cycle 1) were still failure-free with an overall survival rate of 88% and with no difference between the treatment groups. The trial was registered at ClinicalTrials.gov Identifier: NCT01609010.

Successful change of treatment strategy in elderly patients with primary central nervous system lymphoma by de-escalating induction and introducing temozolomide maintenance: results from a phase II study by the Nordic Lymphoma Group.

The Nordic Lymphoma Group has conducted a phase ll trial in newly diagnosed primary central nervous system lymphoma patients applying an age-adjusted multi-agent immunochemotherapy regimen, which in elderly patients included temozolomide maintenance treatment. Patients aged 18-75 years were eligible. Thirty-nine patients aged 18-65 years and 27 patients aged 66-75 years were enrolled. The median age of the two age groups was 55 and 70 years, respectively. The overall response rate was 73.8% for the entire cohort: 69.9% in the younger and 80.8% in the elderly subgroup. With a median follow up of 22 months, the 2-year overall survival probability was 60.7% in patients aged 65 years or under and 55.6% in patients aged over 65 years (P=0.40). The estimated progression-free survival at two years was 33.1% (95%CI: 19.1%-47.9%) in patients aged under 65 years and 44.4% (95%CI: 25.6%-61.8%) in the elderly subgroup (P=0.74). Median duration of response was ten months in the younger subgroup, and not reached in the elderly patient subgroup (P=0.33). Four patients aged 64-75 years (6%) died from treatment-related complications. Survival in the two age groups was similar despite a de-escalation of induction treatment in patients aged over 65 years. Duration of response in elderly patients receiving maintenance temozolomide was longer than in the younger age subgroup. While toxicity during induction is still of concern, especially in the elderly patients, we conclude from these data that de-escalation of induction therapy in elderly primary central nervous system lymphoma patients followed by maintenance treatment seems to be a promising treatment strategy. (clinicaltrials.gov identifier:01458730).

Treatment outcome in T-cell lymphoblastic lymphoma in adults - a population-based study from the Swedish Lymphoma Registry.

BACKGROUND: T-cell lymphoblastic lymphoma (T-LBL) is a rare neoplasm of precursor lymphoblast origin, for which there is no standard treatment for adults. Results of current treatment strategies in selected populations do exist but are largely unreported for unselected series. Here, we aimed to investigate treatment outcome in a population-based cohort. MATERIAL AND METHODS: Patients were identified through the Swedish Lymphoma Registry and data was retrospectively collected for all adult (≥ 18 years) Swedish T-LBL patients diagnosed during 2000-2009. RESULTS: A total of 39 patients with median age 40 years (range 18-78) were identified with females being significantly older than males (median age 66 vs. 37, p = 0.027). The five-year overall survival for all patients was 42%. Female gender was associated with shorter survival also when adjusted for treatment strategy and age [hazard ratio (HR) 4.29; p = 0.002]. Thirty patients received intensive chemotherapy, otherwise used for treatment of acute lymphoblastic leukemia (ALL), which resulted in an overall response rate of 97% and a five-year progression-free survival (PFS) of 49%. In this group only CNS involvement at diagnosis predicted shorter PFS (HR 13.3; p = 0.03). Among patients treated with hyper-CVAD the addition of mediastinal irradiation resulted in prolonged time to progression compared to patients receiving only chemotherapy (p = 0.047). The major reason for treatment failure was relapse and in this series 18-fluoro-deoxyglucose positron emission tomography (PET) did not predict this risk. CONCLUSION: This population-based study indicates that all fit T-LBL patients should be considered for intensive treatment. Our results also suggest a beneficial effect of mediastinal irradiation in combination with hyper-CVAD treatment. Relapsing patients have a dismal outcome irrespective of salvage treatment.