Background Preoperative chemoradiotherapy with infusional fluorouracil, total mesorectal excision surgery, and postoperative chemotherapy with fluorouracil was established by the German CAO/ARO/AIO-94 trial as a standard combined modality treatment for locally advanced rectal cancer. Here we compare the previously established regimen with an investigational regimen in which oxaliplatin was added to both preoperative chemoradiotherapy and postoperative chemotherapy.Methods In this multicentre, open-label, randomised, phase 3 study we randomly assigned patients with rectal adenocarcinoma, clinically staged as cT3-4 or any node-positive disease, to two groups: a control group receiving standard fluorouracil-based combined modality treatment, consisting of preoperative radiotherapy of 50.4 Gy in 28 fractions plus infusional fluorouracil (1000 mg/m(2) on days 1-5 and 29-33), followed by surgery and four cycles of bolus fluorouracil (500 mg/m(2) on days 1-5 and 29); or to an investigational group receiving preoperative radiotherapy of 50.4 Gy in 28 fractions plus infusional fluorouracil (250 mg/m(2) on days 1-14 and 22-35) and oxaliplatin (50 mg/m(2) on days 1, 8, 22, and 29), followed by surgery and eight cycles of oxaliplatin (100 mg/m(2) on days 1 and 15), leucovorin (400 mg/m(2) on days 1 and 15), and infusional fluorouracil (2400 mg/m(2) on days 1-2 and 15-16). Randomisation was done with computer-generated block-randomisation codes stratified by centre, clinical T category (cT1-3 vs cT4), and clinical N category (cN0 vs cN1-2) without masking. The primary endpoint was disease-free survival, defined as the time between randomisation and non-radical surgery of the primary tumour (R2 resection), locoregional recurrence after R0/1 resection, metastatic disease or progression, or death from any cause, whichever occurred first. Survival and cumulative incidence of recurrence analyses followed the intention-to-treat principle; toxicity analyses included all patients treated. Enrolment of patients in this trial is completed and follow-up is ongoing. This study is registered with ClinicalTrials.gov, number NCT00349076.Findings Of the 1265 patients initially enrolled, 1236 were assessable (613 in the investigational group and 623 in the control group). With a median follow-up of 50 months (IQR 38-61), disease-free survival at 3 years was 75.9% (95% CI 72.4-79.5) in the investigational group and 71.2% (95% CI 67.6-74.9) in the control group (hazard ratio [HR] 0.79, 95% CI 0.64-0.98; p=0.03). Preoperative grade 3-4 toxic effects occurred in 144 (24%) of 607 patients who actually received fluorouracil and oxaliplatin during chemoradiotherapy and in 128 (20%) of 625 patients who actually received fluorouracil chemoradiotherapy. Of 445 patients who actually received adjuvant fluorouracil and leucovorin and oxaliplatin, 158 (36%) had grade 3-4 toxic effects, as did 170 (36%) of 470 patients who actually received adjuvant fluorouracil. Late grade 3-4 adverse events in patients who received protocol-specified preoperative and postoperative treatment occurred in 112 (25%) of 445 patients in the investigational group, and in 100 (21%) of 470 patients in the control group.Interpretation Adding oxaliplatin to fluorouracil-based neoadjuvant chemoradiotherapy and adjuvant chemotherapy (at the doses and intensities used in this trial) significantly improved disease-free survival of patients with clinically staged cT3-4 or cN1-2 rectal cancer compared with our former fluorouracil-based combined modality regimen (based on CAO/ARO/AIO-94). The regimen established by CAO/ARO/AIO-04 can be deemed a new treatment option for patients with locally advanced rectal cancer.

Monitoring of donor chimerism in sorted CD34

Allogeneic stem cell transplantation (SCT) is best performed with an HLA-identical sibling donor (matched related donor, MRD) to reduce the risk of early complications such as acute graft-vs.-host disease (aGvHD). However, as only about 30% of recipients have an MRD for this potentially curative approach, the use of family donors with one or two mismatches in the HLA-antigens (mismatch related donor, MMRD) or fully matched unrelated donors (MUD) (''alternative donors'') has been introduced in the allogeneic SCT setting in recent years. To evaluate the feasibility of allogeneic SCT from alternative donors by using peripheral blood stem cells (PBSC) we initiated a prospective, phase II study in 1996. From April 1996 to July 1998, 18 patients with various hematological malignancies underwent allogeneic SCT from alternative donors (two patients with MUD and 16 patients with MMRD). All patients received stable engraftment and none of the patients had graft rejection. The rate of aGvHD (grades II-IV) and the relapse rate at last follow-up (seven to nine yr after SCT) were with 40% and 24%, respectively, comparable with those found in patients receiving allogeneic SCT from MRD. However, five yr after allogeneic SCT only 17% were alive, which was mainly due to the treatment-related mortality (TRM) rate of 59%. We conclude that allogeneic PBSC transplantation by using alternative donors is associated with an unsatisfying long-term TRM rate. The significance of TRM and particular late deaths has to be evaluated further in this transplantation setting.

Bone marrow or blood stem cell transplantation is the only cure for β-thalassemia major, however, despite myeloablative conditioning regimens, the basic difficulty is a 15-30% graft failure rate in these patients. Our hypothesis is that there may be a T-cell dependent graft-versus-myelon effect that establishes and stabilizes the engraftment of allogeneic blood stem cells in patients with thalassemia major. In a first attempt, we assessed the CD3 chimerism early after transplantation in a pediatric case series of six transplantations (2 related, 4 unrelated donors) transplanted from 2001 to 2004 with a minimum follow-up period of 2 years after transplantation. The donors were fully matched at HLA-DRB1 (high resolution) and HLA-A and -B (low resolution). Peripheral blood CD3 chimerism was determined at day +30 (median). Chimerism of unfractionated WBC was determined patients beginning day +13 (median) and repeated until a stable engraftment or graft failure was achieved. Patients (n = 4) with a CD3 donor chimerism of >80% established a long term engraftment and remained free of erythrocyte transfusions (days +133, +775, +815, +2033). Two of these patients developed a low total chimerism (minimum 42% on day +93, and 45% on day +42, resp.) after that a higher total donor chimerism had been achieved (90% on day +17 and 92% on day +20, resp.). We stopped the immunosuppressive therapy in both patients as soon as the result of the CD3 chimerism was available. Both patients increased their total chimerism up to 98%; one developed GvHD II° of the skin that resolved after steroid therapy without impairment of the total chimerism. Two patients with a CD3 donor chimerism <10% lost their graft completely, despite the fact, that one patient showed a high total chimerism of 89% on day +6. One patient is again on the erythrocyte transfusion programme, the other engrafted after re-transplant from an unrelated donor. We conclude that early determination of the CD3 chimerism may be helpful for patient management. In addition, monitoring of the CD3 chimerism should be included in transplant protocols for beta-thalassemia major.

16523 Background: Malignant diseases arising from donor derived cells are an exceptionally rare condition with approximately 20 cases only reported in the literature. We report on diagnosis and salvage chemotherapy of a CML transplant patient relapsing with donor cell derived secondary MDS resp. AML. Methods: Chimerism analysis were performed by quantitative short tandem repeat (STR) DNA detection in bone marrow as well as in peripheral blood, detection limit 0.5%. Standard procedures were used for all other methods. Results: In a female patient transplanted with a HLA-DRB1 mismatched female unrelated donor in July 1998 for Ph+ CML, secondary MDS was diagnosed in March 2005 transforming into secondary AML in June 2005. The results from chimerism analysis after diagnosis of sMDS resp. sAML in this transplant patient, i.e. no detection of the STR pattern of the recipient, clearly confirmed a donor cell derived sMDS resp. sAML almost 7 years after allogeneic BMT. Cytogenetics showed a normal female karyotype, and no molecular aberrations were detected by FISH resp. PCR. After diagnosis of sAML the patient received 2 induction courses consisting of FLAG-Ida and MTC regimen, respectively. Bone marrow analysis after the first and second course revealed no evidence of blasts whereas the MDS continued to be detectable. Cytogenetics during and after reinduction therapy were normal. Repeated chimerism analysis showed complete donor chimerism (> 99.5%). Thus, a complete remission of donor cell derived sAML using conventional induction chemotherapy was achieved. This remission is now lasting 6 months without intensification. Medical evaluation of the donor did not reveal any disturbed or malignant hematological disorder. Conclusions: This is an interesting case of rare donor cell derived leukemia and its successful treatment. The question arises with regard to altered stromal factors in the bone marrow of the patient as potential cause of the disease. No significant financial relationships to disclose.

We describe successful treatment of a 38-year-old patient with composite lymphoma stage IVA, who presented with multifocal enlarged lymph nodes. The lymph node histology showed classic morphologic features of Hodgkin's disease, mixed cellularity subtype and follicular B-cell lymphoma. Immunophenotypic analysis showed immunoreactivity for CD20, CD10 and Ki-67 in the malignant small cell population. The areas of Hodgkin's disease demonstrated positive immunoreactivity for CD30 and CD20 in the Hodgkin's cells. Both cell populations were bcl2-oncoprotein positive. Eight courses of dose-escalated BEACOPP were administered. Restaging after chemotherapy showed radiological partial remission, but biopsy confirmed persisting follicular B-cell lymphoma without bone marrow infiltration and no evidence of Hodgkin's disease. He was treated with monoclonal CD 20-antibody (Rituximab) 10 mg/kg weekly for eight consecutive weeks due to marked positivity of CD 20-antigen in follicular lymphoma cells. This treatment was well tolerated and final staging showed complete remission of the composite lymphoma. This patient continues to be in remission 28 months after the end of the treatment. In conclusion, in the very rare case of composite lymphoma a combination of chemotherapy and subsequent immunotherapy might be considered as a promising therapeutic option.

6690 Background: Due to intensified standard radio-chemotherapy a substantial proportion of patients will be cured of Hodgkin's Lymphoma. In patients with relapse after standard therapy, the therapy of choice is an autologous stem cell transplantation with high remission rates. Despite therapeutic progress some patients suffer from refractory or relapsing disease. As graft versus Hodgkin's lymphoma effects have been described allready, allogeneic stem cell transplantation might be an therapeutic effort in these high risk patients. Methods: We analysed the course of 14 patients receiving an allogeneic transplant between 07/99 and 11/03. Results: Median age was 23 years (range 19 to 41) and patients received a median of 4.5 chemotherapies (range 2 to 8) before transplant. All but one received previously an autologous transplant. Disease status at transplant was CR in 2, PR in 1, SD in 5, and PD in 6 patients. Eight patients received a transplant from a related HLA-identical donor and 6 from an unrelated donor (4 matched, 2 DRB1 mismatch). All but one received peripheral blood stem cell grafts. Different conditioning regimens were used (Fludarabine (Flu)/busulfan (Bu) "b ATG n=6, Flu/Melphalan (Mel) "b Campath n=5, Bu/Cy n=1, TBI/Cy n=1, Mel/Thiotepa/ATG n=1). Four patients received donor lymphocyte infusions in escalating dosage for SD (n=2), PD (n=1), or mixed chimerism (n=1), respectively. OS is 43% and DFS 28.6% after a median FU of 25 months (1 to 52 months). TRM is 14.3 %. Five patients died due to disease progression and one due to refractory GVHD. Conclusions: Taking into account that all patients were heavily pre-treated and that only two patients were transplanted in CR these data argue for a strong graft versus Hodgkin effect. Especially a melphalan/fludarabin "b ATG reduced conditioning seems to be very effective in this setting. Furthermore, it's speculative but very likely that the results of allogeneic stem cell transplantation will improve significantly if patients receive the allo transplant earlier during their disease. Thus, risk factors should be defined and those patients with a high risk feature should be scheduled for allo transplant within a controlled clinical trial. No significant financial relationships to disclose.

Allogeneic stem-cell transplantation (alloSCT) is the most powerful antileukemic post-remission strategy in patients with acute myeloid leukemia (AML), and has shown its capability of increase leukemia-free survival and survival in earlier phases of the disease. However, the possible role of alloSCT in AML patients not in CR is mostly unknown, and deserves specific investigation. For this purpose, a survey within the EBMT registry including patients who underwent an undepleted alloSCT from an HLA-identical sibling for advanced AML (not in CR) was performed. We have analyzed 977 adults patients with AML submitted to alloSCT for a primary refractory disease (REF, n=346), first relapse (REL1, n=506) or second relapse (REL2, n=125) from 1990 to 2002 in EBMT centers. Median age was 40 (16 – 73) and 55% of patients were male. FAB classification was: M1/M2, 44%; M4/M5, 33%; M6, 5%; M0, 4%; M3, 3%; M7, 3%. Median time from diagnosis to alloSCT was 136, 219 and 403 days for REF, REL1, and REL2 subgroups, respectively. Bone marrow was the source of stem cells in a higher proportion of patients with relapsed disease as compared to refractory AML (59% for REL1 + REL2 vs 41% for REF, p<0001). Conditioning regimen included TBI in 56% of cases. No significant differences among subgroups (REF/REL1/REL2) were observed in terms of donor-recipient’s CMV status and TBI usage. After a median follow-up of 22 months, the main estimates of the outcome at 2 years are depicted in the following table: | Group | Refractory | 1st relapse | 2nd relapse | |:---------------------------------------- | ---------- | ----------- | ----------- | | * All the results are expressed in % ±SE | | Relapse incidence | 57 ±6 | 51 ±4 | 54 ±8 | | Transplant-related mortality | 25 ±5 | 26 ±4 | 31 ±6 | | Overall survival | 25 ±3 | 26 ±2 | 24 ±2 | | Leukemia-free survival | 18 ±2 | 23 ±2 | 16 ±3 | In conclusion, although the overall outcome of HLA-identical sibling allotransplant for patients with non-CR AML is poor, a small fraction of patients, of approximately 20%, seems to benefit from the procedure in this otherwise incurable disease. A further analysis is addressed to the recognition of favorable prognostic factors in order to identify subgroups of patients with advanced AML who are candidates to allogeneic transplantation.

PURPOSE:The role of unrelated allogeneic stem-cell transplantation in acute lymphoblastic leukemia (ALL) patients is still not clear, and only limited data are available from the literature. We analyzed factors affecting clinical outcome of ALL patients receiving a related or unrelated stem-cell graft from matched donors.PATIENTS AND METHODS:The total study population was 264 adult patients receiving a myeloablative allogeneic stem-cell transplant for ALL at nine bone marrow transplantation centers between 1990 and 2002. Of these, 221 patients receiving a matched related or unrelated graft were analyzed. One hundred forty-eight patients received transplantation in complete remission; 62 patients were in relapse; and 11 patients were refractory to chemotherapy before transplant. Fifty percent of patients received bone marrow, and 50% received peripheral blood stem cell from a human leukocyte antigen-identical related (n = 103), or matched unrelated (n = 118) donor.RESULTS:Disease-free survival (DFS) at 5 years was 28%, with 76 patients (34%) still alive (2.2 to 103 months post-transplantation), and 145 deceased (65 relapses, transplant-related mortality, 45%). We observed an advantage regarding DFS in favor of patients receiving transplantation during their first complete remission (CR) in comparison with patients receiving transplantation in or after second CR (P =.014) or who relapsed (P <.001). We observed a clear trend toward improved survival in favor of B-lineage ALL patients compared with T-lineage ALL patients (P =.052), and Philadelphia chromosome-positive patients had no poorer outcome than Philadelphia chromosome-negative patients. Total-body irradiation-based conditioning improved DFS in comparison with busulfan (P =.041).CONCLUSION:Myeloablative matched related or matched unrelated allogeneic hematopoietic stem-cell transplantation in ALL patients should be performed in first CR.