Summary:While allogeneic stem cell transplantation (SCT) is curative for a significant number of patients with AML, relapse of disease within the bone marrow and/or extramedullary (EM) sites following high-dose therapy continues to limit the success of this treatment. Between October 1985 and December 1996, 81 adults underwent allogeneic SCT for de novo AML at our centre. Fortytwo patients remain alive and free of leukaemia with a median follow-up of 50 months. The 5-year actuarial event-free survivals (EFS) for all patients and for those undergoing SCT in CR1 or with advanced disease were 46% (95% confidence interval (CI) 34-58%), 63% (CI 46-76%), and 19% (CI 7-36%), respectively. Twentytwo patients relapsed at a median of 8 (range 1.6-54.5) months with the actuarial risk of relapse for all, CR1 and advanced disease patients being 38%, (CI 27-52%), 23% (CI 13-40%) and 68% (CI 46-88%), respectively. Ten patients relapsed at EM sites; six of these (27% of relapses) had an isolated EM relapse at a median of 31 (range 8.5-54) months. Three of the patients with isolated EM relapse survived у24 months following relapse and two patients remain disease-free at 29+ and 33+ months. BuCy conditioning followed by allogeneic SCT in AML results in satisfactory EFS although there is a significant risk of late isolated EM relapse. Keywords: acute myelogenous leukemia; extramedullary relapse; allogeneic BMT Allogeneic stem cell transplantation (SCT) is an effective therapy for patients with AML. 1-3 Long-term event-free survival (EFS) can be achieved in approximately 60% of patients undergoing SCT in first complete remission (CR1) 4-9 and 25-30% of those with more advanced disease. 1,2,4,10,11 However, there remains some controversy regarding the optimal transplant preparative regimen in AML. For patients transplanted in CR1, one randomized study demonstrated a regimen employing TBI to be superior to busulfan/cyclophosphamide (BuCy) conditioning, 7 while another showed the regimens to be equivalent. 8 One of the contributing factors to an unsuccessful result with SCT regardless of the preparative regimen utilized is relapse, occurring in 20-25% and 30-50% of AML patients transplanted during CR1 or with advanced disease, respectively. 1,2,4,7,9 The site of relapse after a TBI-based preparative regimen is usually the marrow with or without extramedullary (EM) disease. 12 Isolated EM relapse occurred in only 13% of patients developing recurrent disease after TBI conditioning in one study. 12 Little is known about the risk of isolated EM relapse of AML following BuCy with a small number of such patients reported recently in a survey by the European Group for Blood and Marrow Transplantation (EBMT) of more than 3000 AML transplants. 13 The present review was prompted by the observation that several patients receiving allogeneic SCT after BuCy at our institution experienced isolated EM relapse.

patients had tumoral PD-L1 expression !5%. Patients with tumoral PD-L1 !5% had better OS vs those with lower expression, HRZ0.29 (CI 0.10-0.78), pZ0.009; 10 years OS: 84% for PD-L1 !5% vs. 46% for PD-L1 <5%. On univariate analysis, OS was associated with PD-L1 status, as well as T stage, N stage, ECOG status and gender. On multivariate analysis, PD-L1 !5% remained statistically significant for better OS, HRZ0.35 (CI 0.12-0.99), pZ0.047. 33 of 65 (51%) of tumors had high CD8 levels (3 or 4). There was no association between CD8 status and OS; further stratifying PD-L1 high patients by CD8 did not improve the prognostic impact vs PD-L1 status alone. Conclusion: This is the first study reporting significant association of PD-L1 expression with OS in patients with anal cancer treated with CRT. PD-L1 status warrants consideration in the prognostication of patients with anal cancer. Future studies are required to determine the benefit of alternative treatment strategies based on PD-L1 status.