Maximum tumor diameter is associated with event-free survival in PET-negative patients with stage I/IIA Hodgkin lymphoma.

Introduction: the high cure rates achieved in early-stage (ES) Hodgkin lymphoma (HL) are one of the great successes of hemato-oncology, but late treatment-related toxicity undermines long-term survival. Improving overall survival and quality of life further will require maintaining disease control while potentially de-escalating chemotherapy and/or omitting radiotherapy to reduce late toxicity. Accurate stratification of patients is required to facilitate individualized treatment approaches. Response assessment using 18F-fluorodeoxyglucose positron emission tomography (PET) is a powerful predictor of outcome in HL,1,2 and has been used in multiple studies, including the United Kingdom National Cancer Research Institute Randomised Phase III Trial to Determine the Role of FDG–PET Imaging in Clinical Stages IA/IIA Hodgkin’s Disease (UK NCRI RAPID) trial, to investigate whether patients achieving complete metabolic remission (CMR) can be treated with chemotherapy alone.3-5 These PET-adapted trials have demonstrated that omitting radiotherapy results in higher relapse rates, but without compromising overall survival.3-5 For the 75% of patients who achieved CMR in RAPID, neither baseline clinical risk stratification (favorable/unfavorable) nor PET (Deauville score 1/2) predicted disease relapse; additional biomarkers are needed.1 Tumor bulk has long been recognized as prognostic in HL,1,6 but there remains uncertainty about the significance and definition of bulk in the era of PET-adapted treatment.7 We performed a subsidiary analysis of RAPID to assess the prognostic value of baseline maximum tumor dimension (MTD) in patients achieving CMR. Methods: ee have previously reported the RAPID trial design, primary results, and outcomes according to pretreatment risk stratification and PET score.1,3 Patients were aged 16 to 75 years with untreated ES-HL and without B-symptoms or mediastinal bulk (mass > 1/3 internal mediastinal diameter at T5/6).6 Metabolic response after 3 cycles of ABVD chemotherapy (doxorubicin, bleomycin, vinblastine, and dacarbazine) was centrally assessed using PET (N = 562). Patients with CMR (ie, Deauville score 1-2) were randomly assigned to receive involved field radiotherapy (IFRT; n = 208) or no further therapy (NFT; n = 211). PET-positive patients (score, 3-5; n = 143) received a fourth cycle of ABVD and IFRT. Baseline disease assessment was performed by computed tomography, and bidimensional target lesion measurements were reported by local radiologists in millimeters. The association of baseline MTD with HL-related event-free survival (EFS: progression or HL-related death) and progression-free survival (PFS) (progression or any-cause death) was assessed using Kaplan-Meier and Cox regression analyses. Non-HL deaths were either related to primary treatment toxicity or occurred in HL remission.1 United Kingdom ethical approval for the RAPID trial was via the UK Multicentre Research ethics committee. Results and discussion: baseline patient characteristics have been previously described.1 Median age was 34 years (range, 16-75 years); 184 (37.4%) of 492 patients had unfavorable risk by European Organisation for Research and Treatment of Cancer criteria, and 155 (32.3%) of 480 by German Hodgkin Study Groupcriteria. Median MTD for patients achieving CMR was 3.0 cm (interquartile range, 2.0-4.0 cm) and 3.0 cm (interquartile range, 1.8-4.5 cm) in the NFT and IFRT groups, respectively, whereas PET-positive patients had a median MTD of 3.9 cm (interquartile range, 2.8-5.1 cm). After a median follow-up of 61.6 m, 44 HL progression events occurred: 21 NFT, 9 IFRT and 14 PET-positive. No patient received salvage treatment without documented progression. Only 5 HL-related deaths occurred (1 IFRT, 4 PET-positive), and 12 non-HL deaths (4 NFT, 6 IFRT, 2 PET-positive).1 For patients with CMR (N = 419), there was a strong association between MTD and EFS (hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.02-1.39; P = .02), adjusting for treatment group, with an approximate 19% increase in HL risk per centimeter increase in MTD. The association was similar in both treatment groups (NFT HR, 1.20 [95% CI, 0.99-1.44; P = .06]; IFRT HR, 1.19 [95% CI, 0.92-1.55; P = .19]). The observed effect sizes did not markedly change after adjusting for baseline clinical risk factors, and similar results were observed for PFS (supplemental Table 1). In contrast, for PET-positive patients, there was no association between MTD and EFS (HR, 0.88; 95% CI, 0.70-1.11; P = .29) or PFS (HR, 0.87; 95% CI, 0.70-1.08; P = .21). In an exploratory analysis within the NFT group, MTD was dichotomized using increasing 1-cm intervals to investigate the relationship between MTD thresholds and EFS. The largest effect size was observed with an MTD threshold of ≥5 cm (Table 1). Similar results were observed for PFS; this threshold also performed best in time-dependent receiver operating characteristic curve analyses. It was not possible to assess MTD thresholds in the IFRT group with only 9 events. Among all randomized patients, 79 (18.9%) had MTD of ≥5 cm, the majority with mediastinal (n = 43), supraclavicular (n = 17), or cervical (n = 16) locations. Five-year EFS for patients with MTD of ≥5 cm randomly assigned to NFT and IFRT was 79.3% (n = 39; 95% CI, 66.6%-92.0%) and 94.9% (n = 40; 95% CI, 88.0%-100%), respectively (P = .03; Figure 1)

Chemosensitivity of radioresistant cells in the multicellular spheroids of A549 lung adenocarcinoma

<p>Abstract</p> <p>Background</p> <p>The relapse of cancer after radiotherapy is a clinical knotty problem. Previous studies have demonstrated that the elevation of several factors is likely in some way to lead to the development of treatment tolerance, so it is necessary to further explore the problem of re-proliferated radioresistant cells to chemotherapeutic agents. In the present study, we aimed to investigate the chemosensitivity of radioresistant cells originated from the multicellular spheroids of A549 lung adenocarcinoma.</p> <p>Methods</p> <p>After irradiated with 25 Gy of 6 MV X-ray to A549 multicellular spheroids, whose 10th re-proliferated generations were employed as radioresistant cells, and the control groups were A549 parental cells and MCF7/VCR resistant cells. The chemo-sensitivity test was made by six kinds of chemotherapeutic drugs which were DDP, VDS, 5-Fu, HCP, MMC and ADM respectively, while verapamil (VPL) was used as the reversal agent. Then the treatment effect was evaluated by MTT assay, and the multidrug resistant gene expressions of <it>mdr1 </it>and <it>MRP </it>were measured by RT-PCR.</p> <p>Results</p> <p>Both A549 parental cells and A549 derived radioresistant cells were resistant to DDP, but sensitive to VDS, 5-Fu, HCP, MMC and ADM. The inhibitory rates of VPL to these two types of cell were 98% and 25% respectively (P < 0.001). In addition, without drugs added, the absorbance value (A value) of A549 parental cells was 2-folds higher than that of their radioresistant cells (P < 0.001). As to the MCF7/VCR cells, they were resistant to DDP and VDS, but slight sensitive to MMC, ADM, 5-Fu, and HCP with 80% of inhibitory rate to VPL. The subsequent RT-PCR demonstrated that the <it>Mdr1</it>/β2-MG and <it>MRP</it>/β2-MG of all A549 cells were about 0 and 0.7 respectively, and those of MCF7/VCR cells were 35 and 4.36.</p> <p>Conclusion</p> <p>The chemosensitivity of A549 radioresistant cells had not changed markedly, and the decreased sensitivity to VPL could not be explained by the gene expression of <it>mdr1 </it>and <it>MRP</it>. It is possible that the changes in the cell membrane and decreased proliferate ability might be attributed to the resistance. Unlike multidrug resistance induced by chemotherapy, VPL may be not an ideal reverser to radioresistant cells. Therefore, the new biological strategy needs to be developed to treat recurring radioresistant tumor in combination with chemotherapy.</p

Immunosuppressive effects of radiation on human dendritic cells: reduced IL-12 production on activation and impairment of naïve T-cell priming

Dendritic cells (DC) are professional antigen-presenting cells (APC) of the immune system, uniquely able to prime naïve T-cell responses. They are the focus of a range of novel strategies for the immunotherapy of cancer, a proportion of which include treating DC with ionising radiation to high dose. The effects of radiation on DC have not, however, been fully characterised. We therefore cultured human myeloid DC from CD14+ precursors, and studied the effects of ionising radiation on their phenotype and function. Dendritic cells were remarkably resistant against radiation-induced apoptosis, showed limited changes in surface phenotype, and mostly maintained their endocytic, phagocytic and migratory capacity. However, irradiated DC were less effective in a mixed lymphocyte reaction, and on maturation produced significantly less IL-12 than unirradiated controls, while IL-10 secretion was maintained. Furthermore, peptide-pulsed irradiated mature DC were less effective at naïve T-cell priming, stimulating fewer effector cells with lower cytotoxicity against antigen-specific targets. Hence irradiation of DC in vitro, and potentially in vivo, has a significant impact on their function, and may shift the balance between T-cell activation and tolerisation in DC-mediated immune responses

The use of gamma-irradiation and ultraviolet-irradiation in the preparation of human melanoma cells for use in autologous whole-cell vaccines

<p>Abstract</p> <p>Background</p> <p>Human cancer vaccines incorporating autologous tumor cells carry a risk of implantation and subsequent metastasis of viable tumor cells into the patient who is being treated. Despite the fact that the melanoma cell preparations used in a recent vaccine trial (Mel37) were gamma-irradiated (200 Gy), approximately 25% of the preparations failed quality control release criteria which required that the irradiated cells incorporate ³H-thymidine at no more than 5% the level seen in the non-irradiated cells. We have, therefore, investigated ultraviolet (UV)-irradiation as a possible adjunct to, or replacement for gamma-irradiation.</p> <p>Methods</p> <p>Melanoma cells were gamma- and/or UV-irradiated. ³H-thymidine uptake was used to assess proliferation of the treated and untreated cells. Caspase-3 activity and DNA fragmentation were measured as indicators of apoptosis. Immunohistochemistry and Western blot analysis was used to assess antigen expression.</p> <p>Results</p> <p>UV-irradiation, either alone or in combination with gamma-irradiation, proved to be extremely effective in controlling the proliferation of melanoma cells. In contrast to gamma-irradiation, UV-irradiation was also capable of inducing significant levels of apoptosis. UV-irradiation, but not gamma-irradiation, was associated with the loss of tyrosinase expression. Neither form of radiation affected the expression of gp100, MART-1/MelanA, or S100.</p> <p>Conclusion</p> <p>These results indicate that UV-irradiation may increase the safety of autologous melanoma vaccines, although it may do so at the expense of altering the antigenic profile of the irradiated tumor cells.</p

Mifepristone prevents repopulation of ovarian cancer cells escaping cisplatin-paclitaxel therapy

<p>Abstract</p> <p>Background</p> <p>Advanced ovarian cancer is treated with cytoreductive surgery and combination platinum- and taxane-based chemotherapy. Although most patients have acute clinical response to this strategy, the disease ultimately recurs. In this work we questioned whether the synthetic steroid mifepristone, which as monotherapy inhibits the growth of ovarian cancer cells, is capable of preventing repopulation of ovarian cancer cells if given after a round of lethal cisplatin-paclitaxel combination treatment.</p> <p>Methods</p> <p>We established an <it>in vitro</it> approach wherein ovarian cancer cells with various sensitivities to cisplatin or paclitaxel were exposed to a round of lethal doses of cisplatin for 1 h plus paclitaxel for 3 h. Thereafter, cells were maintained in media with or without mifepristone, and short- and long-term cytotoxicity was assessed.</p> <p>Results</p> <p>Four days after treatment the lethality of cisplatin-paclitaxel was evidenced by reduced number of cells, increased hypodiploid DNA content, morphological features of apoptosis, DNA fragmentation, and cleavage of caspase-3, and of its downstream substrate PARP. Short-term presence of mifepristone either enhanced or did not modify such acute lethality. Seven days after receiving cisplatin-paclitaxel, cultures showed signs of relapse with escaping colonies that repopulated the plate in a time-dependent manner. Conversely, cultures exposed to cisplatin-paclitaxel followed by mifepristone not only did not display signs of repopulation following initial chemotherapy, but they also had their clonogenic capacity drastically reduced when compared to cells repopulating after cisplatin-paclitaxel.</p> <p>Conclusions</p> <p>Cytostatic concentrations of mifepristone after exposure to lethal doses of cisplatin and paclitaxel in combination blocks repopulation of remnant cells surviving and escaping the cytotoxic drugs.</p

Dependence of surface monoclonal antibody binding on dynamic changes in FcγRIIb expression

Receptors for the Fc region of immunoglobulin G (FcγRs) are expressed on a broad range of haematopoietic cell types and are responsible for regulating antibody production and linking the humoral and effector responses. In response to a number of stimuli, such as cytokine signals or inflammation, FcγR expression at the cell surface is dynamically regulated. On B cells, we observed what appeared to be a correlation between CD22 expression and FcγRIIb expression when the latter was varied in a number of models. Further investigation revealed that this was specific to a particular anti-CD22 monoclonal antibody, which appeared to require stabilization by interaction with FcγRIIb for optimal binding to CD22. Since alterations in the regulation of FcγR expression are important in controlling immune responses and have been associated with a number of immune-mediated disease states, we suggest that it might be prudent to confirm the expression of cell surface markers by two independent methods. Furthermore, because the efficacy of therapeutic antibodies may depend upon their interaction with FcγRs, our results are relevant to their design and assessment