Identification, validation and biological characterisation of novel glioblastoma tumour microenvironment subtypes: implications for precision immunotherapy.

BACKGROUND: New precision medicine therapies are urgently required for glioblastoma (GBM). However, to date, efforts to subtype patients based on molecular profiles have failed to direct treatment strategies. We hypothesised that interrogation of the GBM tumour microenvironment (TME) and identification of novel TME-specific subtypes could inform new precision immunotherapy treatment strategies. MATERIALS AND METHODS: A refined and validated microenvironment cell population (MCP) counter method was applied to >800 GBM patient tumours (GBM-MCP-counter). Specifically, partition around medoids (PAM) clustering of GBM-MCP-counter scores in the GLIOTRAIN discovery cohort identified three novel patient clusters, uniquely characterised by TME composition, functional orientation markers and immune checkpoint proteins. Validation was carried out in three independent GBM-RNA-seq datasets. Neoantigen, mutational and gene ontology analysis identified mutations and uniquely altered pathways across subtypes. The longitudinal Glioma Longitudinal AnalySiS (GLASS) cohort and three immunotherapy clinical trial cohorts [treatment with neoadjuvant/adjuvant anti-programmed cell death protein 1 (PD-1) or PSVRIPO] were further interrogated to assess subtype alterations between primary and recurrent tumours and to assess the utility of TME classifiers as immunotherapy biomarkers. RESULTS: TMEHigh tumours (30%) displayed elevated lymphocyte, myeloid cell immune checkpoint, programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 transcripts. TMEHigh/mesenchymal+ patients featured tertiary lymphoid structures. TMEMed (46%) tumours were enriched for endothelial cell gene expression profiles and displayed heterogeneous immune populations. TMELow (24%) tumours were manifest as an 'immune-desert' group. TME subtype transitions upon recurrence were identified in the longitudinal GLASS cohort. Assessment of GBM immunotherapy trial datasets revealed that TMEHigh patients receiving neoadjuvant anti-PD-1 had significantly increased overall survival (P = 0.04). Moreover, TMEHigh patients treated with adjuvant anti-PD-1 or oncolytic virus (PVSRIPO) showed a trend towards improved survival. CONCLUSIONS: We have established a novel TME-based classification system for application in intracranial malignancies. TME subtypes represent canonical 'termini a quo' (starting points) to support an improved precision immunotherapy treatment approach.

Mucinous and non-mucinous colorectal cancers show differential expression of chemotherapy metabolism and resistance genes.

Previous research has identified differences in mutation frequency in genes implicated in chemotherapy resistance between mucinous and non-mucinous colorectal cancers (CRC). We hypothesized that outcomes in mucinous and non-mucinous CRC may be influenced by expression of genes responsible for chemotherapy resistance. Gene expression data from primary tumor samples were extracted from The Cancer Genome Atlas PanCancer Atlas. The distribution of clinical, pathological, and gene expression variables was compared between 74 mucinous and 521 non-mucinous CRCs. Predictors of overall survival (OS) were assessed in a multivariate analysis. Kaplan-Meier curves were constructed to compare survival according to gene expression using the log rank test. The median expression of 5-FU-related genes TYMS, TYMP, and DYPD was significantly higher in mucinous CRC compared to non-mucinous CRC (p < 0.001, p = 0.003, p < 0.001, respectively). The median expression of oxaliplatin-related genes ATP7B and SRPK1 was significantly reduced in mucinous versus non-mucinous CRC (p = 0.004, p = 0.007, respectively). At multivariate analysis, age (odds ratio (OR) = 0.96, p < 0.001), node positive disease (OR = 0.49, p = 0.005), and metastatic disease (OR = 0.32, p < 0.001) remained significant negative predictors of OS, while high SRPK1 remained a significant positive predictor of OS (OR = 1.59, p = 0.037). Subgroup analysis of rectal cancers demonstrated high SRPK1 expression was associated with significantly longer OS compared to low SRPK1 expression (p = 0.011). This study highlights that the molecular differences in mucinous CRC and non-mucinous CRC extend to chemotherapy resistance gene expression. SRPK1 gene expression was associated with OS, with a prognostic role identified in rectal cancers.

New hints towards a precision medicine strategy for IDH wild-type glioblastoma.

Glioblastoma represents the most common primary malignancy of the central nervous system in adults and remains a largely incurable disease. The elucidation of disease subtypes based on mutational profiling, gene expression and DNA methylation has so far failed to translate into improved clinical outcomes. However, new knowledge emerging from the subtyping effort in the IDH-wild-type setting may provide directions for future precision therapies. Here, we review recent learnings in the field, and further consider how tumour microenvironment differences across subtypes may reveal novel contexts of vulnerability. We discuss recent treatment approaches and ongoing trials in the IDH-wild-type glioblastoma setting, and propose an integrated discovery stratagem incorporating multi-omics, single-cell technologies and computational approaches.

Patient-derived glioblastoma cells show significant heterogeneity in treatment responses to the inhibitor-of-apoptosis-protein antagonist birinapant.

BACKGROUND: Resistance to temozolomide (TMZ) greatly limits chemotherapeutic effectiveness in glioblastoma (GBM). Here we analysed the ability of the Inhibitor-of-apoptosis-protein (IAP) antagonist birinapant to enhance treatment responses to TMZ in both commercially available and patient-derived GBM cells. METHODS: Responses to TMZ and birinapant were analysed in a panel of commercial and patient-derived GBM cell lines using colorimetric viability assays, flow cytometry, morphological analysis and protein expression profiling of pro- and antiapoptotic proteins. Responses in vivo were analysed in an orthotopic xenograft GBM model. RESULTS: Single-agent treatment experiments categorised GBM cells into TMZ-sensitive cells, birinapant-sensitive cells, and cells that were insensitive to either treatment. Combination treatment allowed sensitisation to therapy in only a subset of resistant GBM cells. Cell death analysis identified three principal response patterns: Type A cells that readily activated caspase-8 and cell death in response to TMZ while addition of birinapant further sensitised the cells to TMZ-induced cell death; Type B cells that readily activated caspase-8 and cell death in response to birinapant but did not show further sensitisation with TMZ; and Type C cells that showed no significant cell death or moderately enhanced cell death in the combined treatment paradigm. Furthermore, in vivo, a Type C patient-derived cell line that was TMZ-insensitive in vitro and showed a strong sensitivity to TMZ and TMZ plus birinapant treatments. CONCLUSIONS: Our results demonstrate remarkable differences in responses of patient-derived GBM cells to birinapant single and combination treatments, and suggest that therapeutic responses in vivo may be greatly affected by the tumour microenvironment.

A retrospective cohort study evaluating pregnancy outcomes in women with MIDD.

AIMS: The most common pathogenic mitochondrial mutation associated with mitochondrial disease is m.3243A>G. Increased obstetric complications, such as spontaneous abortion, gestational diabetes (GDM), preterm delivery, and preeclampsia, have been reported in women carrying this mutation. We aimed to determine the fetal and maternal outcomes in pregnant women with mitochondrial disease. METHODS: We retrospectively studied the obstetric and perinatal outcomes in 88 pregnancies of 26 women with genetically confirmed mitochondrial disease (m.3243A>G in the MTTL1 gene (n = 25); m.12258C>A in the MT-TS2 gene (n = 1)). Outcomes included pregnancy related complications, mode of delivery, gestational age at delivery and birthweight. RESULTS: Mean heteroplasmy rate was 18%. The miscarriage rate was higher than background at 25%. 21 pregnancies (24%) were complicated by GDM; 9 pregnancies (13.6%) had a preterm delivery and 2 of them (3%) an extreme premature delivery < 32 weeks. One woman had preeclampsia and one had a postpartum hemorrhage. The caesarean section (CS) rate was 20%. For every unit increase in maternal heteroplasmy levels there was a 26% increased risk of undergoing an assisted operative vaginal delivery (OR 1.26, 95% CI 1.04-1.53, P = 0.002, Bonferroni corrected P = 0.005) and an 18% increased risk of undergoing a CS (OR 1.18, 95% CI 1.01-1.39, P = 0.01, Bonferroni corrected P = 0.03) compared to a spontaneous vaginal delivery. There was a statistical significant correlation between maternal and offspring heteroplasmy levels. Spearman correlation rho = 0.96, 95% CI 0.78-0.99, P = 0.0002. CONCLUSION: Women with mitochondrial disease appear to have more frequent obstetric complications including miscarriage and GDM. Pre-pregnancy diagnosis of m.3243A>G will enable the counseling of women and increase awareness of possible obstetric complications.

Investigating factors associated with adherence behaviour in patients with chronic myeloid leukemia: an observational patient-centered outcome study.

BACKGROUND: Optimal adherence to imatinib therapy is of paramount importance to maximise treatment effectiveness in patients with chronic myeloid leukaemia (CML). The main objective of this study was to investigate patient-reported personal factors associated with adherence behaviour. METHODS: Analysis was conducted on 413 CML patients receiving long-term therapy with imatinib. Adherence behaviour was measured with the Morisky Medication Adherence Scale and personal factors investigated included: quality of life, perceived social support, fatigue, symptom burden, psychological wellbeing and desire for additional information. Key socio-demographic and treatment-related factors were also taken into account. Univariate and multivariate logistic regression analyses were used to investigate factors associated with optimal adherence to therapy. RESULTS: In all, 53% of patients reported an optimal adherence behaviour. The final multivariate model retained the following variables as independent predictors of optimal adherence to therapy: desire for more information (ref. no), odds ratio (OR)=0.43 (95% confidence interval (CI), 0.29-0.66; P<0.001), social support (higher score representing greater support), OR=1.29 (95% CI, 1.11-1.49; P<0.001) and concomitant drug burden (ref. no), OR=1.82 (95% CI, 1.18-2.80; P=0.006). CONCLUSION: This study suggests that a higher level of social support, satisfaction with information received and concomitant drug burden are the main factors associated with greater adherence to long-term imatinib therapy.

Tibial tunnel widening associated with anterior cruciate ligament reconstruction using autogenous hamstrings: A comparison between antero-medial portal and transtibial techniques. / Valoración de la apertura del túnel tibial tras la reconstrucción del ligamento cruzado anterior empleando isquiotibiales autógenos: Estudio comparativo entre la técnica de portal anteromedial y la técnica transtibial convencional.

OBJECTIVE: Evaluate the enlargement effect of the tibial tunnel emergence of 2 different of anterior cruciate ligament reconstruction techniques: antero-medial portal (AMP) vs. transtibial (TT) technique. METHODS: A prospective, randomized controlled study was performed in 36 consecutive patients who underwent anterior cruciate ligament reconstruction with autologous hamstring tendon grafts employing the AMP and conventional TT techniques. Lateral and antero-posterior radiographs were obtained for each patient at 6 weeks and 12 months postoperatively. The sclerotic margins of the tibial tunnels were measured at the widest dimension of the tunnel as well as the diameter of the tibial emergence and were compared with the initially drilled tunnel size after correction for radiographic magnification. Statistical analysis was performed to compare the 2 groups by use of the independent-samples t test, with significance set at .05. RESULTS: The mean percentage increase in the diameter of tibial tunnel emergence at 6 weeks after surgery was 8.1%±2.9 for the PAM technique and 21.20%±11.87 for the TT technique on the anteroposterior x-ray view. However, the mean percentage increase in the diameter of the tibial tunnel emergence on the lateral view was 7.1%±4.72 for the medial portal technique and 17.64%±11.48 for the transtibial technique. This difference was statistically significant on both anteroposterior and lateral views. CONCLUSIONS: The diameter of the tibial tunnel emergence for hamstring autologous anterior cruciate ligament reconstructions was significantly lower for the medial portal technique when compared with the conventional TT technique.

Frequent microsatellite instability in post hepatitis B viral cirrhosis.

The molecular basis of cirrhosis, the most frequent underlying liver disease in hepatocellular carcinoma, remains unclear. We investigated microsatellite instability at six different loci on chromosomes 2p, 3p, 5q, 9p, 13q and 17p, in DNA from 38 cirrhotic livers of viral (n=28) and nonviral (n=10) origin. Sixty percent of the patients exhibited microsatellite alterations in at least one chromosome locus. A striking feature was the close association between genomic instability and cirrhosis linked to hepatitis B viral infection (P<0.01). This high instability may be a clue to the etiology of cancer induced by the hepatitis B virus.

Microsatellite instability in European hepatocellular carcinoma.

Genetic instability has been detected in many types of cancers but poorly investigated in hepatocellular carcinoma (HCC). We have studied the incidence of microsatellite instability (MI) at eight highly polymorphic microsatellite markers and the poly A tract BAT26 and tested for mutations at two sites of repetitive sequence (poly-A nucleotides 709-718 and GT repeat-nucleotides 1931-1936) in the Transforming Growth Factor beta (TGFbeta) type II receptor (RII) gene, in a group of 46 European HCCs and the surrounding nontumour tissue. This analysis showed that 63% of HCCs exhibit MI in at least one chromosome locus and 41% in two or more loci. No mutations of the TGFbetaRII gene were found in the MI positive tumours. No correlation was found with clinicopathological characteristics of the tumours such as cirrhosis, etiology, number of nodules, Edmondson's grade and vascular invasion. However, in patients who had a rearranged D16S402 microsatellite in their tumour, the recurrent disease and the number of nodules were significantly higher than in the others (P<0.005 and P<0.02, respectively). We propose to consider D16S402 rearrangement in HCC as a prognostic factor to identify patients presenting a higher risk of recurrence.

Crystal structure of the NADP(H)-dependent ketose reductase from Bemisia argentifolii at 2.3 A resolution.

Polyhydric alcohols are widely found in nature and can be accumulated to high concentrations as a protection against a variety of environmental stresses. It is only recently, however, that these molecules have been shown to be active in protection against heat stress, specifically in the use of sorbitol by the silverleaf whitefly, Bemisia argentifolii. We have determined the structure of the enzyme responsible for production of sorbitol in Bemisia argentifolii, NADP(H)-dependent ketose reductase (BaKR), to 2.3 A resolution. The structure was solved by multiwavelength anomalous diffraction (MAD) using the anomalous scattering from two zinc atoms bound in the structure, and was refined to an R factor of 21.9 % (R(free)=25.1 %). BaKR belongs to the medium-chain dehydrogenase family and its structure is the first for the sorbitol dehydrogenase branch of this family. The enzyme is tetrameric, with the monomer having a very similar fold to the alcohol dehydrogenases (ADHs). Although the structure determined is for the apo form, a phosphate ion in the active site marks the likely position for the adenyl phosphate of NADP(H). The catalytic zinc ion is tetrahedrally coordinated to Cys41, His66, Glu67 and a water molecule, in a modification of the zinc site usually found in ADHs. This modified zinc site seems likely to be a conserved feature of the sorbitol dehydrogenase sub-family. Comparisons with other members of the ADH family have also enabled us to model a ternary complex of the enzyme, and suggest how structural differences may influence coenzyme binding and substrate specificity in the reduction of fructose to sorbitol.

Purification and Properties of a Unique Nucleotide Pyrophosphatase/Phosphodiesterase I That Accumulates in Soybean Leaves in Response to Fruit Removal.

Several unique proteins accumulate in soybean (Glycine max) leaves when the developing fruits are removed. In the present study, elevated levels of nucleotide pyrophosphatase and phosphodiesterase I activities were present in leaves of defruited soybean plants. The soluble enzyme catalyzing these reactions was purified nearly 1000-fold, producing a preparation that contained a single 72-kD polypeptide. The molecular mass of the holoenzyme was approximately 560 kD, indicating that the native enzyme was likely octameric. The purified enzyme hydrolyzed nucleotide-sugars, nucleotide di- and triphosphates, thymidine monophosphate p-nitrophenol, and inorganic pyrophosphate but not nucleotide monophosphates, sugar mono- and bisphosphates, or NADH. The subunit and holoenzyme molecular masses and the preference for substrates distinguish the soybean leaf nucleotide pyrophosphatase/phosphodiesterase I from other plant nucleotide pyrophosphatase/phosphodiesterase I enzymes. Also, the N-terminal sequence of the soybean leaf enzyme exhibited no similarity to the mammalian nucleotide pyrophosphatase/phosphodiesterase I, soybean vegetative storage proteins, or other entries in the data bank. Thus, the soybean leaf nucleotide pyrophosphatase/phosphodiesterase I appears to be a heretofore undescribed protein that is physically and enzymatically distinct from nucleotide pyrophosphatase/phosphodiesterase I from other sources, as well as from other phosphohydrolytic enzymes that accumulate in soybean leaves in response to fruit removal.

Physical and Kinetic Evidence for an Association between Sucrose-Phosphate Synthase and Sucrose-Phosphate Phosphatase.

The possible formation of a multienzyme complex between sucrose (Suc)-phosphate synthase (SPS) and Suc-phosphate phosphatase (SPP) was examined by measuring the rates of Suc-6-phosphate (Suc-6-P) synthesis and hydrolysis in mixing experiments with partially purified enzymes from spinach (Spinacia oleracea) and rice (Oryza sativa) leaves. The addition of SPP to SPS stimulated the rate of Suc-6-P synthesis. SPS inhibited the hydrolysis of exogenous Suc-6-P by SPP when added in the absence of its substrate (i.e. UDP-glucose) but stimulated SPP activity when the SPS substrates were present and used to generate Suc-6-P directly in the reaction. Results from isotope-dilution experiments suggest that Suc-6-P was channeled between SPS and SPP. A portion of the SPS activity comigrated with SPP during native polyacrylamide gel electrophoresis, providing physical evidence for an enzyme-enzyme interaction. Taken together, these results strongly suggest that SPS and SPP associate to form a multienzyme complex.

The Two Forms of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Activase Differ in Sensitivity to Elevated Temperature.

Ribulose-1,5-bisphosphate carboxylase/oxygenase activase often consists of two polypeptides that arise from alternative splicing of pre-mRNA. In this study recombinant versions of the spinach (Spinacea oleracea L.) 45- and 41-kD forms of activase were analyzed for their response to temperature. The temperature optimum for ATP hydrolysis by the 45-kD form was 45[deg]C, approximately 13[deg]C higher than the 41-kD form. When the two forms were mixed, the temperature response of the hybrid enzyme was similar to the 45-kD form. In the absence of adenine nucleotide, preincubation of either activase form at temperatures above 25[deg}C inactivated ATPase activity. Adenosine 5[prime]-([gamma]-thio)triphosphate, but not ADP, significantly enhanced the thermostability of the 45-kD form but was much less effective for the 41-kD form. Intrinsic fluorescence showed that the adenosine 5[prime]-([gamma]-thio)triphosphate-induced subunit aggregation was lost at a much lower temperature for the 41-kD than for the 45-kD form. However, the two activase forms were equally susceptible to limited proteolysis after heat treatment. The results indicate that (a) the 45-kD form is more thermostable than, and confers increased thermal stability to, the 41-kD form, and (b) a loss of subunit interactions, rather than enzyme denaturation, appears to be the initial cause of temperature inactivation of activase.

Long-lasting complete remission in patients with hairy cell leukemia treated with 2-CdA: a 5-year survey.

Between January 1991 and January 1994, 40 patients with hairy-cell leukemia (HCL), 30 males and 10 females, with a median age of 54 years, were treated with a single course of 2-chlorodeoxyadenosine (2-CdA) at a dose of 0.1 mg/kg/day continuous infusion for 7 days. Thirteen patients were untreated and 27 had previously received alpha-interferon. Thirty out of 40 patients (75%) achieved complete remission (CR) and 10 (25%) partial remission (PR). The median follow-up duration for patients in CR has been 48 months (range 30-66). Five of the complete responders (17%) relapsed at 12, 24, 26, 30 and 36 months after treatment as documented by the increase of hairy cells (Hc) in the bone marrow and two of them, who were retreated with 2-CdA after showing an initial impairment of peripheral blood values, obtained a second CR. The remaining three relapsed patients were never retreated and still show normal peripheral counts after 30, 38 and 40 months. Twelve of the continuous complete responder patients are still in CR after more than 5 years. In contrast, 8 out of 10 partial responders progressed after 8-36 months and all of them were retreated with 2-CdA at a dose of 0.15 mg/kg/day for 5 days i.v. Four of them (50%) achieved a CR, three a better PR and one patient died 6 months after the second 2-CdA course because of infectious complications. Two additional patients, both in CR, died after 28 and 37 months because of a second neoplasm. Toxic side-effects consisted of febrile episodes recorded in 16 patients: in seven of them, fever lasted only 24-48 h after the end of treatment and was apparently not infection-related. In the remaining nine patients, showing in addition severe neutropenia (neutrophils less than 1.0 x 10(9)/l), fever was related to bacterial infection requiring systemic antibiotics in all of them and G-CSF in three cases. In conclusion, 2-CdA induces a very high proportion of complete and long-lasting remissions in patients with HCL. In a number of cases relapse at bone marrow level may not affect peripheral blood values for prolonged time. However, in those patients with initial pancytopenia a retreatment with 2-CdA is still effective in inducing a durable second CR.

Molecular basis for thermoprotection in Bemisia: structural differences between whitefly ketose reductase and other medium-chain dehydrogenases/reductases.

The silverleaf whitefly (Bemisia argentifolii, Bellows and Perring) accumulates sorbitol as a thermoprotectant in response to elevated temperature. Sorbitol synthesis in this insect is catalyzed by an unconventional ketose reductase (KR) that uses NADPH to reduce fructose. A cDNA encoding the NADPH-KR from adult B. argentifolii was cloned and sequenced to determine the primary structure of this enzyme. The cDNA encoded a protein of 352 amino acids with a calculated molecular mass of 38.2 kDa. The deduced amino acid sequence of the cDNA shared 60% identity with sheep NAD(+)-dependent sorbitol dehydrogenase (SDH). Residues in SDH involved in substrate binding were conserved in the whitefly NADPH-KR. An important structural difference between the whitefly NADPH-KR and NAD(+)-SDHs occurred in the nucleotide-binding site. The Asp residue that coordinates the adenosyl ribose hydroxyls in NAD(+)-dependent dehydrogenases (including NAD(+)-SDH), was replaced by an Ala in the whitefly NADPH-KR. The whitefly NADPH-KR also contained two neutral to Arg substitutions within four residues of the Asp to Ala substitution. Molecular modeling indicated that addition of the Arg residues and loss of the Asp decreased the electric potential of the adenosine ribose-binding pocket, creating an environment favorable for NADPH-binding. Because of the ability to use NADPH, the whitefly NADPH-KR synthesizes sorbitol under physiological conditions, unlike NAD(+)-SDHs, which function in sorbitol catabolism.

Adult Burkitt's lymphoma: clinical and prognostic evaluation of 20 patients.

Burkitt's lymphoma (BL), a rapidly growing lymphoma, is recognized by its aggressive course, brief median survival, and low rates of long-term survival for patients. Several polychemotherapeutic approaches are utilized. Twenty adult patients with BL identified according to the Kiel classification were analysed retrospectively. Therapeutic modifications depended upon the different times of the diagnosis. Eight patients received the LSA2-L2 regimen, 11 patients were treated with third generation polychemotherapeutic regimens for high-grade non-Hodgkin's lymphomas: F-MACHOP and MACOP-B, and 1 elderly patient was given the COP regimen. Of the 11 patients treated with cyclic conventional therapy (7 with F-MACHOP and 4 with MACOP-B), 8 achieved a complete response (CR). Of the 8 patients who were given the LSA2-L2 protocol, 4 obtained a CR. One elderly patient treated with the COP regimen obtained a partial response. Early stage of disease, low levels of LDH, and the absence of bone marrow involvement were characteristics of patients with good prognoses. Effective conventional third-generation polychemotherapy regimens (F-MACHOP and MACOP-B), normally used for high-grade non-Hodgkin's lymphomas, were equally effective for a large fraction of adults with BL. Furthermore, our study confirms the important role of LDH level, stage, and bone marrow involvement as prognostic factors in BL as well as the roles of tumor burden in the CR rate and relapse-free survival.

Primary Mediastinal B-cell lymphoma with sclerosis: clinical and therapeutic evaluation of 22 patients.

In the last decade, there have been several reports on what is now recognized as a new clinical and pathological entity termed primarily mediastinal B-cell lymphoma (PMBCL) with sclerosis. This lymphoma presents unique clinical characteristics with an aggressive outcome and, at present, the best approach seems to be a combination of chemotherapy and radiotherapy. Between June 1989 and September 1994, twenty-two previously untreated patients with PMBCL with sclerosis were treated with a combination of third-generation chemotherapy regimen (MACOP-B or F-MACHOP) and mediastinal irradiation. All the patients presented with bulky mediastinal involvement; the radiologic clinical stage with evaluation of tumor size included computed tomography and Gallium-67-citrate SPECT. Twenty-one patients (95%) achieved a complete response and only one was resistant to treatment. Regarding 67Ga SPECT, 6 patients, including the nonresponder, showed persistent abnormal 67Ga uptake after chemotherapy; however after the mediastinal radiotherapy, all the patients except for the nonresponder were 67Ga-negative. The overall survival was 87%, with a median follow-up of 24 months from the time of diagnosis. Two of the patients who achieved complete response relapsed 7 and 10 months after completion of treatment, respectively. The relapse-free survival rate was 89% at 62 months (median 20 months). In patients presenting with bulky mediastinal PMBCL with sclerosis combined modality treatment using third-generation chemotherapy regimens and radiotherapy induces a good remission rate with greater than 80% chance of surviving disease-free, at 2 years. A longer follow-up before definitive conclusions are drawn is still warranted.

Primary gastric lymphoma: a clinical and therapeutic evaluation of 82 patients.

Eighty-two patients with primary gastric (IE, II1E, and II2E) non-Hodgkin's lymphoma according to the Musshoff's staging system were treated with combined modality including surgery with/without radiotherapy between January 1985 and December 1991. According to the Updated Kiel classification 54 had high-grade histologic subtypes and 28 low-grade. The strategy throughout the study was to resect primary tumor: all patients underwent gastrectomy, 40 subtotal and 42 total gastrectomy. The resection permitted complete surgical staging utilizing three pathologic features: disease confined within or beyond the serosa, negative/positive regional lymph nodes, and negative/positive surgical margins. If there was no evidence of these pathologic factors, the patients who underwent surgery alone received no further radiotherapy. On the other hand, all patients who presented at least one of three pathologic factors were treated with adjuvant radiotherapy after the resection. All except 14 patients presented at least one of the pathologic features and 50 (61%) patients had involvement of the whole gastric wall. Radiotherapy included the gastric bed and para-aortic lymph nodes and, for the patients, who had positive regional lymph nodes in combination with the complete involvement of the gastric wall, the irradiation included the whole abdominal approach. The complete response rate was 97% and the 9-year disease-free survival was 93%. All but one of the 5 relapses occurred within 18 months stressing the need for more specific staging. Gastric resection with/without radiotherapy may still represent the primary therapeutic procedure in early stage gastric non-Hodgkin's lymphoma.

Is there any difference in PBPC mobilization between cyclophosphamide plus G-CSF and G-CSF alone in patients with non-Hodgkin's Lymphoma?

We attempted to analyze whether the use of high-dose cyclophosphamide (CTX 7g/m2, group A) plus hematopoietic growth factor (G-CSF) or G-CSF alone (10 microg/Kg, group B) as a mobilizing regimen, could result in harvesting different numbers of CD34+ cells, committed progenitors and CD34+ cells subsets. The number of CD34+ cells considered as the target for each high-dose chemotherapy was > or = 2 x 10(6) /Kg/bw. Fifteen leukaphereses procedures were necessary in group A, while 16 procedures were performed in group B. We did not observe any difference between the two groups in terms of CD34+ cells/microl in the peripheral blood (117 vs 78; p = NS), whereas in the aphereses product we found a significant difference between the two groups of patients in terms of CD34+ cells (6.41 vs 2.89 x 10(6) /Kg/bw; p = .009), CFU-GM (82.5 vs 52.3 x 10(4) /Kg/bw; p = .04). Interestingly, we noted a different distribution of CD34+/33- cells between the 2 groups (mean value 39% vs 65%; p < .05), whereas we did not find any differences regarding CD34+/38-, CD34+/Thy1+, CD34+/HLADR-. The higher number of CFU-GM/Kg/bw collected in the former group did not translate into a superior plating efficiency (27.75 vs 30.29). Furthermore, we observed a strong correlation between CD34+ cells/microl in the peripheral blood and the total number of CD34+ cells in the leukaphereses product (r = 0.97), whereas this correlation was not found in group B (r = 0.15). In both groups of patients the number of CD34+ cells collected correlated well with CFU-GM (r = 0.93; r = 0.94), but definitely we did not observe any correlation between CD34+ cells/microl and CFU-GM in patients mobilized with G-CSF alone and this did not allow us to predict the harvest accurately. Finally, we evaluated the engraftment kinetics and we did not observe any statistically significant difference between the two groups of patients.

Molecular analysis of lymphoid malignancies.

Although lymphoid malignancies have been widely studied at the molecular level, no group has reported on the simultaneous investigation of t(14;18) chromosomal translocation, B-cell clonality and bcl2 gene expression. We have performed PCR analysis of t(14;18) translocation and B-cell clonality as well as semi-quantitation of bcl2 expression by Western blotting on a group of 41 patients treated at our institution for lymphoid malignancies. The t(14;18) translocation was observed in 10 out of 40 cases (25%) with a prevalence in the subgroup of centrofollicular lymphoma (9 out of 19, or 47%, which includes one patient in complete clinical remission). bcl2 was overexpressed in 84% of the patients (21/25) and B monoclonality was observed in 21 out of 37 B-cell neoplasia patients (57%) with or without a t(14;18) translocation. In 4 patients, bcl2 overexpression, which has been implicated in the sensitivity to a variety of cytotoxic drugs, was the only abnormality detected. Studies are currently underway to determine whether semi-quantitation of bcl2 expression provides improved prediction of a patient's response to chemotherapy.