Genomic characterization of thymic epithelial tumors in a real-world dataset.

BACKGROUND: Thymic epithelial tumors (TETs) are rare neoplasms arising in the mediastinum, including thymic carcinomas and thymomas. Due to their rarity, little is known about the genomic profiles of TETs. Herein, we investigated the genomic characteristics of TETs evaluated in a large comprehensive genomic profiling database in a real-world setting. METHODS: We included data from two different cohorts: Foundation Medicine Inc. (FMI) in the United States and the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) in Japan. Samples profiled were examined for all classes of alterations in 253 genes targeted across all assays. Tumor mutational burden (TMB) and microsatellite instability (MSI) were also evaluated. RESULTS: A total of 794 patients were collected in our study, including 722 cases from FMI and 72 cases from C-CAT. In the FMI data, CDKN2A (39.9%), TP53 (30.2%) and CDKN2B (24.6%) were frequently altered in thymic carcinoma, versus TP53 (7.8%), DNMT3A (6.8%), and CDKN2A (5.8%) in thymoma. TMB-high (≥10 mutations/Mb) and MSI were present in 7.0% and 2.3% of thymic carcinomas, and 1.6% and 0.3% of thymomas, respectively. Within C-CAT data, CDKN2A (38.5%), TP53 (36.5%) and CDKN2B (30.8%) were also frequently altered in thymic carcinoma, while alterations of TSC1, SETD2 and LTK (20.0% each) were found in thymoma. CONCLUSIONS: To the best of our knowledge, this is the largest cohort in which genomic alterations, TMB and MSI status of TETs were investigated. Potential targets for treatment previously unbeknownst in TETs are identified in this study, entailing newfound opportunities to advance therapeutic development.

First-line nivolumab plus ipilimumab with two cycles of chemotherapy versus chemotherapy alone (four cycles) in advanced non-small-cell lung cancer: CheckMate 9LA 2-year update.

BACKGROUND: To further characterize survival benefit with first-line nivolumab plus ipilimumab with two cycles of chemotherapy versus chemotherapy alone, we report updated data from the phase III CheckMate 9LA trial with a 2-year minimum follow-up. PATIENTS AND METHODS: Adult patients were treatment naïve, with stage IV/recurrent non-small-cell lung cancer, no known sensitizing EGFR/ALK alterations, and an Eastern Cooperative Oncology Group performance status ≤1. Patients were randomized 1 : 1 to nivolumab 360 mg every 3 weeks plus ipilimumab 1 mg/kg every 6 weeks with two cycles of chemotherapy, or four cycles of chemotherapy. Updated efficacy and safety outcomes are reported, along with progression-free survival (PFS) after next line of treatment (PFS2), treatment-related adverse events (TRAEs) by treatment cycle, and efficacy outcomes in patients who discontinued all treatment components in the experimental arm due to TRAEs. RESULTS: With a median follow-up of 30.7 months, nivolumab plus ipilimumab with chemotherapy continued to prolong overall survival (OS) versus chemotherapy. Median OS was 15.8 versus 11.0 months [hazard ratio 0.72 (95% confidence interval 0.61-0.86)]; 2-year OS rate was 38% versus 26%. Two-year PFS rate was 20% versus 8%. ORR was 38% versus 25%, respectively; 34% versus 12% of all responses were ongoing at 2 years. Median PFS2 was 13.9 versus 8.7 months. Improved efficacy outcomes in the experimental versus control arm were observed across most subgroups, including by programmed death-ligand 1 and histology. No new safety signals were observed; onset of grade 3/4 TRAEs was mostly observed during the first two treatment cycles in the experimental arm. In patients who discontinued all components of nivolumab plus ipilimumab with chemotherapy treatment due to TRAEs (n = 61) median OS was 27.5 months; 56% of responders had an ongoing response ≥1 year after discontinuation. CONCLUSIONS: With a 2-year minimum follow-up, nivolumab plus ipilimumab with two cycles of chemotherapy provided durable efficacy benefits over chemotherapy with a manageable safety profile and remains an efficacious first-line treatment of advanced non-small-cell lung cancer.

Targeting KRAS in non-small-cell lung cancer: recent progress and new approaches.

Rat sarcoma (RAS) is the most frequently mutated oncogene in human cancer, with Kirsten rat sarcoma (KRAS) being the most commonly mutated RAS isoform. Overall, KRAS accounts for 85% of RAS mutations observed in human cancers and is present in 35% of lung adenocarcinomas (LUADs). While the use of targeted therapies and immune checkpoint inhibitors (CPIs) has drastically changed the treatment landscape of advanced non-small-cell lung cancer (NSCLC) in recent years, historic attempts to target KRAS (both direct and indirect approaches) have had little success, and no KRAS-specific targeted therapies have been approved to date for patients in this molecular subset of NSCLC. With the discovery by Ostrem, Shokat, and colleagues of the switch II pocket on the surface of the active and inactive forms of KRAS, we now have an improved understanding of the complex interactions involved in the RAS family of signaling proteins which has led to the development of a number of promising direct KRASG12C inhibitors, such as sotorasib and adagrasib. In previously treated patients with KRASG12C-mutant NSCLC, clinical activity has been shown for both sotorasib and adagrasib monotherapy; these data suggest promising new treatment options are on the horizon. With the stage now set for a new era in the treatment of KRASG12C-mutated NSCLC, many questions remain to be answered in order to further elucidate the mechanisms of resistance, how best to use combination strategies, and if KRASG12C inhibitors will have suitable activity in earlier lines of therapy for patients with advanced/metastatic NSCLC.

Newly diagnosed patients with advanced non-small cell lung cancer: A clinical description of those with moderate to severe depressive symptoms.

OBJECTIVES: The aims of this observational study were to 1) accrue newly diagnosed patients with advanced-stage non-small cell lung cancer (NSCLC) awaiting the start of first-line treatment and identify those with moderate to severe depressive symptoms and, 2) provide a clinical description of the multiple, co-occurring psychological and behavioral difficulties and physical symptoms that potentially exacerbate and maintain depressive symptoms. MATERIALS AND METHODS: Patients with stage IV NSCLC (N = 186) were enrolled in an observational study (ClinicalTrials.gov Identifier: NCT03199651) and completed the American Society of Clinical Oncology-recommended screening measure for depression (Patient Health Questionnaire-9 [PHQ-9]). Individuals with none/mild (n = 119; 64 %), moderate (n = 52; 28 %), and severe (n = 15; 8 %) depressive symptoms were identified. Patients also completed measures of hopelessness, generalized anxiety disorder (GAD) symptoms, stress, illness perceptions, functional status, and symptoms. RESULTS: Patients with severe depressive symptoms reported concomitant feelings of hopelessness (elevating risk for suicidal behavior), anxiety symptoms suggestive of GAD, and traumatic, cancer-specific stress. They perceived lung cancer as consequential for their lives and not controllable with treatment. Pain and multiple severe symptoms were present along with substantial functional impairment. Patients with moderate depressive symptoms had generally lower levels of disturbance, though still substantial. The most salient differences were low GAD symptom severity and fewer functional impairments for those with moderate symptoms. CONCLUSIONS: Depressive symptoms of moderate to severe levels co-occur in a matrix of clinical levels of anxiety symptoms, traumatic stress, impaired functional status, and pain and other physical symptoms. All of the latter factors have been shown, individually and collectively, to contribute to the maintenance or exacerbation of depressive symptoms. As life-extending targeted and immunotherapy use expands, prompt identification of patients with moderate to severe depressive symptoms, referral for evaluation, and psychological/behavioral treatment are key to maximizing treatment outcomes and quality of life for individuals with advanced NSCLC.

LKB1 deficiency enhances sensitivity to energetic stress induced by erlotinib treatment in non-small-cell lung cancer (NSCLC) cells.

The tumor suppressor serine/threonine kinase 11 (STK11 or LKB1) is mutated in 20-30% of patients with non-small-cell lung cancer (NSCLC). Loss of LKB1-adenosine monophosphate-activated protein kinase (AMPK) signaling confers sensitivity to metabolic inhibition or stress-induced mitochondrial insults. We tested the hypothesis that loss of LKB1 sensitizes NSCLC cells to energetic stress induced by treatment with erlotinib. LKB1-deficient cells exhibited enhanced sensitivity to erlotinib in vitro and in vivo that was associated with alterations in energy metabolism and mitochondrial dysfunction. Loss of LKB1 expression altered the cellular response to erlotinib treatment, resulting in impaired ATP homeostasis and an increase in reactive oxygen species. Furthermore, erlotinib selectively blocked mammalian target of rapamycin signaling, inhibited cell growth and activated apoptosis in LKB1-deficient cells. Erlotinib treatment also induced AMPK activation despite loss of LKB1 expression, which was partially reduced by the application of a calcium/calmodulin-dependent protein kinase kinase 2 inhibitor (STO-609) or calcium chelator (BAPTA-AM). These findings may have significant implications for the design of novel NSCLC treatments that target dysregulated metabolic and signaling pathways in LKB1-deficient tumors.

Notch3 cooperates with the EGFR pathway to modulate apoptosis through the induction of bim.

Notch signaling is a highly conserved pathway important for normal embryonic development and cancer. We previously demonstrated a role for Notch3 in lung cancer pathogenesis. Notch3 inhibition resulted in tumor apoptosis and growth suppression. In vitro, these effects were enhanced when the epidermal growth factor receptor (EGFR) pathway was also inhibited, suggesting significant cross-talk between the two pathways. How Notch3 and epidermal growth factor receptor-mitogen-activated protein kinase (EGFR-MAPK) pathways cooperate in modulating apoptosis is not yet known. In this study, we provide evidence that Notch3 regulates Bim, a BH-3-only protein, via MAPK signaling. Furthermore, loss of Bim expression prevents tumor apoptosis induced by Notch3 inhibition. Using gamma-secretase inhibitor and erlotinib in a xenograft model, Bim induction and tumor inhibition were observed to be enhanced compared with either agent alone, consistent with our previous observation of significant synergism between Notch and EGFR-ras-MAPK signaling. Thus, our data support the hypothesis that Notch3 not only has a crucial role in lung cancer through regulating apoptosis, but also cooperates with the EGFR-MAPK pathway in modulating Bim.

Restoration of TGF-beta signalling reduces tumorigenicity in human lung cancer cells.

Members of the transforming growth factor-beta (TGF-beta) family regulate a wide range of biological processes including cell proliferation, migration, differentiation, apoptosis, and extracellular matrix deposition. Resistance to TGF-beta-mediated tumour suppressor function in human lung cancer may occur through the loss of type II receptor (TbetaRII) expression. In this study, we investigated the expression pattern of TbetaRII in human lung cancer tissues by RT-PCR and Western blot analyses. We observed downregulation of TbetaRII in 30 out of 46 NSCLC samples (65%) by semiquantitative RT-PCR. Western blot analyses with tumour lysates showed reduced expression of TbetaRII in 77% cases. We also determined the effect of TbetaRII expression in lung adenocarcinoma cell line (VMRC-LCD) that is not responsive to TGF-beta due to lack of TbetaRII expression. Stable expression of TbetaRII in these cells restored TGF-beta-mediated effects including Smad2/3 and Smad4 complex formation, TGF-beta-responsive reporter gene activation, inhibition of cell proliferation and increased apoptosis. Clones expressing TbetaRII showed reduced colony formation in soft-agarose assay and significantly reduced tumorigenicity in athymic nude mice. Therefore, these results suggest that reestablishment of TGF-beta signalling in TbetaRII null cells by stable expression of TbetaRII can reverse malignant behaviour of cells and loss of TbetaRII expression may be involved in lung tumour progression.

Cloned fusion product from a rare t(15;19)(q13.2;p13.1) inhibit S phase in vitro.

BACKGROUND: Somatically acquired chromosomal translocation is a common mechanism of oncogene activation in many haematopoietic tumours and sarcomas. However, very few recurrent chromosomal translocations have been reported in more common epithelial tumours such as lung carcinomas. METHODS: We established a cell line HCC2429 from an aggressive, metastatic lung cancer arising in a young, non-smoking woman, demonstrating a t(15;19)(q13.2;p13.1). The breakpoints on chromosomes 15 and 19 were cloned using long distance inverse PCR and we determined by RT-PCR that the translocation results in a novel fusion transcript in which the 3' end Brd4 on chromosome 19p is fused to the 5' end of NUT on chromosome 15q. RESULTS: In total, 128 lung cancer tissues were screened using fluorescent in situ hybridisation, but none of the tumours screened demonstrated t(15;19), suggesting that this translocation is not commonly found in lung cancer. Consistent with previous literature, ectopic expression of wild type Brd4 was shown to inhibit G(1) to S progression. However, we also found that the Brd4-NUT fusion augments the inhibition of progression to S phase compared with wild type Brd4. CONCLUSION: Alteration in cell cycle kinetics is important in tumorigenesis, although the exact role of Brd4-NUT fusion protein in the pathogenesis of lung cancers remains unclear and need to be further elucidated.

Insulin-like growth factor I receptor blockade enhances chemotherapy and radiation responses and inhibits tumour growth in human gastric cancer xenografts.

BACKGROUND AND AIMS: Insulin-like growth factor (IGF) I receptor (IGF-Ir) signalling is required for carcinogenicity and proliferation of many tumours but this pathway has not been studied in detail in gastric cancer. We have previously shown successful therapy for colorectal, pancreatic, and lung cancer using recombinant adenoviruses expressing dominant negative (dn) IGF-Ir. In this study, we sought to better dissect the role of IGF-Ir on progression of gastric cancer and determine whether IGF-Ir targeted adenoviruses represent potentially effective therapeutics for human gastric cancer. METHODS: We assessed the effect of IGF-Ir ligands on proliferation and survival in gastric cancer cells in culture. Then, recombinant adenoviruses expressing truncated IGF-Ir (482 and 950 amino acids long, IGF-Ir/dn) that function as dn inhibitors were studied in the treatment of human gastric cancer xenografts. We characterised the effects of IGF-Ir/dn on signalling blockade, growth, apoptosis induction, and in vivo therapeutic efficacy. RESULTS: IGF-Ir signalling promoted tumour growth and survival in gastric cancer. IGF-Ir/dn expression suppressed tumorigenicity both in vitro and in vivo and upregulated stressor induced apoptosis. IGF-Ir/dn blocked Akt-1 activation induced by IGF-I, IGF-II, and des(1-3)IGF-I, but not by insulin. IGF-Ir/dn expression increased radiation and chemotherapy induced apoptosis and the combination of IGF-Ir/dn and chemotherapy was very effective against tumours in mice. In an intraperitoneal model, IGF-Ir/dn therapy also suppressed peritoneal dissemination. CONCLUSIONS: IGF-Ir is involved in the regulation of survival and cell growth in human gastric cancer and may be a good molecular therapeutic target. Adenovirus-IGF-Ir/dn may thus have therapeutic use in gastric cancer.

Nuclear survivin as a biomarker for non-small-cell lung cancer.

Survivin inhibits apoptosis and promotes mitosis. We determined whether nuclear or cytoplasmic localisation of survivin predicts survival of 48 patients with resected non-small-cell lung cancer (NSCLC). Patients with nuclear staining of survivin had significantly worse survival (relative risk: 3.9, P=0.02). Therefore, survivin may be a biomarker for NSCLC.

VEGF as a mediator of tumor-associated immunodeficiency.

Decreased immune function in cancer patients is well-characterized (1), and tumor cells have developed a variety of mechanisms to avoid anti-tumor immune responses (2-8). One mechanism for inhibition of immune cell function by tumors is the production of soluble factors, such as IL- 10, TNF, TGF-beta, and Vascular Endothelial Growth Factor (VEGF). The effects of these factors appear to be twofold: To inhibit effector function and to impair the development of immune cells by acting on earlier stages of immunopoiesis. Immune suppression by tumors is accomplished by a variety of cellular and molecular mechanisms, and virtually all branches of the immune system can be affected. VEGF and its receptors have profound effects on the early development and differentiation of both vascular endothelial and hematopoetic progenitors (9). It induces proliferation of mature endothelial cells and is an important component in the formation of tumor neovasculature (10). VEGF is abundantly expressed by a large percentage of solid tumors and this over-expression is closely associated with a poor prognosis (11,12). Some of the earliest hematopoetic progenitors express receptors for VEGF (13), and we have demonstrated that VEGF causes a defect in the functional maturation of dendritic cells (DC) from progenitors. This developmental defect is associated with impaired activation of NF-kappaB (14-17). This review describes research demonstrating that VEGF is not only important for tumor vascularization, but is also a key factor produced by solid tumors to inhibit recognition and destruction of tumor cells by the immune system.

Expression of angiomodulin (tumor-derived adhesion factor/mac25) in invading tumor cells correlates with poor prognosis in human colorectal cancer.

Angiomodulin (tumor-derived adhesion factor/mac25/insulin-like growth factor binding protein-7), a cell-adhesive glycoprotein, is secreted by cancer cells and vascular endothelial cells. It may be involved in angiogenesis and modulation of the vascular functions necessary for tumor development. Although angiomodulin is expressed in colon cancer, there is limited information on it concerning cancer progression. In the present immunohistochemical study, we examined expression of angiomodulin in human colorectal cancer and its relationship with prognosis. A group of 89 surgically resected colorectal cancers was investigated immunohistochemically. In 37 cases (41.6%), angiomodulin was expressed in invading cancer cells. Early recurrence within 12 months after surgery was higher in patients with angiomodulin-expressing cancer than in those without (p < 0.05). The Kaplan-Meier life table revealed that patients with angiomodulin-positive tumor cells had a shorter survival time than those with negative cells (p < 0.01). The prognosis of patients with Dukes' C and angiomodulin-positive cells was apparently worse than that of patients with Dukes' D and angiomodulin-negative cells. Multivariate analysis with logistic regression indicated that only angiomodulin expression in cancer cells, lymph node metastasis and age remained significant prognostic variables for survival (p < 0.05). Angiomodulin showed correlations with poor prognosis, indicating that it may be a useful prognostic marker in patients with colorectal cancer.

Regulation of mast cell survival by IgE.

Mast cells play critical roles in hypersensitivity and in defense against certain parasites. We provide evidence that mouse mast cell survival and growth are promoted by monomeric IgE binding to its high-affinity receptor, Fc epsilon RI. Monomeric IgE does not promote DNA synthesis but suppresses the apoptosis induced by growth factor deprivation. This antiapoptotic effect occurs in parallel with IgE-induced increases in Fc epsilon RI surface expression but requires the continuous presence of IgE. This process does not involve the FasL/Fas death pathway or several Bcl-2 family proteins and induces a distinctly different signal than Fc epsilon RI cross-linking. The ability of IgE to enhance mast cell survival and Fc epsilon RI expression may contribute to amplified allergic reactions.

Phase I study of paclitaxel given by seven-week continuous infusion concurrent with radiation therapy for locally advanced squamous cell carcinoma of the head and neck.

PURPOSE: Paclitaxel is one of the most active agents for squamous cell carcinoma of the head and neck (SCCHN) and an in vitro radiosensitizer. The dose-response relationship for paclitaxel may depend more on exposure duration than on peak concentration. This National Cancer Institute-sponsored phase I trial was designed to determine the feasibility of combining continuous-infusion (CI) paclitaxel with concurrent radiation therapy (RT). PATIENTS AND METHODS: Patients with previously untreated stage IVA/B SCCHN were eligible. Primary end points were determination of the maximum-tolerated dose, dose-limiting toxicity, and pharmacokinetics for paclitaxel given by CI (24 hours a day, 7 days a week for 7 weeks) during RT (70 Gy/7 weeks). RESULTS: Twenty-seven patients were enrolled and assessable for toxicity. Nineteen of the patients who completed > or = 70 Gy were assessable for response. Grade 3 skin and mucosal acute reactions occurred at 10.5 mg/m(2)/d, but uninterrupted treatment was possible in five of six patients. At 17 mg/m(2)/d, skin toxicity required a 2-week treatment break for all three patients. The mean paclitaxel serum concentration at dose levels > or = 6.5 mg/m(2)/d exceeded that reported to achieve in vitro radiosensitization. Initial locoregional control was achieved in 14 (58%) of 24 of patients treated to 70 Gy, and control persisted in nine (38%). CONCLUSION: CI paclitaxel with concurrent RT is a feasible and tolerable regimen for patients with advanced SCCHN and good performance status. Preliminary response and survival data are encouraging and suggest that further study is indicated. The recommended phase II dose of paclitaxel by CI is 10.5 mg/m(2)/d with RT for SCCHN.

Vascular endothelial growth factor effects on nuclear factor-kappaB activation in hematopoietic progenitor cells.

Vascular endothelial growth factor (VEGF) inhibits of the activation of transcription factor nuclear factor-kappaB (NF-kappaB) in hematopoietic progenitor cells (HPCs), and this is associated with alterations in the development of multiple lineages of hematopoietic cells and defective immune induction in tumor-bearing animals. Antibodies to VEGF have been shown to abrogate this effect. The mechanism by which VEGF antagonizes the induction of NF-kappaB was investigated in this study. Using supershift electrophoretic mobility shift analysis, we found that although tumor necrosis factor alpha (TNF-alpha) induced the nuclear translocation and DNA binding of p65-containing complexes, VEGF alone induced nuclear translocation and DNA binding of the complexes containing RelB. These results were confirmed by immunofluorescence confocal microscopy. VEGF effectively blocked TNF-alpha-induced NF-kappaB activation in HPCs from RelB-/- mice, however, similar to the effect observed in HPCs obtained from RelB+/- and RelB+/+ mice. This suggests that RelB is not required for VEGF to inhibit NF-kappaB activation. However, although TNF-alpha induced rapid activation of IkappaB kinase (IKK) as expected, this activity was substantially reduced in the presence of VEGF. This decreased IKK activation correlated with the inhibition of IkappaB alpha phosphorylation and degradation of IkappaB alpha and IkappaB epsilon in HPCs. VEGF alone, however, did not have any effect on phosphorylation of IkappaB alpha or degradation of IkappaB alpha and other inhibitory molecules IkappaB beta, IkappaB epsilon, or Bcl-3. SU5416, a potent inhibitor of the VEGF receptor I (VEGFR1) and VEGFR2 receptor tyrosine kinases, did not abolish the inhibitory effect of VEGF, indicating that the VEGF effect is mediated by a mechanism unrelated to VEGFR1 or VEGFR2 tyrosine kinase activity. Thus, VEGF appears to inhibit TNF-alpha-induced NF-kappaB activation by VEGFR kinase-independent inhibition of IKK. Therapeutic strategies aimed at overcoming VEGF-mediated defects in immune induction in tumor-bearing hosts will need to target this kinase-independent pathway.

Biological considerations in lung cancer.

Our understanding of lung cancer biology has rapidly expanded in recent years. Lung cancer, unlike most human cancers, can be traced to an environmental risk factor in the majority of cases, and this fact is reflected in the vast number of genetic alterations discovered in lung tumors whose pathogenesis is believed to be mediated by carcinogen exposure. The discovery of these alterations has led to a greater understanding of tumor development. The dramatic progress in the understanding of the genetic and molecular basis of oncogenesis and the induction of immunity has led to a rejuvenation of efforts to apply this new knowledge to this common and refractory disease. Further, the resurgent interest in cancer immunology and tumor-host interactions holds promise for the development of new approaches to treatment based on harvesting the immune systems ability to recognize these alterations. Hopefully, this understanding will lead to novel approaches with real and convincing clinical efficacy once some of these strategies are tested in carefully performed randomized clinical trials with appropriate power to detect meaningful differences.

Dendritic cells transduced with full-length wild-type p53 generate antitumor cytotoxic T lymphocytes from peripheral blood of cancer patients.

Accumulation of wild-type or mutant p53 protein occurs in approximately 50% of human malignancies. This overexpression may generate antigenic epitopes recognized by CTLs. Because normal cells have undetectable levels of p53, these CTLs are likely to be tumor specific. Here, for the first time, we test the hypothesis that full-length wild-type p53 protein can be used for generation of an immune response against tumor cells with p53 overexpression. T cells obtained from nine HLA-A2-positive cancer patients and three HLA-A2-positive healthy individuals were stimulated twice with dendritic cells (DCs) transduced with an adenovirus wild-type p53 (Ad-p53) construct. Significant cytotoxicity was detected against HLA-A2-positive tumor cells with accumulation of mutant or wild-type p53 but not against HLA-A2-positive tumor cells with normal (undetectable) levels of p53 or against HLA-A2-negative tumor cells. This response was specific and mediated by CD8+ CTLs. These CTLs recognized HLA-A2-positive tumor cells expressing normal levels of p53 protein after their transduction with Ad-p53 but not with control adenovirus. Stimulation of T cells with Ad-p53-transduced DCs resulted in generation of CTLs specific for p53-derived peptide. These data demonstrate that DCs transduced with the wild-type p53 gene were able to induce a specific antitumor immune response. This offers a new promising approach to immunotherapy of cancer.

Weekly irinotecan and cisplatin in advanced non-small cell lung cancer: a multicenter phase II study.

The combination of weekly irinotecan (CPT-11) and monthly cisplatin has shown promising activity in advanced non-small cell lung cancer (NSCLC) in previous Phase I and II studies. However, same-day administration of these agents may better exploit their therapeutic synergy and minimize toxicities. This multicenter Phase II study was undertaken to evaluate the efficacy and safety of a combination of weekly CPT-11 and weekly cisplatin in patients with advanced NSCLC. Patients with chemotherapy-naive stage IIIB or IV NSCLC were treated with repeated cycles of therapy comprising weekly treatment with both cisplatin and CPT-11 for 4 weeks, followed by a 2-week rest. The starting doses of CPT-11 and cisplatin were 65 and 30 mg/m2, respectively. Treatment was continued until the occurrence of disease progression, unacceptable toxicity, or a maximum of six cycles. Fifty patients were enrolled. The median age was 59 years (range, 44-79 years). Eastern Cooperative Oncology Group performance status was 0 in 22 patients, 1 in 19 patients, and 2 in 9 patients. Seven and 43 patients had stages IIIB and IV disease, respectively. Five patients had brain metastasis. Patients received a median of three 6-week cycles (range, 1-6). The objective response rate was 36% (18 of 50; 95% confidence interval, 24-54%) and included 18 partial responses. Median time to tumor progression was 6.9 months (range, 0.6-15.2). The median survival was 11.6 months (range, 0.16-21.9 months), and the 1-year survival rate was 46%. Grade 3/4 nonhematological toxicities included vomiting (12%) and diarrhea (26%). Grade 3/4 hematological toxicities included anemia (14%), neutropenia (26%), and thrombocytopenia (14%). Relative dose intensities for CPT-11 and cisplatin were 89 and 62%, respectively. Weekly combined administration of CPT-11 and cisplatin achieved a promising overall response rate, median time to tumor progression, and median survival in patients with stage IIIB/IV NSCLC. The regimen was well tolerated, and the planned dose intensity was well maintained. Further evaluation of this combination in NSCLC is warranted.

Increased production of immature myeloid cells in cancer patients: a mechanism of immunosuppression in cancer.

Defective dendritic cell (DC) function caused by abnormal differentiation of these cells is an important mechanism of tumor escape from immune system control. Previously, we have demonstrated that the number and function of DC were dramatically reduced in cancer patients. This effect was closely associated with accumulation of immature cells (ImC) in peripheral blood. In this study, we investigated the nature and functional role of those ImC. Using flow cytometry, electron microscopy, colony formation assays, and cell differentiation in the presence of different cell growth factors, we have determined that the population of ImC is composed of a small percentage (<2%) of hemopoietic progenitor cells, with all other cells being represented by MHC class I-positive myeloid cells. About one-third of ImC were immature macrophages and DC, and the remaining cells were immature myeloid cells at earlier stages of differentiation. These cells were differentiated into mature DC in the presence of 1 microM all-trans-retinoic acid. Removal of ImC from DC fractions completely restored the ability of the DC to stimulate allogeneic T cells. In two different experimental systems ImC inhibited Ag-specific T cell responses. Thus, immature myeloid cells generated in large numbers in cancer patients are able to directly inhibit Ag-specific T cell responses. This may represent a new mechanism of immune suppression in cancer and may suggest a new approach to cancer treatment.