Hyperactive Natural Killer cells in Rag2 knockout mice inhibit the development of acute myeloid leukemia

Immunotherapy has attracted considerable attention as a therapeutic strategy for cancers including acute myeloid leukemia (AML). In this study, we found that the development of several aggressive subtypes of AML is slower in Rag2-/- mice despite the lack of B and T lymphocytes, even compared to the immunologically normal C57BL/6 mice. Furthermore, an orally active p53-activating drug shows stronger antileukemia effect on AML in Rag2-/- mice than C57BL/6 mice. Intriguingly, Natural Killer (NK) cells in Rag2-/- mice are increased in number, highly express activation markers, and show increased cytotoxicity to leukemia cells in a coculture assay. B2m depletion that triggers missing-self recognition of NK cells impairs the growth of AML cells in vivo. In contrast, NK cell depletion accelerates AML progression in Rag2-/- mice. Interestingly, immunogenicity of AML keeps changing during tumor evolution, showing a trend that the aggressive AMLs generate through serial transplantations are susceptible to NK cell-mediated tumor suppression in Rag2-/- mice. Thus, we show the critical role of NK cells in suppressing the development of certain subtypes of AML using Rag2-/- mice, which lack functional lymphocytes but have hyperactive NK cells.

Association of CD4-positive cell infiltration with response to vedolizumab in patients with ulcerative colitis

Not all patients with ulcerative colitis (UC) respond initially to treatment with biologic agents, and predicting their efficacy prior to treatment is difficult. Vedolizumab, a humanized monoclonal antibody against alpha 4 beta 7 (α4β7) integrin, suppresses immune cell migration by blocking the interaction between α4β7 integrin and mucosal addressin cell adhesion molecule 1. Reports about histological features that predict vedolizumab efficacy are scarce. So, we examined the association between histological features and vedolizumab efficacy. This was a multicenter, retrospective study of patients with UC treated with vedolizumab. Biopsy specimens taken from the colonic mucosa prior to vedolizumab induction were used, and the areas positively stained for CD4, CD68, and CD45 were calculated. Clinical and histological features were compared between those with and without remission at week 22, and the factors associated with clinical outcomes were identified. We enrolled 42 patients. Patients with a high CD4+ infiltration showed a better response to vedolizumab [odds ratio (OR) = 1.44, P = 0.014]. The concomitant use of corticosteroids and high Mayo scores had a negative association with the vedolizumab response (OR = 0.11, P = 0.008 and OR = 0.50, P = 0.009, respectively). Histological evaluation for CD4+ cell infiltration may be helpful in selecting patients who can benefit from vedolizumab.

Reduced DEFA5 Expression and STAT3 Activation Underlie the Submucosal Invasion of Early Gastric Cancers

INTRODUCTION

Submucosal invasion is a core hallmark of early gastric cancer (EGC) with poor prognosis. However, the molecular mechanism of the progression from intramucosal gastric cancer (IMGC) to early submucosal-invasive gastric cancer (SMGC) is not fully understood. The objective of this study was to identify genes and pathways involved in the submucosal invasion in EGC using comprehensive gene expression analysis.

METHODS

Gene expression profiling was performed for eight cases of IMGC and eight cases of early SMGC with submucosal invasion ≥500 μm. To validate the findings of gene expression analysis and to examine the gene expression pattern in tissues, immunohistochemical (IHC) staining was performed for 50 cases of IMGC and SMGC each.

RESULTS

Gene expression analysis demonstrated that the expression levels of small intestine-specific genes were significantly decreased in SMGC. Among them, defensin alpha 5 (DEFA5) was the most downregulated gene in SMGC, which was further validated in SMGC tissues by IHC staining. Gene set enrichment analysis showed a strong association between SMGC, the JAK-STAT signaling pathway, and the upregulation of STAT3-activating cytokines. The expression of phosphorylated STAT3 was significant in the nucleus of tumor cells in SMGC tissues but not in areas expressing DEFA5.

CONCLUSION

The results of this study strongly suggest that the downregulation of DEFA5 and the activation of STAT3 play a significant role in the submucosal invasion of EGC.

Case report: Common clonal origin of concurrent langerhans cell histiocytosis and acute myeloid leukemia

Langerhans cell histiocytosis (LCH) and acute myeloid leukemia (AML) are distinct entities of blood neoplasms, and the exact developmental origin of both neoplasms are considered be heterogenous among patients. However, reports of concurrent LCH and AML are rare. Herein we report a novel case of concurrent LCH and AML which shared same the driver mutations, strongly suggesting a common clonal origin.An 84-year-old female presented with cervical lymphadenopathy and pruritic skin rash on the face and scalp. Laboratory tests revealed pancytopenia with 13% of blasts, elevated LDH and liver enzymes, in addition to generalised lymphadenopathy and splenomegaly by computed tomography. Bone marrow specimens showed massive infiltration of MPO-positive myeloblasts, whereas S-100 and CD1a positive atypical dendritic cell-like cells accounted for 10% of the atypical cells on bone marrow pathology, suggesting a mixture of LCH and AML. A biopsy specimen from a cervical lymph node and the skin demonstrated the accumulation of atypical cells which were positive for S-100 and CD1a. LCH was found in lymph nodes, skin and bone marrow; AML was found in peripheral blood and bone marrow (AML was predominant compared with LCH in the bone marrow).

Next generation sequencing revealed four somatic driver mutations (NRAS-G13D, IDH2-R140Q, and DNMT3A-F640fs/-I715fs), equally shared by both the lymph node and bone marrow, suggesting a common clonal origin for the concurrent LCH and AML. Prednisolone and vinblastine were initially given with partial response in LCH; peripheral blood blasts also disappeared for 3 months. Salvage chemotherapy with low dose cytarabine and aclarubicin were given for relapse, with partial response in both LCH and AML. She died from pneumonia and septicemia on day 384. Our case demonstrates a common cell of origin for LCH and AML with a common genetic mutation, providing evidence to support the proposal to classify histiocytosis, including LCH, as a myeloid/myeloproliferative malignancy.

Altered mucosal immunity in HIV-positive colon adenoma: decreased CD4+ T cell infiltration is correlated with nadir but not current CD4+ T cell blood counts

BACKGROUND

People living with HIV (PLWH) face greater risks of developing non-AIDS-defining cancers (NADCs) than the general population; however, the underlying mechanisms remain elusive. The tumor microenvironment plays a significant role in the carcinogenesis of colorectal cancer (CRC), an NADC. We studied this carcinogenesis in PLWH by determining inflammatory phenotypes and assessing PD-1/PD-L1 expression in premalignant CRC stages of colon adenomas in HIV-positive and HIV-negative patients.

METHODS

We obtained polyp specimens from 22 HIV-positive and 61 HIV-negative participants treated with colonoscopy and polyp excision. We analyzed adenomas from 33 HIV-positive and 99 HIV-negative patients by immunohistochemistry using anti-CD4, anti-CD8, anti-FoxP3, and anti-CD163 antibodies. Additionally, we analyzed the expression levels of immune checkpoint proteins. We also evaluated the correlation between cell infiltration and blood cell counts.

RESULTS

HIV-positive participants had fewer infiltrating CD4⁺ T cells than HIV-negative participants (p = 0.0016). However, no statistical differences were observed in infiltrating CD8⁺ and FoxP3⁺ T cells and CD163⁺ macrophages. Moreover, epithelial cells did not express PD-1 or PD-L1. Notably, CD4⁺ T cell infiltration correlated with nadir blood CD4⁺ T cell counts (p <  0.05) but not with current blood CD4⁺ T cell counts.

CONCLUSION

Immune surveillance dysfunction owing to decreased CD4⁺ T cell infiltration in colon adenomas might be involved in colon carcinogenesis in HIV-positive individuals. Collectively, since the nadir blood CD4⁺ T cell count is strongly correlated with CD4⁺ T cell infiltration, it could facilitate efficient follow-up and enable treatment strategies for HIV-positive patients with colon adenomas.

CHIP-associated mutant ASXL1 in blood cells promotes solid tumor progression

Clonal hematopoiesis of indeterminate potential (CHIP) is an age‐associated phenomenon characterized by clonal expansion of blood cells harboring somatic mutations in hematopoietic genes, including DNMT3A, TET2, and ASXL1. Clinical evidence suggests that CHIP is highly prevalent and associated with poor prognosis in solid‐tumor patients. However, whether blood cells with CHIP mutations play a causal role in promoting the development of solid tumors remained unclear. Using conditional knock‐in mice that express CHIP‐associated mutant Asxl1 (Asxl1‐MT), we showed that expression of Asxl1‐MT in T cells, but not in myeloid cells, promoted solid‐tumor progression in syngeneic transplantation models. We also demonstrated that Asxl1‐MT–expressing blood cells accelerated the development of spontaneous mammary tumors induced by MMTV‐PyMT. Intratumor analysis of the mammary tumors revealed the reduced T‐cell infiltration at tumor sites and programmed death receptor‐1 (PD‐1) upregulation in CD8⁺ T cells in MMTV‐PyMT/Asxl1‐MT mice. In addition, we found that Asxl1‐MT induced T‐cell dysregulation, including aberrant intrathymic T‐cell development, decreased CD4/CD8 ratio, and naïve‐memory imbalance in peripheral T cells. These results indicate that Asxl1‐MT perturbs T‐cell development and function, which contributes to creating a protumor microenvironment for solid tumors. Thus, our findings raise the possibility that ASXL1‐mutated blood cells exacerbate solid‐tumor progression in ASXL1‐CHIP carriers.

Small-molecule HDAC and Akt inhibitors suppress tumor growth and enhance immunotherapy in multiple myeloma

Background

Multiple myeloma (MM) is an incurable disease. The acquisition of resistance to drugs, including immunomodulatory drugs (IMiDs), has a negative effect on its prognosis. Cereblon (CRBN) is a key mediator of the bioactivities of IMiDs such as lenalidomide. Moreover, genetic alteration of CRBN is frequently detected in IMiD-resistant patients and is considered to contribute to IMiD resistance. Thus, overcoming resistance to drugs, including IMiDs, is expected to improve clinical outcomes. Here, we examined potential mechanisms of a histone deacetylase (HDAC) inhibitor and Akt inhibitor in relapsed/refractory MM patients.

Methods

We established lenalidomide-resistant cells by knocking down CRBN with RNAi-mediated downregulation or knocking out CRBN using CRISPR-Cas9 in MM cells. Additionally, we derived multi-drug (bortezomib, doxorubicin, or dexamethasone)-resistant cell lines and primary cells from relapsed/refractory MM patients. The effects of HDAC and Akt inhibitors on these drug-resistant MM cells were then observed with a particular focus on whether HDAC inhibitors enhance immunotherapy efficacy. We also investigated the effect of lenalidomide on CRBN-deficient cells.

Results

The HDAC inhibitor suppressed the growth of drug-resistant MM cell lines and enhanced the antibody-dependent cellular cytotoxicity (ADCC) of therapeutic antibodies by upregulating natural killer group 2D (NKG2D) ligands in MM cells. CRBN-deficient cells showed lenalidomide-induced upregulation of phosphorylated glycogen synthase kinase-3 (p-GSK-3) and c-Myc phosphorylation. Moreover, HDAC and Akt inhibitors downregulated c-Myc by blocking GSK-3 phosphorylation. HDAC and Akt inhibitors also exhibited synergistic cytotoxic and c-Myc-suppressive effects. The dual HDAC and PI3K inhibitor, CUDC-907, exhibited cytotoxic and immunotherapy-enhancing effects in MM cells, including multi-drug-resistant lines and primary cells from lenalidomide-resistant patients.

Conclusions

The combination of an HDAC and an Akt inhibitor represents a promising approach for the treatment of relapsed/refractory MM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01909-7.

A pilot study to establish human T-cell leukemia virus type 1 (HTLV-1) carrier model using common marmoset (Callithrix jacchus)

BACKGROUND

For the diagnosis and treatment of adult T-cell leukemia/lymphoma (ATLL) caused by human T-lymphotropic virus type 1 (HTLV-1) are required therapeutic modalities urgently. Non-human primate models for ATLL would provide a valuable information for clinical studies. We did a pilot study to establish an ATLL non-human primate model using common marmosets (Callithrix jacchus).

METHODS

We inoculated HTLV-1-producing MT-2 cells into 9-month-old marmosets, either intraperitoneally or intravenously. We next administrated MT-2 cells into 13-month-old marmosets under cyclosporine A (CsA) treatment to promote infection. HTLV-1 infection was determined by measuring HTLV-1 antibody titer in the common marmosets.

RESULTS

The HTLV-1 antibody titer increased in the intraperitoneally inoculated marmoset with or without CsA treatment, and it kept over five 5 years though proviral copy number (proviral load, PVL) remained low throughout the study.

CONCLUSION

We obtained HTLV-1 asymptomatic carriers of common marmosets by inoculating MT-2 cells.

S-1 and irinotecan plus bevacizumab versus mFOLFOX6 or CapeOX plus bevacizumab as first-line treatment in patients with metastatic colorectal cancer (TRICOLORE): a randomized, open-label, phase III, noninferiority trial

Background

Combination therapy with oral fluoropyrimidine and irinotecan has not yet been established as first-line treatment of metastatic colorectal cancer (mCRC). We carried out a randomized, open-label, phase III trial to determine whether S-1 and irinotecan plus bevacizumab is noninferior to mFOLFOX6 or CapeOX plus bevacizumab in terms of progression-free survival (PFS).

Patients and methods

Patients from 53 institutions who had previously untreated mCRC were randomly assigned (1 : 1) to receive either mFOLFOX6 or CapeOX plus bevacizumab (control group) or S-1 and irinotecan plus bevacizumab (experimental group; a 3-week regimen: intravenous infusions of irinotecan 150 mg/m2 and bevacizumab 7.5 mg/kg on day 1, oral S-1 80 mg/m2 twice daily for 2 weeks, followed by a 1-week rest; or a 4-week regimen: irinotecan 100 mg/m2 and bevacizumab 5 mg/kg on days 1 and 15, S-1 80 mg/m2 twice daily for 2 weeks, followed by a 2-week rest). The primary end point was PFS. The noninferiority margin was 1.25; noninferiority would be established if the upper limit of the 95% confidence interval (CI) for the hazard ratio (HR) of the control group versus the experimental group was less than this margin.

Result

Between June 2012 and September 2014, 487 patients underwent randomization. Two hundred and forty-three patients assigned to the control group and 241 assigned to the experimental group were included in the primary analysis. Median PFS was 10.8 months (95% CI 9.6-11.6) in the control group and 14.0 months (95% CI 12.4-15.5) in the experimental group (HR 0.84, 95% CI 0.70-1.02; P < 0.0001 for noninferiority, P = 0.0815 for superiority). One hundred and fifty-seven patients (64.9%) in the control group and 140 (58.6%) in the experimental group had adverse events of grade 3 or higher.

Conclusion

S-1 and irinotecan plus bevacizumab is noninferior to mFOLFOX6 or CapeOX plus bevacizumab with respect to PFS as first-line treatment of mCRC and could be a new standard treatment.

Clinical trials number

UMIN000007834.

REVERCE: a randomized phase II study of regorafenib followed by cetuximab versus the reverse sequence for previously treated metastatic colorectal cancer patients

BACKGROUND

The objective of this randomized phase II trial was to evaluate efficacy and safety of the therapeutic sequence of regorafenib followed by cetuximab, compared with cetuximab followed by regorafenib, as the current standard sequence for metastatic colorectal cancer patients.

PATIENTS AND METHODS

Patients with KRAS exon 2 wild-type metastatic colorectal cancer after failure of fluoropyrimidine, oxaliplatin, and irinotecan were randomized to receive sequential treatment with regorafenib followed by cetuximab ± irinotecan (R-C arm), or the reverse sequence [cetuximab ± irinotecan followed by regorafenib (C-R arm)]. The primary end point was overall survival (OS). Key secondary end points included progression-free survival (PFS) with initial treatment (PFS1), PFS with second treatment (PFS2), safety, and quality of life. Exploratory end points included serial biomarker analyses, including oncogenic alterations from circulating tumor DNA or multiple serum or plasma proteins.

RESULTS

One-hundred one patients were randomized and eligible for efficacy analysis. Sequential treatment was successful in 86% patients in both arms. Median OS for R-C and C-R was 17.4 and 11.6 months, respectively (P = 0.0293), with a hazard ratio (HR) of 0.61 for OS [95% confidence interval (CI) 0.39-0.96]. The HR for PFS1 (regorafenib in R-C versus cetuximab in C-R) was 0.97 (95% CI 0.61-1.54), and PFS2 (C in R-C versus R in C-R) was 0.29 (95% CI 0.17-0.50). No unexpected safety signals were observed. The quality of life scores during the entire treatment period was not significantly different between the two arms. Circulating biomarker analyses showed emerging oncogenic alterations in RAS, BRAF, EGFR, HER2, and MET, which were more commonly detected after cetuximab than after regorafenib.

CONCLUSIONS

The therapeutic sequence of regorafenib followed by cetuximab suggests a longer OS than the current standard sequence.

Filter paper-assisted cell transfer (FaCT) technique: A novel cell-sampling technique for intraoperative diagnosis of central nervous system tumors

BACKGROUND

Intraoperative diagnosis of central nervous system (CNS) tumors provides critical guidance to surgeons in the determination of surgical resection margins and treatment. The techniques and preparations used for the intraoperative diagnosis of CNS tumors include frozen sectioning and cytologic methods (squash smear and touch imprint). Cytologic specimens, which do not have freezing artifacts, are important as an adjuvant tool to frozen sections. However, if the amount of submitted tissue samples is limited, then it is difficult to prepare both frozen sections and squash smears or touch imprint specimens from a single sample at the same time. Therefore, the objective of this study was to derive cells directly from filter paper on which tumor samples are placed.

METHODS

The authors established the filter paper-assisted cell transfer (FaCT) smear technique, in which tumor cells are transferred onto a glass slide directly from the filter paper sample spot after the biopsy is removed.

RESULTS

Cell yields and diagnostic accuracy of the FaCT smears were assessed in 40 CNS tumors. FaCT smears had ample cell numbers and well preserved cell morphology sufficient for cytologic diagnosis, even if the submitted tissues were minimal. The overall diagnostic concordance rates between frozen sections and FaCT smears were 90% and 87.5%, respectively (no significant differences). When combining FaCT smears with frozen sections, the diagnostic concordance rate rose to 92.5%.

CONCLUSIONS

The current results suggest that the FaCT smear technique is a simple and effective processing method that has significant value for intraoperative diagnosis of CNS tumors. Cancer Cytopathol 2017;125:277-282. © 2016 American Cancer Society.

Randomized phase III study of bevacizumab plus FOLFIRI and bevacizumab plus mFOLFOX6 as first-line treatment for patients with metastatic colorectal cancer (WJOG4407G)

BACKGROUND

FOLFIRI and FOLFOX have shown equivalent efficacy for metastatic colorectal cancer (mCRC), but their comparative effectiveness is unknown when combined with bevacizumab.

PATIENTS AND METHODS

WJOG4407G was a randomized, open-label, phase III trial conducted in Japan. Patients with previously untreated mCRC were randomized 1:1 to receive either FOLFIRI plus bevacizumab (FOLFIRI + Bev) or mFOLFOX6 plus bevacizumab (mFOLFOX6 + Bev), stratified by institution, adjuvant chemotherapy, and liver-limited disease. The primary end point was non-inferiority of FOLFIRI + Bev to mFOLFOX6 + Bev in progression-free survival (PFS), with an expected hazard ratio (HR) of 0.9 and non-inferiority margin of 1.25 (power 0.85, one-sided α-error 0.025). The secondary end points were response rate (RR), overall survival (OS), safety, and quality of life (QoL) during 18 months. This trial is registered to the University Hospital Medical Information Network, number UMIN000001396.

RESULTS

Among 402 patients enrolled from September 2008 to January 2012, 395 patients were eligible for efficacy analysis. The median PFS for FOLFIRI + Bev (n = 197) and mFOLFOX6 + Bev (n = 198) were 12.1 and 10.7 months, respectively [HR, 0.905; 95% confidence interval (CI) 0.723-1.133; P = 0.003 for non-inferiority]. The median OS for FOLFIRI + Bev and mFOLFOX6 + Bev were 31.4 and 30.1 months, respectively (HR, 0.990; 95% CI 0.785-1.249). The best overall RRs were 64% for FOLFIRI + Bev and 62% for mFOLFOX6 + Bev. The common grade 3 or higher adverse events were leukopenia (11% in FOLFIRI + Bev/5% in mFOLFOX6 + Bev), neutropenia (46%/35%), diarrhea (9%/5%), febrile neutropenia (5%/2%), peripheral neuropathy (0%/22%), and venous thromboembolism (6%/2%). The QoL assessed by FACT-C (TOI-PFC) and FACT/GOG-Ntx was favorable for FOLFIRI + Bev during 18 months.

CONCLUSION

FOLFIRI plus bevacizumab was non-inferior for PFS, compared with mFOLFOX6 plus bevacizumab, as the first-line systemic treatment for mCRC.

CLINICAL TRIALS NUMBER

UMIN000001396.

FOLFIRI plus bevacizumab as second-line therapy in patients with metastatic colorectal cancer after first-line bevacizumab plus oxaliplatin-based therapy: the randomized phase III EAGLE study

EAGLE was a randomized, multicenter phase III study which evaluated the superiority of bevacizumab 10 mg/kg plus FOLFIRI compared with bevacizumab 5 mg/kg plus FOLFIRI in patients with mCRC previously treated with first-line bevacizumab plus an oxaliplatin-based regimen. The results suggest that the higher 10 mg/kg dose offers no clear clinical benefit compared with bevacizumab 5 mg/kg in this setting.

Background

A targeted agent combined with chemotherapy is the standard treatment in patients with metastatic colorectal cancer (mCRC). The present phase III study was conducted to compare two doses of bevacizumab combined with irinotecan, 5-fluorouracil/leucovorin (FOLFIRI) in the second-line setting after first-line therapy with bevacizumab plus oxaliplatin-based therapy.

Patients and methods

Patients were randomly assigned to receive FOLFIRI plus bevacizumab 5 or 10 mg/kg in 2-week cycles until disease progression. The primary end point was progression-free survival (PFS), and secondary end points included overall survival (OS), time to treatment failure (TTF), and safety.

Results

Three hundred and eighty-seven patients were randomized between September 2009 and January 2012 from 100 institutions in Japan. Baseline patient characteristics were well balanced between the two groups. Efficacy was evaluated in 369 patients (5 mg/kg, n = 181 and 10 mg/kg, n = 188). Safety was evaluated in 365 patients (5 mg/kg, n = 180 and 10 mg/kg, n = 185). The median PFS was 6.1 versus 6.4 months (hazard ratio, 0.95; 95% confidence interval [CI] 0.75–1.21; P = 0.676), and median TTF was 5.2 versus 5.2 months (hazard ratio, 1.01; 95% CI 0.81–1.25; P = 0.967), respectively, for the bevacizumab 5 and 10 mg/kg groups. Follow-up of OS is currently ongoing. Adverse events, including hypertension and hemorrhage, occurred at similar rates in both groups.

Conclusion

Bevacizumab 10 mg/kg plus FOLFIRI as the second-line treatment did not prolong PFS compared with bevacizumab 5 mg/kg plus FOLFIRI in patients with mCRC. If bevacizumab is continued after first-line therapy in mCRC, a dose of 5 mg/kg is appropriate for use as second-line treatment.

Clinical trial identifier

UMIN000002557.

Rapid immunocytochemistry with simple heat-induced antigen retrieval technique for improvement in the quality of cytological diagnosis

Rapid immunocytochemistry (ICC) can improve the accuracy of intraoperative cytological diagnoses; however, it is usually applied without heat-induced antigen retrieval (HIAR). We established a HIAR method for rapid ICC and evaluated its efficacy and reliability. Rapidly fixed smear samples were immunostained using 35 antibodies. We compared the results of HIAR by boiling in a pot or heating in an electric kettle. The smears were incubated for 3 min with each primary antibody and immuno-enzyme polymer reagent, and for 1 min with diaminobenzidine solution. HIAR for 1 min using the kettle method yielded the best cellular integrity. For 32 out of the 35 antibodies, results achieved using rapid ICC within 11 min were comparable to that achieved using standard ICC. HIAR was essential for 13 antibodies. For two of the antibodies, HIAR was not required when standard ICC was applied, but consistent staining with rapid ICC was obtained only with HIAR. In conclusion, we established a rapid ICC procedure using a simple HIAR method, which allowed efficient immunostaining of a panel of antigens, including nuclear antigens, within only 11 min. The combined use of this rapid ICC technique with other staining techniques could be useful for improving intraoperative cytological diagnoses.

Impact of excision repair cross-complementing gene 1 (ERCC1) on the outcomes of patients with advanced gastric cancer: correlative study in Japan Clinical Oncology Group Trial JCOG9912

BACKGROUND

Since the best chemotherapy regimen for each patient with advanced gastric cancer is uncertain, we aimed to identify molecular prognostic or predictive biomarkers from biopsy specimens in JCOG9912, a randomized phase III trial for advanced gastric cancer.

PATIENTS AND METHODS

Endoscopic biopsy specimens from primary lesions were collected in 445 of 704 randomized patients in JCOG9912. We measured the mRNA expression of excision repair cross-complementing group 1 (ERCC1), thymidylate synthase, dihydropyrimidine dehydrogenase, and five other genes, then, categorized them into low and high groups relative to the median, and examined whether gene expression was associated with efficacy end point.

RESULTS

Multivariate analyses showed that high ERCC1 expression [HR 1.37; 95% confidence interval (CI) 1.08-1.75; P = 0.010], performance status ≥ 1 (HR 1.45; 95% CI 1.13-1.86; P = 0.004), and number of metastatic sites ≥ 2 (HR 1.66; 95% CI 1.28-1.86; P < 0.001) were associated with a poor prognosis, and recurrent disease (versus unresectable; HR 0.75; 95% CI 0.56-1.00; P = 0.049) was associated with a favorable prognosis. None of these molecular factors were a predictive marker for choosing irinotecan plus cisplatin or 5-fluorouracil rather than S-1.

CONCLUSION

These correlative analyses suggest that ERCC1 is an independent prognostic factor for overall survival in the first-line treatment of gastric cancer.

CLINICAL TRIAL NUMBER

C000000062, www.umin.ac.jp.

Optimal antigen retrieval for ethanol-fixed cytologic smears

BACKGROUND

Antigen retrieval, a crucial technique for immunostaining, is often carried out on formalin-fixed, paraffin-embedded (FFPE) tissue sections. The role of antigen retrieval in immunostaining of ethanol-fixed smears remains unclear. The authors evaluated the effects of 2 common antigen retrieval procedures, heat-induced antigen retrieval and protease-induced antigen retrieval, for immunostaining using a broad panel of antibodies.

METHODS

Papanicolaou-stained ethanol-fixed smears from 36 surgical specimens were immunostained with 43 antibodies. Three widely used heat-induced antigen retrieval solutions, namely, citrate buffer (pH 6.0 and pH 7.0) and ethylenediaminetetraacetic acid solution (pH 8.0) for heat-induced antigen retrieval, and pronase were used. The staining results were compared between the ethanol-fixed smears and the corresponding FFPE tissue sections.

RESULTS

Heat-induced antigen retrieval was essential for all the 9 antibodies examined against nuclear antigens, and for 7 of 26 antibodies against cytoplasmic and cell membrane antigens. Superior results were obtained using lower-pH heat-induced antigen retrieval solutions for ethanol-fixed smears than was the case for FFPE tissue sections; use of citrate buffer (pH 6.0) was optimal for most antibodies. For 17 antibodies against cytoplasmic/cell membrane antigens, satisfactory results were obtained even without antigen retrieval on the ethanol-fixed smears, whereas antigen retrieval was necessary for detection on the FFPE tissue sections. Protease-induced antigen retrieval frequently exerted deleterious effects on ethanol-fixed smears. Despite antigen retrieval, detection of 2 lymphocytic markers failed on ethanol-fixed smears. This limitation was overcome by heat-induced antigen retrieval on formalin vapor-fixed smears.

CONCLUSIONS

In ethanol-fixed smears, most of the antibodies can be immunostained successfully without antigen retrieval treatment or mild heat-induced antigen retrieval using citrate buffer (pH 6.0). The optimal antigen retrieval condition for each antibody must be individually determined.

Cediranib in combination with mFOLFOX6 in Japanese patients with metastatic colorectal cancer: results from the randomised phase II part of a phase I/II study

BACKGROUND

Colorectal cancer (CRC) is the second most common malignancy in Japan. Treatment with inhibitors of the vascular endothelial growth factor (VEGF) signalling pathway has proven benefit in metastatic CRC. Cediranib is an oral highly potent VEGF signalling inhibitor that inhibits all three VEGF receptors.

PATIENTS AND METHODS

In this phase II, double-blind, placebo-controlled study, 172 patients with metastatic CRC were randomised to receive once-daily cediranib (20 or 30 mg) or placebo, each combined with modified FOLFOX6 (mFOLFOX6). The primary objective was comparison of progression-free survival (PFS).

RESULTS

The comparison of cediranib 20 mg versus placebo met the primary objective of PFS prolongation [hazard ratio = 0.70 (95% confidence interval 0.44-1.11), P = 0.167], which met the protocol-defined criterion of P < 0.2. Median PFS was 10.2 versus 8.3 months, respectively. The PFS comparison for cediranib 30 mg versus placebo did not meet the criterion. The most common adverse events (AEs) in the cediranib-containing groups were diarrhoea and hypertension.

CONCLUSIONS

Cediranib 20 mg plus mFOLFOX6 met the predefined criteria in terms of improved PFS compared with placebo plus mFOLFOX6. Cediranib 20 mg was generally well tolerated and the AE profile was consistent with previous studies.

Impact of dihydropyrimidine dehydrogenase status of biopsy specimens on efficacy of irinotecan plus cisplatin, S-1, or 5-FU as first-line treatment of advanced gastric cancer patients in JCOG9912

4535

Background: JCOG9912 (randomized phase III trial) showed a significant non-inferiority of S-1 to 5-FU (P<0.001); however, either S-1 or irinotecan plus cisplatin (IP) failed to show superiority to 5-FU (P=0.034 and 0.055, respectively) in overall survival. Excision repair cross-complementing group 1 (ERCC1), thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) are reportedly related to outcome of advanced gastric cancer (AGC) patients (pts) treated with IP or 5-FU. Efficacy analyses are performed to evaluate the status of ERCC1, TS, DPD and 5 biomarkers related to anticancer drug sensitivity in first-line pts treated with IP, S-1, or 5-FU monotherapy under controlled conditions. Methods: Blocks from endoscopic biopsy specimens of primary lesions before chemotherapy were available from 365 of 704 pts in JCOG9912. Using laser-captured microdissection and real-time RT-PCR, we analyzed mRNA expression of ERCC1, TS, DPD in paraffin-embedded specimens. Expression levels of each gene were categorized into low and high values at each median. Results: The subjects with available tissue for analysis were representative of all randomized pts; 232 samples were assessable for TS, 168 for DPD, and 235 for ERCC1. There were no statistical differences in patient numbers between 3 arms. Pts with high TS showed worse progression-free survival (PFS) compared with those with low TS (hazard ratio (HR):1.26 [95%CI: 0.97–1.63]) in all pts; there was no difference in PFS between DPD and ERCC1 expression level. IP showed better PFS than S-1 in low DPD (HR: 0.57 [95%CI: 0.32–1.01]) but not in high DPD (HR: 1.24 [95%CI: 0.76–2.04]); there was no clear difference in PFS between pts treated with IP and S-1 regardless of TS and ERCC1 expression status. S-1 showed almost consistently better PFS than 5-FU regardless of mRNA expression status. Conclusions: This large analysis showed the prognostic value of TS status in AGC pts and the predictive value of DPD status for IP and S-1 as first-line treatment. Studies of DPD as a predictive marker for IP activity in AGC are warranted in future personalized phase III.

[Table: see text]