Germline MLH1 and MSH6 mutations from two Lynch syndrome families identified in a patient with early-onset of endometrial cancer: A case report

Introduction

Lynch syndrome is caused by a germline mutation in mismatch repair (MMR) genes, leading to the loss of expression of MMR heterodimers, either MLH1/PMS2 or MSH2/MSH6, or isolated loss of PMS2 or MSH6. Concurrent loss of both heterodimers is uncommon, and patients carrying pathogenic variants affecting different MMR genes are rare, leading to the lack of cancer screening recommendation for these patients.Case presentation:Here, we reported a female with a family history of Lynch syndrome with MLH1 c.676C > T mutation. She developed endometrial cancer at 37 years old, with loss of MLH1/PMS2 expression. Immunohistochemical staining on tumor samples incidentally detected the additional loss of MSH6 expression. Whole exome sequencing on genomic DNA from peripheral blood revealed MSH6 c.2731C > T mutation, which was confirmed to be inherited from her mother, who had an early-onset ascending colon cancer without cancer family history.

Conclusion

This is a rare case of the Lynch syndrome harboring germline mutations simultaneously in two different MMR genes inherited from two families with Lynch syndrome. The diagnosis of endometrial cancer at the age less than 40 years is uncommon for Lynch syndrome-related endometrial cancer. This suggests an earlier cancer screening for patients carrying two MMR mutations.

Tight junction protein cingulin variant is associated with cancer susceptibility by overexpressed IQGAP1 and Rac1-dependent epithelial-mesenchymal transition

BACKGROUND

Cingulin (CGN) is a pivotal cytoskeletal adaptor protein located at tight junctions. This study investigates the link between CGN mutation and increased cancer susceptibility through genetic and mechanistic analyses and proposes a potential targeted therapeutic approach.

METHODS

In a high-cancer-density family without known pathogenic variants, we performed tumor-targeted and germline whole-genome sequencing to identify novel cancer-associated variants. Subsequently, these variants were validated in a 222 cancer patient cohort, and CGN c.3560C > T was identified as a potential cancer-risk allele. Both wild-type (WT) (c.3560C > C) and variant (c.3560C > T) were transfected into cancer cell lines and incorporated into orthotopic xenograft mice model for evaluating their effects on cancer progression. Western blot, immunofluorescence analysis, migration and invasion assays, two-dimensional gel electrophoresis with mass spectrometry, immunoprecipitation assays, and siRNA applications were used to explore the biological consequence of CGN c.3560C > T.

RESULTS

In cancer cell lines and orthotopic animal models, CGN c.3560C > T enhanced tumor progression with reduced sensitivity to oxaliplatin compared to the CGN WT. The variant induced downregulation of epithelial marker, upregulation of mesenchymal marker and transcription factor, which converged to initiate epithelial-mesenchymal transition (EMT). Proteomic analysis was conducted to investigate the elements driving EMT in CGN c.3560C > T. This exploration unveiled overexpression of IQGAP1 induced by the variant, contrasting the levels observed in CGN WT. Immunoprecipitation assay confirmed a direct interaction between CGN and IQGAP1. IQGAP1 functions as a regulator of multiple GTPases, particularly the Rho family. This overexpressed IQGAP1 was consistently associated with the activation of Rac1, as evidenced by the analysis of the cancer cell line and clinical sample harboring CGN c.3560C > T. Notably, activated Rac1 was suppressed following the downregulation of IQGAP1 by siRNA. Treatment with NSC23766, a selective inhibitor for Rac1-GEF interaction, resulted in the inactivation of Rac1. This intervention mitigated the EMT program in cancer cells carrying CGN c.3560C > T. Consistently, xenograft tumors with WT CGN showed no sensitivity to NSC23766 treatment, but NSC23766 demonstrated the capacity to attenuate tumor growth harboring c.3560C > T.

CONCLUSIONS

CGN c.3560C > T leads to IQGAP1 overexpression, subsequently triggering Rac1-dependent EMT. Targeting activated Rac1 is a strategy to impede the advancement of cancers carrying this specific variant.

Distinct Features of Plasma Ultrashort Single-Stranded Cell-Free DNA as Biomarkers for Lung Cancer Detection

BACKGROUND

Using broad range cell-free DNA sequencing (BRcfDNA-Seq), a nontargeted next-generation sequencing (NGS) methodology, we previously identified a novel class of approximately 50 nt ultrashort single-stranded cell-free DNA (uscfDNA) in plasma that is distinctly different from 167 bp mononucleosomal cell-free DNA (mncfDNA). We hypothesize that uscfDNA possesses characteristics that are useful for disease detection.

METHODS

Using BRcfDNA-Seq, we examined both cfDNA populations in the plasma of 18 noncancer controls and 14 patients with late-stage nonsmall cell lung carcinoma (NSCLC). In comparison to mncfDNA, we assessed whether functional element (FE) peaks, fragmentomics, end-motifs, and G-Quadruplex (G-Quad) signatures could be useful features of uscfDNA for NSCLC determination.

RESULTS

In noncancer participants, compared to mncfDNA, uscfDNA fragments showed a 45.2-fold increased tendency to form FE peaks (enriched in promoter, intronic, and exonic regions), demonstrated a distinct end-motif-frequency profile, and presented with a 4.9-fold increase in G-Quad signatures. Within NSCLC participants, only the uscfDNA population had discoverable FE peak candidates. Additionally, uscfDNA showcased different end-motif-frequency candidates distinct from mncfDNA. Although both cfDNA populations showed increased fragmentation in NSCLC, the G-Quad signatures were more discriminatory in uscfDNA. Compilation of cfDNA features using principal component analysis revealed that the first 5 principal components of both cfDNA subtypes had a cumulative explained variance of >80%.

CONCLUSIONS

These observations indicate that the distinct biological processes of uscfDNA and that FE peaks, fragmentomics, end-motifs, and G-Quad signatures are uscfDNA features with promising biomarker potential. These findings further justify its exploration as a distinct class of biomarker to augment pre-existing liquid biopsy approaches.

Clinical Characteristics and Responses to Immune Checkpoint Inhibitors in RET-Aberrant Digestive Tract Tumours

BACKGROUND

RET plays an oncogenic role, and its aberrations are potentially actionable. However, they have seldom been reported in tumours other than lung or thyroid cancers. The correlation of RET aberrations with clinical characteristics, co-occurring aberrations, and responses to immune checkpoint inhibitors (ICPi) have not been explored in digestive tract tumours.

OBJECTIVES

The aim of the study was to elucidate the clinical characteristics, frequently co-altered genes, and treatment responses in RET-aberrant digestive tract tumours.

PATIENTS AND METHODS

We retrospectively evaluated patients with digestive tract cancers for RET-aberrant tumours via FoundationOne CDx tumour-based selected genome sequencing from Jan 2016 to Jan 2021.

RESULTS

In a median follow-up time of 51 months, a total of 453 patients were analysed. RET-aberrant tumours accounted for 4.4% in the studied population (n = 20), and 1.1% had an oncogenic fusion (n = 5). APC, KRAS, TP53, MSH6 and STK11 were the differentially co-altered genes (all false discovery rates <0.05). The presence of RET aberrations alone was not a significant prognostic factor. Eleven patients with RET-aberrant tumours received ICPi-based treatment and none achieved an objective response. In contrast, 47 patients with non-aberrant tumours received ICPi treatment and had an objective response rate of 27.7% and a significantly longer treatment duration (6.2 vs 2.8 months, p = 0.0008).

CONCLUSIONS

Albeit rarely, RET aberrations can be found in digestive tract tumours. Patients with RET-aberrant tumours have a blunted response to ICPi and a comparable prognosis as compared with RET-wild type tumours. Together, these results provide insights into this rare but potentially actionable target in digestive tract tumours.

Dual role of sprouty2 as an inhibitor of RAS/ERK-driven proliferation and a promoter of cancer invasion in KRAS wild-type colorectal cancer

Sprouty2 (SPRY2) is known to inhibit the RAS/MAPK/ERK pathway, and is a potential study target for cancer. The effect of SPRY2 in colorectal cancer (CRC) and whether it is influenced by KRAS mutation are not known. We manipulated SPRY2 gene expression and used an activating KRAS-mutant plasmid to determine its effect on CRC cell function in vitro and/or in vivo. We performed SPRY2 immunohistochemical staining in 143 CRC specimens and analyzed the staining results with various clinicopathological characteristics in relation to KRAS mutation status. SPRY2 knockdown in Caco-2 cells carrying the wild-type (WT) KRAS gene upregulated phosphorylated ERK (p-ERK) levels and increased cell proliferation in vitro, but inhibited cell invasion. However, SPRY2 knockdown in SW480 cells (activating KRAS mutant) or Caco-2 cells transfected with KRAS-mutant plasmid did not significantly alter p-ERK levels, cell proliferation, or invasion. The xenografts of SPRY2-knockdown Caco-2 cells were larger with less deep muscle invasion than those of control cells. The clinical cohort study revealed a positive association of SPRY2 protein expression with pT status, lymphovascular invasion, and perineural invasion in KRAS-WT CRCs. However, the associations were not observed in KRAS-mutant CRCs. Interestingly, high SPRY2 expression was related to shorter cancer-specific survival in both KRAS-WT and KRAS-mutant CRC patients. Our study demonstrated the dual role of SPRY2 as an inhibitor of RAS/ERK-driven proliferation and as a promoter of cancer invasion in KRAS-WT CRC. SPRY2 may promote the invasion and progression of KRAS-WT CRC, and might also enhance KRAS-mutant CRC progression through pathways other than invasion.

HER2 amplification in colorectal cancer with brain metastasis: A propensity score matching study

BACKGROUND

The association between human epidermal growth factor receptor-2 (HER2) amplification and brain metastasis (BM) in patients having colorectal cancer (CRC) has been suggested but not yet established. This study investigated the expression patterns of HER2, its association with BM, and its prognostic value in patients having CRC.

METHODS

We retrospectively identified 99 patients having metastatic CRC (mCRC) and BM (the BM cohort) and compared them with a cohort of 249 patients having mCRC and without BM (the stage IV cohort) by propensity score matching. Immunohistochemical studies of HER2 on all available paraffin-embedded tumour samples, either from the primary tumour, the metastasis (brain and/or extracranial sites) or both, were performed and analysed. HER2 fluorescent in situ hybridisation was applied when necessary. The expression of HER2 was compared and correlated with survival.

RESULTS

HER2 amplifications were detected in 16 (18.4%) of 87 and 9 (3.6%) of 249 patients who had specimens available in the BM and stage IV cohorts, respectively (P < .001). After propensity score matching, HER2 amplification was significantly associated with BM (odds ratio: 5.38, P = .003). HER2 heterogeneity was frequently observed not only at the single tumour level but also in paired tumour samples. A marginally significant longer survival since BM was found in patients having HER2-amplified mCRC than in those without (P = .07).

CONCLUSIONS

HER2 amplification was significantly associated with BM in patients having mCRC and might have prognostic value for survival since BM. Given the heterogeneity of HER2 expression, the testing of HER2 status on available tissues from both primary and metastatic tumours should be encouraged.

Cutting-Edge AI Technologies Meet Precision Medicine to Improve Cancer Care

To provide precision medicine for better cancer care, researchers must work on clinical patient data, such as electronic medical records, physiological measurements, biochemistry, computerized tomography scans, digital pathology, and the genetic landscape of cancer tissue. To interpret big biodata in cancer genomics, an operational flow based on artificial intelligence (AI) models and medical management platforms with high-performance computing must be set up for precision cancer genomics in clinical practice. To work in the fast-evolving fields of patient care, clinical diagnostics, and therapeutic services, clinicians must understand the fundamentals of the AI tool approach. Therefore, the present article covers the following four themes: (i) computational prediction of pathogenic variants of cancer susceptibility genes; (ii) AI model for mutational analysis; (iii) single-cell genomics and computational biology; (iv) text mining for identifying gene targets in cancer; and (v) the NVIDIA graphics processing units, DRAGEN field programmable gate arrays systems and AI medical cloud platforms in clinical next-generation sequencing laboratories. Based on AI medical platforms and visualization, large amounts of clinical biodata can be rapidly copied and understood using an AI pipeline. The use of innovative AI technologies can deliver more accurate and rapid cancer therapy targets.

Abstract CT504: A phase 1 clinical trial to evaluate safety, tolerability, pharmacokinetics (PK) and efficacy of D-1553, a novel KRASG12C inhibitor, in patients with advanced or metastatic solid tumor harboring KRASG12C mutation

Background: KRASG12C mutation is an oncogenic driver that occurs in approximately 15% of non-small cell lung cancer (NSCLC), 3% of colorectal cancer (CRC), and ~1% of several other solid tumors. D-1553 is a novel, potent and orally bioavailable KRASG12C inhibitor. Here we present the safety, tolerability and PK and preliminary efficacy of D-1553 from a phase I trial in patients (pts) with advanced or metastatic solid tumors harboring KRASG12C mutation.

Method: Key inclusion criteria: KRASG12C identified by molecular testing, measurable disease, and refractory to or intolerant of standard therapy. D-1553 dose escalation included oral daily (QD) doses of 150, 300, 600, 800, and 1200 mg, and twice daily (BID) doses of 400, 600, and 800 mg. Primary endpoint: safety, tolerability, dose-limiting toxicity (DLT), maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Secondary endpoints: PK parameters, objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and duration of response (DOR), evaluated per RECIST 1.1.

Results: As of Dec 27, 2021, 22 pts (12 [54.5%] male, median age 65 [range: 49-90]), including 14 pts with CRC, 6 pts with NSCLC, and 2 pts with other solid tumors, were enrolled. D-1553 was well absorbed, with a median time to reach maximum plasma concentration (Tmax) of 1-4 hours. The Cmax and AUC of each dose group (150-600 mg, QD; 400-600 mg, BID) increased linearly as the dose increased. However, the changes of Cmax and AUC in 600-1200 mg (QD), 600-800 mg (BID) groups were not in a dose-dependent manner. The most frequently reported treatment-related adverse events (TRAEs) (frequency ≥ 10%) were diarrhea, nausea, vomiting, headache, and lethargy, all grade ≤ 2. Thirteen pts (59.1%) had TRAEs: 11 pts (52.4%) had grade 2 or lower TRAEs; 2 (9.1%) had three grade ≥3 TRAEs (hypokalemia, hypertension, anaemia). No DLT has been reported. MTD was not reached. One pt (4.5%) discontinued the D-1553 therapy due to cerebral hemorrhage. This event was evaluated by investigator as unlikely related to the drug. Among 21 evaluable pts (including 14 CRC, 6 NSCLC, and 1 endometrial carcinoma (EC), confirmed ORR and DCR were 19.0% (4/21) and 85.7% (18/21), respectively. One pt with EC achieving PR had the best tumor burden reduction of 80%.

Conclusion: In patients with KRASG12C mutated solid tumor, D-1553 is well tolerated with no DLTs at studied doses. The RP2D has been determined to be 600 mg BID. Preliminary efficacy results demonstrate promising clinical activity of single-agent D-1553 in pts with KRASG12C mutated solid tumor. This study is ongoing (NCT04585035) and more results will be presented at the meeting.

Citation Format: Timothy Price, Jaspreet Grewal, Afaf Abed, Melissa Moore, Yu-Min Yeh, Shirish Gadgeel, Gary Richardson, Craig Underhill, Vinod Ganju, Keun-Wook Lee, Seok Jae Huh, Sang-We Kim, Chih-Hsin Yang, Yuh-Min Chen, Ziyong Xiang, Zhe Shi, Yaolin Wang, Ling Zhang, Michael Millward. A phase 1 clinical trial to evaluate safety, tolerability, pharmacokinetics (PK) and efficacy of D-1553, a novel KRASG12C inhibitor, in patients with advanced or metastatic solid tumor harboring KRASG12C mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT504.

A phase 1 dose-escalation and -expansion study of IMP7068, a WEE1 inhibitor, in patients with advanced solid tumors

e15052

Background: WEE1 kinase is a cell-cycle regulator that is important in DNA repair, and a validated antitumor target. IMP7068 is a potent and selective WEE1 inhibitor that has demonstrated antitumor activity in preclinical pharmacological models. A first-in-human, multicenter, open-label study was conducted to evaluate the safety, tolerability, pharmacokinetic (PK) characteristics, pharmacodynamic (PD) profiles and preliminary antitumor activity of IMP7068 in patients (pts) with advanced solid tumors. Methods: This phase 1 study included both a dose-escalation and dose-expansion stage. The dose-escalation stage was designed with 6 dose cohorts of IMP7068 at 30, 60, 120, 200, 300, and 400 mg (administered orally, once daily [QD] for 3 days, followed by 4 days off weekly for 21-day cycles). An accelerated titration design was used for the 30- and 60-mg dose levels, and an i3+3 design for all doses > 60 mg. Pts were adults (age ≥18 years) with confirmed advanced solid tumors that were refractory or intolerant to standard treatment, or for which no standard treatment exists. The objectives of the dose-escalation stage were to evaluate the safety and tolerability, PK and PD profiles, and antitumor activity (per RECIST v1.1) of IMP7068. Results: As of Jan 7, 2022, 9 pts were enrolled in the dose-escalation phase (average age, 56 years). An additional cohort of IMP7068 160 mg was recommended by the Safety Monitoring Committee based on PK data from the 120-mg cohort. Pts received escalating doses at 30 mg (n = 1), 60 mg (n = 1), 120 mg (n = 3), and 160 mg (n = 4). No dose-limiting toxicities (DLTs) were observed. Treatment-related adverse events (TRAEs) occurred in 4 pts, most frequently alanine aminotransferase (ALT) increased, aspartate aminotransferase (AST) increased, and diarrhea (all in 2 pts each). Most TRAEs were grade 1 or 2 in severity; and only 1 patient had grade 3 TRAEs (AST and ALT increased). Time to reach the maximum plasma concentration of IMP7068 was approximately 2–6 hours following administration of 30–160 mg doses, respectively. Following repeated QD administration for 3 days, the accumulation ratios for IMP7068 exposure parameters Cmax and AUC0-tau were 1.74–2.49 and 3.17–3.46, respectively, across the dose levels. The elimination half-life was approximately 10–28 hours after administration of 60–160 mg IMP7068. PD data showed that levels of phosphorylated cyclin-dependent kinase 1 decreased by ≥50% after treatment in the 160-mg cohort. Five of 8 evaluable pts had a best tumor response of stable disease (SD); 1 patient with colorectal cancer maintained a best response of SD for 22 weeks. Four pts remain on study. Conclusions: IMP7068 was well-tolerated with no DLTs, and conferred a meaningful PD effect and preliminary antitumor activity at doses of up to 160 mg in pts with advanced solid tumors. Dose escalation to establish the recommended phase 2 dose and/or maximum tolerated dose is continuing. Clinical trial information: NCT04768868.

Phase 1b study of pegylated arginine deiminase (ADI-PEG 20) plus Pembrolizumab in advanced solid cancers

Background

Pegylated arginine deiminase (ADI-PEG 20) is a metabolism-based strategy that depletes arginine, resulting in tumoral stress and cytotoxicity. Preclinically, ADI-PEG 20 modulates T-cell activity and enhances the therapeutic efficacy of programmed death-1 (PD-1) inhibition.

Methods

A phase 1b study, including a dose-escalation cohort and an expansion cohort, was undertaken to explore the effects of ADI-PEG 20 in combination with pembrolizumab, an anti-PD-1 antibody, for safety, pharmacodynamics, and response. CD3 levels and programmed death-ligand 1 (PD-L1) expression were assessed in paired biopsies collected prior to and after ADI-PEG 20 treatment but before pembrolizumab.

Results

Twenty-five patients, nine in the dose-escalation cohort and sixteen in the expansion cohort, were recruited. Treatment was feasible with adverse events consistent with those known for each agent, except for Grade 3/4 neutropenia which was higher than expected, occurring in 10/25 (40%) patients. Mean arginine levels were suppressed for 1-3 weeks, but increased gradually. CD3+ T cells increased in 10/12 (83.3%) subjects following ADI-PEG 20 treatment, including in three partial responders (p = .02). PD-L1 expression was low and increased in 3/10 (30%) of subjects. Partial responses occurred in 6/25 (24%) heavily pretreated patients, in both argininosuccinate synthetase 1 proficient and deficient subjects.

Conclusions

The immunometabolic combination was safe with the caveat that the incidence of neutropenia might be increased compared with either agent alone. ADI-PEG 20 treatment increased T cell infiltration in the low PD-L1 tumor microenvironment. The recommended phase 2 doses are 36 mg/m2 weekly for ADI-PEG 20 and 200 mg every 3 weeks for pembrolizumab.

Clinical Utility of a Cell-Free DNA Assay in Patients With Colorectal Cancer

The analysis of cell-free DNA (cfDNA) is rapidly emerging as a powerful approach to guide the clinical care of cancer patients. Several comprehensive cfDNA assays designed to detect mutations across several genes are now available. Here, we analyzed the use of a cfDNA panel in colorectal cancer (CRC) patients. Twenty-eight CRC patients with relapse or metastatic disease and 31 patients with no evidence of disease (NED) were enrolled. Genomic alterations in cfDNA were analyzed by the Oncomine™ Pan-Cancer Cell-Free Assay that detects hotspot mutations, small indels, copy number changes, and gene fusions across 52 genes. In the NED group, genomic alterations in cfDNA were detected in 12/31 patients (38.7%). The detection of alterations was more common in patients who were ≥60 years old, and the most common genomic alteration was a TP53 mutation. Fifty percent of the TP53 mutations were frequently or very frequently found in human cancers. Among 28 patients with relapse or metastatic disease, 22 (78.6%) had genomic alterations in cfDNA. The alterations were detected most frequently in TP53 (n = 10), followed by KRAS (n = 9). Actionable targets for CRC, including ERBB2 amplification and BRAF mutations, could be identified by this cfDNA assay. Compared with mutational profiling routinely analyzed using tumor samples, several additional targets with currently available therapies, including IDH1, IDH2, and PDGFRA mutations, were discovered. The cfDNA assay could identify potentially actionable targets for CRC. Identifying how to filter out cancer-like genomic alterations not derived from tumors remains a challenge.

Targeting lysosomal cysteine protease cathepsin S reveals immunomodulatory therapeutic strategy for oxaliplatin-induced peripheral neuropathy

Rationale: Oxaliplatin-induced peripheral neuropathy (OIPN) is a common adverse effect that causes delayed treatment and poor prognosis among colorectal cancer (CRC) patients. However, its mechanism remains elusive, and no effective treatment is available.

Methods: We employed a prospective cohort study of adult patients with pathologically confirmed stage III CRC receiving adjuvant chemotherapy with an oxaliplatin-based regimen for investigating OIPN. To further validate the clinical manifestations and identify a potential therapeutic strategy, animal models, and in vitro studies on the mechanism of OIPN were applied.

Results: Our work found that (1) consistent with clinical findings, OIPN was observed in animal models. Targeting the enzymatic activity of cathepsin S (CTSS) by pharmacological blockade and gene deficiency strategy alleviates the manifestations of OIPN. (2) Oxaliplatin treatment increases CTSS expression by enhancing cytosol translocation of interferon response factor 1 (IRF1), which then facilitates STIM-dependent store-operated Ca²⁺ entry homeostasis. (3) The cytokine array demonstrated an increase in anti-inflammatory cytokines and suppression of proinflammatory cytokines in mice treated with RJW-58. (4) Mechanistically, inhibiting CTSS facilitated olfactory receptors transcription factor 1 release from P300/CBP binding, which enhanced binding to the interleukin-10 (IL-10) promoter region, driving IL-10 downstream signaling pathway. (5) Serum CTSS expression is increased in CRC patients with oxaliplatin-induced neurotoxicity.

Conclusions: We highlighted the critical role of CTSS in OIPN, which provides a therapeutic strategy for the common adverse side effects of oxaliplatin.

Comprehensive assessments of germline deletion structural variants reveal the association between prognostic MUC4 and CEP72 deletions and immune response gene expression in colorectal cancer patients

Background

Functional disruptions by large germline genomic structural variants in susceptible genes are known risks for cancer. We used deletion structural variants (DSVs) generated from germline whole-genome sequencing (WGS) and DSV immune-related association tumor microenvironment (TME) to predict cancer risk and prognosis.

Methods

We investigated the contribution of germline DSVs to cancer susceptibility and prognosis by silicon and causal inference models. DSVs in germline WGS data were generated from the blood samples of 192 cancer and 499 non-cancer subjects. Clinical information, including family cancer history (FCH), was obtained from the National Cheng Kung University Hospital and Taiwan Biobank. Ninety-nine colorectal cancer (CRC) patients had immune response gene expression data. We used joint calling tools and an attention-weighted model to build the cancer risk predictive model and identify DSVs in familial cancer. The survival support vector machine (survival-SVM) was used to select prognostic DSVs.

Results

We identified 671 DSVs that could predict cancer risk. The area under the curve (AUC) of the receiver operating characteristic curve (ROC) of the attention-weighted model was 0.71. The 3 most frequent DSV genes observed in cancer patients were identified as ADCY9, AURKAPS1, and RAB3GAP2 (p < 0.05). The DSVs in SGSM2 and LHFPL3 were relevant to colorectal cancer. We found a higher incidence of FCH in cancer patients than in non-cancer subjects (p < 0.05). SMYD3 and NKD2DSV genes were associated with cancer patients with FCH (p < 0.05). We identified 65 immune-associated DSV markers for assessing cancer prognosis (p < 0.05). The functional protein of MUC4 DSV gene interacted with MAGE1 expression, according to the STRING database. The causal inference model showed that deleting the CEP72 DSV gene affect the recurrence-free survival (RFS) of IFIT1 expression.

Conclusions

We established an explainable attention-weighted model for cancer risk prediction and used the survival-SVM for prognostic stratification by using germline DSVs and immune gene expression datasets. Comprehensive assessments of germline DSVs can predict the cancer risk and clinical outcome of colon cancer patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40246-020-00302-3.

Clinicopathological features of mismatch repair protein expression patterns in colorectal cancer

Microsatellite instability (MSI) is reflective of a deficient mismatch repair (dMMR) system, which is mostly associated with the methylation of mismatch repair (MMR) genes and BRAF mutations in sporadic colorectal cancers (CRCs). We performed a retrospective study to analyze the clinicopathological features of dMMR CRCs and their association with the BRAF V600E mutation. The incidence of dMMR CRCs in our cohort was 7.4 % (118/1603). Immunohistochemistry (IHC) revealed four common dMMR IHC patterns in 116 dMMR CRCs from 110 patients. dMMR type 1 (MLH1-/PMS2-) CRCs were the most frequent pattern, usually showing typical proximal location and MSI histology. The BRAF V600E mutation was almost exclusively observed in dMMR type 1 (32 of 72) and dMMR type 2 (PMS- only, 7 of 18) CRCs (p = 0.001). Patients with dMMR type 3 (MSH2-/MSH6-) CRCs were usually diagnosed at younger ages (p < 0.001) and had the strongest family history of Lynch syndrome-associated tumors (p = 0.002). dMMR type 3 CRCs frequently presented at advanced stages (p = 0.005) with perineural invasion (p = 0.021). We also found a significant positive association of dMMR type 1 and type 3 with advanced stages of CRC, whereas dMMR types 2 and 4 (MSH6- only) were usually diagnosed at early stages of CRC (p < 0.001). In conclusion, BRAF V600E mutations almost exclusively occurred in dMMR type 1 and 2 CRCs. Patterns of MMR protein expression display distinct associations with tumor staging and age at diagnosis.

Intratumor Heterogeneity of MYO18A and FBXW7 Variants Impact the Clinical Outcome of Stage III Colorectal Cancer

Many studies failed to demonstrate benefit from the addition of targeted agents to current standard adjuvant FOLFOX chemotherapy in stage III colorectal cancer (CRC) patients. Intratumor heterogeneity may foster the resistant subclones and leads to cancer recurrence. Here, we built a cancer evolution model and applied machine learning analysis to identify potential therapeutic targets. Among 78 CRC cases, whole-genome (WGS) and deep targeted sequencing data generated from paired blood and primary tumor were used for phylogenetic tree reconstruction. Genetic alterations in the PI3K/AKT, and RTK oncogenic signaling pathways were commonly detected in founding clones. The dominant subclones frequently exhibited dysregulations in the TP53, FBXW7/NOTCH1 tumor suppression, and DNA repair pathways. Fourteen genetic mutations were simultaneously selected by random forest and LASSO methods. The logistic regression model had better accuracy (79%), precision (70%), and recall (65%) and area under the curve (AUC) (82%) for cancer recurrence prediction. Three genes, including MYO18A in the founding clone, FBXW7, and ATM in the dominant subclone, affected the prognosis were selected simultaneously by different feature sets. The in vitro studies, HCT-116 cells transfected with MYO18A siRNA demonstrated a significant reduction in cell migration activity by 20-40%. These results indicate that MYO18A plays a crucial role in the migration of human CRC cells. The cancer evolution model revealed the critical mutations in the founding and dominant subclones. They can be used to predict clinical outcomes and the development of novel therapeutic targets for stage III CRC.

Treatment monitoring of colorectal cancer by integrated analysis of plasma concentration and sequencing of circulating tumor DNA

Circulating cell-free DNA (cfDNA) analysis is an important tool for cancer monitoring. The patient-specific mutations identified in colorectal cancer (CRC) tissues are usually used to design the cfDNA analysis. Despite high specificity in predicting relapse, the sensitivity in most studies is around 40–50%. To improve this weakness, we designed a cfDNA panel according to the CRC genomic landscape and recurrent-specific mutations. The pathological variants in cfDNA samples from 60 CRC patients were studied by a next-generation sequencing (NGS) method incorporating the dual molecular barcode. Interestingly, patients in the disease positive group had a significantly higher cfDNA concentration than those in the disease negative group. Based on receiver operating characteristic analysis, the cfDNA concentration of 7 ng/mL was selected into the analytical workflow. The sensitivity in determining the disease status was 72.4%, which represented a considerable improvement on prior studies, and the specificity remained high at 80.6%. Compared to standard imaging and laboratory studies, earlier detection of residual disease and clinical benefits were shown on two cases by this cfDNA assay. We conclude this integrative framework of cfDNA analytical pipeline with a satisfactory sensitivity and specificity could be used in postoperative CRC surveillance.

Neratinib Plus Capecitabine Versus Lapatinib Plus Capecitabine in HER2-Positive Metastatic Breast Cancer Previously Treated With ≥ 2 HER2-Directed Regimens: Phase III NALA Trial

PURPOSE

NALA (ClinicalTrials.gov identifier: NCT01808573) is a randomized, active-controlled, phase III trial comparing neratinib, an irreversible pan-HER tyrosine kinase inhibitor (TKI), plus capecitabine (N+C) against lapatinib, a reversible dual TKI, plus capecitabine (L+C) in patients with centrally confirmed HER2-positive, metastatic breast cancer (MBC) with ≥ 2 previous HER2-directed MBC regimens.

METHODS

Patients, including those with stable, asymptomatic CNS disease, were randomly assigned 1:1 to neratinib (240 mg once every day) plus capecitabine (750 mg/m² twice a day 14 d/21 d) with loperamide prophylaxis, or to lapatinib (1,250 mg once every day) plus capecitabine (1,000 mg/m² twice a day 14 d/21 d). Coprimary end points were centrally confirmed progression-free survival (PFS) and overall survival (OS). NALA was considered positive if either primary end point was met (α split between end points). Secondary end points were time to CNS disease intervention, investigator-assessed PFS, objective response rate (ORR), duration of response (DoR), clinical benefit rate, safety, and health-related quality of life (HRQoL).

RESULTS

A total of 621 patients from 28 countries were randomly assigned (N+C, n = 307; L+C, n = 314). Centrally reviewed PFS was improved with N+C (hazard ratio [HR], 0.76; 95% CI, 0.63 to 0.93; stratified log-rank P = .0059). The OS HR was 0.88 (95% CI, 0.72 to 1.07; P = .2098). Fewer interventions for CNS disease occurred with N+C versus L+C (cumulative incidence, 22.8% v 29.2%; P = .043). ORRs were N+C 32.8% (95% CI, 27.1 to 38.9) and L+C 26.7% (95% CI, 21.5 to 32.4; P = .1201); median DoR was 8.5 versus 5.6 months, respectively (HR, 0.50; 95% CI, 0.33 to 0.74; P = .0004). The most common all-grade adverse events were diarrhea (N+C 83% v L+C 66%) and nausea (53% v 42%). Discontinuation rates and HRQoL were similar between groups.

CONCLUSION

N+C significantly improved PFS and time to intervention for CNS disease versus L+C. No new N+C safety signals were observed.

Immune Checkpoint Inhibitors and Immune-Related Adverse Events in Patients With Advanced Melanoma: A Systematic Review and Network Meta-analysis

IMPORTANCE

Since 2011, immune checkpoint inhibitors (ICIs) have been effective treatment options for advanced melanoma. Little is known about how risks of immune-related adverse events (irAEs) vary by ICIs.

OBJECTIVE

To compare the risk of irAEs across different treatment regimens for advanced melanoma using network meta-analysis.

DATA SOURCES

PubMed/MEDLINE, Embase, Web of Science, and Scopus were searched for all randomized clinical trial (RCT) articles published from January 1, 2010, through June 30, 2019.

STUDY SELECTION

Studies included phases 2 and 3 RCTs in the treatment of advanced melanoma that compared ICIs (ipilimumab, nivolumab, and pembrolizumab) with chemotherapy drugs (eg, dacarbazine, carboplatin, and paclitaxel) or different ICI regimens.

DATA EXTRACTION AND SYNTHESIS

Different treatment regimens were compared using bayesian network meta-analysis with Markov chain Monte Carlo simulation with noninformative prior distribution and random-effects generalized linear models.

MAIN OUTCOMES AND MEASURES

Primary outcomes were the cumulative incidence of any irAEs (regardless of severity) and severe irAEs (grades 3-5). Based on the pooled odds ratios (ORs) and 95% credible intervals (95% CrI), the probability of being associated with the lowest irAE risks was estimated for each treatment regimen.

RESULTS

Nine RCTs with 8 different treatment regimens for advanced melanoma and involving a total of 5051 patients were included. Overall, the 3 ICI treatment regimens associated with the lowest risk of any or severe irAEs were pembrolizumab, 2 mg/kg, every 3 weeks; nivolumab, 3 mg/kg, every 2 weeks; and pembrolizumab, 10 mg/kg, every 3 weeks. Compared with ipilimumab, 10 mg/kg, every 3 weeks, only nivolumab, 3 mg/kg, every 2 weeks, was associated with a decreased risk for any irAEs (OR, 0.34; 95% CrI, 0.13-0.94). A decreased risk for severe irAEs was observed for ipilimumab, 3 mg/kg, every 3 weeks (OR, 0.35; 95% CrI, 0.14-0.74); pembrolizumab, 10 mg/kg, every 2 weeks (OR, 0.22; 95% CrI, 0.05-0.95) and 10 mg/kg every 3 weeks (OR, 0.20; 95% CrI, 0.06-0.68); and nivolumab, 3 mg/kg, every 2 weeks (OR, 0.20; 95% CrI, 0.07-0.48) compared with ipilimumab, 10 mg/kg, every 3 weeks. An increased risk for severe irAEs was associated with nivolumab, 1 mg/kg, every 3 weeks combined with ipilimumab, 3 mg/kg, every 3 weeks compared with other ICI regimens (ORs ranging from 4.09 [95% CrI, 1.73-10.99] to 7.40 [95% CrI, 1.12-49.29]) except ipilimumab, 10 mg/kg, every 3 weeks.

CONCLUSIONS AND RELEVANCE

These findings suggest that for patients with advanced melanoma at high risk of irAEs, pembrolizumab, 2 mg/kg, every 3 weeks, nivolumab, 3 mg/kg, every 2 weeks, and pembrolizumab, 10 mg/kg, every 3 weeks may be the preferred treatment regimens (with respect to irAE risks) among the ICI regimens reported, whereas ipilimumab, 10 mg/kg, every 3 weeks alone and nivolumab, 1 mg/kg, every 3 weeks combined with ipilimumab, 3 mg/kg, every 3 weeks should be used with caution. A network analysis may be valuable for clinical decision-making when evidence from head-to-head comparisons is lacking.

Comprehensive assessment of HER2 alteration in a colorectal cancer cohort: from next-generation sequencing to clinical significance

Purpose

Human epidermal growth factor receptor 2 (HER2) is an emerging therapeutic target in colorectal cancer (CRC). Currently, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) have been used to determine HER2-positive CRCs; however, the clinical utility of next-generation sequencing (NGS)-based techniques for determining HER2 status in CRC has been limited. Here, we detail our experience regarding the assessment of HER2 alterations in a CRC cohort.

Materials and methods

We prospectively enrolled 73 CRC patients who underwent surgery and received adjuvant oxaliplatin treatment. We then examined HER2 alterations using the Oncomine Comprehensive Assay version 1, as well as clinical outcomes, in this cohort.

Results

Using the NGS-based assay, HER2 copy number gains in 12 of 73 CRCs were determined to range from 2.74 to 92.62. Of these 12 tumors, 6 had HER2 high-level copy number gain (92.6, 57.9, 57.0, 52.0, 35.2, and 8.42) and were all defined as HER2-positive CRC using HERACLES Diagnostic Criteria. Nevertheless, other 6 patients with low-level copy number gain (ranging from 2.74 to 3.04) and the remaining 61 patients without increase in HER2 copy number were all HER2-negative. Among the 6 HER2-positive CRCs, KRAS and PIK3CA mutations were detected in 1 (17%; G13D) and 2 (33.3%; 1 Q546R and 1 H1047R) patients, respectively. Moreover, 2 of the 6 (33.3%) HER2-positive patients had recurrent disease, while one patient had a partial response after anti-HER2 therapy.

Conclusion

NGS-based tools could assist in the simultaneous detection of HER2 and other genomic alterations in patients with CRC. Only CRCs with HER2 high-level copy number gain were HER2-postive by current diagnostic criteria.

Emergence of RAS mutations in patients with metastatic colorectal cancer receiving cetuximab-based treatment: a study protocol

Background

In the management of patients with RAS wild-type metastatic colorectal cancer (mCRC), anti-epidermal growth factor receptor (EGFR) therapies have demonstrated a clinical benefit, with longer survival. However, the correlation between the emergence of circulating RAS mutations and secondary resistance to anti-EGFR therapies requires further elucidation. In this study, we aim to examine evolutionary changes in RAS mutations through liquid biopsy in patients with mCRC during and after anti-EGFR therapy.

Methods

A total of 120 patients diagnosed with RAS wild-type mCRC will be enrolled in this study. Patients will receive a cetuximab-based infusional 5-fluorouracil regimen as first-line treatment. Cetuximab-based treatment is expected to continue until disease progression, intolerable toxic effects, or withdrawal of consent. Blood samples from enrolled patients will be collected before and then every 3 months during cetuximab-based treatment and also at disease progression. These blood samples will be evaluated for RAS resistance mutations by using the MassARRAY platform. The primary endpoint is the percentage of RAS mutations detected in circulating DNA from patients during cetuximab treatment. The correlation between the tumor response and survival outcomes of these patients and the emergence of circulating RAS mutations will be further analyzed.

Discussion

Liquid biopsy is a powerful technology that can represent tumor heterogeneity in a relatively noninvasive manner. Because RAS mutations play a major role in resistance to anti-EGFR therapy for mCRC, examining evolutionary changes in these mutations during such treatment through liquid biopsy would be useful. After comprehensively analyzing the emergence of circulating RAS mutations and its clinical relevance in this study, our results should provide practical guidance on anti-EGFR therapy for mCRC.

Trial registration

The date of trial registration (NCT03401957) in this study was January 17, 2018.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5826-7) contains supplementary material, which is available to authorized users.

Germline susceptibility variants impact clinical outcome and therapeutic strategies for stage III colorectal cancer

Although somatic mutations are the main cause of cancer, underlying germline alterations may affect cancer outcome. There is little information on comprehensive analysis of germline genome sequencing for cancer healthcare strategy. Here we studied the implication of germline cancer-associated variants on cancer counselling and therapeutic strategies by germline whole genome and tumor targeted sequencing. Fifty-five gynecological and 104 colorectal cancer (CRC) patients were enrolled. We identified 22 germline pathogenic variants in 16 cancer-associated genes. Most of them are involved in DNA repair signaling, including MLH1, BRCA1/2, MUTYH, ATM, PMS2, MSH6, BAP1, and FANCA. About 6% of cancer patients presented the secondary findings of germline variants with non-oncogenic impact, mainly on the cardiovascular system which should be carefully monitored during chemotherapy. CRC patients carrying germline susceptibility variants had better disease-free survival than those without variants. Importantly, in the CRC model, the underlying germline alterations mold the tumor somatic alteration landscape. NOTCH1 mutation was the most common somatic mutation in recurrent CRC, implying a potential therapeutic target in adjuvant setting. In conclusion, both tumor genome and germline sequence data have to be analyzed to have a more complete picture of the overall genetic foundation of cancer.

The c.1085A>G Genetic Variant of CSF1R Gene Regulates Tumor Immunity by Altering the Proliferation, Polarization, and Function of Macrophages

Purpose: Targeting tumor-associated macrophages with colony-stimulating factor 1 receptor (CSF-1R) inhibition reveals a strategy for cancer therapy. Here, we studied the impact of CSF1R germline genetic variant on CSF-1R signaling and the susceptibility to CSF-1R inhibitors.Experimental designs:CSF1R germline genetic variants were studied in 140 cancer patients. CSF-1R phosphorylation, endocytosis, and macrophage polarization were measured as the response to CSF-1 stimulation. Tumor-associated macrophages in surgical specimens and sensitivity to CSF-1R inhibitors were used to determine macrophage function.Results: A CSF1R c.1085A>G genetic variant causing the change of histidine to arginine in the domain of receptor dimerization was identified as a high allele frequency in Eastern Asian population. Cancer patients with this variant allele had less M2-like tumor-associated macrophages accompanied by low VEGF expression in tumor tissues. Importantly, CSF1R genetic variant was significantly associated with disease-free survival in colorectal, endometrial, and ovarian cancer. In terms of differentiation, macrophages with CSF1R c.1085A>G genetic variant displayed a refractory response to CSF-1 stimulation and macrophage survival was sensitive to CSF-1R inhibitors with IC₅₀ of 0.1 to 1 nmol/L range. On contrast, CSF-1 induced a prominent phosphorylation and rapid endocytosis of CSF-1R, leading to an M2-like dominant polarization in macrophages with CSF1R c.1085 genotype A_A, in which CSF-1R inhibitors of PLX3397, BLZ945, and GW2580 inhibited macrophage survival with IC₅₀ of 10 to 100 nmol/L range.Conclusions: The CSF1R c.1085A>G genetic variant regulates tumor immunity by altering the polarization and function of macrophages. This genetic variant confers the sensitivity to CSF-1R inhibitors, implying as a biomarker in targeting CSF-1R signaling for cancer treatment. Clin Cancer Res; 23(20); 6021-30. ©2017 AACR.

Minoxidil is a potential neuroprotective drug for paclitaxel-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment. No medication has been shown to be effective in the treatment of CIPN. This study aims to integrate the image-based high-content screening, mouse behavior models and mechanistic cell-based assays to discover potential neuroprotective drugs. Among screened compounds, minoxidil showed the most potent neuroprotective effect against paclitaxel, with regard to neurite outgrowth of dorsal root ganglia (DRG). Minoxidil protected mice from thermal insensitivity and alleviated mechanical allodynia in paclitaxel-treated mice. The ultrastructure and quantified G-ratio of myelin integrity of sciatic nerve tissues supported the observations in mouse behavioral tests. The mechanistic study on DRG neurons suggested that minoxidil suppressed neuroinflammation and remodeled the dysregulation of intracellular calcium homeostasis provoked by paclitaxel. Importantly, minoxidil showed a synergistic anti-tumor effect with paclitaxel both in tumor xenograft models of cervical and breast cancer. Interestingly, the quantitative assays on hair length and hair growth both exhibited that minoxidil significantly improved the hair quality after chemotherapy. Since minoxidil is a drug approved by the Food and Drug Administration (FDA), the safety and biocompatibility are well documented. The immediate next step is to launch an early-stage clinical trial intending to prevent CIPN by minoxidil.

Monoclonality and cytogenetic abnormalities in hyaline vascular Castleman disease

Hyaline vascular Castleman disease is traditionally regarded as a reactive hyperplastic process. Occasional cases, however, have been reported with cytogenetic anomalies bringing this concept into question. In this study, we used conventional and methylation-specific polymerase chain reaction methods to assess the human androgen receptor α (HUMARA) gene in 29 female patients with hyaline vascular Castleman disease and compared the results with three cases of plasma cell Castleman disease and 20 cases of age-matched lymphoid hyperplasia. We also assessed for immunoglobulin gene and T-cell receptor gene rearrangements, and conventional cytogenetic analysis was performed in three cases of hyaline vascular Castleman disease. In cases with informative results, conventional and methylation-specific human androgen receptor α gene analyses yielded a monoclonal pattern in 10 of 19 (53%) and 17 of 23 (74%) cases of hyaline vascular Castleman disease, respectively. A monoclonal pattern was also detected in three cases of plasma cell Castleman disease but not in cases of lymphoid hyperplasia. The frequency of monoclonality was higher for lesions >5 cm in size (100%) and for the stromal-rich variant (91%). Cytogenetic abnormalities in stromal cells were revealed in two cases of hyaline vascular Castleman disease and no cases showed monoclonal immunoglobulin or T-cell receptor gene rearrangements. Follow-up data showed persistent disease in 4 of 23 (17%) patients. We conclude that hyaline vascular Castleman disease is often a monoclonal proliferation, most likely of lymph node stromal cells.

Ran GTPase-activating protein 1 is a therapeutic target in diffuse large B-cell lymphoma

Lymphoma-specific biomarkers contribute to therapeutic strategies and the study of tumorigenesis. Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma. However, only 50% of patients experience long-term survival after current treatment; therefore, developing novel therapeutic strategies is warranted. Comparative proteomic analysis of two DLBCL lines with a B-lymphoblastoid cell line (LCL) showed differential expression of Ran GTPase-activating protein 1 (RanGAP1) between them, which was confirmed using immunoblotting. Immunostaining showed that the majority of DLBCLs (92%, 46/50) were RanGAP1(+), while reactive lymphoid hyperplasia (n = 12) was RanGAP1(+) predominantly in germinal centers. RanGAP1 was also highly expressed in other B-cell lymphomas (BCL, n = 180) with brisk mitotic activity (B-lymphoblastic lymphoma/leukemia: 93%, and Burkitt lymphoma: 95%) or cell-cycle dysregulation (mantle cell lymphoma: 83%, and Hodgkin's lymphoma 91%). Interestingly, serum RanGAP1 level was higher in patients with high-grade BCL (1.71 ± 2.28 ng/mL, n = 62) than in low-grade BCL (0.75 ± 2.12 ng/mL, n = 52) and healthy controls (0.55 ± 1.58 ng/mL, n = 75) (high-grade BCL vs. low-grade BCL, p = 0.002; high-grade BCL vs. control, p < 0.001, Mann-Whitney U test). In vitro, RNA interference of RanGAP1 showed no effect on LCL but enhanced DLBCL cell death (41% vs. 60%; p = 0.035) and cell-cycle arrest (G0/G1: 39% vs. 49%, G2/M: 19.0% vs. 7.5%; p = 0.030) along with decreased expression of TPX2 and Aurora kinases, the central regulators of mitotic cell division. Furthermore, ON 01910.Na (Estybon), a multikinase inhibitor induced cell death, mitotic cell arrest, and hyperphosphorylation of RanGAP1 in DLBCL cell lines but no effects in normal B and T cells. Therefore, RanGAP1 is a promising marker and therapeutic target for aggressive B-cell lymphoma, especially DLBCL.

Large B cell lymphoma presenting initially in bone marrow, liver and spleen: an aggressive entity associated frequently with haemophagocytic syndrome

AIMS

To describe diffuse large B cell lymphoma (DLBCL) presenting initially in bone marrow, liver and spleen (BLS-type) without lymphadenopathy.

METHODS AND RESULTS

The clinicopathological and cytogenetic features of 11 such cases (eight men, three women; mean age: 62.7 years are described). Usually presenting with fever and haemophagocytic syndrome suggesting infection and complicating timely diagnosis, bone marrow examination showed patchy and interstitial infiltration of large tumour cells without sinusoidal involvement. All cases had a high Ki-67 index (≥90%), commonly a non-germinal centre/activated B cell immunophenotype and were negative for Epstein-Barr virus and human herpesvirus 6 and 8. The more frequent cytogenetic changes involved chromosomal loci 14q32 and 9p24, as well as del(3)(q21), add(7)(p22), t(3;6), del(8)(p22), +18 and add(19)(p13). Clinical behaviour was very aggressive, with a 2-year survival rate of 18% (45% of patients died within 3 weeks). High-dose chemotherapy with haematopoietic stem cell transplantation prolonged survival in one patient.

CONCLUSIONS

Although it shares with intravascular LBCL a subtle presentation and an aggressive clinical course, this primary BLS large cell lymphoma variant is distinguished by lacking an intravascular component and having different cytogenetic findings.

High percentage of JAK2 exon 12 mutation in Asian patients with polycythemia vera

We examined the occurrence of JAK2(V617F) and JAK2 exon 12 mutations in a clinical cohort of polycythemia vera (PV) in Taiwan. Of 22 patients with PV, 17 (77%) had the V617F mutation, and all 5 V617F-negative patients (23%) had the exon 12 mutation. We found 3 different exon 12 mutations: 3 N542-E543del, 1 F537-K539delinsL, and 1 novel mutation, I540-E543delinsKK. Patients with V617F showed significantly higher WBC and platelet counts at diagnosis than patients with exon 12 mutations (P = .021 and P = .038, respectively). We report a surprisingly high incidence of exon 12 mutations in Taiwanese patients with PV, a result quite different from reports in the Western literature (P = .001). Our data suggest that exon 12 mutation of JAK2 in patients with PV may have an uneven geographic distribution. A clinical laboratory providing the V617F test alone may risk missing a substantial number of patients with PV in areas with a high incidence of exon 12 mutation.

Hypocholesterolemic agents VII: Inhibition of beta-hydroxy-beta-methylglutaryl-CoA reductase by monoesters of substituted glutaric acids

A series of 1-(4-biphenylyl)pentyl hydrogen 3-alkylglutarates and 3-hydroxy-3-alkylglutarates was synthesized and assayed for inhibition of rat liver beta-hydroxy-beta-methylglutaryl-CoA reductase. Limited solubility of the monoesters in the enzyme assay system prevented the determination of the I50 values. However, the limited data indicated no significant changes in the activity of the analogs when they were assayed at identical concentrations.