The role of tumor-associated macrophages in gastric cancer development and their potential as a therapeutic target

Gastric cancer (GC) represents the fifth cause of cancer-related death worldwide. Molecular biology has become a central area of research in GC and there are currently at least three major classifications available to elucidate the mechanisms that drive GC oncogenesis. Further, tumor microenvironment seems to play a crucial role, and tumor-associated macrophages (TAMs) are emerging as key players in GC development. TAMs are cells derived from circulating chemokine- receptor-type 2 (CCR2) inflammatory monocytes in blood and can be divided into two main types, M1 and M2 TAMs. M2 TAMs play an important role in tumor progression, promoting a pro-angiogenic and immunosuppressive signal in the tumor. The diffuse GC subtype, in particular, seems to be strongly characterized by an immuno-suppressive and pro-angiogenic phenotype. No molecular targets in this subgroup have yet been identified. There is an urgent need to understand the molecular pathways and tumor microenvironment features in the GC molecular subtypes. The role of anti-angiogenics and checkpoint inhibitors has recently been clinically validated in GC. Both ramucirumab, a fully humanized IgG1 monoclonal anti-vascular endothelial growth factor receptor 2 (VEGFR2) antibody, and checkpoint inhibitors in Epstein Bar Virus (EBV) and Microsatellite Instable (MSI) subtypes, have proved beneficial in advanced GC. Nevertheless, there is a need to identify predictive markers of response to anti-angiogenics and immunotherapy in clinical practice for a personalized treatment approach. The importance of M2 TAMs in development of solid tumors is currently gaining increasing interest. In this literature review we analyze immune microenvironment composition and signaling related to M1 and M2 TAMs in GC as well as its potential role as a therapeutic target.

Targeted next-generation sequencing of circulating-tumor DNA for tracking minimal residual disease in localized colon cancer

BACKGROUND

A high percentage of patients diagnosed with localized colon cancer (CC) will relapse after curative treatment. Although pathological staging currently guides our treatment decisions, there are no biomarkers determining minimal residual disease (MRD) and patients are at risk of being undertreated or even overtreated with chemotherapy in this setting. Circulating-tumor DNA (ctDNA) can to be a useful tool to better detect risk of relapse.

PATIENTS AND METHODS

One hundred and fifty patients diagnosed with localized CC were prospectively enrolled in our study. Tumor tissue from those patients was sequenced by a custom-targeted next-generation sequencing (NGS) panel to characterize somatic mutations. A minimum variant allele frequency (VAF) of 5% was applied for variant filtering. Orthogonal droplet digital PCR (ddPCR) validation was carried out. We selected known variants with higher VAF to track ctDNA in the plasma samples by ddPCR.

RESULTS

NGS found known pathological mutations in 132 (88%) primary tumors. ddPCR showed high concordance with NGS (r = 0.77) for VAF in primary tumors. Detection of ctDNA after surgery and in serial plasma samples during follow-up were associated with poorer disease-free survival (DFS) [hazard ratio (HR), 17.56; log-rank P = 0.0014 and HR, 11.33; log-rank P = 0.0001, respectively]. Tracking at least two variants in plasma increased the ability to identify MRD to 87.5%. ctDNA was the only significantly independent predictor of DFS in multivariable analysis. In patients treated with adjuvant chemotherapy, presence of ctDNA after therapy was associated with early relapse (HR 10.02; log-rank P < 0.0001). Detection of ctDNA at follow-up preceded radiological recurrence with a median lead time of 11.5 months.

CONCLUSIONS

Plasma postoperative ctDNA detected MRD and identified patients at high risk of relapse in localized CC. Mutation tracking with more than one variant in serial plasma samples improved our accuracy in predicting MRD.

Current questions for the treatment of advanced gastric cancer

BACKGROUND

Gastric cancer remains a major health problem worldwide. Treatment of advanced gastric cancer is controversial and there is no standard regimen for first- or second-line chemotherapy (CT). This review aims to give an overview of the hot topics concerning treatment, prognostic factors and new strategies in advanced gastric cancer.

MATERIAL AND METHODS

Seven questions of special clinical interest have been formulated previously to the literature review. With the aim of answering each of these questions, a specific search of the relevant trials and meta-analyses published or communicated from 1990 to date was performed.

RESULTS

Patients treated with CT have a survival benefit over those treated with only best supportive care (BSC). Such active cytotoxic drugs as cisplatin or docetaxel and targeted agents as trastuzumab showed superiority in randomized trials. Other agents such as oxaliplatin, oral fluoropyrimidines and irinotecan showed non-inferiority or less toxic results, positioning them as valuable alternatives to classical schedules. Combination regimens seem to be an improvement over single agent therapy. However, increased toxicity of some regimens makes their general use difficult. Second-line CT is of value for selected patients with good performance status. Trastuzumab is the only targeted agent showing better survival when added to chemotherapy in HER2-driven tumors.

CONCLUSIONS

With the introduction of new agents, management of advanced gastric cancer has experienced important changes. First and second-line CT improve survival in patients with good performance status. Future trials should address how to better select patients for new, targeted agents, based upon validated predictive biomarkers.

Determination of L-ascorbic acid in Lycopersicon fruits by capillary zone electrophoresis

This study shows an improved method for the determination of L-ascorbic acid (l-AA) in fruits of Lycopersicon by capillary zone electrophoresis (CZE). Two backgrounds electrolytes (BGEs) have been tested: (i) 400 mM borate at pH 8.0 and 1 x 10(-2)% hexadimethrine bromide, for the separation of Eulycopersicon subgenus species; and (ii) as in BGE(i) but supplemented with 20% (v/v) acetonitrile, for the separation of species of the Eriopersicon subgenus. The present procedures were compared with two routine methods-enzymatic assay and potentiometric titration with 2,6-dichlorophenol-indophenol. While these routine methods presented some difficulties in quantifying l-AA in several Lycopersicon fruits, CZE was successfully applied in all the analyzed samples. The proposed CZE protocols give lower detection limits (<0.4 microg ml(-1)); are cheaper, quicker, and highly reproducible; and can be applied to analyze large series of samples (ca. 50 samples per day) which is utmost importance, not only in screening trials for internal quality and tomato breeding programs, but also in systematic and routine characterization of Lycopersicon fruits.

Phase I study of FOLFIRI plus pimasertib as second-line treatment for KRAS-mutated metastatic colorectal cancer

Background:

The mitogen-activated protein kinase (MAPK) pathway has been implicated in the molecular pathogenesis of human cancers, including metastatic colorectal cancer (mCRC). This provides a rationale for the development of MAPK-targeted agents such as pimasertib.

Methods:

Patients with KRAS mutant mCRC were treated in the second-line setting with FOLFIRI (5-fluorouracil/folinic acid/irinotecan) plus pimasertib. The primary objective of the safety run-in phase was to determine the maximum-tolerated dose (MTD) and the recommended phase II dose of pimasertib combined with FOLFIRI.

Results:

Sixteen patients were enrolled in the trial. Ten and six patients were treated daily with 45 and 60 mg of pimasertib plus FOLFIRI, respectively. The MTD was considered to be 45 mg per day. The most common treatment-emergent adverse events were diarrhoea, nausea, vomiting, asthenia and skin/rash event. Of the 15 patients in the efficacy analysis group, two patients had partial response, nine patients had stable disease, three patients had progressive disease as their best overall response and one patient could not be evaluated.

Conclusions:

Dose escalation of pimasertib in combination with FOLFIRI was limited by toxicity. At the MTD of 45 mg per day, pimasertib was adequately tolerated in patients with mCRC and no unexpected or new safety signals or concerns were identified.

Towards precision oncology for HER2 blockade in gastroesophageal adenocarcinoma

Gastroesophageal adenocarcinoma (GEA) represents a very heterogeneous disease and patients in advanced stages have a very poor prognosis. Although several molecular classifications have been proposed, precision medicine for HER2-amplified GEA patients still represents a challenge. Despite improvement in clinical outcomes obtained by adding trastuzumab to first-line platinum-based chemotherapy, no other anti-HER2 agents used first-line or beyond progression have demonstrated any benefit. Several factors contribute to this failure. Among them, variable HER2 amplification assessment, tumour heterogeneity, molecular mechanisms of resistance and microenvironmental factors could limit the effectiveness of anti-HER2 blockade. Identifying the factors responsible for both primary and acquired resistance is a priority for providing an improved, personalised approach. In this review, we examine current treatments for HER2-amplified GEA, their potential mechanisms of resistance and the ways to overcome them, investigating the most relevant translational studies with anti-HER2 agents in GEA, as well as novel agents under development in this field.

Phase I pharmacokinetic (PK) and pharmacodynamic (PD) study of MLN8237, a novel selective aurora A kinase (AAK) inhibitor, in patients (pts) with advanced solid tumors

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Background: MLN8237 is a second-generation, selective AAK inhibitor, designed to avoid benzodiazepine-like effects (somnolence) observed with another agent, MLN8054. This phase I trial examines the safety, PK, and PD of MLN8237 administered orally (PO) in pts with advanced solid tumors. Methods: Pts received MLN8237 PO once daily (QD) or twice daily (BID) for 7 days (d) followed by a 14d recovery period. Tumor and skin biopsies were done serially to evaluate bioactivity measured by mitotic index and chromosome and spindle abnormalities in mitotic cells. Doses were increased in cohorts of 3–6 pts until dose-limiting toxicity (DLT) evaluated in the first cycle was seen in ≥2 pts in a cohort. Results: As of 12-Dec-08, 27 pts received MLN8237 (median 2 cycles, range 1–10+); median age was 57 yr (range 31–78). The first cohort received 5mg QD. Higher QD doses were safe in another Phase 1 study (Infante et al, EJC Suppl 2008;6[12]:90), so subsequent cohorts in this study started at 80mg QD (Table). DLTs at 60–100mg PO BID included neutropenia, pancytopenia, stomatitis, and somnolence. Somnolence (of any grade) was seen with QD dosing, but was reduced with divided doses each <100 mg. Antitumor activity was seen in a pt in cohort 4 with a large treatment-resistant pleomorphic liposarcoma. Preliminary PK analyses showed dose-dependent increases in AUC0–24 and Cmax. Consistent with Aurora A inhibition, increased mitotic index in skin and tumor biopsies after MLN8237 dosing was coupled with decreased bipolar spindles and aligned chromosomes in mitotic cells from tumor biopsies. Conclusions: At the doses and schedule evaluated, MLN8237 is tolerable with BID dosing x7d and exhibits favorable PK, PD, and clinical antitumor activity. Additional planned cohorts include extended dosing for 14–21d in 28–35d cycles. The results support future phase 2 development.

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[Table: see text]

Parotid gland metastasis of a breast cancer

Parotid gland metastases from malignant tumors are extremely rare. A 61-year-old woman was diagnosed with an early breast cancer with no expression of oestrogen and progesterone receptors. Five years later the patient presented a tumour in parotid gland. After total parotidectomy, microscopic analysis of the gland demonstrated an invasive duct carcinoma (IDC) with positive expression of oestrogen receptor. The patient was treated with chemotherapy followed by complementary local radiotherapy. Diagnosis of a metastasic tumour in parotid gland poses a challenge. In our case an immunohistochemical study of oestrogen receptor was fundamental to establish a diagnosis.

Phase I pharmacokinetic (PK) and pharmacodynamic (PD) study of the selective aurora A kinase (AAK) inhibitor MLN8054 in patients (pts) with advanced solid tumors

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Background: MLN8054, a first-generation, selective AAK inhibitor, induces chromosome alignment and segregation defects during mitosis, leading to cell death (Hoar et al, MolCellBio 2007;27:4513). This phase I trial examined the safety, PK, and PD of MLN8054 administered orally to adult pts with advanced solid tumors. Methods: Pts received increasing oral doses of MLN8054 until dose-limiting toxicity (DLT) in the first cycle was seen in ≥2 of 3–6 pts in a cohort. Two cohorts received 10 and 20 mg once daily (QD) on d1–5 and d8–12 of 28d cycles. Benzodiazepine-like adverse effects (somnolence) associated with chemical structure and presumably unrelated to AAK inhibition were observed with QD dosing in another Phase 1 study (Dees et al, EJC Suppl 2008;6[12]:91), so subsequent cohorts in this trial were treated with 25, 35, 45, 55, 60, 70, and 80 mg/d in four divided doses (QID) on d1–14, with the largest dose at night. To manage somnolence, methylphenidate 5–15 mg was permitted with daytime doses in the 45–80 mg cohorts. Results: 43 pts received MLN8054 (median 1 cycle [range 1–10]). Dose escalation stopped at 80 mg/d due to DLTs including G3 somnolence (n=1) and G3 transaminitis (n=1). G2 oral mucositis (n=1), which may signal target-related toxicity, was observed first at 80 mg/d, a dose considered to be above the MTD. In PK analyses, MLN8054 was absorbed rapidly (Tmax = 1–2h) and terminal half-life was 30–40h, presenting a linear exposure-dose profile. In PD analyses, MLN8054 at higher doses increased mitotic count in skin and tumor biopsies and reduced chromosome alignment and spindle bipolarity in the mitotic cells in tumor biopsies, outcomes consistent with AAK inhibition. Stable disease (range 4–9 cycles) was observed in 3 pts (colorectal, non-small cell lung, and melanoma). Conclusions: MLN8054 was absorbed rapidly with a long half-life; PD findings supported MLN8054 inhibition of AAK at higher doses. Dosing for 14d of a 28-d cycle was feasible, but off-target DLTs limited dose escalation before mechanism-based toxicity was seen. MLN8237, a second-generation AAK inhibitor designed with greater mechanistic potency and to minimize benzodiazepine effects, is now in clinical trials.

[Table: see text]

Impact of the COVID-19 Pandemic on a Cancer Fast-Track Programme

INTRODUCTION

The COVID-19 pandemic has disrupted many aspects of clinical practice in oncology, particularly regarding early cancer diagnosis, sparking public health concerns that possible delays could increase the proportion of patients diagnosed at advanced stages. In 2009, a cancer fast-track program (CFP) was implemented at the Clinico-Malvarrosa Health Department in Valencia, Spain with the aim of shortening waiting times between suspected cancer symptoms, diagnosis and therapy initiation.

OBJECTIVES

The study aimed to explore the effects of the COVID-19 pandemic on our cancer diagnosis fast-track program.

METHODS

The program workflow (patients included and time periods) was analysed from the beginning of the state of alarm on March 16th, 2020 until March 15th, 2021. Data was compared with data from the same period of time from the year before (2019).

RESULTS

During the pandemic year, 975 suspected cancer cases were submitted to the CFP. The number of submissions only decreased during times of highest COVID-19 incidence and stricter lockdown, and overall, referrals were slightly higher than in the previous 2 years. Cancer diagnosis was confirmed in 197 (24.1%) cases, among which 33% were urological, 23% breast, 16% gastrointestinal and 9% lung cancer. The median time from referral to specialist appointment was 13 days and diagnosis was reached at a median of 18 days. In confirmed cancer cases, treatment was started at around 30 days from time of diagnosis. In total, 61% of cancer disease was detected at early stage, 20% at locally advanced stage, and 19% at advanced stage, displaying time frames and case proportions similar to pre-pandemic years.

CONCLUSIONS

Our program has been able to maintain normal flow and efficacy despite the challenges of the current pandemic, and has proven a reliable tool to help primary care physicians referring suspected cancer patients.

The action of glucosulphone [N,N'-di (glucose sodium sulphonate) of 4,4'-diaminodiphenyl sulphone] on pancreatic kallikrein

1. The effects of sulphone have been studied on kinin production in dog plasma and on capillary permeability in the skin of rabbits.2. Dog plasma was used as a substrate for pancreatic kallikrein in vitro and the addition of sulphone caused an inhibition of kinin production, which was dependent on the concentration of the drug.3. The increased vascular permeability produced in vivo by intradermal injections of kallikrein was partially inhibited by sulphone injected intravenously. The same doses of sulphone also inhibited the increase in permeability produced by bradykinin and histamine in the skin of rabbits.