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Invasion and metastasis are hallmarks of cancer. In addition to the well-recognized hematogenous and lymphatic pathways of metastasis, cancer cell dissemination can occur via the transcoelomic and perineural routes, which are typical of ovarian and pancreatic cancer, respectively. Macrophages are a universal major component of the tumor microenvironment and, in established tumors, promote growth and dissemination to secondary sites. Here, we review the role of tumor-associated macrophages (TAMs) in cancer cell dissemination and metastasis, emphasizing the diversity of myeloid cells in different tissue contexts (lungs, liver, brain, bone, peritoneal cavity, nerves). The generally used models of lung metastasis fail to capture the diversity of pathways and tissue microenvironments. A better understanding of TAM diversity in different tissue contexts may pave the way for tailored diagnostic and therapeutic approaches., (© 2024. The Author(s).)

Tumour-associated macrophages are an essential component of the tumour microenvironment and have a role in the orchestration of angiogenesis, extracellular matrix remodelling, cancer cell proliferation, metastasis and immunosuppression, as well as in resistance to chemotherapeutic agents and checkpoint blockade immunotherapy. Conversely, when appropriately activated, macrophages can mediate phagocytosis of cancer cells and cytotoxic tumour killing, and engage in effective bidirectional interactions with components of the innate and adaptive immune system. Therefore, they have emerged as therapeutic targets in cancer therapy. Macrophage-targeting strategies include inhibitors of cytokines and chemokines involved in the recruitment and polarization of tumour-promoting myeloid cells as well as activators of their antitumorigenic and immunostimulating functions. Early clinical trials suggest that targeting negative regulators (checkpoints) of myeloid cell function indeed has antitumor potential. Finally, given the continuous recruitment of myelomonocytic cells into tumour tissues, macrophages are candidates for cell therapy with the development of chimeric antigen receptor effector cells. Macrophage-centred therapeutic strategies have the potential to complement, and synergize with, currently available tools in the oncology armamentarium., (© 2022. Springer Nature Limited.)

Myeloid cells in tumor tissues constitute a dynamic immune population characterized by a non-uniform phenotype and diverse functional activities. Both tumor-associated macrophages (TAMs), which are more abundantly represented, and tumor-associated neutrophils (TANs) are known to sustain tumor cell growth and invasion, support neoangiogenesis and suppress anticancer adaptive immune responses. In recent decades, several therapeutic approaches have been implemented in preclinical cancer models to neutralize the tumor-promoting roles of both TAMs and TANs. Some of the most successful strategies have now reached the clinic and are being investigated in clinical trials. In this review, we provide an overview of the recent literature on the ever-growing complexity of the biology of TAMs and TANs and the development of the most promising approaches to target these populations therapeutically in cancer patients.

The peripheral nervous system and the immune system are critically involved in the surveillance of our body, having the ability to sense the environment, recognize danger signals and orchestrate an appropriate response. Despite the fact that these two systems have been historically considered autonomous entities, a large body of evidence has shown how they interact in many homeostatic responses and how these interactions are critically involved in pathologic contexts too, including inflammation, infection and autoimmunity. In the context of cancer, where it is already known that inflammation plays a key role, the cross-regulation of immune cells and neural components is still somewhat unexplored. Detailed characterization of the mediators and pathways involved in neuro-immune interactions in cancer is expected to provide insights into the pathogenesis of disease and open new possibilities related to therapeutic strategies., (Copyright © 2020 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.)

Tumor tissues are populated by a multitude of macrophages, highly different in functional activity, localization and morphology. A clear contribution to disease progression has been shown in multiple cancer types, holding promise for the development of innovative macrophage-based prognostic tools. Current studies aimed at assessing the prognostic role of macrophages have documented the relevance of the macrophage population as a whole. However, dissecting the diversity of mononuclear phagocytes in tumor tissues has provided important information about the coexistence of distinct populations of macrophages with different prognostic significance. Here we summarize evidence of macrophage prognostic function in human cancer and focus on classical and modern strategies aimed at measuring macrophage features and deciphering their diversity. The wealth of new data generated will reshape our knowledge of macrophage complexity and hopefully foster the forthcoming development of these new metrics into prognostic tools as well as new therapeutic strategies., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Macrophages are essential elements in the tumor microenvironment, where they can promote tumor growth but also influence the efficacy of anticancer strategies. In conventional therapies, chemotherapy and radiotherapy, TAMs play a dichotomous role, contributing to antitumor activity or hindering the efficacy of cytoreductive therapies. Macrophages express checkpoint ligands and are therefore targets of immunotherapy approaches based on checkpoint inhibitors. Targeted therapies with monoclonal antibodies elicit TAMs to engage in antitumor functions such as antibody-dependent phagocytosis through the activation of Fc receptors. New approaches to exploit macrophage effector functions induced by therapeutic antibodies are under investigation. Finally, strategies aimed at targeting TAM recruitment, survival and functional polarization are advancing towards the clinic. Collectively, TAM-centered strategies will hopefully complement conventional and unconventional anticancer therapies to achieve improved therapeutic benefit.

We have reported that cancer patients treated with anthracycline-based or nonanthracycline chemotherapy developed an early impairment of myocardial relaxation at echocardiography or persistent elevations of the cardiac hormone B-type natriuretic peptide (BNP). Post-hoc pharmacologic analyses showed that BNP elevations were induced by impaired relaxation and caused positive lusitropic effects that maintained normal relaxation. High BNP levels and impaired relaxation were therefore characterized as mutually exclusive manifestations of diastolic dysfunction, but high BNP levels resulted in positive chronotropism and inappropriate tachycardia. Some patients developed increased circulating levels of cardiac troponin I isoform (cTnI), a marker of cardiomyocyte necrosis. Here we have characterized whether cTnI elevations correlated with diastolic dysfunction that manifested as impaired relaxation or a high level of BNP. The effects of high BNP levels on cTnI elevations were also characterized. We show that impaired relaxation or high BNP levels were significantly more frequent in patients with cTnI elevations. High BNP levels diminished the plasma peak and area under the curve of cTnI, but this result was accompanied by inappropriate tachycardia. cTnI elevations occurred only in patients treated with anthracyclines; moreover, the association of impaired relaxation or high BNP levels with cTnI elevations was significantly more frequent in doxorubicin-treated patients compared with patients treated with its analog, epirubicin. These findings describe cause-and-effect relations between impaired relaxation and cardiomyocyte necrosis, illuminate the role of anthracycline analogs, denote that the beneficial effects of BNP in relieving impaired relaxation and cardiomyocyte necrosis are counterbalanced by inappropriate tachycardia. Patients showing troponin elevations and impaired relaxation or high BNP levels should be treated with lusitropic drugs that lack a positive chronotropism., (Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.)

Asymptomatic diastolic dysfunction (DD) with preserved left ventricular ejection fraction (LVEF) is suspected to precede late cardiac events in cancer survivors treated by chemotherapy. We conducted the first multicenter study of early DD induced by chemotherapy. Patients who were candidates for standard dose chemotherapy were screened for the absence of cardiovascular risk factors, LVEF ≥50%, normal-for-age diastolic function at echocardiography (E/A ratio, E wave deceleration time; DT), normal levels of potential DD biomarkers like Nt-proBNP (≤125 pg/mL), and cardiac troponin I (cTnI, ≤0.05 ng/mL). Mitral Doppler (E/E') was left at the investigator's discretion. Chemotherapy-induced DD with preserved LVEF was diagnosed for patients showing LVEF ≥50% and any of the following: Nt-proBNP > 125 pg/mL, cTnI > 0.05 ng/mL, and out-of-range E/A and DT. Eighty patients (68 females, 12 males, median age 49 years) were evaluated at 1 week after chemotherapy (T1) [corrected]. Thirty-three protocol-defined diastolic events were observed (15 Nt-proBNP > 125 pg/mL, 14 grade I DD by E/A and DT, 4 cTnI > 0.05 ng/mL). The events occurred in 29 asymptomatic patients with LVEF ≥50% (36% incidence of DD with preserved LVEF). Interactions occurred between biomarkers and grade I DD. E/E' abnormalities were not observed. Both anthracycline-based and nonanthracycline regimens induced DD. These findings show that biomarkers and echocardiography intercept early DD in otherwise asymptomatic low-risk cancer patients treated by standard dose chemotherapy. These findings therefore call for the adequate cardiac management of cancer patients., (© 2018 S. Karger AG, Basel.)

Macrophages are crucial drivers of tumour-promoting inflammation. Tumour-associated macrophages (TAMs) contribute to tumour progression at different levels: by promoting genetic instability, nurturing cancer stem cells, supporting metastasis, and taming protective adaptive immunity. TAMs can exert a dual, yin-yang influence on the effectiveness of cytoreductive therapies (chemotherapy and radiotherapy), either antagonizing the antitumour activity of these treatments by orchestrating a tumour-promoting, tissue-repair response or, instead, enhancing the overall antineoplastic effect. TAMs express molecular triggers of checkpoint proteins that regulate T-cell activation, and are targets of certain checkpoint-blockade immunotherapies. Other macrophage-centred approaches to anticancer therapy are under investigation, and include: inhibition of macrophage recruitment to, and/or survival in, tumours; functional re-education of TAMs to an antitumour, 'M1-like' mode; and tumour-targeting monoclonal antibodies that elicit macrophage-mediated extracellular killing, or phagocytosis and intracellular destruction of cancer cells. The evidence supporting these strategies is reviewed herein. We surmise that TAMs can provide tools to tailor the use of cytoreductive therapies and immunotherapy in a personalized medicine approach, and that TAM-focused therapeutic strategies have the potential to complement and synergize with both chemotherapy and immunotherapy.

The 129 mouse strain is commonly used for the generation of genetically engineered mice. Genetic drift or accidental contamination during outcrossing has resulted in several 129 substrains. Comprehensive data on spontaneous age-related pathology exist for the 129S4/SvJae substrain, whereas only limited information is available for other 129 substrains. This longitudinal aging study describes the life span and spontaneous lesions of 44 male and 18 female mice of the 129S6/SvEvTac substrain. Median survival time was 778 and 770 days for males and females, respectively. Tumors of lung and Harderian gland were the most common neoplasms in both sexes. Hepatocellular tumors occurred mainly in males. Hematopoietic tumors were observed at low frequency. Suppurative and ulcerative blepharoconjunctivitis was the most common nonneoplastic condition in both sexes. Corynebacteria (primarily Corynebacterium urealyticum and C. pseudodiphtheriticum) were isolated from animals with blepharoconjunctivitis and in some cases from unaffected mice, although a clear causal association between corynebacterial infections and blepharoconjunctivitis could not be inferred. Polyarteritis occurred only in males and was identified as the most common nonneoplastic contributory cause of death. Eosinophilic crystalline pneumonia occurred in both sexes and was a relevant cause of death or comorbidity. Epithelial hyalinosis at extrapulmonary sites was noted at higher frequency in females. This study contributes important data on the spontaneous age-related pathology of the 129S6/SvEvTac mouse substrain and is a valuable reference for evaluation of the phenotype in genetically engineered mice obtained with this 129 substrain., (© The Author(s) 2015.)

Recruitment of immune and inflammatory cells in the microenvironment of solid tumors is highly heterogeneous and follows patterns, varying according to the organ of origin and stage of disease, with critical roles in the process of cancer onset and progression. While adaptive cells are endowed with anti-tumor activities, inflammatory components of the immune infiltrate orchestrate an immunosuppressive microenvironment that reveals ambivalent functions of the immune contexture in the tumor milieu. The balance between opposing pro-tumoral and anti-tumoral immune pathways, which occur concomitantly in the tumor microenvironment, and the regulatory networks of these phenomena have been the target of several immunotherapeutic strategies. While the scarcity of adaptive immune effectors in tumors correlates with dismal prognosis, the pathways of activation of tumor-specific lymphocytes are yet to be fully elucidated. Recently, the occurrence of tertiary lymphoid tissue was revealed to be critical in mediating the dynamics of T cell recruitment and local activation of immune cells in the tumor microenvironment. Thus, tertiary lymphoid tissue assessment and targeting emerge as a promising approach for the design of novel prognostic immune signatures and immunotherapeutic strategies. The immunological behavior of tertiary lymphoid tissue, its occurrence in the tumor immune microenvironment and its clinical relevance are discussed here.

Tumor-associated macrophages (TAMs) are key components of the tumor macroenvironment. Cancer- and host cell-derived signals generally drive the functions of TAMs towards an M2-like polarized, tumor-propelling mode; however, when appropriately re-educated. TAMs also have the potential to elicit tumor destructive reactions. Here, we discuss recent advances regarding the immunobiology of TAMs and highlight open questions including the mechanisms of their accumulation (recruitment versus proliferation), their diversity and how to best therapeutically target these cells., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Chemokines are key players of the cancer-related inflammation. Chemokine ligands and receptors are downstream of genetic events that cause neoplastic transformation and are abundantly expressed in chronic inflammatory conditions which predispose to cancer. Components of the chemokine system affect multiple pathways of tumor progression including: leukocyte recruitment, neo-angiogenesis, tumor cell proliferation and survival, invasion and metastasis. Evidence in pre-clinical and clinical settings suggests that the chemokine system represents a valuable target for the development of innovative therapeutic strategies., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Inflammation has been suggested to represent the seventh hallmark of cancer. Myelomonocytic cells are a key component of cancer-related inflammation. Tumor-associated macrophages and their mediators affect key elements in the multistep process of invasion and metastasis, from interaction with the extracellular matrix to the construction of a pre-metastatic niche. Evidence indicating that inflammatory mediators affect genetic stability and cause persistent epigenetic alterations suggests that inflammatory components of the tumor microenvironment impacts on fundamental mechanisms responsible for the generation of metastatic variants. These results provide impetus for efforts aimed at translating cancer-related inflammation into diagnostic-prognostic markers and innovative therapeutic strategies.

EUROCARE-4 analysed about three million adult cancer cases from 82 cancer registries in 23 European countries, diagnosed in 1995-1999 and followed to December 2003. For each cancer site, the mean European area-weighted observed and relative survival at 1-, 3-, and 5-years by age and sex are presented. Country-specific 1- and 5-year relative survival is also shown, together with 5-year relative survival conditional to surviving 1-year. Within-country variation in survival is analysed for selected cancers. Survival for most solid cancers, whose prognosis depends largely on stage at diagnosis (breast, colorectum, stomach, skin melanoma), was highest in Finland, Sweden, Norway and Iceland, lower in the UK and Denmark, and lowest in the Czech Republic, Poland and Slovenia. France, Switzerland and Italy generally had high survival, slightly below that in the northern countries. There were between-region differences in the survival for haematologic malignancies, possibly due to differences in the availability of effective treatments. Survival of elderly patients was low probably due to advanced stage at diagnosis, comorbidities, difficult access or lack of availability of appropriate care. For all cancers, 5-year survival conditional to surviving 1-year was higher and varied less with region, than the overall relative survival.

This paper describes the collection, standardisation and checking of cancer survival data included in the EUROCARE-4 database. Methods for estimating relative survival are also described. Incidence and vital status data on newly diagnosed European cancer cases were received from 93 cancer registries in 23 countries, covering 151,400,000 people (35% of the participating country population). The third revision of the International Classification of Diseases for Oncology was used to specify tumour topography and morphology. Records were extensively checked for consistency and compatibility using multiple routines; flagged records were sent back for correction. An algorithm assigned standardised sequence numbers to multiple cancers. Only first malignant cancers were used to estimate relative survival from registry, year, sex and age-specific life tables. Age-adjusted and Europe-wide survival were also estimated. The database contains 13,814,573 cases diagnosed in 1978-2002; 92% malignant. A negligible proportion of records was excluded for major errors. Of 5,753,934 malignant adult cases diagnosed in 1995-2002, 5.3% were second or later cancers, 2.7% were known from death certificates only and 0.4% were discovered at autopsy. The remaining 5,278,670 cases entered the survival analyses, 90% of these had microscopic confirmation and 1.3% were censored alive after less than five years' follow-up. These indicators suggest satisfactory data quality that has improved since EUROCARE-3.

Fotemustine is a cytotoxic alkylating agent, belonging to the group of nitrosourea family. Its mechanism of action is similar to that of other nitrosoureas, characterized by a mono-functional/bi-functional alkylating activity. Worth of consideration is the finding that the presence of high levels of the DNA repair enzyme O6-methylguanine-DNA-methyltransferase (MGMT) in cancer cells confers drug resistance. In different clinical trials Fotemustine showed a remarkable antitumor activity as single agent, and in association with other antineoplastic compounds or treatment modalities. Moreover, its toxicity is generally considered acceptable. The drug has been employed in the treatment of metastatic melanoma, and, on the basis of its pharmacokinetic properties, in brain tumors, either primitive or metastatic. Moreover, Fotemustine shows pharmacodynamic properties similar to those of mono-functional alkylating compounds (e.g. DNA methylating drugs, such as Temozolomide), that have been recently considered for the management of acute refractory leukaemia. Therefore, it is reasonable to assume that this agent could be a good candidate to play a potential role in haematological malignancies.

Environmental signals polarize mononuclear phagocytes which can express different functional programmes. Fully polarized type I and type II (or alternatively activated) macrophages are the extremes of a continuum of functional states. Tumor-derived and T cell-derived cytokines stimulate tumor associated macrophages (TAM) to acquire a polarized type II phenotype. These functionally polarized cells, and similarly oriented or immature dendritic cells present in tumors, play a key role in subversion of adaptive immunity and in inflammatory circuits which promote tumor growth and progression.