Meta-analyses of phase I dose-finding studies: Application for the development of protein kinase inhibitors in oncology.

This study aimed to assess the feasibility of applying two recent phase I meta-analyses methods to protein kinase inhibitors (PKIs) developed in oncology and to identify situations where these methods could be both feasible and useful. This ancillary study used data from a systematic review conducted to identify dose-finding studies for PKIs. PKIs selected for meta-analyses were required to have at least five completed dose-finding studies involving cancer patients, with available results, and dose escalation guided by toxicity assessment. To account for heterogeneity caused by various administration schedules, some studies were divided into study parts, considered as separate entities in the meta-analyses. For each PKI, two Bayesian random-effects meta-analysis methods were applied to model the toxicity probability distribution of the recommended dose and to estimate the maximum tolerated dose (MTD). Meta-analyses were performed for 20 PKIs including 96 studies corresponding to 115 study parts. The median posterior probability of toxicity probability was below the toxicity thresholds of 0.20 for 70% of the PKIs, even if the resulting credible intervals were very wide. All approved doses were below the MTD estimated for the minimum toxicity threshold, except for one, for which the approved dose was above the MTD estimated for the maximal threshold. The application of phase I meta-analysis methods has been feasible for the majority of PKI; nevertheless, their implementation requires multiple conditions. However, meta-analyses resulted in estimates with large uncertainty, probably due to limited patient numbers and/or between-study variability. This calls into question the reliability of the recommended doses.

The evidence base of US Food and Drug Administration approvals of novel cancer therapies from 2000 to 2020.

Concerns have been raised that regulatory programs to accelerate approval of cancer drugs in cancer may increase uncertainty about benefits and harms for survival and quality of life (QoL). We analyzed all pivotal clinical trials and all non-pivotal randomized controlled trials (RCTs) for all cancer drugs approved for the first time by the FDA between 2000 and 2020. We report regulatory and trial characteristics. Effects on overall survival (OS), progression-free survival and tumor response were summarized in meta-analyses. Effects on QoL were qualitatively summarized. Between 2000 and 2020, the FDA approved 145 novel cancer drugs for 156 indications based on 190 clinical trials. Half of indications (49%) were approved without RCT evidence; 82% had a single clinical trial only. OS was primary endpoint in 14% of trials and QoL data were available from 25%. The median OS benefit was 2.55 months (IQR, 1.33-4.28) with a mean hazard ratio for OS of 0.75 (95%CI, 0.72-0.79, I2  = 42). Improvement for QoL was reported for 7 (4%) of 156 indications. Over time, priority review was used increasingly and the mean number of trials per indication decreased from 1.45 to 1.12. More trials reported results on QoL (19% in 2000-2005; 41% in 2016-2020). For 21 years, novel cancer drugs have typically been approved based on one single, often uncontrolled, clinical trial, measuring surrogate endpoints. This leaves cancer patients without solid evidence that novel drugs improve their survival or QoL and there is no indication towards improvement.

Tivozanib in renal cell carcinoma: a systematic review of the evidence and its dissemination in the scientific literature.

BACKGROUND: Tivozanib (Fotivda) is an anti-angiogenic tyrosine kinase inhibitor that was denied access to the US market by the Food and Drug Administration (FDA). In contrast, it was granted approval by the European Medicines Agency (EMA) for the treatment of Renal Cell Carcinoma in adults. Given the conflicting decisions from these regulatory agencies, the objectives of the following study are (i) to critically review the evidence supporting the approval of tivozanib; (ii) to analyse the dissemination of this evidence in the literature by way of a citation analysis. METHODS: Pivotal trials were searched by two independent reviewers using Medline, Cochrane Library, ClinicalTrials.gov and the European Public Assessment Report. The risk of bias for each trial was then inductively assessed. Articles citing any of these trials were identified using Web of Sciences. Finally, the quality of the citations was evaluated by two independent reviewers according to standard data extraction methods. RESULTS: The search for primary evidence identified two pivotal studies: TIVO-1 upon which the FDA and the EMA decisions were based, and TIVO-3 which was conducted after the agencies' decisions had been issued. The TIVO-1 trial presented several limitations that compromised causal inference, in relation to (i) design (absence of blinding, inappropriate comparator, and one-way crossover), (ii) poor internal consistency in the results for the primary endpoint, (iii) a discrepancy between a benefit observed for progression-free survival (HR: 0.80, 95% CI [0.64-0.99]) and the absence of difference for overall survival (HR: 1.25, 95% CI [0.95 - 1.62]). Our citation search protocol identified 229 articles that cited TIVO-1 in the 7 years following its publication, among which 151 (65.9%) citing articles discussing efficacy. Presence of spin was identified in 64 (42.4%) of these 151 citing articles, and 39 (25.8%) additional articles citing results without providing enough elements to interpret the TIVO-1 results. CONCLUSION: EMA's approval was based on a single pivotal trial presenting critical limitations, rendering the results from the trial potentially inconclusive. The broad dissemination of TIVO-1 results in the scientific literature may have been affected by spin or results were presented in an inadequate critical manner.

Simultaneous Versus Delayed Resection for Initially Resectable Synchronous Colorectal Cancer Liver Metastases: A Prospective, Open-label, Randomized, Controlled Trial.

OBJECTIVE: To answer whether synchronous colorectal cancer liver metastases (SLM) should be resected simultaneously with primary cancer or should be delayed. SUMMARY BACKGROUND DATA: Numerous studies have compared both strategies. All were retrospective and conclusions were contradictory. METHODS: Adults with colorectal cancer and resectable SLM were randomly assigned to either simultaneous or delayed resection of the metastases. The primary outcome was the rate of major complications within 60 days following surgery. Secondary outcomes included overall and disease-free survival. RESULTS: A total of 105 patients were recruited. Eighty-five patients (39 and 46 in the simultaneous- and delayed-resection groups, respectively) were analyzed. The percentage of major perioperative complications did not differ between groups (49% and 46% in the simultaneous- and delayed-resection groups, respectively, adjusted OR 0.84, 95% CI 0.35-2.01; P = 0.70, logistic regression). Complications rates were 28% and 13% (P = 0.08, χ2 test) at colorectal site and 15% and 17% (P = 0.80, χ2 test) at liver site, in simultaneous- and delayed-resection groups, respectively. In the delayed-resection group, 8 patients did not reach the liver resection stage, and this was due to disease progression in 6 cases. After 2 years, overall and disease-free survival tended to be improved in simultaneous as compared with delayed-resection groups (P = 0.05), a tendency which persisted for OS after a median follow-up of 47 months. CONCLUSIONS: Complication rates did not appear to differ when colorectal cancer and synchronous liver metastases are resected simultaneously. Delayed resection tended to impair overall survival.

The role of eosinophil morphology in distinguishing between reactive eosinophilia and eosinophilia as a feature of a myeloid neoplasm.

Morphological features of eosinophils in patients with reactive eosinophilia (28 patients) and clonal eosinophilia (26 patients) have been compared with each other and with the eosinophil characteristics of healthy volunteers (three subjects) and of patients with the idiopathic hypereosinophilic syndrome (three patients). Morphological features, assessed in isolation from other haematological abnormalities, were found to have poor specificity for a myeloid neoplasm. The most useful feature was the presence of basophilic granules in mature eosinophils, which was associated particularly with acute myeloid leukaemia with inv(16). Marked reduction in granules occurred more often in some subsets of the myeloid neoplasm group but nevertheless was lacking in specificity since it was not infrequently seen in reactive eosinophilia. Although experienced morphologists more often considered that a myeloid neoplasm was likely in patients in whom this was the diagnosis (69%), myeloid neoplasia was also considered likely in a considerable proportion (39%) of patients with reactive eosinophilia. Morphological abnormalities of eosinophils therefore cannot be assessed in isolation in seeking to make a diagnosis of a myeloid neoplasm. Morphology is, however, needed and should be integrated with the results of other investigations.

Effects of sildenafil on maximum walking time in patients with arterial claudication: The ARTERIOFIL study.

BACKGROUND: Patients with lower extremity peripheral artery disease (PAD) frequently experience claudication, a clinical symptom indicative of reduced walking capacity. Recommended care consists of exercise rehabilitation combined with optimal medical treatment and surgery. The effects of a single oral dose of sildenafil, a phosphodiesterase type-5 inhibitor, on patients with claudication are discussed. The aim of this study was to test the efficacy of a single 100 mg dose of sildenafil compared to placebo in terms of maximal walking time (MWT) in patients with claudication. METHODS: The ARTERIOFIL study is a crossover, double-blind, prospective, randomized, single-center study conducted at Angers University Hospital in France. MWT (primary endpoint) was assessed using a treadmill test (10% incline; 3.2 km/h). Secondary endpoints (pain-free walking time (PFWT), transcutaneous oximetry during exercise and redox cycle parameters and safety) were also studied. RESULTS: Fourteen patients were included of whom two were ultimately excluded. In the 12 remaining patients, the MWT was significantly improved during the sildenafil period compared with the placebo period (300 s [95% CI 172 s-428 s] vs 402 s [95% CI 274 s-529 s] p < 0.01). Sildenafil had no significant effect on pain-free walking time or skin tissue oxygenation during exercise. According to redox cycle parameters, sildenafil significantly reduced blood glucose and pyruvate levels and the 3-hydroxybutyrate/acetoacetate ratio, while there was no significant effect on lactate, 3-hydroxybutyrate, acetoacetate and free fatty acid levels. Symptomatic transient hypotension was observed in two women. CONCLUSIONS: The ARTERIOFIL study has shown that a single 100 mg oral dose of sildenafil had a significant effect on increase in MWT but had no significant effects on PFWT and oxygenation parameters in patients with claudication. A double-blind, prospective, randomized, multicenter study (VIRTUOSE©) is ongoing to evaluate the chronic effect of six month-long sildenafil treatment on MWT in PAD patients with claudication. CLINICAL TRIAL REGISTRATION: This clinical trial was registered at clinicaltrials.gov, registration. number: NCT02832570, (https://clinicaltrials.gov/ct2/show/NCT02832570).

Impact of an Educational Intervention on Ankle-Brachial Index Performance Among Medical Students and Fidelity Assessment at Six Months.

BACKGROUND: The resting ankle-brachial index (ABI) is a clinical test to diagnose peripheral artery disease. The Wyatt's score has been proposed to assess the students' performance on ABI measurement on a healthy volunteer (HV). No study has shown that this score is sensitive to different teaching methods. In this randomized controlled trial, we wanted to determine whether didactic learning alone or didactic learning combined with experiential learning improves proficiency in the ABI procedure assessed by the Wyatt's score. METHODS: Medical students (n = 30) received a didactic learning, including (1) a presentation of the ABI guidelines and (2) a video demonstration. Each student was then randomized into 2 groups ("the no experiential learning group" and "the experiential learning group"). An initial evaluation was performed after the didactic learning and then the final evaluation at the end of the intervention. A student was considered to be proficient when he performed a correct ABI procedure on an HV. The correct procedure corresponds to the following: (1) correctly answered Wyatt's score and (2) a difference in the ABI measurement between a professor in vascular medicine and a student was ≤0.15. RESULTS: No student was proficient at the initial evaluation. At the final evaluation, there was a significant difference between the number of proficient students for the Wyatt's score depending on their learning group [didactic alone (1/10) or didactic + experiential training (15/20)] and also for the ABI procedure [didactic alone (0/10) or didactic + experiential training (16/20)]. At 6 months, among the 12 students who passed the final evaluation, 4 students passed both the Wyatt's score and the ABI measurement. CONCLUSIONS: Our study demonstrates that the Wyatt's score was sensitive to an educational intervention and no improvement was found in the case of "no experiential learning." The Wyatt's score could be used to evaluate the student on ABI measurement after an educational intervention. TRIAL REGISTRATION: A randomized controlled trial was conducted in the Vascular Medicine Department of Rennes University Hospital (France). This was approved by the ethics review board of our institution (no. 16.150).

Effect of a Perioperative Nutritional Supplementation with Oral Impact® in Patients undergoing Hepatic Surgery for Liver Cancer: A Prospective, Placebo-Controlled, Randomized, Double-Blind Study.

Perioperative nutrition with supplements containing L-arginine, ω3-polyunsaturated fatty acids, and nucleotides could boost liver function recovery, immune response, and resistance to infection after hepatic resection. We conducted a placebo-controlled, randomized, double-blind study to assess the effect of a perioperative nutritional supplementation with Oral Impact® in patients undergoing hepatic surgery for liver cancer. Treatment was given three times daily for 7 days before and 3 days after surgery. Primary outcome was factor V, 3 days after surgery. Thirty-five patients (placebo: 17; Oral Impact: 18) were included. Five patients (placebo: three; Oral Impact: two) were not operated and five (placebo: two; Oral Impact: three) did not undergo hepatic resection. Factor V (mean ± SD) was 70 ± 27% and 79 ± 25% (P = 0.409) 3 days after surgery and 90 ± 30% and 106 ± 16% (P = 0.066) 5 days after surgery, in placebo and Oral Impact groups, respectively. There were no significant differences between groups on other outcomes assessing liver function recovery (bile production, γ-glutamyl transferase, α-fetoprotein), immune response (CD3, CD4, CD8 cells, CD4/CD8 ratio, natural killer cells, B lymphocytes), number of infections, and tolerance. A 10-day perioperative nutritional supplementation with Oral Impact does not improve hepatic function, immune response, and resistance to infection in patients undergoing hepatic surgery for liver cancer.

Combined evaluation of LC3B puncta and HMGB1 expression predicts residual risk of relapse after adjuvant chemotherapy in breast cancer.

In spite of adjuvant chemotherapy, a significant fraction of patients with localized breast cancer (BC) relapse after optimal treatment. We determined the occurrence of cytoplasmic MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3B)-positive puncta, as well as the presence of nuclear HMGB1 (high mobility group box 1) in cancer cells within surgical BC specimens by immunohistochemistry, first in a test cohort (152 patients) and then in a validation cohort of localized BC patients who all received adjuvant anthracycline-based chemotherapy (1646 patients). Cytoplasmic LC3B(+) puncta inversely correlated with the intensity of SQSTM1 staining, suggesting that a high percentage cells of LC3B(+) puncta reflects increased autophagic flux. After setting optimal thresholds in the test cohort, cytoplasmic LC3B(+) puncta and nuclear HMGB1 were scored as positive in 27.2% and 28.6% of the tumors, respectively, in the validation cohort, while 8.7% were considered as double positive. LC3B(+) puncta or HMGB1 expression alone did not constitute independent prognostic factors for metastasis-free survival (MFS) in multivariate analyses. However, the combined positivity for LC3B(+) puncta and nuclear HMGB1 constituted an independent prognostic factor significantly associated with prolonged MFS (hazard ratio: 0.49 95% confidence interval [0.26-0.89]; P = 0.02), and improved breast cancer specific survival (hazard ratio: 0.21 95% confidence interval [0.05-0.85]; P = 0.029). Subgroup analyses revealed that within patients with poor-prognosis BC, HMGB1(+) LC3B(+) double-positive tumors had a better prognosis than BC that lacked one or both of these markers. Altogether, these results suggest that the combined positivity for LC3B(+) puncta and nuclear HMGB1 is a positive predictor for longer BC survival.

Cell-death-associated molecular patterns as determinants of cancer immunogenicity.

SIGNIFICANCE: Accumulating evidence indicates that the success of some anticancer treatments (select chemotherapies or radiotherapy or trastuzumab) could be related to the stimulation of an anticancer immune response through the induction of an immunogenic tumor cell death (ICD). RECENT ADVANCES: Preclinical data revealed that dying tumor cells can emit a series of danger signals (so-called "cell-death-associated molecular patterns" (CDAMP)) that will dictate the recruitment and activation of specific inflammatory phagocytes. Hence, tumor cells succumbing to ICD are characterized by specific metabolic and molecular changes that will trigger a hierarchy of polarizing cytokine-producing cells, culminating in the recruitment and reactivation of antitumor interferon-γ-producing effector T cells which contribute to the success of cytotoxic treatments. CRITICAL ISSUES: In this review, we summarize the molecular and cellular bases of this ICD, underscoring the crucial role of high mobility group box 1 protein (HMGB1) and adenosine tri-phosphate, both of which are released from dying tumor cells during ICD and are implicated in the chemotherapy-elicited anticancer immune response. FUTURE DIRECTIONS: We discuss here how such CDAMP could serve as predictive biomarkers that could discriminate immunogenic from nonimmunogenic anti-cancer compounds, and, in case of deficiency, could be compensated by surrogate products to ameliorate the success rate of conventional anticancer treatment modalities.

Crosstalk between ER stress and immunogenic cell death.

Preclinical and clinical findings suggest that tumor-specific immune responses may be responsible--at least in part--for the clinical success of therapeutic regimens that rely on immunogenic cell death (ICD) inducers, including anthracyclines and oxaliplatin. The molecular pathways whereby some, but not all, cytotoxic agents promote bona fide ICD remain to be fully elucidated. Nevertheless, a central role for the endoplasmic reticulum (ER) stress response has been revealed in all scenarios of ICD described thus far. Hence, components of the ER stress machinery may constitute clinically relevant druggable targets for the induction of ICD. In this review, we will summarize recent findings in the field of ICD research with a special focus on ER stress mechanisms and their implication for cancer therapy.

Immune infiltrates are prognostic factors in localized gastrointestinal stromal tumors.

Cancer immunosurveillance relies on effector/memory tumor-infiltrating CD8(+) T cells with a T-helper cell 1 (TH1) profile. Evidence for a natural killer (NK) cell-based control of human malignancies is still largely missing. The KIT tyrosine kinase inhibitor imatinib mesylate markedly prolongs the survival of patients with gastrointestinal stromal tumors (GIST) by direct effects on tumor cells as well as by indirect immunostimulatory effects on T and NK cells. Here, we investigated the prognostic value of tumor-infiltrating lymphocytes (TIL) expressing CD3, Foxp3, or NKp46 (NCR1) in a cohort of patients with localized GIST. We found that CD3(+) TIL were highly activated in GIST and were especially enriched in areas of the tumor that conserve class I MHC expression despite imatinib mesylate treatment. High densities of CD3(+) TIL predicted progression-free survival (PFS) in multivariate analyses. Moreover, GIST were infiltrated by a homogeneous subset of cytokine-secreting CD56(bright) (NCAM1) NK cells that accumulated in tumor foci after imatinib mesylate treatment. The density of the NK infiltrate independently predicted PFS and added prognostic information to the Miettinen score, as well as to the KIT mutational status. NK and T lymphocytes preferentially distributed to distinct areas of tumor sections and probably contributed independently to GIST immunosurveillance. These findings encourage the prospective validation of immune biomarkers for optimal risk stratification of patients with GIST.

Phase I clinical trial combining imatinib mesylate and IL-2: HLA-DR+ NK cell levels correlate with disease outcome.

We performed a Phase I clinical trial from October 2007 to October 2009, enrolling patients affected by refractory solid tumors, to determine the maximum tolerated dose (MTD) of interleukin (IL)-2 combined with low dose cyclophosphamide (CTX) and imatinib mesylate (IM). In a companion paper published in this issue of OncoImmunology, we show that the MTD of IL-2 is 6 MIU/day for 5 consecutive days, and that IL-2 increases the impregnation of both IM and of its main metabolite, CGP74588. Among the secondary objectives, we wanted to determine immunological markers that might be associated with progression-free survival (PFS) and/or overall survival (OS). The combination therapy markedly reduced the absolute counts of B, CD4+ T and CD8+ T cells in a manner that was proportional to IL-2 dose. There was a slight (less than 2-fold) increase in the proportion of regulatory T cells (Tregs) among CD4+ T cells in response to IM plus IL-2. The natural killer (NK)-cell compartment was activated, exhibiting a significant upregulation of HLA-DR, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and CD56. The abundance of HLA-DR+ NK cells after one course of combination therapy positively correlated with both PFS and OS. The IL-2-induced rise of the CD4+:CD8+ T-cell ratio calculated after the first cycle of treatment was also positively associated with OS. Overall, the combination of IM and IL-2 promoted the rapid expansion of HLA-DR+ NK cells and increased the CD4+:CD8+ T-cell ratio, both being associated with clinical benefits. This combinatorial regimen warrants further investigation in Phase II clinical trials, possibly in patients affected by gastrointestinal stromal tumors, a setting in which T and NK cells may play an important therapeutic role.

Phase I clinical trial combining imatinib mesylate and IL-2 in refractory cancer patients: IL-2 interferes with the pharmacokinetics of imatinib mesylate.

Imatinib mesylate (IM) is a small molecule inhibitor of protein tyrosine kinases. In addition to its direct effect on malignant cells, it has been suggested IM may activate of natural killer (NK) cells, hence exerting immunomodulatory functions. In preclinical settings, improved antitumor responses have been observed when IM and interleukin-2 (IL-2), a cytokine that enhances NK cells functions, were combined. The goals of this study were to determine the maximum tolerated dose (MTD) of IL-2 combined with IM at a constant dose of 400 mg, the pharmacokinetics of IM and IL-2, as well as toxicity and clinical efficacy of this immunotherapeutic regimen in patients affected by advanced tumors. The treatment consisted in 50 mg/day cyclophosphamide from 21 d before the initiation of IM throughout the first IM cycle (from D-21 to D14), 400 mg/day IM for 14 d (D1 to D14) combined with escalating doses of IL-2 (3, 6, 9 and 12 MIU/day) from days 10 to 14. This treatment was administered at three week intervals to 17 patients. Common side effects of the combination were mild to moderate, including fever, chills, fatigue, nausea and hepatic enzyme elevation. IL-2 dose level II, 6 MIU/day, was determined as the MTD with the following dose-limiting toxicities: systemic capillary leak syndrome, fatigue and anorexia. Pharmacokinetic studies revealed that the area under the curve and the maximum concentration of IM and its main metabolite CGP74588 increased significantly when IM was concomitantly administered with IL-2. In contrast, IM did not modulate IL-2 pharmacokinetics. No objective responses were observed. The best response obtained was stable disease in 8/17 (median duration: 12 weeks). Finally, IL-2 augmented the impregnation of IM and its metabolite. The combination of IM (400 mg/day) and IL-2 (6 MIU/day) in tumors that express IM targets warrants further investigation.

Natural killer cells in non-hematopoietic malignancies.

Natural killer (NK) cells belong to the innate immune system and were initially described functionallywise by their spontaneous cytotoxic potential against transformed or virus-infected cells. A delicate balance between activating and inhibiting receptors regulates NK cell tolerance. A better understanding of tissue resident NK cells, of NK cell maturation stages and migration patterns has evolved allowing a thoughtful evaluation of their modus operandi. While evidence has been brought up for their relevance as gate keepers in some hematopoietic malignancies, the role of NK cells against progression and dissemination of solid tumors remains questionable. Hence, many studies pointed out the functional defects of the rare NK cell infiltrates found in tumor beds and the lack of efficacy of adoptively transferred NK cells in patients. However, several preclinical evidences suggest their anti-metastatic role in a variety of mouse tumor models. In the present review, we discuss NK cell functions according to their maturation stage and environmental milieu, the receptor/ligand interactions dictating tumor cell recognition and recapitulate translational studies aimed at deciphering their prognostic or predictive role against human solid malignancies.

An immunosurveillance mechanism controls cancer cell ploidy.

Cancer cells accommodate multiple genetic and epigenetic alterations that initially activate intrinsic (cell-autonomous) and extrinsic (immune-mediated) oncosuppressive mechanisms. Only once these barriers to oncogenesis have been overcome can malignant growth proceed unrestrained. Tetraploidization can contribute to oncogenesis because hyperploid cells are genomically unstable. We report that hyperploid cancer cells become immunogenic because of a constitutive endoplasmic reticulum stress response resulting in the aberrant cell surface exposure of calreticulin. Hyperploid, calreticulin-exposing cancer cells readily proliferated in immunodeficient mice and conserved their increased DNA content. In contrast, hyperploid cells injected into immunocompetent mice generated tumors only after a delay, and such tumors exhibited reduced DNA content, endoplasmic reticulum stress, and calreticulin exposure. Our results unveil an immunosurveillance system that imposes immunoselection against hyperploidy in carcinogen- and oncogene-induced cancers.

Cardiac glycosides exert anticancer effects by inducing immunogenic cell death.

Some successful chemotherapeutics, notably anthracyclines and oxaliplatin, induce a type of cell stress and death that is immunogenic, hence converting the patient's dying cancer cells into a vaccine that stimulates antitumor immune responses. By means of a fluorescence microscopy platform that allows for the automated detection of the biochemical hallmarks of such a peculiar cell death modality, we identified cardiac glycosides (CGs) as exceptionally efficient inducers of immunogenic cell death, an effect that was associated with the inhibition of the plasma membrane Na(+)- and K(+)-dependent adenosine triphosphatase (Na(+)/K(+)-ATPase). CGs exacerbated the antineoplastic effects of DNA-damaging agents in immunocompetent but not immunodeficient mice. Moreover, cancer cells succumbing to a combination of chemotherapy plus CGs could vaccinate syngeneic mice against a subsequent challenge with living cells of the same type. Finally, retrospective clinical analyses revealed that the administration of the CG digoxin during chemotherapy had a positive impact on overall survival in cohorts of breast, colorectal, head and neck, and hepatocellular carcinoma patients, especially when they were treated with agents other than anthracyclines and oxaliplatin.

Contribution of IL-17-producing gamma delta T cells to the efficacy of anticancer chemotherapy.

By triggering immunogenic cell death, some anticancer compounds, including anthracyclines and oxaliplatin, elicit tumor-specific, interferon-γ-producing CD8(+) αß T lymphocytes (Tc1 CTLs) that are pivotal for an optimal therapeutic outcome. Here, we demonstrate that chemotherapy induces a rapid and prominent invasion of interleukin (IL)-17-producing γδ (Vγ4(+) and Vγ6(+)) T lymphocytes (γδ T17 cells) that precedes the accumulation of Tc1 CTLs within the tumor bed. In T cell receptor δ(-/-) or Vγ4/6(-/-) mice, the therapeutic efficacy of chemotherapy was compromised, no IL-17 was produced by tumor-infiltrating T cells, and Tc1 CTLs failed to invade the tumor after treatment. Although γδ T17 cells could produce both IL-17A and IL-22, the absence of a functional IL-17A-IL-17R pathway significantly reduced tumor-specific T cell responses elicited by tumor cell death, and the efficacy of chemotherapy in four independent transplantable tumor models. Adoptive transfer of γδ T cells restored the efficacy of chemotherapy in IL-17A(-/-) hosts. The anticancer effect of infused γδ T cells was lost when they lacked either IL-1R1 or IL-17A. Conventional helper CD4(+) αß T cells failed to produce IL-17 after chemotherapy. We conclude that γδ T17 cells play a decisive role in chemotherapy-induced anticancer immune responses.

Harnessing dendritic cells in cancer.

Dendritic cells (DCs) are central to the initiation of tumor-specific immune responses. However, the tumor microenvironment generates immunosuppressive cells and soluble mediators that compromise DC functions and limit the success of DC-based therapies. Progress in understanding DC metabolism in cancer is uncovering novel therapeutic targets that could restore DC capacity to prime T cells and trigger effective anticancer responses. Accumulating evidence also indicates that conventional chemo- and radiotherapy protocols can cause DC activation, enhance antigen cross-presentation, selectively eliminate immunosuppressive cells and revert the immunosuppression state caused by cancer, suggesting that relevant chemoimmunotherapy associations could fully exploit DC capacity to trigger anticancer responses. Here, we discuss recent strategies that harness DC against cancer.

How to improve the immunogenicity of chemotherapy and radiotherapy.

Chemotherapy or radiotherapy could induce various tumor cell death modalities, releasing tumor-derived antigen as well as danger signals that could either be captured for triggering antitumor immune response or ignored. Exploring the interplay among therapeutic drugs, tumor cell death and the immune cells should improve diagnostic, prognostic, predictive, and therapeutic management of tumor. We summarized some of the cell death-derived danger signals and the mechanism for host to sense and response to cell death in the tumor microenvironment. Based on the recent clinical or experimental findings, several strategies have been suggested to improve the immunogenicity of cell death and augment antitumor immunity.