Effective personalized neoantigen vaccine plus anti-PD-1 in a PD-1 blockade-resistant lung cancer patient.

Background: Although significant progress has been made in immune checkpoint inhibitor (ICI) treatment of advanced squamous cell carcinoma (SqCC), most patients still experience acquired drug resistance. Methods: We used a dendritic cell-based neoantigen vaccine combined with ICIs to treat advanced SqCC in a PD-1 blockade-resistant patient. Results: The follow-up of this patient after 12 months revealed significant tumor regression. We also identified a new JAK1 ICI-resistant mutation that could become a potential universal neoantigen target for tumor vaccines. Conclusion: Individualized management of advanced SqCC through a combined neoantigen vaccine and ICI administration could yield beneficial clinical outcomes. Vaccines targeting anti-PD-1-resistant JAK1 mutations might be of particular benefit to a specific group of solid tumor patients.

Immunotherapy based on immune checkpoint inhibitors (ICIs) is very effective in lung cancer treatment. However, many patients with initial response will later develop resistance. There are not many treatment options for patients with drug resistance. Herein, we report a patient with lung cancer who became resistant to ICI, treated with personalized vaccine plus ICI. Based on the patient's own somatic mutational profile, personalized neoantigen vaccines were designed and manufactured unique to the patient. Our report indicated that personalized vaccine plus ICI was safe and might overcome ICI resistance. A new ICI resistance mutation on JAK1 as a potential universal neoantigen target for off-the-shelf vaccine was found, which is promising for the effective treatment of a specific group of patients with JAK1 mutations.

Fusobacterium nucleatum enhances the efficacy of PD-L1 blockade in colorectal cancer.

Given that only a subset of patients with colorectal cancer (CRC) benefit from immune checkpoint therapy, efforts are ongoing to identify markers that predict immunotherapeutic response. Increasing evidence suggests that microbes influence the efficacy of cancer therapies. Fusobacterium nucleatum induces different immune responses in CRC with different microsatellite-instability (MSI) statuses. Here, we investigated the effect of F. nucleatum on anti-PD-L1 therapy in CRC. We found that high F. nucleatum levels correlate with improved therapeutic responses to PD-1 blockade in patients with CRC. Additionally, F. nucleatum enhanced the antitumor effects of PD-L1 blockade on CRC in mice and prolonged survival. Combining F. nucleatum supplementation with immunotherapy rescued the therapeutic effects of PD-L1 blockade. Furthermore, F. nucleatum induced PD-L1 expression by activating STING signaling and increased the accumulation of interferon-gamma (IFN-γ)+ CD8+ tumor-infiltrating lymphocytes (TILs) during treatment with PD-L1 blockade, thereby augmenting tumor sensitivity to PD-L1 blockade. Finally, patient-derived organoid models demonstrated that increased F. nucleatum levels correlated with an improved therapeutic response to PD-L1 blockade. These findings suggest that F. nucleatum may modulate immune checkpoint therapy for CRC.

A Novel Combined Conjugate Therapeutic Cancer Vaccine, Recombinant EGF-CRM197, in Patients With Advanced Solid Tumors: A Phase I Clinical Study.

INTRODUCTION: The therapeutic cancer vaccine recombinant Epidermal Growth Factor (EGF)-CRM197 is a novel combined conjugate EGF with CRM197 as a carrier protein. Immunization with the EGF-CRM197 vaccine can induce high levels of neutralizing anti-EGF antibodies that inhibit EGF/EGFR signaling and thereby suppress growth of tumors that rely on this signaling pathway. Herein, we characterize the humoral immune responses elicited by the recombinant EGF-CRM197 vaccine in patients with advanced solid tumors in a phase I clinical trial and assess the safety, tolerability, and immunogenicity of this vaccine (CTR20190473). METHODS: A total of 16 subjects were enrolled in this study. Under 6 + 3 design, patients in each dosing cohort were administrated subcutaneously at a dosage of 0.4 mg, 0.8 mg, and 1.6 mg, respectively. The patients received vaccinations for immune induction (once a week for 4 consecutive weeks) and booster vaccinations (once every 4 weeks). Safety evaluation was performed 1 week after the immune induction. Booster vaccination was given until the occurrence of disease progression, intolerance, withdrawal of informed consent by the patient, or negative result of anti-EGF test after two booster vaccinations. RESULTS: Vaccination with EGF-CRM197 is safe and well-tolerated in patients with advanced solid tumors. Adverse reactions at the injection site were the most common adverse events (AEs) in recipients. No severe adverse reactions post vaccination were observed in the present study. Vaccinated patients developed a robust neutralizing antibody response triggered by EGF-CRM197 that significantly reduced the levels of EGF in serum. For lung cancer patients who were super good antibody responders (sGAR) to EGF-CRM197, the median progress-free survival (PFS) was 4.83 months, significantly longer than that of the good antibody responder (GAR) patients with lung cancer whose median PFS was 2.10 months (P=0.0018). The median overall survival (OS) of GAR lung cancer patients was 10.67 months while the OS) for sGAR lung cancer patients was not reached until analysis was performed. The median follow-up of the sGAR lung cancer patients was 14.6 months. CONCLUSION: Our study demonstrates that the recombinant EGF-CRM197 therapeutic cancer vaccine can induce a good immune response in patients with advanced solid tumors and is safe and well tolerated, which ensures further clinical development of the vaccine for extending the survival time of EGF-CRM197 sensitive patients with advanced solid tumors. CLINICAL TRIAL REGISTRATION: http://www.chinadrugtrials.org.cn, identifier CTR20190473, EGF-CRM197.

Immune checkpoint inhibitor combined with anti-angiogenesis agent inhibits metastasis of advanced adenoid cystic carcinoma of the tongue base to the lung: a case report.

Patients diagnosed with advanced adenoid cystic carcinoma (ACC) with metastasis to the lung generally have poor prognosis when they exhibit resistance to conventional therapies. Programmed cell-death protein 1 (PD-1) inhibitors, a type of Immune checkpoint inhibitors (ICI), have shown good response in the treatment of various types of malignant tumors; however, objective response rates of monotherapy for advanced ACC are low. Anlotinib, a novel, orally managed tyrosine kinase inhibitor, that targets vascular endothelial growth factor receptor (VEGFR), fibroblast growth factor receptor (FGFR), platelet-derived growth factor receptor (PDGFR), and c-kit, has appeared great adequacy in treating numerous sorts of malignant tumors, particularly tumors with lung metastases. Here, we have presented a case of refractory ACC with lung metastases that was reduced after combinatorial treatment using the immune checkpoint inhibitor (ICI) toripalimab and anti-angiogenesis agent anlotinib. The patient achieved a reduction in lung metastases by chest computed tomography (CT) examination, with an outcome of stable disease (SD) of 5 months, a significant decrease in the levels of peripheral blood cytokines interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α), as well as good tolerance without noteworthy unfavorable reactions, indicating that the combined therapy of toripalimab and anlotinib may be utilized in the management of advanced ACC.

Targeted genomic profiling revealed a unique clinical phenotype in intrahepatic cholangiocarcinoma with fibroblast growth factor receptor rearrangement.

Genomic aberrations (GAs) in fibroblast growth factor receptors (FGFRs) are involved in the pathogenesis of intrahepatic cholangiocarcinoma (ICC), and clinical trials have shown efficacy of FGFR inhibitors in treating ICC patients with FGFR GAs such as FGFR2 rearrangement. To clarify the FGFRs GA profile and corresponding clinicopathological features in Chinese patients with ICC, a total of 257 cases were identified. Fourteen cases (5.45%) were positive for FGFR2 rearrangement. Further analysis on the 110 FGFR2 rearrangement negative cases showed that 13 patients present additional FGFRs GAs, including FGFR3 rearrangement (2.73%), and FGFRs mutations. When compared with patients without FGFRs GAs, those with FGFR2 or FGFR3 rearrangement presented more under the age of 58 years, female sex, HBsAb positivity, CD10 expression, and PD-L1 expression. The clinical characteristics between patients with FGFRs mutation and those without FGFRs GAs were similar, with the exception that cases with FGFRs mutation have more hepatolithiasis. We concluded that FGFR rearrangement is associated with unique clinical phenotypes in ICC.

The upregulation of PYCR2 is associated with aggressive colon cancer progression and a poor prognosis.

PYCR2 has previously been shown to be related to a range of malignancies including hepatocellular carcinoma and melanoma, but its mechanistic functions and prognostic relevance in colon cancer patients remain to be defined. Herein, we used the Oncomine, Human Protein Atlas, The Cancer Genome Atlas (TCGA), and UALCAN databases to explore the expression of this gene in different human cancer, after which the relationship between PYCR2 expression and patient clinicopathologic characteristics was evaluated. We utilized an in vitro approach to evaluate the association between PYCR2 expression and colon cancer cell proliferation, migration, invasion, and tumor microsphere formation. The cell apoptosis was analyzed by flow cytometry. Gene set enrichment analysis (GSEA) approaches were additionally used to probe signaling pathways related to PYCR2. These analyses confirmed that PYCR2 was upregulated in several cancer types including colon cancer, with such upregulation correlating with a poor patient prognosis and with malignant clinicopathological characteristics. PYCR2 expression was identified as an independent predictor of colon cancer patients' survival, and in vitro analyses suggested that knocking down this gene was sufficient to disrupt the proliferative, migratory, invasive, and microsphere formation activities of colon cancer cells. Moreover, shPYCR2 transfection induced colon cancer cell apoptosis. GSEA suggested that high PYCR2 expression correlates with the differential enrichment of the Wnt ß-catenin signaling, MYC targets, RNA polymerase, and Notch signaling pathways. Overall, these data indicate that PYCR2 is an important mediator of tumor progression and metastasis, and suggest that it may be a valuable prognostic indicator for colon cancer patient evaluation.

Targeting STAT3 Abrogates Tim-3 Upregulation of Adaptive Resistance to PD-1 Blockade on Regulatory T Cells of Melanoma.

Background: Less than 20% of melanoma patients respond to programmed cell death-1 (PD-1) blockade immunotherapies. Thus, it is crucial to understand the dynamic changes in the tumor microenvironment (TME) after PD-1 blockade, for developing immunotherapy efficacy. Methods: A genomic analysis was conducted by The Cancer Genome Atlas (TCGA) datasets and web platform TIMER2.0 datasets. Pathway enrichment analysis was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Peripheral blood mononuclear cells (PBMCs), regulatory T (Treg) cells, and B16-F10 melanoma mice were used as models. The cellular and molecular characteristics and mechanisms of Treg cells in melanoma were assessed by performing gene expression studies, immunohistochemistry, RNA sequencing, and flow cytometry. Results: Here, we evaluate the countenance of T cell immunoglobulin and mucin-domain containing-3 (Tim-3), and various immunosuppressive factors within tumor-infiltrated Treg cells after treatment with anti-PD-1 or the indicator transduction and activator of transcription 3 (STAT3) inhibitors. Increased expression of Tim-3 is markedly observed within the tissues of the PD-1 blockade resistance of melanoma patients. Targeting STAT3 significantly boosts the response of resistant-PD-1 therapy within the melanoma mouse model. Mechanistically, the manifestation of STAT3 decreases the expression of Tim-3 and various cytokines in the purified Treg cells from individual PBMCs and the murine melanoma model, limiting the immunosuppression of Treg cells. Conclusions: Our findings indicate that Tim-3 expression on Treg cells within the TME is STAT3-dependent, providing support to STAT3 as a target and enhancing the immunotherapy for patients suffering from melanoma.

αPD-1-mesoCAR-T cells partially inhibit the growth of advanced/refractory ovarian cancer in a patient along with daily apatinib.

Epithelial ovarian cancer (EOC) is the leading cause of death among gynecological malignancies in China. In particular, advanced/refractory ovarian cancer lacks effective targeted therapies due to the immunosuppressive and proangiogenic tumor microenvironment. Mesothelin (MSLN) has been found to be highly expressive in most EOC. Targeting MSLN by antibodies or chimeric antigen receptor-modified T (CAR-T) cells and immune checkpoint blockades as well as apatinib, an anti-angiogenic drug, have been used in patients with refractory ovarian cancer. Apatinib was reported to promote the infiltration of CD8+ T cells in lung cancer. However, the combination therapy of CAR-T secreting anti-PD-1 antibody with apatinib in EOC has not been reported. CASE PRESENTATION: Here we report a case of refractory EOC in a patient who had relapsed after multiline chemotherapy. The patient received autologous T cells that contained sequences encoding single-chain variable fragments specific for MSLN and full-length antibody for PD-1 (αPD-1). The modified T cells were called αPD-1-mesoCAR-T cells. After infusion, the copy number and PD-1 antibody secretion of the CAR-T cells were increased in the blood. By application of multimodality tumor tracking, MRI of the liver showed shrinkage of metastatic nodules from average diameter of 71.3-39.1 mm at month 2. The patient achieved partial response and survived more than 17 months. IL-6 levels in the patient fluctuated from the baseline to 2-4-folds after treatment, but side effects were mild with only grade 1 hypertension and fatigue. CONCLUSION: αPD-1-mesoCAR-T cell therapy combined with apatinib demonstrates a potential therapeutic effect on advanced refractory ovarian cancer. TRIAL REGISTRATION NUMBER: NCT03615313.

Personalized neoantigen pulsed dendritic cell vaccine for advanced lung cancer.

Neoantigens are considered to be ultimate target of tumor immunotherapy due to their high tumor specificity and immunogenicity. Dendritic cell (DCs) vaccines based on neoantigens have exciting effects in treatment of some malignant tumors and are a promising therapeutic modality. Lung cancer is a lethal disease with the highest morbidity and mortality rate in the world. Despite the rapid development of targeted therapy and immune checkpoint inhibitors for lung cancer in recent years, their efficacy is still unsatisfactory overall. Therefore, there is an urgent unmet clinical need for lung cancer treatment. Here, we attempted to treat lung cancer using a personalized neoantigen peptide-pulsed autologous DC vaccine and conducted a single-arm, 2 medical centers, pilot study initiated by the investigator (ChiCTR-ONC-16009100, NCT02956551). The patients enrolled were patients with heavily treated metastatic lung cancer. Candidate neoantigens were derived from whole-exome sequencing and RNA sequencing of fresh biopsy tissues as well as bioinformatics analysis. A total of 12 patients were enrolled in this study. A total of 85 vaccine treatments were administered with a median value of 5 doses/person (range: 3-14 doses/person). In total, 12-30 peptide-based neoantigens were selected for each patient. All treatment-related adverse events were grade 1-2 and there were no delays in dosing due to toxic effects. The objective effectiveness rate was 25%; the disease control rate was 75%; the median progression-free survival was 5.5 months and the median overall survival was 7.9 months. This study provides new evidence for neoantigen vaccine therapy and new therapeutic opportunities for lung cancer treatment.

Liposomal doxorubicin-related palmar-plantar erythrodysesthesia (hand-foot syndrome): a case report.

Hand-foot syndrome (HFS) is a skin toxicity that occurs in areas of compressed skin. HFS manifests mainly in insensitive palms and the soles of the feet or in erythematous areas on the extremities caused by chemotherapy, which may be related to the dosage. This paper reports a case of HFS caused by liposomal doxorubicin. A 64-year-old Asian woman presented with severe erythema, ulceration, pruritus, and edema-related pain in her back, hands, and feet after receiving four cycles of liposomal doxorubicin. Clinicians and a pharmacist analyzed and evaluated the patient's adverse reactions. After symptomatic treatment and patient education, her HFS symptoms were significantly relieved. The purpose of this study was to raise clinical awareness regarding adverse events following liposomal doxorubicin injection, and to provide new ideas for the clinical treatment of these adverse events.

Targeting STAT3 enhances NDV-induced immunogenic cell death in prostate cancer cells.

Oncolytic Newcastle disease virus (NDV) induces immunogenic cell death (ICD), liberating danger-associated molecular patterns (DAMPs) that provokes defiance in neoplastic malignancy. The present study aims to investigate whether and how oncolytic NDV triggers ICD in prostate cancer cells. We show that NDV/FMW, an oncolytic NDV strain FMW, elicited the expression and release of several ICD markers, that is calreticulin (CRT), heat shock proteins (HSP70/90) and high-mobility group box 1 (HMGB1), in prostate cancer cells. Furthermore, pharmacological repression of apoptosis, necroptosis, autophagy or endoplasmic reticulum (ER) stress exerted diverse effects on the HMGB1 and HSP70/90 evacuation in NDV/FMW-infected prostate cancer cells. Moreover, ICD markers induced in prostate cancer cells upon NDV/FMW infection, were enhanced by either treatment with a STAT3 (signal transducer and activator of transcription 3) inhibitor or shRNA-mediated knockdown of STAT3. In nude mice bearing prostate cancer cell-derived tumours, the tumours injected with the supernatants of NDV/FMW-infected cells grew smaller than mock-treated tumours. These results indicate that oncolytic NDV provokes the expression of ICD makers in prostate cancer cells. Our data also suggest that a combination of inhibition of STAT3 with oncolytic NDV could boost NDV-based anti-tumour effects against prostate cancer.

STAT3 Contributes To Oncolytic Newcastle Disease Virus-Induced Immunogenic Cell Death in Melanoma Cells.

Background: Oncolytic viruses (OVs) are emerging as potent inducers of immunogenic cell death (ICD), releasing danger-associated molecular patterns (DAMPs) that induce potent anticancer immunity. Oncolytic Newcastle disease virus (NDV) has been shown to educe ICD in both glioma and lung cancer cells. The objective of this study is to investigate whether oncolytic NDV induces ICD in melanoma cells and how it is regulated. Methods: Various time points were actuated to check the expression and release of ICD markers induced by NDV strain, NDV/FMW in melanoma cell lines. The expression and release of ICD markers induced by oncolytic NDV strain, NDV/FMW, in melanoma cell lines at various time points were determined. Surface-exposed calreticulin (CRT) was inspected by confocal imaging. The supernatants of NDV/FMW infected cells were collected and concentrated for the determination of ATP secretion by ELISA, HMGB1, and HSP70/90 expression by immunoblot (IB) analysis. Pharmacological inhibition of apoptosis, autophagy, necroptosis, ER Stress, and STAT3 (signal transducer and activator of transcription 3) was achieved by treatment with small molecule inhibitors. Melanoma cell lines stably depleted of STAT3 were established with lentiviral constructs. Supernatants from NDV-infected cells were intratumorally injected to mice bearing melanoma cells-derived tumors. Results: Oncolytic NDV induced CRT exposure, the release of HMGB1 and HSP70/90 as well as secretion of ATP in melanoma cells. Inhibition of apoptosis, autophagy, necroptosis or ER stress attenuated NDV/FMW-induced release of HMGB1 and HSP70/90. Moreover, NDV/FMW-induced ICD markers in melanoma cells were also suppressed by either treatment with a STAT3 inhibitor or shRNA-mediated depletion of STAT3. Of translational importance, treatment of mice bearing melanoma cells-derived tumors with supernatants from NDV/FMW-infected cells significantly inhibited tumor growth. Conclusions: Our data authenticate that oncolytic NDV/FMW might be a potent inducer of ICD in melanoma cells, which is amalgamated with several forms of cell death. We also show that STAT3 plays a role in NDV/FMW-induced ICD in melanoma cells. Together, our data highlight oncolytic NDV as propitious for cancer therapeutics by stimulatingan anti-melanoma immune response.

A case report of small bowel adenocarcinoma with liver metastases: genetic profiling and clinical management.

Small bowel adenocarcinoma (SBA) is a rare cancer. Optimal treatment regimens have not been established for SBA. This is due in part to the low disease incidence and subsequently, the lack of large, properly designed, randomized clinical trials. In this study, we present a case of an advanced small bowel adenocarcinoma patient with a prolonged progression-free survival of more than 3 years. Genetic profiling of this patient was used to predict prognosis and guide clinical management of the disease. The patient was treated with bevacizumab in combination with XELOX based on her genetic background and our experience in treating colorectal cancer. This treatment strategy, which was tolerable and effective, may be considered as a viable therapeutic strategy for the treatment of metastatic SBA.

Docetaxel-mediated autophagy promotes chemoresistance in castration-resistant prostate cancer cells by inhibiting STAT3.

Signal transducer and activator of transcription (STAT)3 expression is correlated with neoplasm growth, metastasis, and prognosis; it has also been implicated in the regulation of autophagy, which may in turn contribute to tumor chemoresistance. However, it is unknown whether STAT3 is involved in cancer cell survival in response to chemotherapy. In this study, we show that autophagy is triggered during chemotherapy and that inhibiting autophagy increased chemosensitivity of castration-resistant prostate cancer (CRPC) cells. Meanwhile, docetaxel induced autophagy was inhibited by STAT3 activation, which increased mitochondrial damage and decreased CRPC cell viability. These results suggest that STAT3 contributes to CRPC cell survival and chemoresistance by modulating autophagy.

Inhibition of autophagy in hepatocarcinoma cells promotes chemotherapeutic agent-induced apoptosis during nutrient deprivation.

Autophagy is a lysosome-dependent process involved in protein and organelle degradation. It has been suggested that autophagy is activated in nutrient-deficient condition and plays an important role in protecting cells from nutrient shortage. However, the effect of autophagy on chemotherapy during nutrient deficiency has been rarely researched. In the present study, we discovered that hepatocarcinoma cells exhibit chemoinsensitivity accompanied by the activation of autophagy when cultured in nutrient-deprived medium. Inhibition of autophagy by 3-methyladenine or siRNA­targeted Beclin 1 increased the nutrient deprivation­induced apoptosis and chemosensitivity in hepatocarcinoma cells. Furthermore, decreased mitochondrial mass was detected when cells underwent autophagy. The present study suggests that induction of autophagy confers a survival advantage for hepatocarcinoma cells during nutrient deprivation, not only rescuing cells from nutrient deficiency-induced cell apoptosis, but also protecting cells from chemotherapy-induced cell death. Combined usage of the inhibition of autophagy and conventional chemotherapeutic agents could be an effective therapy for hepatocarcinoma during nutrient deprivation.

SHP2 negatively regulates HLA-ABC and PD-L1 expression via STAT1 phosphorylation in prostate cancer cells.

Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2) is a ubiquitous protein tyrosine phosphatase that activates the signal transduction pathways of several growth factors and cytokines. In our study, SHP2 expression was very high in prostate cancer (PCa) cell lines, and the expression of phospho-signal transducer and activator of transcription 1 (p-STAT1) and STAT1 was very low. SHP2 knockdown upregulated the expression of p-STAT1 and downregulated phospho-extracellular signal regulated kinase (p-ERK). SHP2 depletion also increased the expression of human leukocyte antigen (HLA)-ABC and programmed death ligand 1 (PD-L1). When tumor cells were pretreated with Janus kinase 2 (JAK2) inhibitor, SHP2 depletion failed to induce HLA-ABC and PD-L1 expression. Furthermore, treating tumor cells with the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) inhibitor PD0325901 did not upregulate HLA-ABC and PD-L1. SHP2 depletion was associated with increased T-cell activation (CD25 MFI of CD8+) by coculture of allogeneic healthy donor peripheral blood monocytes (PBMC) with SHP2 siRNA pretreated PCa cell lines. These results show that SHP2 targeting upregulates HLA-ABC and PD-L1 expression via STAT1 phosphorylation in PCa cells and SHP2 depletion could increase T-cell activation.

EGFR-induced phosphorylation of type Iγ phosphatidylinositol phosphate kinase promotes pancreatic cancer progression.

Pancreatic cancer is one of the deadliest malignancies and effective treatment has always been lacking. In current study, we investigated how the type Iγ phosphatidylinositol phosphate kinase (PIPKIγ) participates in the progression of pancreatic ductal adenocarcinoma (PDAC) for novel therapeutic potentials against this lethal disease. We found that PIPKIγ is up-regulated in all tested PDAC cell lines. The growth factor (including EGFR)-induced tyrosine phosphorylation of PIPKIγ is significantly elevated in in situ and metastatic PDAC tissues. Loss of PIPKIγ inhibits the aggressiveness of PDAC cells by restraining the activities of AKT and STAT3, as well as MT1-MMP expression. Therefore when planted into the pancreas of nude mice, PIPKIγ-depleted PDAC cells exhibits substantially repressed tumor growth and metastasis comparing to control PDAC cells. Results from further studies showed that the phosphorylation-deficient PIPKIγ mutant, unlike its wild-type counterpart, cannot rescue PDAC progression inhibited by PIPKIγ depletion. These findings indicate that PIPKIγ, functioning downstream of EGFR signaling, is critical to the progression of PDAC, and suggest that PIPKIγ is potentially a valuable therapeutic target for PDAC treatment.

Effect of Carotene and Lycopene on the Risk of Prostate Cancer: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies.

BACKGROUND: Many epidemiologic studies have investigated the association between carotenoids intake and risk of Prostate cancer (PCa). However, results have been inconclusive. METHODS: We conducted a systematic review and dose-response meta-analysis of dietary intake or blood concentrations of carotenoids in relation to PCa risk. We summarized the data from 34 eligible studies (10 cohort, 11 nested case-control and 13 case-control studies) and estimated summary Risk Ratios (RRs) and 95% confidence intervals (CIs) using random-effects models. RESULTS: Neither dietary ß-carotene intake nor its blood levels was associated with reduced PCa risk. Dietary α-carotene intake and lycopene consumption (both dietary intake and its blood levels) were all associated with reduced risk of PCa (RR for dietary α-carotene intake: 0.87, 95%CI: 0.76-0.99; RR for dietary lycopene intake: 0.86, 95%CI: 0.75-0.98; RR for blood lycopene levels: 0.81, 95%CI: 0.69-0.96). However, neither blood α-carotene levels nor blood lycopene levels could reduce the risk of advanced PCa. Dose-response analysis indicated that risk of PCa was reduced by 2% per 0.2mg/day (95%CI: 0.96-0.99) increment of dietary α-carotene intake or 3% per 1mg/day (95%CI: 0.94-0.99) increment of dietary lycopene intake. CONCLUSIONS: α-carotene and lycopene, but not ß-carotene, were inversely associated with the risk of PCa. However, both α-carotene and lycopene could not lower the risk of advanced PCa.