Treatment Outcomes of Patients with Ependymoma Receiving Radiotherapy: A Single Institution Experience.

INTRODUCTION: The study explored the failure pattern and clinical outcomes in patients with ependymoma undergoing radiotherapy. METHODS: Between January 2004 and June 2022, we included 32 patients with ependymoma who underwent radiotherapy as part of the multimodality treatment at our institution. Of these, 27 (84.4%) underwent adjuvant radiotherapy, four received radiotherapy after local recurrence, and one received definitive CyberKnife radiotherapy (21 Gy in three fractions). The median prescribed dose was 54 Gy in patients who received conventional radiotherapy. We analyzed the local progression-free survival (LPFS), distant metastasis-free survival (DMFS), progression-free survival (PFS), overall survival (OS), and potential prognostic factors. RESULTS: The median age was 29.8 years. Approximately 28.1% were pediatric patients. Fifteen tumors (46.9%) were World Health Organization (WHO) grade II, 10 (31.3%) were WHO grade III, and seven (22.8%) were WHO grade I. Among them, 15 patients (46.9%) had posterior fossa tumors, 10 (31.3%) had supratentorial tumors, and seven (22.8%) had spinal tumors. Of the 31 patients who underwent upfront surgical resection, 19 (61.3%) underwent gross total resection or near total resection. Seventeen of 19 patients with first failures (89.5%) had isolated local recurrences. Of the 19 patients with disease progression, 11 (57.9%) were disease-free or had stable disease after salvage therapy, and five (26.3%) had disease-related mortality. Most of the first local recurrences after radiotherapy occurred in the infield (13 of 16, 81.3%). The 5-year LPFS, DMFS, PFS, and OS rates were 48.5%, 89.6%, 45.1%, and 88.4%, respectively, at a median follow-up of 6.25 years. Subtotal resection was associated with poorer LPFS and PFS in patients with intracranial ependymoma (hazard ratio = 3.69, p = 0.018 for LPFS; hazard ratio = 3.20, p = 0.029 for PFS). CONCLUSION: Incorporating radiotherapy into multimodal treatment has led to favorable outcomes in patients with ependymoma, and the extent of resection is a prognostic factor for the local control of intracranial ependymoma.

Synergistic effect of Abraxane that combines human IL15 fused with an albumin-binding domain on murine models of pancreatic ductal adenocarcinoma.

Nab-paclitaxel (Abraxane), which is a nanoparticle form of albumin-bound paclitaxel, is one of the standard chemotherapies for pancreatic ductal adenocarcinoma (PDAC). This study determined the effect of Abraxane in combination with a fusion protein, hIL15-ABD, on subcutaneous Panc02 and orthotopic KPC C57BL/6 murine PDAC models. Abraxane combined with hIL15-ABD best suppressed tumour growth and produced a 40%-60% reduction in the tumour size for Panc02 and KPC, compared to the vehicle group. In the combination group, the active form of interferon-γ (IFN-γ)-secreting CD8+ T cells and CD11b+ CD86+ M1 macrophages in tumour infiltrating lymphocytes (TILs) were increased. In the tumour drainage lymph nodes (TDLNs) of the combination group, there was a 18% reduction in CD8+ IFN-γ+ T cells and a 0.47% reduction in CD4+ CD25+ FOXP3+ regulatory T cells, as opposed to 5.0% and 5.1% reductions, respectively, for the control group. Superior suppression of CD11b+ GR-1+ myeloid-derived suppressor cells (MDSCs) and the induction of M1 macrophages in the spleen and bone marrow of mice were found in the combination group. Abraxane and hIL15-ABD effectively suppressed NF-κB-mediated immune suppressive markers, including indoleamine 2,3-dioxygenase (IDO), Foxp3 and VEGF. In conclusion, Abraxane combined with hIL15-ABD stimulates the anticancer activity of effector cells, inhibits immunosuppressive cells within the tumour microenvironment (TME) of PDAC, and produces a greater inhibitory effect than individual monotherapies.

Affibody-conjugated 5-fluorouracil prodrug system preferentially targets and inhibits HER2-expressing cancer cells.

Overexpression of HER2 is associated with cancer phenotypes, such as proliferation, survival, metastasis and angiogenesis, and has been validated as a therapeutic target. However, only a portion of patients benefited from anti-HER2 treatments, and many would develop resistance. A more effective HER2 targeted therapeutics is needed. Here, we adopted a prodrug system that uses 5-fluorocytosine (5-FC) and a HER2-targeting scaffold protein, ZHER2:2891, fused with yeast cytosine deaminase (Fcy) to target HER2-overexpressing cancer cells and to convert 5-FC to a significantly more toxic chemotherapeutic, 5-fluorouracil (5-FU). We cloned the coding gene of ZHER2:2891 and fused with those of ABD (albumin-binding domain) and Fcy. The purified ZHER2:2891-ABD-Fcy fusion protein specifically binds to HER2 with a Kd value of 1.6 nM ZHER2:2891-ABD-Fcy binds to MDA-MB-468, SKOV-3, BT474, and MC38-HER2 cells, which overexpress HER2, whereas with a lower affinity to HER2 non-expresser, MC38. Correspondingly, the viability of HER2-expressing cells was suppressed by relative low concentrations of ZHER2:2891-ABD-Fcy in the presence of 5-FC, and the IC50 values of ZHER2:2891-ABD-Fcy for HER2 high-expresser cells were approximately 10-1000 fold lower than those of non-HER2-targeting Fcy, and ABD-Fcy. This novel prodrug system, ZHER2:2891-ABD-Fcy/5-FC, might become a promising addition to the existing class of therapeutics specifically target HER2-expressing cancers.

Extended-field bone marrow sparing radiotherapy for primary chemoradiotherapy in cervical cancer patients with para-aortic lymphadenopathy: Volumetric-modulated arc therapy versus helical tomotherapy.

BACKGROUND: Extended-field (EF) bone marrow-sparing (BMS) radiotherapy is attracting interest for cervical cancer patients with para-aortic lymphadenopathy. OBJECTIVE: To compare dosimetric quality of volumetric-modulated arc therapy (VMAT) vs. helical tomotherapy (HT) during EF BMS radiotherapy. METHODS: HT dose-volume histogram parameters including (1) coverage, homogeneity, and conformity of target volumes, (2) sparing of organs-at-risk, (3) monitor units, and (4) estimated treatment time were compared with those of VMAT in 20 cervical cancer patients who underwent EF BMS radiotherapy. The pelvic and para-aortic regions received 45-Gy dose (25 fractions), with simultaneous integrated boost of 55 Gy (25 fractions) for pelvic and para-aortic lymphadenopathy, followed by a parametrial boost of 9 Gy (5 fractions). RESULTS: The HT-based and VMAT techniques achieved adequate and similar target volume coverage with good dose homogeneity and conformity, while sparing all organs-at-risk, including the rectum, bladder, bowel, bone marrow, femoral head, kidney, and spinal cord. The HT treatment plan had significantly higher monitor units (p < 0.001) and longer estimated treatment times (p < 0.001). CONCLUSIONS: VMAT and HT plans are suitable for EF BMS radiotherapy, which can achieve adequate target volume coverage while sufficiently sparing normal tissue. In addition, VMAT, compared to HT planning, yielded shorter estimated treatment times.

Higher HOPX expression is associated with distinct clinical and biological features and predicts poor prognosis in de novo acute myeloid leukemia.

Homeodomain-only protein homeobox (HOPX) is the smallest homeodomain protein. It was regarded as a stem cell marker in several non-hematopoietic systems. While the prototypic homeobox genes such as the HOX family have been well characterized in acute myeloid leukemia (AML), the clinical and biological implications of HOPX in the disease remain unknown. Thus we analyzed HOPX and global gene expression patterns in 347 newly diagnosed de novo AML patients in our institute. We found that higher HOPX expression was closely associated with older age, higher platelet counts, lower white blood cell counts, lower lactate dehydrogenase levels, and mutations in RUNX1, IDH2, ASXL1, and DNMT3A, but negatively associated with acute promyelocytic leukemia, favorable karyotypes, CEBPA double mutations and NPM1 mutation. Patients with higher HOPX expression had a lower complete remission rate and shorter survival. The finding was validated in two independent cohorts. Multivariate analysis revealed that higher HOPX expression was an independent unfavorable prognostic factor irrespective of other known prognostic parameters and gene signatures derived from multiple cohorts. Gene set enrichment analysis showed higher HOPX expression was associated with both hematopoietic and leukemia stem cell signatures. While HOPX and HOX family genes showed concordant expression patterns in normal hematopoietic stem/progenitor cells, their expression patterns and associated clinical and biological features were distinctive in AML settings, demonstrating HOPX to be a unique homeobox gene. Therefore, HOPX is a distinctive homeobox gene with characteristic clinical and biological implications and its expression is a powerful predictor of prognosis in AML patients.

The outcome and prognostic factors for lymph node recurrence after node-sparing definitive external beam radiotherapy for localized prostate cancer.

BACKGROUND: The prognostic factors for the recurrence of lymph node (LN) metastasis after dose-escalated radiotherapy (RT) in prostate cancer patients have not been well investigated. We report the prognostic factors and outcomes in patients receiving salvage treatment for LN recurrence after high-dose intensity-modulated RT (IMRT). METHODS: We studied a cohort of 419 patients with localized prostate adenocarcinoma undergoing definitive IMRT (78 Gy). LN recurrence was diagnosed by size criteria using computed tomography (CT) or magnetic resonance imaging, or abnormal uptake of (18)F-fluorocholine by LNs on positron emission tomography/CT. Overall survival and LN recurrence-free survival (LNRFS) were calculated, and prognostic factors were evaluated. RESULTS: With a median follow-up of 60 months, 18 patients (4.3 %) had LN recurrence and a significantly lower 5-year overall survival rate (60 vs. 90 %, p = 0.003). Univariate analysis showed that T3/T4 stage (p = 0.003), Gleason score >7 (p < 0.001), and estimated risk of pelvic LN involvement of >30 % by the Roach formula (p = 0.029) were associated with significantly lower LNRFS. On multivariate analysis, high Gleason score (hazard ratio = 5.99, p = 0.007) was the only independent factor. The 1/2-year overall survivals after LN recurrence were 67/54 %. Patients with isolated LN recurrence (p = 0.003), prostate-specific antigen (PSA) doubling time >5 months (p = 0.009), interval between PSA nadir and biochemical failure >12 months (p = 0.035), and PSA <10 ng/ml at LN recurrence (p = 0.003) had significantly better survival. Patients with isolated LN recurrence had significantly better survival when treated with combined RT and hormones than when treated with hormones alone (p = 0.011). CONCLUSIONS: Gleason score of >7 may predict LN recurrence in prostate cancer patients treated with definitive IMRT. Small number of patients limits the extrapolation of this risk with the primary treatment strategy. Combined RT and hormones may prolong survival in patients with isolated LN recurrence.

Preoperative prognostic neurologic index for glioblastoma patients receiving tumor resection.

BACKGROUND: Neurologic status is one of the major prognostic factors in glioblastoma patients; however, no consensus exists on a clinical index for predicting patient outcomes. The purpose of this study was to evaluate the correlation between neurologic deficits and clinical outcomes in glioblastoma patients, and to develop a prognostic neurologic index for identifying patients with poor outcomes. METHODS: Patients receiving tumor resection with pathologically confirmed glioblastoma were retrospectively evaluated. The patients' preoperative neurologic deficits were categorized, and patients with poor overall survival (OS) were identified. Other common prognostic factors, including age, performance, imaging findings, and extent of resection, were analyzed. RESULTS: We evaluated 162 glioblastoma patients receiving tumor resection between February 2000 and December 2011, of whom 54 received adjuvant radiotherapy (RT) alone and 84 received concurrent chemo-RT with temozolomide. At a median follow-up of 57.6 (range 26.3-88.9) months, 26 patients had survived without loss to follow-up. We defined adverse neurologic status by using an index of combined increased intracranial pressure (IICP) and non-IICP signs. In univariate analysis, the median OS of patients with and without adverse neurologic status were 9.6 and 18.7 months, respectively (p < 0.001). In multivariate analyses, adverse neurologic status remained significantly associated with poor OS (hazard ratio 2.18, 95 % confidence interval 1.54-3.10). CONCLUSIONS: Our proposed neurologic index enables significantly identifying glioblastoma patients receiving tumor resection with poor outcomes, independent of other common prognostic factors. Using the index provides a preoperative predictor of prognosis in glioblastoma patients receiving tumor resection.

A DNA vaccine against cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) prevents tumor growth.

Co-stimulatory signaling pathway triggered by the binding of B7.1/B7.2 (CD80/86) of antigen-presenting cells (APCs) to CD28 of T cells is required for optimal T-cell activation. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is a negative regulator of T cell activation, which competes with CD28 for B7.1/B7.2 binding with a greater affinity. Ipilimumab, a monoclonal antibody against CTLA-4, has shown positive efficacy in a pivotal clinical trial for the treatment of metastatic melanoma and was approved by FDA. However, the cost of monoclonal antibody-based therapeutics might limit the number of patients treated. To develop a novel therapeutics specifically targeting CTLA-4, we constructed a DNA vaccine by cloning the sequence of CTLA-4 fused with a transmembrane domain sequence of placental alkaline phosphatase (PLAP) into a mammalian expression plasmid, pVAC-1. Immunization with the resulting construct, pVAC-1-hCTLA-4, elicited antibody specific to human CTLA-4 with cross reactivity to murine CTLA-4, which was sufficient for inhibiting B16F10 tumor growth in c57BL/6 mice in the absence of measurable toxicity. Coupling liposome with pVAC-1-mCTLA-4 could break tolerance to self-antigen in BALB/c mice and induce potent immunity against murine CTLA-4, and suppress growth of subcutaneous renal cell carcinoma (Renca).

Amiodarone inhibits the entry and assembly steps of hepatitis C virus life cycle.

HCV (hepatitis C virus) infection affects an estimated 180 million people in the world's population. Adverse effects occur frequently with current standard treatment of interferon and ribavirin, while resistance of new direct anti-viral agents, NS3 protease inhibitors, is a major concern because of their single anti-HCV mechanism against the viral factor. New anti-viral agents are needed to resolve the problems. Amiodarone, an anti-arrhythmic drug, has recently been shown to inhibit HCV infection in vitro. The detailed mechanism has yet to be clarified. The aim of the present study was to elucidate the molecular mechanism of the inhibitory effect of amiodarone on HCV life cycle. The effect of amiodarone on HCV life cycle was investigated in Huh-7.5.1 cells with HCVcc (cell culture-derived HCV), HCVpp (HCV pseudoviral particles), sub-genomic replicons, IRES (internal ribosomal entry site)-mediated translation assay, and intracellular and extracellular infectivity assays. The administration of amiodarone appeared to inhibit HCV entry independent of genotypes, which was attributed to the down-regulation of CD81 receptor expression. The inhibitory effect of amiodarone also manifested in the HCV assembly step, via the suppression of MTP (microsomal triacylglycerol transfer protein) activity. Amiodarone revealed no effects on HCV replication and translation. With the host factor-targeting characteristics, amiodarone may be an attractive agent for the treatment of HCV infection.

5-Fluorocytosine combined with Fcy-hEGF fusion protein targets EGFR-expressing cancer cells.

Human epithelial cancers account for approximately 50% of all cancer deaths. This type of cancer is characterized by excessive activation and expression of the epidermal growth factor receptor (EGFR). The EGFR pathway is critical for cancer cell proliferation, survival, metastasis and angiogenesis. The EGF-EGFR signaling pathway has been validated as an important anticancer drug target. Increasing numbers of targeted therapies against this pathway have been either approved or are currently under development. Here, we adopted a prodrug system that uses 5-fluorocytosine (5-FC) and human EGF (hEGF) fused with yeast cytosine deaminase (Fcy) to target EGFR-overexpressing cancer cells and to convert 5-FC to a significantly more toxic chemotherapeutic, 5-fluorouracil (5-FU). We cloned and purified the Fcy-hEGF fusion protein from Pichia pastoris yeast. This fusion protein specifically binds to EGFR with a similar affinity as hEGF, approximately 10 nM. Fcy-hEGF binds tightly to A431 and MDA-MB-468 cells, which overexpress EGFR, but it binds with a lower affinity to MDA-MB-231 and MCF-7, which express lower levels of EGFR. Similarly, the viability of EGFR-expressing cells was suppressed by Fcy-hEGF in the presence of increasing concentrations of 5-FC, and the IC(50) values for A431 and MDA-MB-468 were approximately 10-fold lower than those of MDA-MB-231 and MCF-7. This novel prodrug system, Fcy-hEGF/5-FC, might represent a promising addition to the available class of inhibitors that specifically target EGFR-expressing cancers.

PTEN activation contributes to tumor inhibition by trastuzumab, and loss of PTEN predicts trastuzumab resistance in patients.

The ErbB2-targeting antibody, trastuzumab (Herceptin), has remarkable therapeutic efficacy in certain patients with ErbB2-overexpressing tumors. The overall trastuzumab response rate, however, is limited and what determines trastuzumab response is poorly understood. Here we report that PTEN activation contributes to trastuzumab's antitumor activity. Trastuzumab treatment quickly increased PTEN membrane localization and phosphatase activity by reducing PTEN tyrosine phosphorylation via Src inhibition. Reducing PTEN in breast cancer cells by antisense oligonucleotides conferred trastuzumab resistance in vitro and in vivo. Patients with PTEN-deficient breast cancers had significantly poorer responses to trastuzumab-based therapy than those with normal PTEN. Thus, PTEN deficiency is a powerful predictor for trastuzumab resistance. Additionally, PI3K inhibitors rescued PTEN loss-induced trastuzumab resistance, suggesting that PI3K-targeting therapies could overcome this resistance.

Chimeric immune checkpoint protein vaccines inhibit the tumorigenesis and growth of rat cholangiocarcinoma.

Cholangiocarcinoma (CCA) is the second most common primary liver malignancy and carries a dismal prognosis due to difficulties in achieving an optimal resection, and poor response to current standard-of-care systemic therapies. We previously devised a CTLA4-PD-L1 DNA cancer vaccine (DNA vaccine) and demonstrated its therapeutic effects on reducing tumor growth in a thioacetamide (TAA)-induced rat intrahepatic CCA (iCCA) model. Here, we developed a CTLA4-PD-L1 chimeric protein vaccine (Protein vaccine), and examined its effects in the rat iCCA model. In a therapeutic setting, iCCA-bearing rats received either DNA plus Protein vaccines or Protein vaccine alone, resulting in increased PD-L1 and CTLA-4 antibody titers, and reduced iCCA tumor burden as verified by animal positron emission tomography (PET) scans. Treating iCCA-bearing rats with Protein vaccine alone led to the increase of CTAL4 antibody titers that correlated with the decrease of tumor SUV ratio, indicating regressed tumor burden, along with increased <i>CD8</i> and granzyme A (<i>GZMA</i>) expression, and decreased PD-L1 expression on tumor cells. In a preventive setting, DNA or Protein vaccines were injected in rats before the induction of iCCA by TAA. Protein vaccines induced a more sustained PD-L1 and CTLA-4 antibody titers compared with DNA vaccines, and was more potent in preventing iCCA tumorigenesis. Correspondingly, Protein vaccines, but not DNA vaccines, downregulated PD-L1 gene expression and hindered the carcinogenesis of iCCA. Taken together, the CTLA4-PD-L1 chimeric protein vaccine may function both as a therapeutic cancer vaccine and as a preventive cancer vaccine in the TAA-induced iCCA rat model.

Propensity score matching analysis comparing radical prostatectomy and radiotherapy with androgen deprivation therapy in locally advanced prostate cancer.

To compare clinical outcomes between the use of robotic-assisted laparoscopic radical prostatectomy (RP) and radiotherapy (RT) with long-term androgen deprivation therapy (ADT) in locally advanced prostate cancer (PC), 315 patients with locally advanced PC (clinical T-stage 3/4) were considered for analysis retrospectively. Propensity score-matching at a 1:1 ratio was performed. The median follow-up period was 59.2 months (IQR 39.8-87.4). There were 117 (37.1%) patients in the RP group and 198 (62.9%) patients in the RT group. RT patients were older and had higher PSA at diagnosis, higher Gleason score grade group and more advanced T-stage (all p < 0.001). After propensity score-matching, there were 68 patients in each group. Among locally advanced PC patients, treatment with RP had a higher risk of biochemical recurrence compared to the RT group. In multivariate Cox regression analysis, treatment with RT plus ADT significantly decreased the risk of biochemical failure (HR 0.162, p < 0.001), but there was no significant difference in local recurrence, distant metastasis and overall survival (p = 0.470, p = 0.268 and p = 0.509, respectively). This information supported a clinical benefit in BCR control for patients undergoing RT plus long-term ADT compared to RP.

Real-World Evaluation of Modern Adjuvant Radiotherapy in Women with Stage IB Endometrial Cancer.

The optimal adjuvant treatment for stage IB endometrial cancer remains undefined. We investigated the benefit of modern adjuvant radiotherapy for women with stage IB endometrial cancer. We retrospectively reviewed patients with surgically staged, pure stage IB endometrioid adenocarcinoma (2010 to 2018). Adjuvant modern radiotherapy consists of external-beam radiotherapy (EBRT) by intensity, volumetric-modulated arc radiotherapy, or image-guided vaginal brachytherapy (VBT). The study included 180 stage IB patients. Patients with grade 3 diseases had frequent aggressive histology patterns (lymphovascular space invasion (LVSI); low uterine segment involvement) and experienced significantly shorter recurrence-free survival (RFS) and overall survival (OS) than patients with grade 1/2 diseases. Adjuvant modern radiotherapy decreased the incidence of acute/chronic grade ≥2 gastrointestinal toxicity. In IB grade 1/2 patients, EBRT significantly lengthened survival (RFS/OS); patients with age >60 years, myometrial invasion beyond the outer third, or LVSI benefited the most from EBRT. EBRT also significantly improved survival (RFS/OS) in IB grade 3 patients, where patients with bulky tumors or LVSI benefited the most from EBRT. Therefore, EBRT may be beneficial for all stage IB patients.

A multipurpose brachytherapy catheter to enable intratumoral injection.

PURPOSE: To create and test a multipurpose brachytherapy catheter prototype enabling intratumoral injection and brachytherapy after a single catheter insertion. METHODS AND MATERIALS: The design of the prototype consists of an outer tube and an inner syringe tube that can be filled with injectable agent. The outer sheath and inner syringe tube were constructed using polytetrafluoroethylene tubing, and the other components were 3D printed using dental resin and polylactic acid material. To demonstrate functionality, we injected in vitro phantoms with dyed saline. For proof of concept, we demonstrated the potential for the prototype to deliver cell therapy, enhance tumor delineation, deliver tattoo ink for pathology marking, avoid toxicity through local delivery of chemotherapy, and facilitate combination brachytherapy and immunotherapy. RESULTS: The prototype enables accurate injection in vitro and in vivo without altering dosimetry. To illustrate the potential for delivery of cell therapies, we injected luciferase-expressing splenocytes and confirmed their delivery with bioluminescence imaging. To demonstrate feasibility of radiographically visualizing injected material, we delivered iohexol contrast intratumorally and confirmed tumor retention using Faxitron x-ray imaging. In addition, we show the potential of intratumoral administration to reduce toxicity associated with cyclophosphamide compared with systemic administration. To demonstrate feasibility, we treated tumor-bearing mice with brachytherapy (192Ir source, 2 Gy to 5 mm) in combination with intratumoral injection of 375,000 U of interleukin 2 and observed no increased toxicity. CONCLUSIONS: These results demonstrate that a prototype multipurpose brachytherapy catheter enables accurate intratumoral injection and support the feasibility of combining intratumoral injection with brachytherapy.

Impact of adjuvant radiotherapy on the survival of women with optimally resected stage III endometrial cancer in the era of modern radiotherapy: a retrospective study.

BACKGROUND: The optimal adjuvant treatment for stage III endometrial cancer in the era of modern radiotherapy remains undefined. We investigated the benefit of adjuvant radiotherapy for women who underwent optimal resection for stage III endometrial cancer in the era of modern radiotherapy. METHODS: We retrospectively reviewed patients with endometrial cancer who were treated between 2010 and 2018. Adjuvant treatment included radiotherapy by modern radiotherapy techniques (intensity-modulated or volumetric modulated arc radiotherapy), chemotherapy, or both. Recurrence-free survival (RFS) and overall survival (OS) were calculated using the Kaplan-Meier method and analyzed via multivariate Cox proportional hazards models. RESULTS: One hundred sixty-one patients were initially included (52, 9, and 100 with stages IIIA, IIIB, and IIIC cancer, respectively); 154 patients (96%) received adjuvant therapy. Such adjuvant treatment was associated with improved RFS (p = 0.014) and OS (p = 0.044) over surgery alone. Adjuvant radiotherapy by modern radiotherapy techniques led to low incidence of acute (25%) and chronic (7%) grade ≥ 2 gastrointestinal toxicity. On univariate analysis, non-endometrioid histology and grade 3 status were associated with higher risks of tumor recurrence and death, whereas adjuvant radiotherapy alone or in combination chemotherapy reduced their risks. On multivariate analysis, non-endometrioid histology was associated with increased recurrence (hazard ratio [HR], 2.95; p = 0.009), whereas adjuvant radiotherapy alone or with chemotherapy was associated with lower recurrence (HR, 0.62; p = 0.042). Patients > 60 years of age (p = 0.038) as well as those with endometrioid histology (p = 0.045), lymphovascular space invasion (p = 0.031), and ≥ 2 positive lymph nodes (p = 0.044) benefited most from adjuvant radiotherapy. CONCLUSIONS: Modern adjuvant radiotherapy (intensity-modulated or volumetric modulated arc radiotherapy) alone or with chemotherapy should be considered for women with optimally resected stage III endometrial cancer. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04251676. Registered 24 January 2020. Retrospectively registered.

Tumor-Specific Antibody, Cetuximab, Enhances the In Situ Vaccine Effect of Radiation in Immunologically Cold Head and Neck Squamous Cell Carcinoma.

In head and neck squamous cell carcinoma (HNSCC) tumors that over-expresses huEGFR, the anti-EGFR antibody, cetuximab, antagonizes tumor cell viability and sensitizes to radiation therapy. However, the immunologic interactions between cetuximab and radiation therapy are not well understood. We transduced two syngeneic murine HNSCC tumor cell lines to express human EGFR (MOC1- and MOC2-huEGFR) in order to facilitate evaluation of the immunologic interactions between radiation and cetuximab. Cetuximab was capable of inducing antibody-dependent cellular cytotoxicity (ADCC) in MOC1- and MOC2-huEGFR cells but showed no effect on the viability or radiosensitivity of these tumor cells, which also express muEGFR that is not targeted by cetuximab. Radiation enhanced the susceptibility of MOC1- and MOC2-huEGFR to ADCC, eliciting a type I interferon response and increasing expression of NKG2D ligands on these tumor cells. Co-culture of splenocytes with cetuximab and MOC2-huEGFR cells resulted in increased expression of IFNγ in not only NK cells but also in CD8+ T cells, and this was dependent upon splenocyte expression of FcγR. In MOC2-huEGFR tumors, combining radiation and cetuximab induced tumor growth delay that required NK cells, EGFR expression, and FcγR on host immune cells. Combination of radiation and cetuximab increased tumor infiltration with NK and CD8+ T cells but not regulatory T cells. Expression of PD-L1 was increased in MOC2-huEGFR tumors following treatment with radiation and cetuximab. Delivering anti-PD-L1 antibody with radiation and cetuximab improved survival and resulted in durable tumor regression in some mice. Notably, these cured mice showed evidence of an adaptive memory response that was not specifically directed against huEGFR. These findings suggest an opportunity to improve the treatment of HNSCC by combining radiation and cetuximab to engage an innate anti-tumor immune response that may prime an effective adaptive immune response when combined with immune checkpoint blockade. It is possible that this approach could be extended to any immunologically cold tumor that does not respond to immune checkpoint blockade alone and for which a tumor-specific antibody exists or could be developed.

Maintenance BEZ235 Treatment Prolongs the Therapeutic Effect of the Combination of BEZ235 and Radiotherapy for Colorectal Cancer.

Our previous study demonstrated that administration of NVP-BEZ235 (BEZ235), a dual PI3K/mTOR inhibitor, before radiotherapy (RT) enhanced the radiotherapeutic effect in colorectal cancer (CRC) cells both in vitro and in vivo. Here, we evaluated whether maintenance BEZ235 treatment, after combinatorial BEZ235 + RT therapy, prolonged the antitumor effect in CRC. K-RAS mutant CRC cells (HCT116 and SW480), wild-type CRC cells (HT29), and HCT116 xenograft tumors were separated into the following six study groups: (1) untreated (control); (2) RT alone; (3) BEZ235 alone; (4) RT + BEZ235; (5) maintenance BEZ235 following RT + BEZ235 (RT + BEZ235 + mBEZ235); and (6) maintenance BEZ235 following BEZ235 (BEZ235 + mBEZ235). RT + BEZ235 + mBEZ235 treatment significantly inhibited cell viability and increased apoptosis in three CRC cell lines compared to the other five treatments in vitro. In the HCT116 xenograft tumor model, RT + BEZ235 + mBEZ235 treatment significantly reduced the tumor size when compared to the other five treatments. Furthermore, the expression of mTOR signaling molecules (p-rpS6 and p-eIF4E), DNA double-strand break (DSB) repair-related molecules (p-ATM and p-DNA-PKcs), and angiogenesis-related molecules (VEGF-A and HIF-1α) was significantly downregulated after RT + BEZ235 + mBEZ235 treatment both in vitro and in vivo when compared to the RT + BEZ235, RT, BEZ235, BEZ235 + mBEZ235, and control treatments. Cleaved caspase-3, cleaved poly (ADP-ribose) polymerase (PARP), 53BP1, and γ-H2AX expression in the HCT116 xenograft tissue and three CRC cell lines were significantly upregulated after RT + BEZ235 + mBEZ235 treatment. Maintenance BEZ235 treatment in CRC cells prolonged the inhibition of cell viability, enhancement of apoptosis, attenuation of mTOR signaling, impairment of the DNA-DSB repair mechanism, and downregulation of angiogenesis that occurred due to concurrent BEZ235 and RT treatment.

Preclinical testing of clinically applicable strategies for overcoming trastuzumab resistance caused by PTEN deficiency.

PURPOSE: We have previously shown that PTEN loss confers trastuzumab resistance in ErbB2-overexpressing breast cancer using cell culture, xenograft models, and patient samples. This is a critical clinical problem because trastuzumab is used in a variety of therapeutic regimens, and at the current time, there are no established clinical strategies to overcome trastuzumab resistance. Here, we did preclinical studies on the efficacy of clinically applicable inhibitors of the Akt/mammalian target of rapamycin (mTOR) pathway to restore trastuzumab sensitivity to PTEN-deficient cells. EXPERIMENTAL DESIGN: Cell culture and xenograft models were used to test a panel of clinically applicable, small-molecule inhibitors of the Akt/mTOR signal transduction pathway, a critical pathway downstream of ErbB2, and identify compounds with the ability to restore trastuzumab sensitivity to PTEN-deficient cells. RESULTS: When trastuzumab was combined with the Akt inhibitor triciribine, breast cancer cell growth was inhibited and apoptosis was induced. In a xenograft model, combination therapy with trastuzumab and triciribine dramatically inhibited tumor growth. The combination of trastuzumab and the mTOR inhibitor RAD001 also slowed breast cancer cell growth in vitro and in vivo. CONCLUSIONS: Combining trastuzumab with inhibitors of the Akt/mTOR pathway is a clinically applicable strategy and combinations of trastuzumab with triciribine or RAD001 are promising regimens for rescue of trastuzumab resistance caused by PTEN loss.

Selective inhibition of ErbB2-overexpressing breast cancer in vivo by a novel TAT-based ErbB2-targeting signal transducers and activators of transcription 3-blocking peptide.

ErbB2 is an excellent target for cancer therapies. Unfortunately, the outcome of current therapies for ErbB2-positive breast cancers remains unsatisfying due to resistance and side effects. New therapies for ErbB2-overexpressing breast cancers continue to be in great need. Peptide therapy using cell-penetrating peptides (CPP) as peptide carriers is promising because the internalization is highly efficient, and the cargoes delivered can be bioactive. However, the major obstacle in using these powerful CPPs for therapy is their lack of specificity. Here, we sought to develop a peptide carrier that could introduce therapeutics specifically to ErbB2-overexpressing breast cancer cells. By modifying the HIV TAT-derived CPP and conjugating anti-HER-2/neu peptide mimetic (AHNP), we developed the peptide carrier (P3-AHNP) that specifically targeted ErbB2-overexpressing breast cancer cells in vitro and in vivo. A signal transducers and activators of transcription 3 (STAT3)-inhibiting peptide conjugated to this peptide carrier (P3-AHNP-STAT3BP) was delivered more efficiently into ErbB2-overexpressing than ErbB2 low-expressing cancer cells in vitro and successfully decreased STAT3 binding to STAT3-interacting DNA sequence. P3-AHNP-STAT3BP inhibited cell growth in vitro, with ErbB2-overexpressing 435.eB breast cancer cells being more sensitive to the treatment than the ErbB2 low-expressing MDA-MB-435 cells. Compared with ErbB2 low-expressing MDA-MB-435 xenografts, i.p. injected P3-AHNP-STAT3BP preferentially accumulated in 435.eB xenografts, which led to more reduction of proliferation and increased apoptosis and targeted inhibition of tumor growth. This novel peptide delivery system provided a sound basis for the future development of safe and effective new-generation therapeutics to cancer-specific molecular targets.