Challenges and Opportunities Associated With the MD Anderson IMPACT2 Randomized Study in Precision Oncology

We investigated the challenges of conducting IMPACT2, an ongoing randomized study that evaluates molecular testing and targeted therapy (ClinicalTrials.gov: NCT02152254). Patients with metastatic cancer underwent tumor profiling and were randomized between the two arms when eligibility criteria were met (Part A). In Part B, patients who declined randomization could choose the study arm. In Part A, 69 (21.8%) of 317 patients were randomized; 78.2% were not randomized because of non-targetable alterations (39.8%), unavailability of clinical trial (21.8%), other reasons (12.6%), or availability of US Food and Drug Administration (FDA)-approved drugs for the indication (4.1%). In Part B, 32 (20.4%) of 157 patients were offered randomization; 16 accepted and 16 selected their treatment arm; 79.0% were not randomized (patient\u27s/physician\u27s choice, 29.3%; treatment selection prior to genomic reports, 16.6%; worsening performance status/death, 12.7%; unavailability of clinical trials, 6.4%; other, 6.4%; non-targetable alterations, 5.7%; or availability of FDA-approved drugs for the indication, 1.9%). In conclusion, although randomized controlled trials have been considered the gold standard for drug development, the execution of randomized trials in precision oncology in the advanced metastatic setting is complicated. We encountered various challenges conducting the IMPACT2 study, a large precision oncology trial in patients with diverse solid tumor types. The adaptive design of IMPACT2 enables patient randomization despite the continual FDA approval of targeted therapies, the evolving tumor biomarker landscape, and the plethora of investigational drugs. Outcomes for randomized patients are awaited

Duration of androgen deprivation therapy with postoperative radiotherapy for prostate cancer: a comparison of long-course versus short-course androgen deprivation therapy in the RADICALS-HD randomised trial

Background Previous evidence supports androgen deprivation therapy (ADT) with primary radiotherapy as initial treatment for intermediate-risk and high-risk localised prostate cancer. However, the use and optimal duration of ADT with postoperative radiotherapy after radical prostatectomy remains uncertain. Methods RADICALS-HD was a randomised controlled trial of ADT duration within the RADICALS protocol. Here, we report on the comparison of short-course versus long-course ADT. Key eligibility criteria were indication for radiotherapy after previous radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to add 6 months of ADT (short-course ADT) or 24 months of ADT (long-course ADT) to radiotherapy, using subcutaneous gonadotrophin-releasing hormone analogue (monthly in the short-course ADT group and 3-monthly in the long-course ADT group), daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as metastasis arising from prostate cancer or death from any cause. The comparison had more than 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 75% to 81% (hazard ratio [HR] 0·72). Standard time-to-event analyses were used. Analyses followed intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov , NCT00541047 . Findings Between Jan 30, 2008, and July 7, 2015, 1523 patients (median age 65 years, IQR 60–69) were randomly assigned to receive short-course ADT (n=761) or long-course ADT (n=762) in addition to postoperative radiotherapy at 138 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 8·9 years (7·0–10·0), 313 metastasis-free survival events were reported overall (174 in the short-course ADT group and 139 in the long-course ADT group; HR 0·773 [95% CI 0·612–0·975]; p=0·029). 10-year metastasis-free survival was 71·9% (95% CI 67·6–75·7) in the short-course ADT group and 78·1% (74·2–81·5) in the long-course ADT group. Toxicity of grade 3 or higher was reported for 105 (14%) of 753 participants in the short-course ADT group and 142 (19%) of 757 participants in the long-course ADT group (p=0·025), with no treatment-related deaths. Interpretation Compared with adding 6 months of ADT, adding 24 months of ADT improved metastasis-free survival in people receiving postoperative radiotherapy. For individuals who can accept the additional duration of adverse effects, long-course ADT should be offered with postoperative radiotherapy. Funding Cancer Research UK, UK Research and Innovation (formerly Medical Research Council), and Canadian Cancer Society

Abstract A53: Antiangiogenic activity of GER, a derivative of sweet leaf tea extract, is mediated by the downregulation of bFGF and VEGF

Abstract Mounting evidence indicates that angiogenesis is essential for the proliferation and survival of number of malignant diseases, thus inhibition of angiogenesis might be an effective therapeutic strategy. Antiangiogenic agent that targets both bFGF and VEGF (VEGFR) are considered to be effective adjuncts to the treatment of solid tumors or cancer preventive. Chinese sweet leaf tea, a hot water extract of Rubus suavissimus S. Lee (Rosaceae) (RUS) has been reported to have antiangiogenic activities evidenced by its ability to inhibit the angiogenic initiation and growth of human placental vein tissue (Liu et al., Phytother, Res. 20: 806-813, 2006) and experimental corneal neovascularization (Hakan, O.F., et al, Pharmaceu. Biol. 45: 44-47, 2007). We reported that this particular extract has the ability to inhibit the endothelial tubule formation, migration, and VEGF (VEGFR) of the HUVEC cells (Proc. Am. Assoc. Cancer Res, 1432, 2009). Here we investigated the anti-angiogenic activity of GER, a combination of gallic acid, ellagic acid, and rubusoside purified from the RUS and the relevant molecular mechanisms using HUVEC cells. Our preliminary data demonstrated that GER (5 to 25 µg/ml) markedly inhibited migration of HUVEC cells compared to the vehicle control. This inhibitory effect was concentration-dependent. At a similar concentration, the endothelial tubule formation was almost completely inhibited. When HUVEC cells were treated with GER (5 to 20 µg/ml), the expression of both bFGF and VEGF were markedly inhibited even at the lowest starting concentration. These inhibitory effects were also concentration-dependent. To further confirm the involvement of VEGF pathway in GER-induced anti-angiogenic activity, the protein level of tyrosine kinase receptor VEGFR2 (Flk-1/KDR) was examined. Intriguingly, the expression of Flk-1 was significantly suppressed in HUVEC cells treated with GER (40 µg/ml) by 54.1% ± 2.3% in comparison to that of vehicle control. In contrast, VEGFR2 kinase activity and protein levels of VEGFR1 remained unchanged compared to that of the vehicle control. These results suggest that GER derived from the sweet leaf tea extract may be completely responsible for the observed anti-angiogenic effect of the sweet leaf tea reported previously by down-regulating proangiogenic factors bFGF and VEGF. The chemopreventive effect of GER and its parent extract RUS on the development of human pancreatic carcinoma (L3.6pl cells) in mouse orthotopic model is currently under investigation and will be reported. This study was supported by NIH grant 1R21 AT002882-01A2. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A53.</jats:p

Abstract B81: Prostate 5LX® inhibits proliferation of prostate cancer cells through alteration of inflammatory pathways

Abstract Purpose: Inflammation has been recognized as a key factor in the development of age-related degenerative diseases including cancer. Among important pro-inflammatory factors, bioactive lipids derived from cyclooxygenase (COX) or lipoxygenase (LOX) enzymes have been implicated as key targets for treatment and prevention of cancers. Here we report the effect of a multi-herb product “Prostate 5LX” on metabolism of inflammatory mediators in human prostate cancer and rat macrophage cells and their association with anti-proliferative activity. Methods: The effect of Prostate 5LX and its individual components on eicosanoid metabolism in human prostate cancer PC3, LNCaP, rat leukemia RBL-1 and macrophage RAW267.4 cells were examined using a validated LC/MS/MS analytical method. The effect of this natural product on the expression of inflammation associated genes in RAW267.4 cells was measured using TaqMan inflammation array kits and RT-PCR. Protein expression of relevant enzymes was evaluated by Western blot using appropriate antibodies. Results: When PC3 cells were treated with as little as 50 μg (0.1μl) Prostate 5LX/ml, the relative formation of 5-LOX products, LTB4 and 5-HETE was reduced by 69.2% and 36.7%, respectively. Similarly, Prostate 5LX at this concentration almost totally blocked the formation of LTB4 and 5-HETE in RBL-1 cells which are known to have relatively higher levels of 5-LOX and are a good model for evaluation of 5-LOX activity. The effect of Prostate 5LX on inhibition of 5-LOX activity was concentration-dependent. Unexpectedly, the level of 12-HETE, a 12-LOX metabolite, in PC3 or RBL-1 cells treated with Prostate 5LX was also significantly reduced in a concentration-dependent manner compared to untreated controls. To further our understanding of the role of individual botanical extracts in contributing to these unique biological activities, the effect of individual extracts on 5-LOX and 12-LOX metabolism was evaluated against the parent product in RBL-1 cells. While Saw Palmetto (80 μg/ml), green tea (50 μg/ml) and rosemary (10 μg/ml) significantly inhibited formation of 5-HETE by 67.1±11.2%, 45.3±8.3% and 68.5± 12.1%, respectively, stinging nettle (50 μg/ml) extract inhibited production of 12-HETE by 46.1% in RBL-1 cells. Intriguingly, the inhibitory effect of Prostate 5LX in the concentration comparable to that used for those individual botanical extracts, was much more stronger than any of the individual components evidenced by a 97.1% reduced formation of 5-HETE. The expression of both 5-LOX and 12-LOX proteins was reduced by Prostate 5LX in PC3, LNCaP and RBL-1 cells. Furthermore, the expression of LTA4 hydrolyase and leukotriene receptors were also markedly reduced by Prostate 5LX in Raw 267.4 cells. Interestingly, the growth of prostate cancer PC3 and LNCaP cells were significantly inhibited by Prostate 5LX (250 μg/ml) and these inhibitory effects appeared to be mediated through inhibition of 5-LOX and 12-LOX pathways in LNCaP and PC3 cells, respectively. Conclusions: Taken together, these preliminary data suggest that Prostate 5LX is capable of inhibiting the proliferation of prostate cancer cells mediated by alteration of lipoxygenase pathways, especially 5- and 12-LOX pathways. Given that inflammation plays an important role in prostate cancer initiation and development, these data may provide new insight on how this natural product affects prostate health, particularly prevents the development of prostate cancer. Citation Information: Cancer Prev Res 2011;4(10 Suppl):B81.</jats:p

Abstract 768: Sweet gum extract inhibits proliferation of prostate cancer PC3 cells through suppression of mTOR pathway, but through MAPK pathways in DU145 prostate cancer cells

Abstract A methanolic fruit extract (LIS-100) of sweet gum (Liquidambar styraciflua L.) containing lupine and oleanane-type triterpenoids has shown potential in inhibiting the proliferation of multiple human cancer cell lines particularly against human prostate cancer cells (Proc. Am. Assoc. Cancer Res, 1431, 2008). Here we further investigated the inhibition of LIS-100 on prostate cancer cells with wildtype PTEN (DU145) and PTEN -mutant (PC3) prostate cancer cells and associated molecular mechanisms. LIS-100 inhibited the proliferation of PC3 cells at IC50 of 3.0 ± 0.2 µg/ml and DU145 cells at IC50 of 39.1 ± 2.5 μg/ml, a 13-fold potency difference. LIS-100 altered the cell cycle at G1 phase and induced apoptosis at 10 µg/ml in the PC3 and LNCaP cells, whereas it induced autophagic cell death at 25 to 40 µg/ml in the DU145 cells evidenced by increased expression of LC3 proteins (hallmark for autophagic cell death) and acrine orange staining. These effects were time- (24 to 72 hrs) and concentration-dependent (2.5 to 10 µg/ml for PC3 and 10 to 40 µg/ml for DU145). In PC3 cells, the expression of CDK4 and Cyclin D1 was inhibited. In contrast, it was CDK2 and CDK7 that were reduced in DU145 cells, suggesting different molecular targets of LIS-100 in PC3 and DU145 cells. When PC3 cells were treated with LIS-100 (0.5 to 5 µg/ml), the activity of both PI3K and mTOR were inhibited at almost equal ED50 (5.5 and 4.25 µg/ml, respectively). However, the expression of mTOR was inhibited to a greater degree, at least 3-fold, over PI3K/Akt proteins in PC3 cells. Functional Proteomic Array analyses confirmed that LIS-100 (2.5 to 5 µg/ml) not only inhibited proteins associated with PI3K/Akt/mTOR pathways (e.g. Akt, p70S6K, S6, elF4EP, GSK3, TSC2), also suppressed upstream of PI3-kinase cell signaling pathways (IGFr, and IRS-1 proteins) in PC3 cells. Furthermore, the anti-proliferative effect of LIS-100 was reduced by 46% in mTOR siRNA-transfected PC3 cells from the control siRNA-transfected cells, confirming the important role of mTOR cell signaling pathway in LIS-100 mediated cell growth suppression in this particular cell. In contrast, when DU145 cells were treated with LIS-100 at 25 µg/ml, the phosphorylation of Akt, p70S6K, and pS6 was not affected, whereas pERK and pSTAT3 levels were reduced. Interestingly, LIS-100 reduced the formation of both anti-apoptotic lipid mediators 5-HETE and 12-HETE and increased the production of tumor suppressor 15-HETE in both PC3 and LNCaP cells, no such effects were observed in DU145 cells. These results suggest antiproliferative effect of sweet gum in prostate cancer cells is mediated through different molecular mechanisms. The important role of PTEN status on sweet gum elicited anti-proliferative activity on prostate cancer is currently under investigation. This study was supported by NIH grant 1R21 AT004514-01A1 to P. Yang. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 768.</jats:p

Abstract 3206: Mistletoe extract inhibits the proliferation of human hepatocellular carcinoma cells by induction of apoptosis and downregulation of c-MYC

Abstract Mistletoe extracts including Viscum Fraxini (extract of mistletoe growing on ash trees) have been used extensively in European medical clinics to treat various cancers including hepatocellular carcinoma (HCC). Results from a phase II clinical trial have shown that subcutaneous administration of Fraxini leads to either complete or partial response in 20% of chemo-naïve patients with HCC. However, how mistletoe extract exerts its antitumor activity in HCC is largely unknown. We examined the effect of Fraxini on the growth of human HCC Hep3B and HepG2 cells by MTT assay, apoptosis by PI and Annexin V staining and molecular mechanisms using Reverse Phase Proteomic Array (RPPA). All three mistletoe extracts, Fraxini, Iscador Q and M (growing on oak and maple trees, respectively), exerted relatively strong antiproliferative activity in the Hep3B cells, with IC50 values at 0.5, 6.49, and 5.7 µg/ml, respectively. A slightly weaker anticancer effect was observed in the HepG2 cells treated with the above three extracts. The antiproliferative effect of Fraxini was almost 10 and 6 times stronger than that of Iscador M and Iscador Q, respectively, in both Hep3B and HepG2 cells. Intriguingly, the water-soluble fraction of Fraxini exerted similar anticancer activity as Fraxini, but no inhibitory effect of lipid soluble fraction of Fraxini was observed. Treatment with Fraxini induced Hep3B cells to undergo apoptotic cell death, evidenced by the increased number (5-fold) of subG1/G0 phase cells in the Fraxini-treated (5 µg/ml) Hep3B cells than in the control cells and increased apoptotic cell population (by Annexin V staining). Additionally, notable ultrastructural changes i.e. extremely condensed mitochondria in perinuclear positions by transmission electron microscopy (TEM), were observed in Fraxini-treated (10 μg/ml) Hep3B cells compared to control treated cells. Proteomic array analysis suggested that Fraxini dose-dependently inhibited expression of Bcl-xl, BCl-2, Bim, and pRB proteins while increased cleaved caspase 7 and 8 as well as CHEK 1 and 2, suggesting that the apoptotic effect of Fraxini was mediated through regulation of BCL-2 family proteins and caspase activation, which correlated with the mitochondrial changes observed in the TEM study. Strikingly, c-Myc protein was strongly downregulated in a dose dependent fashion in the Hep3B cells treated with Fraxini (&amp;gt; 84% at 5 μg/ml), as examined by both RPPA and Western blotting, suggesting that the c-Myc protein could be an important target for Fraxini-elicited anticancer activity in HCC. Given that HCC is one of the few cancers whose death rate nearly equals its incidence and c-Myc is required for hepatocyte proliferation and liver tumorigenesis, Fraxini could have great potential in HCC treatment and therefore warrants further investigation. Citation Format: Xiaoping Ding, Carrie Cartwright, Lin Tan, Richard Lee, Peiying Yang. Mistletoe extract inhibits the proliferation of human hepatocellular carcinoma cells by induction of apoptosis and downregulation of c-MYC. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3206. doi:10.1158/1538-7445.AM2014-3206</jats:p