Abstract P2-08-09: Progression-free survival results in postmenopausal Asian women: Subgroup analysis from a phase 3 randomized trial of fulvestrant 500 mg vs anastrozole for hormone receptor-positive advanced breast cancer (FALCON)

BACKGROUND

Fulvestrant is a selective estrogen receptor degrader (SERD) with no known agonist effects. In the open-label Phase 2 FIRST study, fulvestrant 500 mg suggested improved efficacy as first-line treatment vs anastrozole in patients with hormone receptor-positive locally advanced or metastatic breast cancer (LA/MBC). The Phase 3, randomized, double-blind, multicenter FALCON trial (NCT01602380) compared fulvestrant 500 mg with anastrozole 1 mg in patients with hormone receptor-positive LA/MBC who had not received prior hormonal therapy. The primary endpoint of the study, progression-free survival (PFS) assessed via RECIST 1.1, surgery/radiotherapy for disease worsening, or death (any cause), was met, as shown by a statistically significant improvement in PFS for fulvestrant 500 mg vs anastrozole. This analysis evaluated PFS in the Asian patient subgroup, which included all randomized patients from centers in China, Japan, and Taiwan.

METHODS

Eligible patients had ER and/or progesterone receptor-positive breast cancer, WHO performance status 0–2, and ≥1 measurable/non-measurable lesion(s). Patients were randomized (1:1) to receive fulvestrant 500 mg (IM on Days 0, 14, 28, and each 28 days thereafter) or anastrozole 1 mg daily, and were stratified according to LA or MBC; prior or no prior treatment with chemotherapy for LA/MBC; and measurable or non-measurable disease. The consistency of effect across patient subgroups was assessed via hazard ratios and 95% confidence intervals using a log-rank test.

RESULTS

In total, 462 patients were randomized (n=230 fulvestrant 500 mg; n=232 anastrozole). The Asian subgroup comprised 67 patients (n=34 fulvestrant 500 mg; n=33 anastrozole). PFS outcomes for the Asian and non-Asian subgroups are presented (Table). The most commonly reported adverse event (AE) was arthralgia (18.2% vs 12.1% of patients with fulvestrant 500 mg and anastrozole, respectively). The rate of AEs leading to discontinuation of treatment was 3.0% and 3.0%, respectively.

CONCLUSIONS

Based on a preliminary assessment of 67 patients, the treatment effect in the Asian patient subgroup from the FALCON trial appears to be broadly consistent with the non-Asian population.

PFS in Asian and non-Asian patient subgroupsGeographic regionNumber of patients (%) with event Hazard ratio (95% CI) Fulvestrant 500 mg n=230Anastrozole n=232 Asia19/34 (55.9%)22/33 (66.7%)0.81 (0.44, 1.50)Non-Asia124/196 (63.3%)144/199 (72.4%)0.79 (0.62, 1.01)

Citation Format: Shao Z, Ellis MJ, Robertson JFR, Grinsted LM, Fazal M, Noguchi S. Progression-free survival results in postmenopausal Asian women: Subgroup analysis from a phase 3 randomized trial of fulvestrant 500 mg vs anastrozole for hormone receptor-positive advanced breast cancer (FALCON) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-08-09.

Abstract P2-08-02: Progression-free survival results in patient subgroups from a Phase 3 randomized trial of fulvestrant 500 mg vs anastrozole for hormone receptor-positive advanced breast cancer (FALCON)

BACKGROUND

Improved efficacy was suggested for fulvestrant 500 mg, a selective estrogen receptor degrader (SERD), vs anastrozole as first-line treatment for hormone receptor-positive locally advanced or metastatic breast cancer (LA/MBC) in the open-label Phase 2 FIRST trial. The Phase 3, randomized, double-blind, multicenter FALCON trial (NCT01602380) compared fulvestrant 500 mg with anastrozole 1 mg in patients with hormone receptor-positive LA/MBC who had not received prior hormonal therapy. The primary endpoint of the study was met, such that there was a statistically significant improvement in progression-free survival (PFS) for fulvestrant 500 mg vs anastrozole. We present an analysis of PFS for pre-specified patient subgroups in the FALCON trial.

METHODS

Eligible patients had ER and/or progesterone receptor (PgR)-positive breast cancer, WHO performance status 0–2 and ≥1 measurable/non-measurable lesion(s). Patients were randomized (1:1) to receive fulvestrant 500 mg (IM on Days 0, 14, 28, and each 28 days thereafter) or anastrozole 1 mg daily. The primary endpoint was PFS, assessed via RECIST 1.1, surgery/radiotherapy for disease worsening, or death (any cause). PFS was evaluated in patient subgroups defined by pre-specified baseline covariates. The consistency of effect across patient subgroups was assessed via hazard ratios and 95% confidence intervals using a log-rank test.

RESULTS

Overall, 462 patients were randomized to treatment: 230 received fulvestrant 500 mg and 232 received anastrozole. PFS outcomes in each patient subgroup are presented in the Table.

CONCLUSIONS

This analysis of patient subgroups from the FALCON trial suggests that treatment effects were largely consistent across the subgroups analyzed with some possible exceptions (e.g. patients with visceral vs non-visceral disease). Further work is ongoing to understand the possible treatment effect in these subgroups.

PFS in pre-specified patient subgroupsSubgroup Number of patients (%) with event Hazard ratio (95% CI)  Fulvestrant 500 mg n=230 Anastrozole n=232 Breast cancer type   Locally advanced11/28 (39.3%)14/32 (43.8%)0.79 (0.36, 1.73)Metastatic132/202 (65.3%)152/200 (76.0%)0.78 (0.62, 0.99)Prior chemotherapy for LA/MBC   Yes31/36 (86.1%)33/43 (76.7%)1.08 (0.66, 1.77)No112/194 (57.7%)133/189 (70.4%)0.75 (0.59, 0.97)Geographic regiona   US/Canada16/25 (64.0%)19/24 (79.2%)0.66 (0.34, 1.30)Non-US/Canada127/205 (62.0%)147/208 (70.7%)0.81 (0.64, 1.03)Measurable disease   Yes124/193 (64.2%)143/196 (73.0%)0.76 (0.60, 0.97)No19/37 (51.4%)23/36 (63.9%)0.99 (0.53, 1.82)ER-positive and PgR-positive   Yes103/175 (58.9%)127/179 (70.9%)0.73 (0.56, 0.94)No40/55 (72.7%)39/53 (73.6%)1.04 (0.67, 1.62)Bisphosphonate use at baseline   Yes44/61 (72.1%)53/62 (85.5%)0.69 (0.46, 1.03)No99/169 (58.6%)113/170 (66.5%)0.82 (0.63, 1.07)Visceral disease   Yes92/135 (68.1%)87/119 (73.1%)0.99 (0.74, 1.33)No51/95 (53.7%)79/113 (69.9%)0.59 (0.42, 0.84)ªData for Asia/non-Asia subgroups are presented in a separate abstract

Citation Format: Robertson JFR, Noguchi S, Shao Z, Grinsted LM, Fazal M, Ellis MJ. Progression-free survival results in patient subgroups from a Phase 3 randomized trial of fulvestrant 500 mg vs anastrozole for hormone receptor-positive advanced breast cancer (FALCON) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-08-02.

Abstract P2-01-27: Sentinel lymph node biopsy by contrast-enhanced ultrasonography with sonazoid in patients with breast cancer - Prospective multicenter study

Background: The aim of this prospective study is to evaluate feasibility of the periareolar injection of contrast agent (Sonazoid (SNZ)) followed by ultrasonography (US) for identification of sentinel lymph node (SLN) in breast cancer patients with clinically negative node.

Patients and Methods: Patients with T1-2N0M0 breast cancer were recruited in this study. They received the periareolar injection of SNZ followed by US to identify contrast-enhanced SLN. Fine needle aspiration biopsy (FNAB) was done for each CE-SLN. Then, they underwent SLN biopsy with the conventional method, blue dye and/or radiotracer (B/R).

Results: In almost all cases, contrast-enhanced lymphatic vessels were clearly visualized US soon after the periareolar injection of SNZ, and SLN, into which lymphatic flow was draining, was easily identified. The identification rate of SLN was 98% (98/100) by SNZ and 100% (100/100) by B/R. The number of SLNs identified by SNZ (mean per patient, 1.52) was significantly (P < 0.001) lower than that of those by B/R (2.22). Twenty-five patients had at least one metastasis in the SLNs identified by SNZ and/or B/R. In these patients, SLNs (n=39) identified by both SNZ and B/R showed a significantly (P < 0.0001) higher positivity (74.4%) for metastases than those (n=19) identified by B/R alone (21.1%).

Conclusion: Identification of SLN by periareolar injection of SNZ followed by US is a technically easy method and the identification rate of SLN was as high as 98%, being comparable to the conventional B/R. SLNs detected by SNZ seem to represent the true SLNs which first receive lymphatic flow from the tumor among the SLNs detected by B/R.

Citation Format: Shimazu K, Ito T, Uji K, Miyake T, Motomura K, Noguchi S. Sentinel lymph node biopsy by contrast-enhanced ultrasonography with sonazoid in patients with breast cancer - Prospective multicenter study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-27.

Development of hepatocellular carcinoma after long-term immunosuppressive therapy including danazol in a dog

A 2-year-old female beagle was referred to our hospital for evaluation of anemia. Laboratory tests, including bone marrow cytology, revealed non-regenerative immune-mediated anemia (NRIMA). Although initial immunosuppressive multi-drug therapy was not effective, additional administration of danazol was successful in treating the anemia. However, hepatocellular carcinoma (HCC) developed about 20 months after the administration of danazol. In humans, several cases of development of HCC after the administration of danazol have been reported. The present report describes a case of HCC development in a dog after chronic administration of danazol in addition to other immunosuppressive drugs.

Programmed Cell Death Ligand 1 Expression in Canine Cancer

BACKGROUND

Antibody therapy targeting programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) is a promising therapy in human cancer, but only limited information on PD-L1 expression in canine tumors is available.

MATERIALS AND METHODS

PD-L1 expression was examined in 31 canine tumor cell lines of various origins by flow cytometry and western blotting, and in canine tumor and normal tissue specimens by immunohistochemistry.

RESULTS

PD-L1 was only expressed on the cell surface of a small number of cell lines but was found expressed within the cells of almost all cell lines. Immunohistochemistry revealed that PD-L1 is frequently expressed in malignant melanoma, mammary gland tumor, mast cell tumor and lymphoma, but less frequently in soft-tissue sarcoma and hemangiosarcoma. PD-L1 was also expressed in some of the cells of normal canine tissue specimens.

CONCLUSION

Canine tumors with PD-L1 expression that were identified in this study are potential candidates for antiPD-1 and antiPD-L1 therapy.

The histopathological comparison on the destruction of the periodontal tissue between normal junctional epithelium and long junctional epithelium

BACKGROUND AND OBJECTIVE

The barrier function of long junctional epithelium is thought to be important after periodontal initial therapy and periodontal surgery. Although the difference between long junctional epithelium and normal junctional epithelium regarding their resistance to destruction of periodontal tissue has been investigated, the mechanism still remains unclear. Using our rat experimental periodontitis model in which loss of attachment and resorption of alveolar bone is induced by the formation of immune complexes, we investigated the resistance of periodontal tissue containing long junctional epithelium and normal junctional epithelium to destruction.

MATERIAL AND METHODS

Rats were divided into four groups. In the immunized long junctional epithelium (I-LJE) group, rats were immunized with lipopolysaccharide (LPS), and curettage and root planing procedures were performed on the palatal gingiva of the maxillary first molars to obtain reattachment by long junctional epithelium. In the immunized normal junctional epithelium (I-JE) group, rats were immunized without curettage and root planing procedures. In the nonimmunized long junctional epithelium (nI-LJE) group, rats were not immunized but curettage and root-planing procedures were performed. In the control group, neither immunization nor curettage and root-planing was performed. In all rats, periodontal inflammation was induced by topical application of LPS into the palatal gingival sulcus of maxillary first molars. The rats were killed at baseline and after the third and fifth applications of LPS. Attachment loss and the number of inflammatory cells and osteoclasts in the four groups were compared histopathologically and histometrically.

RESULTS

After the third application of LPS in the I-LJE group, attachment loss showed a greater increase than in control and nI-LJE groups, and inflammatory cell infiltration and osteoclasts were increased more than in the other groups. After the fifth application of LPS, attachment loss was greater and there was a higher degree of inflammatory cell infiltration in nI-LJE and I-LJE groups than in control and I-JE groups.

CONCLUSION

Our findings suggest that the destruction of periodontal tissue is increased in tissue containing long junctional epithelium compared with normal junctional epithelium and that the immunized condition accelerates the destruction by forming immune complexes.

Abstract P2-08-27: Prediction of bone metastases of breast cancer using combined markers of bone metabolism and inflammation

Introduction

Luminal breast cancer patients show a relatively favorable prognosis when treated with adjuvant hormonal therapy alone. However, some of these patients develop recurrence and they might derive benefit from adjuvant chemotherapy. Although several genomic profilings successfully developed to decide whether to administer adjuvant chemotherapy, clinically practical prediction methods of recurrence sites do not exist. Our previous study showed a possible prediction of bone metastases by using two serum markers; TRACP-5b as a marker of bone metabolism; likelihood of bone metastases, and CRP as a marker of inflammation; likelihood of distant recurrence. The incidence of bone metastases was significantly higher in high risk patients(+/+) than in the others(odds ratio: 10.9, P=0.040). In this study, we examined the potential of the two-marker prediction in the newly enrolled luminal patients.

Patients and methods

One hundred sixty luminal patients who underwent surgery were enrolled in this study. Their serum levels of TRACP-5b and CRP were measured in a blinded manner at the R & D laboratory of Nittobo Medical Co., Ltd. In the preliminary study, we identified that the median value of TRACP-5b in the premenopausal patients was lower than in the postmenopausal patients. We adjusted the value of TRACP-5b in the premenopausal patients and the cutoff value of TRACP-5b from 334 to 396mU/dL. The cutoff value of CRP was same as previous study(0.016 mg/dL). The odds ratio between +/+ and the others were calculated using MedCalc statistical software.

Results

One hundred sixty patients stratified into four classes according to the value of TRACP-5b and CRP: +/+ (n=43), +/- (n=38), -/+ (n=42) and -/- (n=37). Six of the 160 patients developed bone metastases as the initial site of replase within five years from surgery. The Incidence of bone metastases was 9.3%(4/43) in the +/+ patients and 1.7%(2/117) in the others. The incidence was significantly higher in the +/+ patients than in the others(odds ratio: 5.9, 95% CI 1.31 to 33.46, p= 0.045). When the other relapses than bone metastases were included in the analysis, no significant difference was observed between the two groups (odds ratio: 0.4, 95% CI 0.02 to 7.43, P=0.521). TRACP-5b concentration alone could not classify the patients into two groups according to significantly different incidences of bone metastases(odds ratio: 13.7, 95% CI 0.76 to 247.22, P=0.076).

Conclusion

The results in here show that the prediction of bone metastases by the combination of TRACP-5b and CRP concentrations is clinically relevant in the luminal patients. Reliable prediction of bone metastases would be realized by combination of our prediction method and one of genomic profilings. We plan to increase the number of patients to provide sufficient statistical power to confirm this diagnostic potential.

Citation Format: Shimoda M, Nishimukai A, Shibata N, Kikuchi W, Hutawatari H, Ishihara H, Miyoshi Y, Noguchi S. Prediction of bone metastases of breast cancer using combined markers of bone metabolism and inflammation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-27.

Abstract P3-06-05: Importance of TGFβ-SMAD3 axis in resistance to anti-HER2 drugs

Aim: The aim of this study was to elucidate the role of transforming growth factor β (TGFβ) in the resistance of HER2-positive breast cancer cells to anti-HER2 drugs including trastuzumab and lapatinib.

Methods: A HER2-positive breast cancer cell line, SKBR3, was cultured in the presence or absence of TGFβ for 14 days. Subsequently, TGFβ-treated cells were cultured for seven days with or without the anti-HER2 drugs. Sensitivity to trastuzumab and lapatinib was estimated by the WST-8 cell viability assay or absolute cell counts using In Cell Analyzer (GE Healthcare). Proportion of CD44+ CD24– breast cancer stem cells was estimated by flow cytometry of cells immunostained with anti-CD44 and anti-CD24 antibodies. For clinical study, 33 patients with HER2-positive breast cancer receiving neoadjuvant paclitaxel plus trastuzumab in our institution were analyzed. Among the cases, 27 biopsy samples obtained before any treatment from 27 patients who completed 12 cycles of weekly paclitaxel and trastuzumab were subjected to CD24 immunohistochemistry.

Results: SKBR3 cells cultured with TGFβ for 14 days exhibited decreased sensitivity to both trastuzumab and lapatinib. Time course study revealed that continuous stimulation for 14 days with TGFβ was required for the resistance to anti-HER2 drugs. Activation of SMAD3, a downstream target molecule of TGFβ, was enhanced over time, judged by the increase in phosphorylation and in nuclear translocation. During 14 day culture with TGFβ, proportion of CD44+ CD24– cells were dramatically increased, and mammosphere formation, another marker of breast cancer stem cells, was significantly enhanced compared to cells treated without TGFβ. Among four HER2-positive breast cancer cell lines, only SKBR3 cells showed increased proportion of CD44+ CD24– cells and resistance to the anti-HER2 drugs, while other two cell lines exhibited epithelial-mesenchymal transition (EMT) in response to TGFβ. To explore the possibility of targeting TGFβ-SMAD3 axis to overcome resistance to anti-HER2 therapy, we used SIS3, a specific inhibitor of SMAD3. Importantly, SIS3 completely restored the sensitivity to both trastuzumab and lapatinib of TGFβ-treated SKBR3 cells, with the decrease in the proportion of CD44+ CD24– cells. These in vitro results suggest that CD24 downregulation can be a surrogate marker of resistance to anti-HER2 therapy. To establish this, we evaluated the CD24 expression in tumor samples of breast cancer patients who received paclitaxel plus trastuzumab in the neoadjuvant setting. Weak CD24 expression in tumor cells in biopsy samples obtained before any treatment was significantly correlated with poorer response to the drugs.

Conclusion: These data clearly indicate the importance of TGFβ-SMAD3 axis in the acquired resistance to anti-HER2 drugs. Moreover, resistance to anti-HER2 therapy is associated with the property of breast cancer stem cells rather than EMT. Targeting TGFβ-SMAD3 axis warrants further investigation for overcoming resistance to anti-HER2 therapeutics.

Citation Format: Shimoda M, Chihara Y, Kagara N, Naoi Y, Shimomura A, Shimazu K, Kim SJ, Noguchi S. Importance of TGFβ-SMAD3 axis in resistance to anti-HER2 drugs. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-06-05.

Oncolytic reovirus synergizes with chemotherapeutic agents to promote cell death in canine mammary gland tumor

The oncolytic effects of reovirus in various cancers have been proven in many clinical trials in human medicine. Oncolytic virotherapy using reovirus for canine cancers is being developed in our laboratory. The objective of this study was to examine the synergistic anti-cancer effects of a combination of reovirus and low doses of various chemotherapeutic agents on mammary gland tumors (MGTs) in dogs. The first part of this study demonstrated the efficacy of reovirus in canine MGTs in vitro and in vivo. Reovirus alone exerted significant cell death by means of caspase-dependent apoptosis in canine MGT cell lines. A single injection of reovirus impeded growth of canine MGT tumors in xenografted mice, but was insufficient to induce complete tumor regression. The second part of this study highlighted the anti-tumor effects of reovirus in combination with low doses of paclitaxel, carboplatin, gemcitabine, or toceranib. Enhanced synergistic activity was observed in the MGT cell line treated concomitantly with reovirus and in all the chemotherapeutic agents except toceranib. In addition, combining reovirus with paclitaxel or gemcitabine at half dosage of half maximal inhibitory concentration (IC50) enhanced cytotoxicity by activating caspase 3. Our data suggest that the combination of reovirus and low dose chemotherapeutic agents provides an attractive option in canine cancer therapy.

Toxic Takifugu pardalis eggs found in Takifugu niphobles gut: Implications for TTX accumulation in the pufferfish

Pufferfish (Takifugu spp.) possess a potent neurotoxin, tetrodotoxin (TTX). TTX has been detected in various organisms including food animals of pufferfish, and TTX-producing bacteria have been isolated from these animals. TTX in marine pufferfish accumulates in the pufferfish via the food web starting with marine bacteria. However, such accumulation is unlikely to account for the amount of TTX in the pufferfish body because of the minute amounts of TTX produced by marine bacteria. Therefore, the toxification process in pufferfish still remains unclear. In this article we report the presence of numerous Takifugu pardalis eggs in the intestinal contents of another pufferfish, Takifugu niphobles. The identity of T. pardalis being determined by direct sequencing for mitochondrial DNA. LC-MS/MS analysis revealed that the peak detected in the egg samples corresponded to TTX. Toxification experiments in recirculating aquaria demonstrated that cultured Takifugu rubripes quickly became toxic upon being fed toxic (TTX-containing) T. rubripes eggs. These results suggest that T. niphobles ingested the toxic eggs of another pufferfish T. pardalis to toxify themselves more efficiently via a TTX loop consisting of TTX-bearing organisms at a higher trophic level in the food web.

Phylogenetic position of Scombropidae within teleostei: the complete mitochondrial genome of the gnomefish, Scombrops gilberti

The complete mitochondrial genome of the Japanese gnomefish, Scombrops gilberti, was determined using a PCR-based method. The total length of mitochondrial DNA (mtDNA) is 16 518 bp, which includes 13 protein-coding genes, two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and one control region. The mitochondrial gene arrangement of S. gilberti was found to be identical to that of other scombropid and indeed, other teleosts as well. Maximum likelihood analysis revealed that Scombropidae forms a sister group to Pempheriformes.

Expression of O(6)-methylguanine-DNA methyltransferase causes lomustine resistance in canine lymphoma cells

The DNA repair protein O (6)-methylguanine-DNA methyltransferase (MGMT) causes resistance to nitrosoureas in various human cancers. In this study, we analyzed the correlation between canine lymphomas and MGMT in vitro. Two of five canine lymphoma cell lines required higher concentrations of lomustine to inhibit cell growth by 50%, but their sensitivity to the drug increased when they were cultured with an MGMT inhibitor. Fluorometric oligonucleotide assay and real-time polymerase chain reaction of these cell lines revealed MGMT activity and high MGMT mRNA expression, respectively. We analyzed the methylation status of the CpG islands of the canine MGMT gene by the bisulfite-sequencing method. Unlike human cells, the canine lymphoma cell lines did not show significant correlation between methylation status and MGMT suppression levels. Our results suggest that in canine lymphoma MGMT activity may influence sensitivity to nitrosoureas; thus, inhibition of MGMT activity would benefit nitrosourea-resistant patients. Additional studies are necessary to elucidate the mechanism of regulation of MGMT expression.

Acquired Fanconi syndrome in a dog exposed to jerky treats in Japan

A 6-year-old spayed female Jack Russell Terrier presented with a 1-month history of lethargy, anorexia, vomiting and weight loss. The dog was fed beef and chicken jerky treats daily in addition to a commercial diet. Laboratory tests revealed azotemia, hypokalemia, hyperchloremia, metabolic acidosis and glucosuria with normoglycemia. Urine amino acid analysis showed significant amino acid loss into the urine. Thus, Fanconi syndrome was diagnosed, and based on the case history and extensive diagnostic testing, excessive consumption of jerky treats was strongly suspected as the cause. Glucosuria resolved 7 days after the withdrawal of jerky treats and fluid therapy. Aminoaciduria was substantially, but not completely, improved 3 months after diagnosis. Mild azotemia remained, suggesting chronic renal disease. To the best of our knowledge, this is the first reported case of Fanconi syndrome following the consumption of jerky treats in Japan.

Hypoxia inducible factor 1α expression and effects of its inhibitors in canine lymphoma

Hypoxic conditions in various cancers are believed to relate with their malignancy, and hypoxia inducible factor-1α (HIF-1α) has been shown to be a major regulator of the response to low oxygen. In this study, we examined HIF-1α expression in canine lymphoma using cell lines and clinical samples and found that these cells expressed HIF-1α. Moreover, the HIF-1α inhibitors, echinomycin, YC-1 and 2-methoxyestradiol, suppressed the proliferation of canine lymphoma cell lines. In a xenograft model using NOD/scid mice, echinomycin treatment resulted in a dose-dependent regression of the tumor. Our results suggest that HIF-1α contributes to the proliferation and/or survival of canine lymphoma cells. Therefore, HIF-1α inhibitors may be potential agents to treat canine lymphoma.

The oncolytic effects of reovirus in canine solid tumor cell lines

Oncolytic virotherapy is a new strategy for cancer treatment for humans and dogs. Reovirus has been proven to be a potent oncolytic virus in human medicine. Our laboratory has previously reported that canine mast cell tumor and canine lymphoma were susceptible to reovirus. In this study, canine solid tumor cell lines (mammary gland tumor, osteosarcoma and malignant melanoma) were tested to determine their susceptibility towards reovirus. We demonstrated that reovirus induces more than 50% cell death in three canine mammary gland tumors and one canine malignant melanoma cell line. The reovirus-induced cell death occurred via the activation of caspase 3. Ras activation has been shown to be one of the important mechanisms of reovirus-susceptibility in human cancers. However, Ras activation was not related to the reovirus-susceptibility in canine solid tumor cell lines, which was similar to reports in canine mast cell tumor and canine lymphoma. The results of this study highly suggest that canine mammary gland tumor and canine malignant melanoma are also potential candidates for reovirus therapy in veterinary oncology.

Everolimus plus exemestane for hormone-receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer: overall survival results from BOLERO-2†

BACKGROUND

The BOLERO-2 study previously demonstrated that adding everolimus (EVE) to exemestane (EXE) significantly improved progression-free survival (PFS) by more than twofold in patients with hormone-receptor-positive (HR(+)), HER2-negative advanced breast cancer that recurred or progressed during/after treatment with nonsteroidal aromatase inhibitors (NSAIs). The overall survival (OS) analysis is presented here.

PATIENTS AND METHODS

BOLERO-2 is a phase III, double-blind, randomized international trial comparing EVE 10 mg/day plus EXE 25 mg/day versus placebo (PBO) + EXE 25 mg/day in postmenopausal women with HR(+) advanced breast cancer with prior exposure to NSAIs. The primary end point was PFS by local investigator assessment; OS was a key secondary end point.

RESULTS

At the time of data cutoff (3 October 2013), 410 deaths had occurred and 13 patients remained on treatment. Median OS in patients receiving EVE + EXE was 31.0 months [95% confidence interval (CI) 28.0-34.6 months] compared with 26.6 months (95% CI 22.6-33.1 months) in patients receiving PBO + EXE (hazard ratio = 0.89; 95% CI 0.73-1.10; log-rank P = 0.14). Poststudy treatments were received by 84% of patients in the EVE + EXE arm versus 90% of patients in the PBO + EXE arm. Types of poststudy therapies were balanced across arms, except for chemotherapy (53% EVE + EXE versus 63% PBO + EXE). No new safety concerns were identified.

CONCLUSIONS

In BOLERO-2, adding EVE to EXE did not confer a statistically significant improvement in the secondary end point OS despite producing a clinically meaningful and statistically significant improvement in the primary end point, PFS (4.6-months prolongation in median PFS; P < 0.0001). Ongoing translational research should further refine the benefit of mTOR inhibition and related pathways in this treatment setting.

TRIAL REGISTRATION NUMBER

NCT00863655.

Analysis of microRNA-203 function in CREB/MITF/RAB27a pathway: comparison between canine and human melanoma cells

MicroRNA (miR)-203 is downregulated and acts as an anti-oncomir in melanoma cells. Here, using human and canine melanoma cells, we elucidated the effects of miR-203 on cyclic adenosine monophosphate response element binding protein (CREB)/microphthalmia-associated transcription factor (MITF)/RAB27a pathway, which is known to be important for the development and progression of human melanoma. In this study, we showed that miR-203 directly targeted CREB1 and regulated its downstream targets, MITF and RAB27a. miR-203 significantly suppressed the growth of human and canine melanoma cells and inhibited melanosome transport through the suppression of the signalling pathway. In conclusion, miR-203 was shown to be a common tumour-suppressive miRNA in human and canine melanoma and thus to play a crucial role in the biological mechanisms of melanoma development.