Abstract P2-09-31: Predictive impact of absolute lymphocyte counts for progression-free survival in HER2-positive advanced breast cancer treated with pertuzumab and trastuzumab plus eribulin or nab-paclitaxel

Background: Tumor-infiltrating lymphocytes might be a one of predictive outcome of human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer (ABC) patients (pts) who treated with trastuzumab and pertuzumab (TP) plus docetaxel. Although peripheral blood-based parameter (PBBP) is reported as a prognostic indicator of patients with early breast cancers, utility of PBBP has not been studied in HER2-positive ABC.

Objective:The aim of our study was to determine whether PBBP is significant for predictive efficacy in HER2-positive ABC treated with TP combined with eribulin (ERI) or nab-paclitaxel (Nab-PTX).

Methods: The 51 patients' data from two single arm phase II trials was included in this retrospective-prospective study; ERI + TP (n=30) or Nab-PTX + TP (n=21) registered with UMIN000012375 or UMIN000006838, respectively. We assessed the PBBP in prospectively collected data and investigated their association with progression-free survival (PFS). In consideration of PBBP, we evaluated absolute lymphocyte count (ALC), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR). The cutoff values of ALC, NLR, and PLR were set at 1000 cells/μL, 2, and 250, respectively.

Results:Median age at baseline was 58 years (range: 31-77). Median number of previous chemotherapy was 3 (range: 1-10). Pts had multiple metastases, 53% with LNs, 35% with bone, 25% with lung, 20% with liver, and 6% with brain. The objective response rate (CR+PR) and clinical benefit rate (CR+PR+ more than 6 month SD) were 37% (n=19) and 59% (n=30), respectively. The median PFS of all pts was 301 days (range: 21-1281). The PFS of pts with ALC-High was significantly better than those of ALC-low (hazard ratio (HR): 2.74, 95% confidence interval (CI): 1.28 to 5.86; p= .0097). Furthermore, improved PFS was obtained in pts with ALC greater than 1500 cells/μL compared with less than 1000 cells/uL (HR: 4.05, 95% CI: 1.60 to 11.6; p= .0029). Significant associations seem to exist irrespective of number of previous chemotherapy. Since we combined different studies for evaluating PBBP, ERI and Nab-PTX were calculated separately. Marginally significant associations between ALC and PFS were obtained both in ERI (HR: 2.18, 95% CI: 0.87 to 5.60; p=.0973) and Nab-PTX (HR: 3.26, 95% CI: 0.80 to 12.4; p=.0939). The PFS of NLR-low pts was significantly better than those of NLR-high (HR: 2.29, 95% CI: 1.01 to 5.90; p= .0477), but this statistical difference was inferior to those of ALC. There was no significant association between PLR and PFS.

Conclusions: Pre-treatment ALC-High was significantly correlated with favorable PFS of pts treated with TP irrespective of combination chemotherapy in HER2-positve ABC. Prolonged PFS of TP combination therapy might be obtained mediating through host systemic onco-immunity. These data obtained here suggest that a usefulness of ALC for selecting pts who might have clinical benefit from TP combination therapy for heavily treated HER2-positve ABC.

Citation Format: Araki K, Ito Y, Fukada I, Kobayashi K, Ohno S, Miyagawa Y, Imamura M, Kira A, Takatsuka Y, Egawa C, Suwa H, Miyoshi Y. Predictive impact of absolute lymphocyte counts for progression-free survival in HER2-positive advanced breast cancer treated with pertuzumab and trastuzumab plus eribulin or nab-paclitaxel [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-31.

Salt-inducible kinase 3 regulates the mammalian circadian clock by destabilizing PER2 protein

Salt-inducible kinase 3 (SIK3) plays a crucial role in various aspects of metabolism. In the course of investigating metabolic defects in Sik3-deficient mice (Sik3^-/-), we observed that circadian rhythmicity of the metabolisms was phase-delayed. Sik3^-/- mice also exhibited other circadian abnormalities, including lengthening of the period, impaired entrainment to the light-dark cycle, phase variation in locomotor activities, and aberrant physiological rhythms. Ex vivo suprachiasmatic nucleus slices from Sik3^-/- mice exhibited destabilized and desynchronized molecular rhythms among individual neurons. In cultured cells, Sik3-knockdown resulted in abnormal bioluminescence rhythms. Expression levels of PER2, a clock protein, were elevated in Sik3-knockdown cells but down-regulated in Sik3-overexpressing cells, which could be attributed to a phosphorylation-dependent decrease in PER2 protein stability. This was further confirmed by PER2 accumulation in the Sik3^-/- fibroblasts and liver. Collectively, SIK3 plays key roles in circadian rhythms by facilitating phosphorylation-dependent PER2 destabilization, either directly or indirectly.

Abstract OT3-07-02: Influence of exercise or educational programs on long-term physical activity by patients after surgery for primary breast cancer: A randomized trial

[Background]

Past studies revealed that a moderate to high level of physical activity after diagnosis of breast cancer reduces both the risk of breast cancer-related death and death from all causes. Furthermore, some randomized studies suggested that exercise programs improve the percentage of patients who complete the chemotherapy and quality of life, and decrease fatigue, and adverse events. The issues to be determined include defining an established uniform exercise program and the efficacy of a long-term exercise program after breast cancer surgery.

[Object] To elucidate the efficacy of a long-term exercise program and to verify the safety and feasibility of a uniform exercise program using an ‘existing social resource’ after primary therapy of breast cancer.

[Design] A multi-center, randomized trial.

[Method] Subjects: The subjects included patients who had completed treatment for primary breast cancer, including surgery and/or adjuvant chemotherapy. Patients with metastatic breast cancer were excluded.

Randomization & intervention: The patients were randomly assigned to three groups.

The first group followed an exercise program at Curves® that involved 30 minutes of exercise, including aerobics, weight training, and stretching 3 times a week for 4 months. The second group was given life-style guidance at least once that patients participate in a lecture program about recommended exercise at this point and the importance of weight control after diagnosis of breast cancer using a brochure. The third group served as controls that the patients receive a brochure used same one in the second group. The variables included age and weight.

Outcome: The primary endpoint is level of physical activity at 1 year after randomization, and the secondary endpoints are the percentage of those completing the exercise program, patient reported outcomes (QOL, cancer or treatment associated symptoms, fatigue, depression, and anxiety), body mass index, bone density, and level of lymphedema.

Period of research: The study will last 2 years beginning March 2016.

Sample size: We plan to enroll 400 patients to detect 20% difference with 90% power.

Additional study: Some biochemical markers in the blood will be evaluated to determine the mechanism of the effect of exercise on the human body.

Citation Format: Kawada K, Taira N, Hatono M, Takahashi Y, Miyoshi Y, Nogami T, Iwamoto T, Motoki T, Sien T, Matsuoka J, Doihara H, Ikeda M, Ogasawara Y, Takabatake D, Yoshitomi S, Kiyoto S, Yamamoto S, Mizota Y, Oka K. Influence of exercise or educational programs on long-term physical activity by patients after surgery for primary breast cancer: A randomized trial [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 OT3-07-02.

Abstract P2-05-27: Baseline serum CA15-3 levels are associated with prognosis for breast cancer patients with non-complete pathological response to neoadjuvant chemotherapy

Background: It has been well demonstrated that patients who achieved pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) had a favorable prognosis compared with patients who did not (non-pCR). Even though pCR was not attained, reduction in tumor volume after chemotherapy may be associated with improved prognosis for a certain number of patients. However, the association between residual tumor volume and prognosis is not necessarily consistent. In order to identify substitute markers for breast cancer patients with non-pCR after NAC, we investigated the impact of serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA15-3) at baseline as well as post-NAC.

Patients and Methods: Ninety-six breast cancer patients treated with NAC and operated on at the Hyogo College of Medicine were recruited for this study. Serum CEA and CA15-3 were measured prior to chemotherapy as well as at completion of pre-operative treatment. The optimal cutoff points for CEA (1.55ng/m, normal range: <5.0ng/ml) and CA15-3 (13.25U/ml, normal range: <28.0U/ml) for relapse-free survival (RFS) were determined by analyzing the area under receiver operating characteristic curves in another study involving 613 breast cancer patients. Expression levels of Ki67 in samples obtained at pre- and post-NAC were also determined by means of immunohistochemical staining. Pathological complete response was classified as the absence of residual invasive cancer in the breast and lymph nodes. During a 2.13 years median follow-up period, 15 patients suffered relapse.

Results: pCR and non-pCR was attained by 21 and 75 patients, respectively. For the non-pCR patients, serum CEA levels at baseline were classified into high (n=35) and low (n=38) and serum CA15-3 levels at baseline into high (n=31) and low (n=43). RFS of non-pCR patients with high serum CA15-3 levels was significantly worse than of those with low levels (3-year RFS: 0.47 vs 0.93; p=0.0009). RFS for patients with high and low serum levels of CA15-3 after NAC was also significantly different (p=0.037). As for CEA, no significant association with RFS was observed either at baseline or post-NAC. Univariate analysis demonstrated that tumor size and baseline CA15-3 were significant prognostic factors for RFS. Multivariate analysis showed that both tumor size (hazard ratio (HR): 3.88, 95% confidence interval (CI): 1.21-12.35, p=0.023) and baseline CA15-3 (HR: 13.51, 95% CI: 1.74-105.08, p=0.013) were significant and independent risk factors for relapse. As for lymph node metastasis, tumor grade, residual tumor size and pre- and post-NAC Ki67 expression levels of patients with non-pCR showed no significant association with RFS.

Conclusion and discussion: High levels of serum CA15-3 at baseline constituted a significantly worse prognosis for breast cancer patients with non-pCR. Tumor size at baseline but not residual size and baseline CA15-3 seems to suitable as a substitute for prediction of outcome for patients with non-pCR. Our findings suggest that these markers may be useful for identifying patients with poor prognosis who may be candidates for additional adjuvant treatment.

Citation Format: Fujimoto Y, Imamura M, Higuchi T, Nishimukai A, Yanai A, Miyagawa Y, Murase K, Takatsuka Y, Miyoshi Y. Baseline serum CA15-3 levels are associated with prognosis for breast cancer patients with non-complete pathological response to neoadjuvant chemotherapy [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 P2-05-27.

High serum dihydrotestosterone examined by ultrasensitive LC-MS/MS as a predictor of benign prostatic hyperplasia or Gleason score 6 cancer in men with prostate-specific antigen levels of 3-10 ng/mL

There has been no consensus on the role of serum androgen concentrations in prostate cancer detection in men with prostate-specific antigen levels of 3-10 ng/mL. In this study, testosterone and dihydrotestosterone concentrations in blood were examined by a newly developed method using ultrasensitive liquid chromatography with two serially linked mass spectrometers (LC-MS/MS). We investigated the correlation between serum androgen levels and Gleason scores at biopsy. We analyzed data of 157 men with a total prostate-specific antigen range of 3-10 ng/mL who underwent initial systematic prostate needle biopsy for suspected prostate cancer between April 2000 and July 2003. Peripheral blood testosterone and dihydrotestosterone concentrations were determined by LC-MS/MS. Blood levels of testosterone and dihydrotestosterone were compared with pathological findings by multivariate analyses. Median values of prostate-specific antigen and prostate volume measured by ultrasound were 5.7 ng/mL and 31.4 cm³ , respectively. Benign prostatic hyperplasia was diagnosed in 97 patients (61.8%), and prostate cancer was diagnosed in 60 (38.2%) patients, including 31 (19.7%) patients with a Gleason score of 6 and 29 (18.5%) patients with a Gleason score of 7-10. Median values of testosterone and dihydrotestosterone in blood were 3798.7 and 371.7 pg/mL, respectively. There was a strong correlation between serum testosterone and dihydrotestosterone. In multivariate analysis, age, prostate volume, and serum dihydrotestosterone were significant predictors of benign prostatic hyperplasia or prostate cancer with a Gleason score of 6. The area under the receiver operating characteristics curve for age, prostate volume, and serum dihydrotestosterone were 0.67, 0.67, and 0.67, respectively . We confirmed that high dihydrotestosterone blood levels can predict benign prostatic hyperplasia or prostate cancer with a Gleason score of 6 in men with prostate-specific antigen levels of 3-10 ng/mL.

Cellular zinc is required for intestinal epithelial barrier maintenance via the regulation of claudin-3 and occludin expression

Intracellular zinc is required for a variety of cell functions, but its precise roles in the maintenance of the intestinal tight junction (TJ) barrier remain unclear. The present study investigated the essential roles of intracellular zinc in the preservation of intestinal TJ integrity and the underlying molecular mechanisms. Depletion of intracellular zinc in both intestinal Caco-2 cells and mouse colons through the application of a cell-permeable zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) induced a disruption of the TJ barrier, as indicated by increased FITC-labeled dextran flux and decreased transepithelial electrical resistance. The TPEN-induced TJ disruption is associated with downregulation of two TJ proteins, occludin and claudin-3. Biotinylation of cell surface proteins revealed that the zinc depletion induced the proteolysis of occludin but not claudin-3. Occludin proteolysis was sensitive to the inhibition of calpain activity, and increased calpain activity was observed in the zinc-depleted cells. Although quantitative PCR analysis and promoter reporter assay have demonstrated that the zinc depletion-induced claudin-3 downregulation occurred at transcriptional levels, a site-directed mutation in the egr1 binding site in the claudin-3 promoter sequence induced loss of both the basal promoter activity and the TPEN-induced decreases. Reduced egr1 expression by a specific siRNA also inhibited claudin-3 expression and transepithelial electrical resistance maintenance in cells. This study shows that intracellular zinc has an essential role in the maintenance of the intestinal epithelial TJ barrier through regulation of occludin proteolysis and claudin-3 transcription.

Nivolumab, an Anti-Programmed Cell Death-1 Antibody, Induces Fulminant Type 1 Diabetes

Programmed cell death-1 (PD-1), an immunoreceptor, is located on T cells and pro-B cells and interacts with its ligands to inhibit T cell activation and proliferation, thereby promoting immunological self-tolerance. Nivolumab, an anti-PD1 antibody, blocks PD-1 and can restore anticancer immune responses by abrogating PD-1 pathway-mediated T-cell inhibition. Autoimmune adverse events are expected with PD-1 therapy. Fulminant type 1 diabetes is the subtype of type 1 diabetes. The clinical feature is the extremely rapid progression of hyperglycemia and ketoacidosis. Here we describe a 66-year-old woman with advanced melanoma who was treated with nivolumab. After 4 months and six doses of the medicine, the patient was admitted to the hospital with complaints of nausea and vomiting. The laboratory data showed ketonuria, hyperglycemia (531 mg/dl), high anion gap metabolic acidosis, HbA1c (7.3%), and absence of insulin-secreting capacity. These data are compatible with the criteria of fulminant type 1 diabetes. The patient was diagnosed with diabetic ketoacidosis because of fulminant type 1 diabetes. The findings of this case indicated that nivolumab can cause fulminant type 1 diabetes. Diabetic ketoacidosis due to fulminant type 1 diabetes is potentially fatal condition. Thus, diabetic ketoacidosis due to fulminant type 1 diabetes should be considered in the differential diagnosis when patients treated with nivolumab complain of gastrointestinal symptoms.

Abstract P5-08-15: Prognostic value of aldehyde dehydrogenase 1 (ALDH1) and tumor infiltrating lymphocytes (TIL) to predict the late recurrence in ER positive, HER2 negative breast cancer

Introduction: Aldehyde dehydrogenase 1(ALDH1) is known to be cancer stem cell marker. Also, tumor infiltrating lymphocytes (TILs) are known to be prognostic factor for triple negative breast cancer. It is reported that these factors have the correlation with chemosensitivity. Meanwhile, the late recurrence (LRec; 5 years after primary surgery) of ER positive breast cancer is the major problem. Significance of expressions of ALDH1 and TILs in primary tumor as predictive factors for late recurrence in ER positive, HER2 negative breast cancer is still unknown.

Methods: ER-positive, and HER2-negative breast cancer patients who underwent surgery or received neoadjuvant chemotherapy between January 2000 and December 2004 were registered from nine institutes belonging the Collaborative Study Group of Scientific Research of the Japanese Breast Cancer Society. For each LRec patient, approximately two matched control patients without relapse for more than ten years were selected. Expression of ALDH1 was assessed by immunohistochemistry. Positive ALDH1 was defined as tumor including more than 1% cancer cells with ALDH1 expression. TIL was assessed by single whole section according to Denkert's definition. A tumor showing high ki67 and/or low PgR expressions was categorized into Luminal B-like group.

Results: 639 patients (184 with early recurrence (ERec), 134 with LRec and 321 with no recurrence (NoRec)) were analyzed. The rates of positive ALDH1 in ERec, LRec and NoRec groups were 18%, 13% and 8%, respectively. ALDH1 positivity was significantly higher in ERec compared with NoRec group (p<0.01). There was no significant difference between LRec and NoRec group (p=0.12). Positive ALDH1 showed significantly shorter DFS and OS in multivariate analyses (DFS: p=0.03, OS: p<0.01). Especially, that was the significantly prognostic factor in the Luminal B like tumor with adjuvant or neoadjuvant chemotherapy (p=0.01), but not in those without any chemotherapy (p=0.53). High TILs in ERec, LRec and NoRec was 1.1%, 1.5% and 3.7%, respectively. There was no significant difference among three recurrent groups (p=0.13). High TILs was not significantly associated with DFS (p=0.09) and OS (p=0.72). However, there was significant correlation between High TILs and DFS in Luminal B like group (p=0.04) and ALDH1-negative group (p=0.02).

Conclusion: In ER-positive, and HER2-negative breast cancer, ALDH1 was an independent prognostic factor (a predictor of ERec, but not LRec). ALDH1 might be a predictor of benefit from chemotherapy in Luminal B like subtype. TILs was neither a predictor of ERec nor LRec. However, significance of TILs as prognostic factor might differ depending on subtypes and cancer stemness.

Citation Format: Miyoshi Y, Shien T, Ogiya A, Ishida N, Yamazaki K, Horii R, Horimoto Y, Masuda N, Yasojima H, Inao T, Osako T, Takahashi M, Tomioka N, Hagio K, Endo Y, Hosoda M, Yamashita H. Prognostic value of aldehyde dehydrogenase 1 (ALDH1) and tumor infiltrating lymphocytes (TIL) to predict the late recurrence in ER positive, HER2 negative breast cancer. [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 P5-08-15.

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 P2-08-24: High levels of serum C-terminal crosslinking telopeptide of type 1 collagen at baseline are associated with poor prognosis for breast cancer patients

Background: It has been demonstrated that adjuvant treatment using bisphosphonate may reduce recurrence among breast cancer patients. However, these improved prognoses of patients are reportedly limited to breast cancers of estrogen receptor (ER)-positive and postmenopausal women. Although the mechanisms of the effects of bisphosphonate remain unknown, this finding seems to represent support for the hypothesis that suppression of bone resorption by bisphosphonate results in favorable prognoses at least for patients in this subset. In order to determine the prognostic significance of bone resorption in breast cancer patients, we investigated these markers c-terminal crosslinking telopeptide of type I collagen (1CTP) and N-telopeptide of type I collagen (NTX).

Patients and Methods: 469 breast cancer patients were recruited who were operated on Hyogo College of Medicine and histologically confirmed to have invasive carcinoma. Serum 1CTP and NTX were measured preoperatively with the two-antibody radioimmunoassay and enzyme-linked immunosorbent assay methods, respectively, and blood samples were obtained before treatment from patients who were treated with neoadjuvant chemotherapy or endocrine therapy. The area under receiver operating characteristic curves were applied and optimal cutoff values were set at 3.6ng/ml for 1CTP, and 10.55nmolBCE/L premenopausal and 14.05nmolBCE/L postmenopausal for NTX. The relationships between these bone turnover markers and various clinicopathological characteristics were evaluated with the chi square or Fisher's exact test. The log-rank test was used to compare relapse-free survival (RFS) in Kaplan-Meier plots. Associations of RFS were assessed with a Cox proportional-hazards model based on the results of univariate and multivariate analyses. Differences were considered statistically significant if p<0.05.

Results: There were significantly more 1CTP-high patients among postmenopausal women and RFS of 1CTP-high patients was significantly worse than that of 1CTP-low patients (5-year RFS: 0.65 vs 0.86; p=0.0002). Similarly, NTX-high patients were significantly associated with postmenopausal status, but there was no significant association between NTX-high worse RFS (p=0.0976). Multivariate analysis of tumor size, lymph node metastasis and nuclear grade identified 1CTP (hazard ratio: 2.04, 95% confidence interval: 1.13-3.68; p=0.018) as a significant independent prognostic factor. Subset analyses of 1CTP showed that prognosis was consistently worse recognized for postmenopausal (p=0.0002), but not premenopausal (p=0.37) patients. Furthermore, prognosis for 1CTP-high patients was worse for the estrogen receptor (ER)-positive subset (p=0.0005) but not for the ER-negative subset (p=0.22).

Conclusion and discussion: High levels of serum bone resorption markers at baseline were identified as significant unfavorable prognostic factors for breast cancer patients. The prognostic significance of 1CTP seems to be prominent for postmenopausal patients with ER-positive breast cancers. These findings suggest the use of bone-modifying agents as an adjuvant therapy may be beneficial for breast cancer patients, especially for patients with high serum levels of 1CTP.

Citation Format: Imamura M, Nishimikai A, Yanai A, Miyagawa Y, Higuchi T, Ozawa H, Murase K, Takatsuka Y, Miyoshi Y. High levels of serum C-terminal crosslinking telopeptide of type 1 collagen at baseline are associated with poor prognosis for breast cancer patients. [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 P2-08-24.

Abstract P6-16-01: Differences in patterns of change of bone turnover markers during treatment with bone-modifying agents of breast cancer patients with bone metastases

Background: Bone-modifying agents have demonstrated their efficacy for treatment by suppressing osteoclast function. The activity of bone-modifying agents can be monitored by means of bone resorption markers such as c-terminal crosslinking telopeptide of type I collagen (1CTP) and N-telopeptide of type I collagen (NTX) as well as bone forming marker bone-specific alkaline phosphatase (BAP). In contrast to these markers which indirectly indicate bone turnover, tartrate-resistant acid phosphatase-5b (Tracp-5b) has been established as a direct marker showing osteoclast number and activity. The aim of this study was to identify the relative significance of these bone turnover markers as indicators of treatment efficacy induced by bone-modifying agents for breast cancer patients with bone metastases.

Patients and Methods: For this study, 52 breast cancer patients with bone metastases treated with bone-modifying agents were recruited. Zoledronic acid and denosumab were administered as bone-modifying agents to 36 and 22 patients, respectively (for 6 patients, denosumab was used after zoledronic acid). Serum Tracp-5b, 1CTP, NTX and BAP were measured with, respectively, the EIA (enzyme immunoassay), RIA (two-antibody radioimmunoassay), ELISA (enzyme-linked immunosorbent assay) and CLEIA (chemiluminescent enzyme immunoassay) method. Blood samples were obtained pretreatment and 1, 3 and 6 months after treatment. Changes in these bone turnover markers were statistically analyzed with Friedman's test, and correlation between serum markers and clinicopathological factors was calculated with Mann-Whitney's test.

Results: Serum tracp-5b decreased significantly after treatment (p<0.0001). The baseline median value of Tracp-5b (457.5mU/dl, range: 173-1630mU/dl) had been reduced to 137mU/dl (91-795mU/dl) 1 month after treatment, but no further reduction was observed after that. For 13 out of 15 patients to whom Tracp-5b was administered, abnormally high levels (above 420mU/dl) decreased to normal range with one month treatment. Serum NTX was also significantly reduced after treatment (p=0.0007). The median baseline value (16.5nmolBCE/L, 6.1-52.2nmolBCE/L) was diminished after 1 month (to 10.9nmolBCE/L, 7.0-49.5nmolBCE/L), and further reduction of NTX was observed after 3 months (9.55nmolBCE/L, 6.4-56.0nmolBCE/L). Similarly, baseline BAP (15.1μg/L, 6.4-81.3μg/L) decreased significantly (p=0.0032), a reduction which was obtained after 3 months (10.15μg/L, 6.1-51.7μg/L), but not after 1 month (13.0μg/L, 7.7-137.0μg/L). On the other hand, reduction in 1CTP was not significant (p=0.83).

Conclusion and discussion: Although baseline values of the bone turnover markers Tracp-5b, NTX and BAP decreased significantly after treatment with bone-modifying agents, the pattern of reduction for these three markers varied. Tracp-5b appears to reflect efficacy of bone-modifying agents most quickly and sensitively, possibly due to its direct link to the number and activity of osteoclasts. These findings may prove usefulness of Tracp-5b when considering the efficacy of various bone-modifying agents in clinical practice.

Citation Format: Higuchi T, Nishimukai A, Yanai A, Miyagawa Y, Murase K, Imamura M, Ozawa H, Takatsuka Y, Miyoshi Y. Differences in patterns of change of bone turnover markers during treatment with bone-modifying agents of breast cancer patients with bone metastases. [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 P6-16-01.

Degradation and synthesis of β-glucans by a Magnaporthe oryzae endotransglucosylase, a member of the glycoside hydrolase 7 family

BACKGROUND

Plant pathogens secrete enzymes that degrade plant cell walls to enhance infection and nutrient acquisition.

RESULTS

A novel endotransglucosylase catalyzes cleavage and transfer of β-glucans and decreases the physical strength of plant cell walls.

CONCLUSION

Endotransglucosylation causes depolymerization and polymerization of β-glucans, depending on substrate molecular size.

SIGNIFICANCE

Enzymatic degradation of plant cell walls is required for wall loosening, which enhances pathogen invasion. A Magnaporthe oryzae enzyme, which was encoded by the Mocel7B gene, was predicted to act on 1,3-1,4-β-glucan degradation and transglycosylation reaction of cellotriose after partial purification from a culture filtrate of M. oryzae cells, followed by liquid chromatography-tandem mass spectrometry. A recombinant MoCel7B prepared by overexpression in M. oryzae exhibited endo-typical depolymerization of polysaccharides containing β-1,4-linkages, in which 1,3-1,4-β-glucan was the best substrate. When cellooligosaccharides were used as the substrate, the recombinant enzyme generated reaction products with both shorter and longer chain lengths than the substrate. In addition, incorporation of glucose and various oligosaccharides including sulforhodamine-conjugated cellobiose, laminarioligosaccharides, gentiobiose, xylobiose, mannobiose, and xyloglucan nonasaccharide into β-1,4-linked glucans were observed after incubation with the enzyme. These results indicate that the recombinant enzyme acts as an endotransglucosylase (ETG) that cleaves the glycosidic bond of β-1,4-glucan as a donor substrate and transfers the cleaved glucan chain to another molecule functioning as an acceptor substrate. Furthermore, ETG treatment caused greater extension of heat-treated wheat coleoptiles. The result suggests that ETG functions to induce wall loosening by cleaving the 1,3-1,4-β-glucan tethers of plant cell walls. On the other hand, use of cellohexaose as a substrate for ETG resulted in the production of cellulose II with a maximum length (degree of polymerization) of 26 glucose units. Thus, ETG functions to depolymerize and polymerize β-glucans, depending on the size of the acceptor substrate.

Abstract P6-07-39: Prognostic Value of Body Mass Index in Japanese Breast Cancer Patients: A Collaborative Study by the Kobe Breast Cancer Oncology Group and Hokkaido Cancer Center

Background: Many recent clinical trials conducted in Western populations suggest that obesity is a prognostic factor after primary treatment in postmenopausal breast cancer patients. However, the incidence of obesity differs substantially between Asian and Western breast cancer patients. Moreover, few studies have reported the relationship between body mass index (BMI) and postsurgical prognosis in Asian breast cancer patients. A previous retrospective analysis of Japanese populations revealed that obesity might be a prognostic risk factor in Japanese breast cancer patients.

Methods: We retrospectively analyzed BMI and clinical outcomes after primary treatment in Japanese breast cancer patients of Hanshin and Hokkaido areas. We reviewed the clinical data (height, weight, BMI, estrogen receptor [ER] status, progesterone receptor status [PgR], human epidermal growth factor receptor 2 [HER2] status, and outcome) of 1,222 primary breast cancer patients with clinical stage I-III disease who were operated on between Jan 2004 and Dec 2005 at Kobe Breast Cancer Oncology Group (KBCOG) and Hokkaido Cancer Center (median follow-up period, 74 months). The patients were categorized into 4 groups: underweight (BMI, <18.5 kg/m2), normal (18.5–24.9 kg/m2), overweight (25–29.9 kg/m2), and obesity (>30.0 kg/m2). Patient characteristics, excluding age and menopausal status, were well-balanced across groups. The correlations of BMI with disease-free survival (DFS) and overall survival (OS) were analyzed using the Cox hazards model.

Results: The normal, underweight, overweight, and obesity groups contained 832 (68.1%), 92 (7.5%), 253 (20.7%), and 45 (3.7%) patients, respectively. Breast cancer recurred in 184 patients (15.0%); 75 patients died due to breast cancer recurrence, 29 died of other diseases, and 6 died of unknown causes. The univariate hazard ratio (HR) values for disease-free survival and overall survival in the overweight group were significantly lower than those in the normal group. However, there were no statistical significant differences among four groups by the multivariate analysis. We added subgroup analysis with classifications by ER and PgR status to speculate the cause for these unexpected results. Although there were no statistically significant differences, HRs for DFS and OS in the obesity group were higher than those in the normal group among ER− and/or PgR-positive patients. However, HRs for DFS and OS tended to be higher in the underweight groups and lower in the overweight groups in ER− and PgR-negative populations.

Conclusions: The incidence of obesity in the Japanese population is much lower than that in the Western population. Although results of this study were slightly different from recent findings, obesity might be a risk factor for DFS and OS in ER-positive Japanese breast cancer patients, similar to that in Western countries. In underweight patients, ER− and PgR-negative status might indicate poor prognosis. However, this study was a retrospective analysis of a limited, heterogeneous patient group. A large-scale cohort study in the Japanese population is, therefore, recommended.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-39.

Abstract P1-14-08: A prospective multicenter randomized phase II neo-adjuvant study of 5-fluorouracil, epirubicin and cyclophosphamide (FEC) followed by docetaxel, cyclophosphamide and trastuzumab (TCH) versus TCH followed by FEC versus TCH alone, in patients (pts) with operable HER2 positive breast cancer: JBCRG-10 study

Background: The current standard treatment of primary systemic therapy (PST) in HER2 positive breast cancer is anthracyclines (A) and/or taxanes combined with trastuzumab (H) which demonstrates high pathological complete response (pCR). The pCR is considered as a predictive marker of prognosis although results are slightly different depending on the hormone receptor status. We conducted a randomized phase II study to examine sequence of treatments and necessity of A in the treatments using TCH to improve outcome and reduce cardiac toxicity in Japanese HER2 positive pts.

Methods: Pts were treated with FEC (5FU 500 mg/m2, epirubicin 100 mg/m2, cyclophosphamide 500 mg/m2) and/or TCH (docetaxel 75 mg/m2, cyclophosphamide 600 mg/m2, H 6 mg/kg, loading by 8 mg) in 3 groups: 4 cycles of FEC followed by 4 cycles of TCH (A-TCH); 4 cycles of TCH followed by 4 cycles of FEC (TCH-A) or 6 cycles of TCH. An unplanned interim analysis was conducted due to one death by interstitial lung disease (ILD) in the A-TCH after completion of 8 cycles. The pCR results suggested A containing regimens did not exceed benefit from the current standard regimen. The study was continued by limiting allocation only to the TCH group considering efficacy and safety. The primary endpoint was pCR and secondary endpoints were overall response rate (ORR) and safety.

Results: A total of 103 pts were enrolled between Sep. 2009 and Sep. 2011; 21 pts in the A-TCH, 22 pts in the TCH-A and 60 pts in the TCH including pts enrolled after termination of random allocation. Characteristics of the 103 pts were; median age of 54 (range, 33–70), median tumor size of 35 mm (range, 12–80), 42 pts with N(+) (40.8%) and 62 ER positive pts (60.2%). Characteristics of pts in the TCH were; median age of 54.5 (range, 33–67), median tumor size of 35.5 mm (range, 12–80), 25 pts with N(+) (41.7%) and 34 ER positive pts (56.7%). No major difference was reported between groups treated with or without A. Per protocol population was 59 pts in the TCH and its pCR rate was 45.8% (95% CI, 32.2–59.3: ER negative, 61.5%; ER positive, 33.3%). ORR was 86.4% assessed by MRI or CT. Although it is an exploratory analysis, the pCR rate of A containing regimens was 39.0% (ER negative, 57.1%; ER positive, 29.6%). Adverse events ≥grade 3 were reported in 50 pts (48.5%). Reported ILD was in 5 pts (A-TCH, 1; TCH-A, 1; TCH, 3). The mean left ventricular ejection fraction (LVEF) decreased from 70.0% to 69.0% after treatment (A-TCH, 65.9%; TCH-A, 70.4%; TCH, 69.0%). Decrease of LVEF in the A-TCH was significant (p < 0.01).

Conclusion: The pCR rate of the TCH group was similar to previous reports on A including regimens. Although ILD had been occurred during the treatment containing the TCH, no other new safety issues were reported. We were not able to conclude preferable sequence of A and T since statistical power was not sufficient. However, the result of LVEF suggested TCH followed by A or TCH were preferable. Six cycles of TCH could be one of treatment options as a PST in HER2 positive breast cancer to exclude A. (UMIN000002365)

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-08.