Norio Kohno

Zoledronic Acid Significantly Reduces Skeletal Complications Compared With Placebo in Japanese Women With Bone Metastases From Breast Cancer: A Randomized, Placebo-Controlled Trial

PURPOSE To investigate the efficacy and safety of zoledronic acid for the treatment of bone metastases from breast cancer. PATIENTS AND METHODS Women with bone metastases (N = 228) were randomly assigned to receive 4 mg zoledronic acid (n = 114) or placebo (n = 114) via 15-minute infusions every 4 weeks for 1 year. The primary efficacy end point was the skeletal-related event (SRE) rate ratio between treatment groups. An SRE was defined as pathologic fracture, spinal cord compression, and radiation or surgery to bone. Secondary end points included percentage of patients with at least one SRE, time-to-first SRE, and Andersen-Gill multiple-event analysis. RESULTS The SRE rate ratio at 1 year (excluding HCM and adjusted for prior fracture) was 0.61 (permutation test; P = .027), indicating that zoledronic acid reduced the rate of SRE by 39% compared with placebo. The percentage of patients with at least one SRE (excluding HCM) was significantly reduced by 20% by zoledronic acid (29.8% v 49.6% for placebo; P = .003). Zoledronic acid significantly delayed time-to-first SRE (median not reached v 364 days; Cox regression; P = .007) and reduced the risk of SREs by 41% in multiple event analysis (risk ratio = 0.59; P = .019) compared with placebo. Zoledronic acid was well tolerated with a safety profile similar to placebo. No patient treated with zoledronic acid had grade 3 or 4 serum creatinine increase. CONCLUSION Zoledronic acid significantly reduced skeletal complications compared with placebo across multiple end points in Japanese women with bone metastases from breast cancer.

Oral Uracil and Tegafur Compared With Classic Cyclophosphamide, Methotrexate, Fluorouracil As Postoperative Chemotherapy in Patients With Node-Negative, High-Risk Breast Cancer: National Surgical Adjuvant Study for Breast Cancer 01 Trial

PURPOSE The primary aim of this study was to compare the effectiveness of oral uracil-tegafur (UFT) with that of classical cyclophosphamide, methotrexate, and fluorouracil (CMF) given as postoperative adjuvant treatment to women with node-negative, high-risk breast cancer. PATIENTS AND METHODS Women with node-negative, high-risk breast cancer were randomly assigned to receive either 2 years of UFT or six cycles of CMF after surgery. The primary end point was relapse-free survival (RFS). Overall survival (OS), toxicity, and quality of life (QOL) were secondary end points. The hypothesis was that UFT was not inferior to CMF in terms of RFS. RESULTS Between October 1996 and April 2001, a total of 733 patients were randomly assigned to receive either treatment. The median follow-up time was 6.2 years. The RFS rates at 5 years were 88.0% in the CMF arm and 87.8% in the UFT arm. OS rates were 96.0% and 96.2%, respectively. The hazard ratios of the UFT arm relative to the CMF arm were 0.98 for RFS (95% CI, 0.66 to 1.45; P = .92) and 0.81 for OS (95% CI, 0.44 to 1.48; P = .49). The toxicity profiles differed between the two groups. The QOL scores were better for patients given UFT than those given CMF. CONCLUSION RFS and OS with oral UFT were similar to those with classical CMF. Given the higher QOL scores, oral UFT is a promising alternative to CMF for postoperative adjuvant chemotherapy in women with node-negative, high-risk breast cancer.

The expression of parathyroid hormone-related protein in human breast cancer with skeletal metastases

The relationship between the expression of parathyroid hormone-related protein (PTHrP) by breast cancer and skeletal metastases, was investigated using a monoclonal antibody against human PTHrP (4133). The immunohistochemical localization of PTHrP was studied in sections of formalin-fixed, paraffin-embeded tissues from 28 breast cancers obtained surgically between 1980 and 1985. Of the 28 patients, 12 developed skeletal metastases, 8 developed lung metastases, and the other 8 were alive and disease-free at the time of this study. Sixteen of the 28 (57%) tumors showed positive immunoreactivity to 4133, the PTHrP positive ratio being 83% in the patients who developed skeletal metastases, 38% in those who developed lung metastases, and 38% in those without recurrence, respectively. Thus, a significantly higher proportion of the patients who developed skeletal metastases were positive for PTHrP than the other two groups (P < 0.05). Furthermore, the level of positive staining was strongly related to positivity for estrogen and progesterone receptors (P < 0.01). These results are consistent with the hypothesis that PTHrP might be necessary for metastases to erode bone and grow in skeletal sites, and its expression could be related to certain hormones.

Treatment of breast cancer with bone metastasis: bisphosphonate treatment — current and future

There are a variety of treatments for patients with bone metastases from breast cancer. These include bisphosphonates, antitumor endocrine and cytotoxic systemic therapies, radiotherapy to the metastatic site, radionucleotides, and conservative treatment (analgesics). The optimal combination treatment for bone metastases is not clear. Bisphosphonates are effective for reducing skeletal complications such as bone pain, pathological fracture, bone surgery, and hypercalcemia. Bisphosphonates are recommended as the gold standard therapy for breast cancer with bone metastases. Treatment guidelines tend to recommend starting a bisphosphonate at the time of diagnosis of bone metastases. Animal models have supported the prevention of bone metastasis by bisphosphonate therapy, but three major adjuvant clinical trials of the oral bisphosphonate clodronate have yielded conflicting results. However, our preliminary trial of an intravenous bisphosphonate, pamidronate, showed effective inhibition of bone metastases. The use of bisphosphonates, especially zoledronic acid, as adjuvant therapy is promising, but it is still investigational.

Significance of serum tumor markers in monitoring advanced breast cancer patients treated with systemic therapy: A prospective study

ObjectiveThe significance of serum tumor markers in monitoring advanced breast cancer patients is still controversial. To clarify this issue, the Tumor Marker Study Group of the Japanese Breast Cancer Society conducted a prospective study.MethodsPatients with advanced breast cancer who were treated with systemic therapy between January and December 2002 were recruited from five collaborative institutes in Japan. The patients were monitored every four weeks using three serum tumor markers, CEA, CA 15-3 and NCC-ST-439 during the therapy.ResultsFindings from 108 eligible patients were analyzed. The pretreatment positivity rates were 51.9% for CEA, 50% for CA 15-3, and 34.3% for NCC-ST-439. The changes in each marker level at 8 and 12 weeks but not at 4 weeks after the start of therapy seemed to correlate with the response to therapy in pretreatment marker-positive patients but not in negative patients. The Cox proportional hazard model revealed a greater than 20% reduction in CEA, CA 15-3 or NCC-ST-439 levels at 4, 8 and/or 12 weeks after the start of therapy to be an independent predictive factor for longer time-to-progression (TTP) in pretreatment marker-positive patients.ConclusionThis prospective study supported the findings obtained from our previous retrospective study that in pretreatment marker-positive patients 1) the changes in serum tumor marker levels after the start of therapy correlate with the response to therapy; and 2) a greater than 20% reduction in the tumor marker levels was a favorable predictive factor for TTP during systemic therapy. When the pretreatment serum level of these markers is over the respective cut-off value, sequential measurement of them may be useful for evaluating the efficacy of treatment as well as monitoring the outcome of patients with advanced breast cancer.

ARHI/NOEY2 Inactivation May Be Important in Breast Tumor Pathogenesis

Allelic loss frequently occurs on the short arm of chromosome 1 in human breast carcinoma, suggesting that the ARHI/NOEY2 gene, an imprinted putative tumor suppressor gene, is involved in the pathogenesis of the tumor entity. To clarify the clinical importance of ARHI/NOEY2 mRNA in breast cancer, we studied whether ARHI/NOEY2 inactivation might contribute to tumors arising in the breast. An ARHI/NOEY2 message was detected by real-time PCR analysis in all noncancerous breast tissues, but was not detected in 2 of 26 breast cancer tissue samples. In 10 of 26 breast cancer tissue samples ARHI/NOEY2 mRNA was substantially reduced. ARHI/NOEY2 expression was lost or markedly reduced in 12 of 26 (46.15%) breast cancer tissue samples. In summary, we conclude that decreased ARHI/NOEY2 mRNA expression may play an important role in the pathogenesis of breast cancer.

Lymphoepithelial cyst of the pancreas with sebaceous differentiation

Abstract: We recently encountered a patient with a lymphoepithelial cyst of the pancreas with sebaceous differentiation. We sought to compare the characteristics of this patient with those previously reported in order to foster a keener understanding of this rare clinical entity. After reviewing the present patients case in detail, we conducted a comprehensive review of the English-language literature and analyzed the clinical characteristics of reported cases of lymphoepithelial cysts. Our patient was an asymptomatic 60-year-old man who presented with an incidental finding of a cystic lesion in the tail of the pancreas documented by computed tomography. The cyst was enucleated, and was found to contain keratinized material. It was lined by squamous epithelium with small sebaceous glands, and surrounded by lymphoid tissue with germinal centers. Of 33 reported cases, only 6 (18%) contained sebaceous glands. In all patients who underwent operation, the cysts were easily resected, and the outcome was favorable. Lymphoepithelial cyst of the pancreas is rare, and may be difficult to differentiate from cystic neoplasms preoperatively. Therefore resection is indicated. The diagnosis, however, can be confirmed by careful histologic review, and the prognosis is excellent.

Combined treatment with SAHA, bortezomib, and clarithromycin for concomitant targeting of aggresome formation and intracellular proteolytic pathways enhances ER stress-mediated cell death in breast cancer cells.

The ubiquitin-proteasome pathway and the autophagy-lysosome pathway are two major intracellular protein degradation systems. We previously reported that clarithromycin (CAM) blocks autophagy flux, and that combined treatment with CAM and proteasome inhibitor bortezomib (BZ) enhances ER-stress-mediated apoptosis in breast cancer cells, whereas treatment with CAM alone results in almost no cytotoxicity. Since HDAC6 is involved in aggresome formation, which is recognized as a cytoprotective response serving to sequester misfolded proteins and facilitate their clearance by autophagy, we further investigated the combined effect of vorinostat (suberoylanilide hydroxamic acid (SAHA)), which has a potent inhibitory effect for HDAC6, with CAM and BZ in breast cancer cell lines. SAHA exhibited some cytotoxicity along with an increased acetylation level of α-tubulin, a substrate of HDAC6. Combined treatment of SAHA, CAM, and BZ potently enhanced the apoptosis-inducing effect compared with treatment using each reagent alone or a combination of two of the three. Expression levels of ER-stress-related genes, including the pro-apoptotic transcription factor CHOP (GADD153), were maximally induced by the simultaneous combination of three reagents. Like breast cancer cell lines, a wild-type murine embryonic fibroblast (MEF) cell line exhibited enhanced cytotoxicity and maximally up-regulated Chop after combined treatment with SAHA, CAM, and BZ; however, a Chop knockout MEF cell line almost completely canceled this enhanced effect. The specific HDAC6 inhibitor tubacin also exhibited a pronounced cytocidal effect with a combination of CAM plus BZ. These data suggest that simultaneous targeting of intracellular proteolytic pathways and HDAC6 enhances ER-stress-mediated apoptosis in breast cancer cells.

Clarithromycin enhances bortezomib-induced cytotoxicity via endoplasmic reticulum stress-mediated CHOP (GADD153) induction and autophagy in breast cancer cells

The specific 26S proteasome inhibitor, bortezomib (BZ) potently induces apoptosis as well as autophagy in metastatic breast cancer cell lines such as MDA-MB-231 and MDA-MB-468. The combined treatment of clarithromycin (CAM) and BZ significantly enhances cytotoxicity in these cell lines. Although treatment with up to 100 μg/ml CAM alone had little effect on cell growth inhibition, the accumulation of autophagosomes and p62 was observed after treatment with 25 μg/ml CAM. This result indicated that CAM blocked autophagy flux. However, the combined treatment of BZ and CAM resulted in more pronounced autophagy induction, as assessed by increased expression ratios of LC3B-II to LC3B-I and clearance of intracellular p62, than treatment with BZ alone. This combination further enhanced induction of the pro-apoptotic transcription factor CHOP (CADD153) and the chaperone protein GRP78. Knockdown of CHOP by siRNA attenuated the death-promoting effect of BZ in MDA-MB-231 cells. A wild-type murine embryonic fibroblast (MEF) cell line also exhibited enhanced BZ-induced cytotoxicity with the addition of CAM, whereas a Chop knockout MEF cell line completely abolished this enhancement and exhibited resistance to BZ treatment. These data suggest that endoplasmic reticulum (ER)-stress mediated CHOP induction is involved in pronounced cytotoxicity by combining these reagents. Simultaneously targeting two major intracellular protein degradation pathways such as the ubiquitin-proteasome system by BZ and the autophagy-lysosome pathway by CAM may improve the therapeutic outcome in breast cancer patients via ER-stress mediated apoptosis.

Epidermal growth factor‐dependent enhancement of invasiveness of squamous cell carcinoma of the breast

Factors that promote the aggressiveness of squamous cell carcinoma of the breast are not well understood. To examine the involvement of cell motility and the mechanism of this behavior, a squamous cell carcinoma cell line of the breast (HBC9) was established from a metastatic lymph node of a Japanese woman. HBC9 expressed epidermal growth factor receptor (EGFR), but was negative for Her2 or Her3.The invasive ability of HBC9 was compared with that of four breast ductal carcinoma cell lines by Matrigel invasion assay. EGF stimulation induced the formation of surface protrusions and cell migration in HBC9 cells, and significantly increased the number of cells migrating through the Matrigel. The invasive ability of HBC9 was compared with other cell lines of breast carcinoma; it was much greater than that of MCF‐7, BT474, or HBC5, but did not differ significantly from that of MDA‐MB‐231. Observation of the surface protrusions of HBC9 by confocal laser microscopy revealed co‐localization of Arp2 and N‐WASP with actin polymerization, detected by visualization with phalloidin, indicating that the protrusions induced by EGF were invadopodia. In HBC9 cells, cortactin also co‐localized with the N‐WASP/Arp2/3 complex in the protrusions. Immunohistochemistry of 12 cases of squamous cell carcinoma of the breast revealed expression of cortactin and EGFR in all of them, and this was confirmed by western blotting in two cases. These results suggest that EGF‐dependent enhancement of cell motility by formation of invadopodia associated with cortactin is a cause of the clinical aggressiveness of squamous cell carcinoma of the breast.