Second-line pemetrexed treatment in Taiwanese patients with advanced nonsmall cell lung cancer: an open-label single-arm study.

BACKGROUND/PURPOSE: Although global and Asian studies on second-line pemetrexed for the treatment of advanced nonsmall cell lung cancer have confirmed its efficacy and safety, a pivotal postcommitment study to consolidate the evidence regarding the Taiwanese population was warranted. This open-label single-arm study assessed the objective response rate to a tailored dose of single-agent pemetrexed in Taiwanese patients with advanced nonsmall cell lung cancer who had received prior chemotherapy. METHODS: Patients with stage IIIB/IV disease were treated with pemetrexed on day 1 of each 21-day cycle. A 500 mg/m(2) dose was administered in cycle 1. For cycle 2, the dose was increased to 1000 mg/m(2) (if there was no toxicity above predefined levels) or decreased to 375 mg/m(2). All patients received standard supplemental therapy. Patient follow-up continued until 18 months after the last patient was enrolled in this study or death. All patients were included in all analyses. RESULTS: Of the 33 patients who were enrolled, 25 (75.8%) received the 1000 mg/m(2) dose during cycle 2; 18 patients were dropped from the study, including 17 (51.5%) who had died by the time of analysis. The objective response and disease control rates were 18.2% (95% confidence limits [CI]: 7.0-35.5) and 54.5% (95% CI: 36.4-71.9), respectively. No patients exhibited a complete response. There were two serious drug-related adverse events (neutropenia and leukopenia) and two drug-related adverse events that resulted in removal from the study. Decreased neutrophil/granulocyte counts were the most frequently observed drug-related grade 3/4 events (9 patients, 24 treatment cycles). CONCLUSION: The objective response rate, disease control rate, and safety and tolerability profile in this population of Taiwanese patients were consistent with the published findings that were conducted using Asian and Western populations. These findings support the use of single-agent, second-line pemetrexed for the treatment of advanced nonsmall cell lung cancer in Taiwanese patients.

The 18 kDa translocator protein (peripheral benzodiazepine receptor) expression in the bone of normal, osteoprotegerin or low calcium diet treated mice.

The presence of the translocator protein (TSPO), previously named as the mitochondrial or peripheral benzodiazepine receptor, in bone cells was studied in vitro and in situ using RT-qPCR, and receptor autoradiography using the selective TSPO ligand PK11195.In vitro, the TSPO is highly expressed in osteoblastic and osteoclastic cells.In situ, constitutive expression of TSPO is found in bone marrow and trabecular bone, e.g., spongiosa. Mice with a reduction of bone turnover induced by a 4-day treatment of osteoprotegerin reduces [(3)H]PK11195 binding in the spongiosa (320±128 Bq x mg(-1), 499±106 Bq x mg(-1) in saline-treated controls). In contrast, mice with an increase in bone turnover caused by a 4-day low calcium diet increases [(3)H]PK11195 binding in the spongiosa (615±90 Bq x mg(-1)). Further, our study includes technical feasibility data on [(18)F]fluoride microPET imaging of rodent bone with altered turnover. Despite [(18)F]fluoride having high uptake, the in vivo signal differences were small. Using a phantom model, we describe the spillover effect and partial volume loss that affect the quantitative microPET imaging of the small bone structures in experimental mouse models. In summary, we demonstrate the expression of TSPO in small rodent bone tissues, including osteoblasts and osteoclasts. A trend increase in TSPO expression was observed in the spongiosa from low to high bone turnover conditions. However, despite the potential utility of TSPO expression as an in vivo biomarker of bone turnover in experimental rodent models, our small animal PET imaging data using [(18)F]fluoride show that even under the condition of a good biological signal-to-noise ratio and high tracer uptake, the currently achievable instrument sensitivity and spatial resolution is unlikely to be sufficient to detect subtle differences in small structures, such as mouse bone.

Phase III, open-label, randomized study comparing concurrent gemcitabine plus cisplatin and radiation followed by adjuvant gemcitabine and cisplatin versus concurrent cisplatin and radiation in patients with stage IIB to IVA carcinoma of the cervix.

PURPOSE: To determine whether addition of gemcitabine to concurrent cisplatin chemoradiotherapy and as adjuvant chemotherapy with cisplatin improves progression-free survival (PFS) at 3 years compared with current standard of care in locally advanced cervical cancer. PATIENTS AND METHODS: Eligible chemotherapy- and radiotherapy-naive patients with stage IIB to IVA disease and Karnofsky performance score ≥ 70 were randomly assigned to arm A (cisplatin 40 mg/m(2) and gemcitabine 125 mg/m(2) weekly for 6 weeks with concurrent external-beam radiotherapy [XRT] 50.4 Gy in 28 fractions, followed by brachytherapy [BCT] 30 to 35 Gy in 96 hours, and then two adjuvant 21-day cycles of cisplatin, 50 mg/m(2) on day 1, plus gemcitabine, 1,000 mg/m(2) on days 1 and 8) or to arm B (cisplatin and concurrent XRT followed by BCT only; dosing same as for arm A). RESULTS: Between May 2002 and March 2004, 515 patients were enrolled (arm A, n = 259; arm B, n = 256). PFS at 3 years was significantly improved in arm A versus arm B (74.4% v 65.0%, respectively; P = .029), as were overall PFS (log-rank P = .0227; hazard ratio [HR], 0.68; 95% CI, 0.49 to 0.95), overall survival (log-rank P = .0224; HR, 0.68; 95% CI, 0.49 to 0.95), and time to progressive disease (log-rank P = .0012; HR, 0.54; 95% CI, 0.37 to 0.79). Grade 3 and 4 toxicities were more frequent in arm A than in arm B (86.5% v 46.3%, respectively; P < .001), including two deaths possibly related to treatment toxicity in arm A. CONCLUSION: Gemcitabine plus cisplatin chemoradiotherapy followed by BCT and adjuvant gemcitabine/cisplatin chemotherapy improved survival outcomes with increased but clinically manageable toxicity when compared with standard treatment.

Accelerated bone resorption, due to dietary calcium deficiency, promotes breast cancer tumor growth in bone.

The skeleton is a major site of breast cancer metastases. High bone turnover increases risk of disease progression and death. However, there is no direct evidence that high bone turnover is causally associated with the establishment and progression of metastases. In this study, we investigate the effects of high bone turnover in a model of breast cancer growth in bone. Female nude mice commenced a diet containing normal (0.6%; 'Normal-Ca') or low (0.1%; 'Low-Ca') calcium content. Mice were concurrently treated with vehicle or osteoprotegerin (1 mg/kg/d s.c; n = 16 per group). Three days later (day 0), 50,000 Tx-SA cells (variant of MDA-MB-231 cells) were implanted by intratibial injection. On day 0, mice receiving Low-Ca had increased serum parathyroid hormone (PTH) and tartrate-resistant acid phosphatase 5b levels, indicating secondary hyperparathyroidism and high bone turnover, which was maintained until day 17. Osteoprotegerin increased serum PTH but profoundly reduced bone resorption. On day 17, in mice receiving Low-Ca alone, lytic lesion area, tumor area, and cancer cell proliferation increased by 43%, 24%, and 24%, respectively, compared with mice receiving Normal Ca (P < 0.01). Osteoprotegerin treatment completely inhibited lytic lesions, reduced tumor area, decreased cancer cell proliferation, and increased cancer cell apoptosis. Increased bone turnover, due to dietary calcium deficiency, promotes tumor growth in bone, independent of the action of PTH. Breast cancer patients frequently have low dietary calcium intake and high bone turnover. Treatment to correct calcium insufficiency and/or treatment with antiresorptive agents, such as osteoprotegerin, may be of benefit in the adjuvant as well as palliative setting.

Inhibition of bone resorption, rather than direct cytotoxicity, mediates the anti-tumour actions of ibandronate and osteoprotegerin in a murine model of breast cancer bone metastasis.

Inhibition of bone resorption either by bisphosphonate (BP) treatment or by blocking RANKL signalling with osteoprotegerin (OPG) has been shown to reduce tumour burden in bone and inhibit bone destruction in murine xenograft models of breast cancer. However, whether the anti-tumour effect of OPG or BP in bone is mediated by inhibition of bone resorption or by direct effects on tumour cells is uncertain. The current study is designed to investigate anti-tumour effects of OPG and ibandronate (IBN), dosed alone or in combination, on tumour growth to determine if there is experimental support for combination treatments and to provide evidence for the presence of direct anti-tumour effects. To this aim, 10 microl (5 x 10(6) cells/ml) of the bone-seeking MDA-MB-231 (Tx-SA) cell line was injected intra-tibially into nude mice. After 10 days, when the tumours were evident radiologically, mice were treated with vehicle, OPG (1 mg/kg/day), ibandronate (IBN) (160 microg/kg/day) or IBN and OPG at the same doses (IBN+OPG) for a week, and the effects of each treatment on lytic lesions, tumour cell growth, cell apoptosis and proliferation were measured by radiography, immunohistochemistry and histomorphometry. Compared to vehicle controls, in vivo treatment with OPG, IBN, or IBN+OPG, each prevented the expansion of osteolytic bone lesions (increase in lytic lesion area day 10 to day 17: OPG -3.2%, IBN 6.6%, IBN+OPG 3.6%, Vehicle 232.5%; p<0.01). Treatment with OPG, IBN or IBN+OPG each produced similar reductions in tumour area relative to vehicle-treated mice (OPG 52%, IBN 54%, IBNp and OPG 48%, p<0.01 vs. vehicle) OPG and IBN alone and in combination each produced a similar increase in cancer cell apoptosis (OPG 330%, IBN 342%, IBN and OPG 347%, p<0.01 vs. vehicle) and a decrease in cancer cell proliferation (OPG 59%, IBN 62%, IBN and OPG 58%, p<0.05 vs. vehicle). Our findings indicate that (i) combined treatment with OPG and a bisphosphonate is not significantly more effective than either agent alone; and that (ii) inhibition of bone resorption, rather than direct anti-tumour action, mediates the effects of these agents on tumour growth in this in vivo model.

Mechanisms of disease: roles of OPG, RANKL and RANK in the pathophysiology of skeletal metastasis.

The discovery of osteoprotegerin, receptor activator of nuclear factor kappa B (RANK) and RANK ligand as critical molecular determinants of osteoclastogenesis and regulators of bone resorption, has revolutionized our understanding of the processes of normal and pathological bone biology. Altering the relative biological availabilities of these molecules has direct consequences for the regulation of both bone resorption and bone remodeling. Importantly, recent research suggests a pivotal role for these molecules in mediating cancer-induced bone destruction. This review summarizes the current evidence of osteoprotegerin, RANK ligand and RANK involvement in the pathophysiology of skeletal metastasis, and of therapeutic targeting of this process.

Osteoprotegerin in prostate cancer bone metastasis.

Osteoprotegerin (OPG), a critical regulator of osteoclastogenesis, is expressed by prostate cancer cells, and OPG levels are increased in patients with prostate cancer bone metastases. The objective of this study was to investigate the effects of OPG overexpression on prostate cancer cells and prostate cancer/bone cell interactions in vitro and in vivo. OPG-transfected C4-2 cells expressed 8.0 ng OPG per mL per 10(6) cells, whereas no OPG was detected in the media of C4-2 cells transfected with a control plasmid. OPG overexpressed by C4-2 cells protected these cells from tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis and decreased osteoclast formation. Subcutaneous OPG-C4-2 and pcDNA-C4-2 tumors exhibited similar growth and take-rate characteristics. However, when grown in bone, tumor volume was decreased in OPG-C4-2 versus pcDNA-C4-2 (P=0.0017). OPG expressed by C4-2 cells caused increases in bone mineral density (P=0.0074) and percentage of trabecular bone volume (P=0.007), and decreases in numbers of osteoblasts and osteoclasts when compared with intratibial pcDNA-C4-2 tumors (P=0.003 and P=0.019, respectively). In summary, our data show that increased expression of OPG in C4-2 cells does not directly affect proliferation of prostate cancer cells but indirectly decreases growth of C4-2 tumors in the bone environment. Our data also show that OPG expressed by C4-2 cells inhibits bone lysis associated with C4-2 bone metastasis, which results in net increases in bone volume. We therefore hypothesize that OPG expressed in prostate cancer patient bone metastases may be at least partially responsible for the osteoblastic character of most prostate cancer bone lesions.