Cysteine-rich protein reverses weight loss in lung cancer patients receiving chemotherapy or radiotherapy.

Oxidative stress plays a role in the tumor-cytotoxic effect of cancer chemotherapy and radiotherapy and also in certain adverse events. In view of these conflicting aspects, a double-blind trial over a 6-month period was performed to determine whether a cysteine-rich protein (IMN1207) may have a positive or negative effect on the clinical outcome if compared with casein, a widely used protein supplement low in cysteine. Sixty-six patients with stage IIIB-IV non-small cell lung cancer were randomly assigned to IMN1207 or casein. Included were patients with a previous involuntary weight loss of > or =3%, Karnofsky status > or =70, and an estimated survival of >3 months. Thirty-five lung cancer patients remained on study at 6 weeks. Overall compliance was not different between treatment arms (42-44% or 13 g/day). The patients treated with the cysteine-rich protein had a mean increase of 2.5% body weight, whereas casein-treated patients lost 2.6% (p = 0.049). Differences in secondary endpoints included an increase in survival, hand-grip force, and quality of life. Adverse events were mild or moderate. Further studies will have to show whether the positive clinical effects can be confirmed and related to specific parameters of oxidative stress in the host.

Doxycycline decreases tumor burden in a bone metastasis model of human breast cancer.

Bone is one of the most frequent sites for metastasis in breast cancer patients,often resulting in significant clinical morbidity and mortality. Increased matrix metalloproteinase (MMP) activity of tumor cells correlates with a higher invasive and metastatic potential. Members of the tetracycline family of antibiotics, including doxycycline, have potential treatment value for bone metastasis; they inhibit cancer cell proliferation, and they are also potent MMP inhibitors and are highly osteotropic. Doxycycline treatment in an experimental bone metastasis mouse model of human breast cancer MDA-MB-231 cells resulted in a 70% reduction in total tumor burden when compared with placebo control animals. In tumor-bearing animals, the amount of doxycycline incorporated into the radius/ulna as assessed by ELISA was lower than in non-tumor-bearing animals. In doxycycline-treated mice, bone formation was significantly enhanced as determined by increased numbers of osteoblasts, osteoid surface, and volume, whereas a decrease in bone resorption was also observed. Doxycycline treatment may be beneficial for breast cancer patients with or at risk for osteolytic bone metastasis; it greatly reduces tumor burden and could also compensate for the increased bone resorption associated with the disease.

ETS proteins and MMPs: partners in invasion and metastasis.

Binding sites for the ETS domain family of transcription factors are found in the promoters of the matrix metalloproteinase (MMP) family of matrix degrading enzymes. Evidence is accumulating that both these groups of molecules are important in the process of angiogenesis in addition to matrix degradation. Furthermore, they are both expressed in tumor tissue as well as in the normal surrounding stroma. These factors along with various sites at which they may be regulated collectively makes them attractive targets to consider for therapeutic intervention in the processes of invasion and metastasis.

A phase II study of ispinesib (SB-715992) in patients with metastatic or recurrent malignant melanoma: a National Cancer Institute of Canada Clinical Trials Group trial.

To assess the response rate and toxicity of the kinesin spindle protein (KSP) inhibitor, ispinesib, in malignant melanoma. Seventeen patients were enrolled from April to November 2005. Ispinesib was administered as a 1-hour infusion at a dose of 18 mg/m2 once every 3 weeks until disease progression. No objective responses were seen. Six patients (35%) had a best response of stable disease for a median duration of 2.8 months. Disease progression was documented in 9 (53%) after 1 or 2 cycles. Eighty-eight percent of patients received > or =90% of planned dose intensity. Grade 3 non-hematologic toxicities included dizziness (1) and blurred vision (1). There was one episode of febrile neutropenia, but no grade 3 or 4 biochemical adverse events. Pharmacokinetics was consistent with prior studies. KSP immunoreactivity was seen in 14 of 16 available archival tissue samples (88%). Ispinesib can be safely administered using the dose and schedule employed, with mild hematologic and non-hematologic toxicity. No objective responses were observed, and further development of single-agent ispinesib in malignant melanoma is not recommended. Although KSP expression appears to be common in melanoma, KSP may not be a suitable target for its treatment.

Effect of letrozole versus placebo on bone mineral density in women with primary breast cancer completing 5 or more years of adjuvant tamoxifen: a companion study to NCIC CTG MA.17.

PURPOSE: Aromatase inhibition depletes estrogen levels and may be associated with accelerated bone resorption. The National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) study MA.17B evaluated bone turnover markers and bone mineral density (BMD) in postmenopausal women randomly assigned to MA.17, a placebo-controlled trial of letrozole after standard adjuvant tamoxifen. PATIENTS AND METHODS: Eligible women had a baseline BMD T score of at least 2.0 in either the hip or L2-4 spine; all received calcium 500 mg and vitamin D 400 U daily. Percentage change in BMD (L2-L4 spine and hip) at 12 and 24 months, rate of osteoporosis, and change in markers of bone formation (serum bone alkaline phosphatase) and resorption (serum C-telopeptide and urine N-telopeptide) at 6, 12, and 24 months were compared. RESULTS: Two hundred twenty-six patients (122 letrozole, 104 placebo) were enrolled. Baseline characteristics were similar in the two groups, including BMD, median age of 60.7 years (81% < 70 years), and median follow-up of 1.6 years. At 24 months, patients receiving letrozole had a significant decrease in total hip BMD (-3.6% v -0.71%; P = .044) and lumbar spine BMD (-5.35% v -0.70%; P = .008). Letrozole increased urine N-telopeptide at 6, 12, and 24 months (P = .054, < .001, and .016, respectively). No patient went below the threshold for osteoporosis in total hip BMD, whereas at the L2-L4 (posteroanterior view), more women became osteoporotic by BMD while receiving letrozole (4.1% v 0%; P = .064). CONCLUSION: After 5 years of adjuvant tamoxifen, subsequent letrozole causes a modest increase in bone resorption and reduction in bone mineral density in the spine and hip compared to placebo. Further follow-up is necessary to evaluate the long-term clinical implications of this difference.

Expression of Ets-related transcription factors and matrix metalloproteinase genes in human breast cancer cells.

The expression levels of ets and MMP genes was examined in two breast cancer cell lines of differing invasive potential. The more invasive MDA-MB-231 cell line had higher levels of Ets-1, Ets-2, PEA3, ERM, Tel, Net, MMP-13 and -14 mRNA than MCF-7 cells. MMP-1, -3 and -16 mRNAs were expressed equally. TPA stimulated MMP-1, -9 and TIMP-1 mRNA expression in both cell lines. MMP-2 and MMP-7 mRNAs were not detected in either cell line. The Ets-1 protein was only detected in MDA-MB-231 cells and its level increased following TPA stimulation. TPA induced MMP-9 activity in MCF-7 cells and increased its activity in MDA-MB-231 cells, however, MMP-2 activity was not detected.

Phase II trial of flavopiridol, a cyclin dependent kinase inhibitor, in untreated metastatic malignant melanoma.

PURPOSE: To test the activity of the cyclin dependent kinase (cdk) inhibitor flavopiridol in malignant melanoma, a disease with frequent abnormalities of the cyclin dependent kinase system. PATIENTS AND METHODS: Patients had histologically proven, unidimensionally measurable malignant melanoma, incurable by standard therapy. Prior adjuvant immunotherapy was allowed, but patients were otherwise untreated for advanced disease. Flavopiridol was administered at a dose of 50 mg/m(2) IV over 1 hour daily x 3 days every 3 weeks. Patients were assessed for response every 2 cycles. RESULTS: 17 patients were accrued over 5 months. No objective responses were documented in the 16 patients evaluable for response. Seven patients (44%) had stable disease after 2 cycles, with a median of 2.8 months (range 1.8-9.2). The most common treatment-related non-hematologic toxicities were diarrhea (82%), nausea (47%), fatigue (41%), anorexia (35%) and vomiting (29%). Most treatment-related toxicities were mild, except for diarrhea (grade 3 in 3 patients, grade 4 in 1 patient), nausea (grade 3 in 1 patient) and tumor pain (grade 3 in 1 patient). Hematologic toxicities were minimal, none worse than grade 2. Eighty-eight percent of patients received >/=90% planned dose intensity; 2 patients had dose reductions for gastrointestinal (GI) toxicity. CONCLUSIONS: Flavopiridol is well tolerated at the dose regimen used in this study, with an acceptable (primarily GI) toxicity profile. Although 7 of the 16 patients had stable disease ranging from 1.8 to 9.2 months in duration, there was no evidence of significant clinical activity in malignant melanoma by objective response criteria.