A phase II trial of docetaxel and estramustine in patients with refractory metastatic breast carcinoma

Management of Androgen-Independent Prostate Cancer

Background

Although androgen withdrawal can control prostate cancer for long periods in many patients, controversy exists regarding management when the tumor becomes androgen independent. Several options are now available.

Methods

A review of the pertinent literature of the last 20 years was conducted to provide guidance in defining and managing hormone-refractory prostate cancer.

Results

Stage D prostate cancer can be subclassified to correlate tumor biology with disease stage. Secondary hormone manipulations may induce responses in patients after failure of initial androgen suppression, and chemotherapy with docetaxel has prolonged survival in patients with androgen-independent prostate cancer (AIPC). The weight of evidence supports the maintenance of castrate levels of testosterone in metastatic AIPC. Bisphosphonates decrease skeletal complications.

Conclusions

Secondary hormone therapy, chemotherapy, and bisphosphonate therapy may provide benefits for selected patients. Correlation of disease stage with biologic characteristics of the tumor and host facilitates proper choices of interventions. Docetaxel-based chemotherapy regimens should be considered for first-line treatment of patients with progressive metastatic AIPC.

Estramustine phosphate sodium in heavily pretreated patients with metastatic breast cancer: a retrospective consecutive case series

BACKGROUND

Estramustine phosphate sodium (EMP) is an oral agent poorly developed--although active--in patients with metastatic breast cancer (MBC). To resume interest in EMP in MBC, we analyzed a retrospective series of consecutive patients with estrogen receptor-positive disease.

METHODS

EMP was given orally at a dose of 140 mg daily. Treatment discontinuation rates due to progressive disease/toxicity and response rates were assessed.

RESULTS

Twenty postmenopausal patients with mainly visceral disease were treated with EMP, in five cases in combination with other anticancer drugs. Median numbers of previous chemotherapies and hormonal treatments were six and four, respectively. From the entire cohort, one complete response and four partial responses were observed. The proportions of patients free of progression at 6 and 12 months were 39 and 8 %, respectively. Six patients discontinued EMP, three each for toxicity and adverse events.

CONCLUSION

Good disease control was obtained in heavily pretreated MBC patients receiving EMP. Toxicity was manageable and reversible although treatment discontinuation has to be considered. A prospective study should be encouraged to identify the optimal use of the drug.

A phase I/II trial of fixed-dose docetaxel plus irinotecan and escalating doses of estramustine phosphate for second-line or greater treatment of selected advanced solid tumors

This phase I/II study evaluated the safety of the combination of irinotecan, docetaxel, and estramustine for selected advanced solid tumors and also obtained initial efficacy data. Twenty-two patients were enrolled in the study. The regimen consisted of docetaxel 30 mg/m(2) and irinotecan 60 mg/m(2) both given intravenously on days 1 and 8 every 21 days in combination with escalating doses of estramustine (500 mg/m(2)/day escalated to 750 mg/m(2)/day on days 0, 1, 2, 7, 8, and 9 given every 21 days) during phase I. Dose escalation was continued until the maximum planned dose level of estramustine (750 mg/m(2)/day) was reached. After the appropriate phase II dose of estramustine was found additional patients were enrolled. Twenty-one of the 22 patients were evaluable for toxicity and 17 for tumor response. The recommended phase II dose of estramustine was found to be 750 mg/m(2)/day orally on days 0, 1, 2, 7, 8, and 9 given every 21 days. Hematologic toxicity was fairly mild, with only one episode of grade 3 neutropenia. Diarrhea was the most common nonhematologic toxicity with grade 3 toxicity occurring in five of 21 patients. Only one episode of venous thrombosis was observed. Objective response rate was 15.8%, overall clinical benefit rate was 63%, and median time to progression was 15 weeks. Estramustine in combination with the doublet of docetaxel and irinotecan is a well-tolerated regimen with minimal hematologic toxicity, mild to moderate nonhematologic toxicity, and promising initial antitumor activity in previously treated patients with advanced solid tumors.

ABCA2 as a therapeutic target in cancer and nervous system disorders

BACKGROUND

Overexpression of ATP-binding cassette (ABC) transporters is a major adaptive advantage used by tumor cells to evade the accumulation of cytotoxic agents. ABCA2, a transporter highly expressed in the cells of the nervous and haematopoetic systems, is associated with lipid transport and drug resistance in cancer cells, including tumor stem cells. Recently, a single nucleotide polymorphism (SNP) in Abca2 was linked to early onset Alzheimer's disease (AD). The characterization of two independent knockout mouse models has shed light on putative in vivo functions of this transporter in the development and maintenance of myelin membrane lipids in the CNS.

OBJECTIVE

The objective of this review is to guide the reader through the existing scope of literature on the ABCA2 transporter, focusing on its potential as a future target in human pathologies, specifically cancer and neurological disease.

METHODS

An NCBI PubMed literature search was conducted to address the growing body of ABCA2 literature that, at the time of publication, included 39 reports. From these, we focused on papers that provided insight into the functional importance of this transporter in tumor stem cells, cancer, drug resistance, Alzheimer's disease and myelination.

RESULTS/CONCLUSION

These studies have implicated ABCA2 as a therapeutic target in modulating the drug resistance phenotype prevalent in human cancers and in the treatment of neuropathies, including Alzheimer's disease and myelin-related disorders.

Administration of zoledronic acid enhances the effects of docetaxel on growth of prostate cancer in the bone environment

Background

After development of hormone-refractory metastatic disease, prostate cancer is incurable. The recent history of chemotherapy has shown that with difficult disease targets, combinatorial therapy frequently offers the best chance of a cure. In this study we have examined the effects of a combination of zoledronic acid (ZOL), a new-generation bisphosphonate, and docetaxel on LuCaP 23.1, a prostate cancer xenograft that stimulates the osteoblastic reaction when grown in the bone environment.

Methods

Intra-tibial injections of LuCaP 23.1 cells were used to generate tumors in the bone environment, and animals were treated with ZOL, docetaxel, or a combination of these. Effects on bone and tumor were evaluated by measurements of bone mineral density and histomorphometrical analysis.

Results

ZOL decreased proliferation of LuCaP 23.1 in the bone environment, while docetaxel at a dose that effectively inhibited growth of subcutaneous tumors did not show any effects in the bone environment. The combination of the drugs significantly inhibited the growth of LuCaP 23.1 tumors in the bone.

Conclusion

In conclusion, the use of the osteolysis-inhibitory agent ZOL in combination with docetaxel inhibits growth of prostate tumors in bone and represents a potential treatment option.

Phase II trial evaluating a docetaxel-capecitabine combination as treatment for hormone-refractory prostate cancer

BACKGROUND

Docetaxel is a well-recognized drug in patients with hormone-refractory prostate cancer (HRPC), either alone or combined with estramustine. In this indication, a Phase II trial was conducted investigating a docetaxel-capecitabine combination.

METHODS

Forty-six patients presenting with documented HRPC were enrolled in the study. The treatment regimen consisted of docetaxel (D) at a dose of 35 mg /m2/week (intravenously, 3 consecutive weeks) plus oral capecitabine (C) at a dose of 625 mg/m2 twice daily (Days 5-18) every 28 days for 4 cycles. The primary endpoint was the biological response defined as a reduction in prostate-specific antigen (PSA) level > or =50%. Secondary endpoints were overall survival, safety, and quality of life.

RESULTS

Thirty of 44 assessable patients (68.2%) achieved a biological response, 14 of whom (31.8%) normalized their PSA value. The median overall survival time was 17.7 months (95% confidence interval, 15.8 to not reached). Four treatment cycles were completed by 87% of the patients. Hematologic toxicity was mild. The main Grade 3-4 toxicities were cutaneous toxicity (13.1%) and changes in nails (6.5%). Physical functioning and role scales were higher before treatment (P = .02 and P = .003, respectively), fatigue and diarrhea were more frequent during and after treatment (P = .0003 and P = .03, respectively), and pain was lower during and after treatment.

CONCLUSIONS

The results of the current study demonstrated the high efficacy of the DC combination in patients with HRPC, and the associated good tolerability. This combination offers a new alternative to the docetaxel-estramustine combination. Further randomized trials are warranted.

Lactandrate: a D-homo-aza-androsterone alkylator in the treatment of breast cancer

The sensitivity of breast neoplasms to hormonal control provides the basis of novel investigational treatments with steroidal alkylators. An androsterone D-lactam steroidal ester, the 3beta-hydroxy-13alpha-amino-13,17-seco- 5alpha-androstan-17-oic-13,17-lactam, p-bis(2-chloroethyl)amino phenyl acetate (lactandrate) was synthesized and tested for antitumor activity against six human breast cancer cell lines in vitro and against two murine and one xenograft mammary tumors in vivo. A docking study on the binding interactions of lactandrate with the ligand-binding domain (LBD) of estrogen receptor-alpha (ERalpha) was inquired. In vitro testing of lactandrate cytostatic and cytotoxic activity was performed on T47D, MCF7, MDA-MB-231, BT-549, Hs578T, MDA-MB-435 breast adenocarcinoma human cell lines. In vivo testing was performed on two murine mammary tumors, the MXT tumor and CD8F1 adenocarcinoma, as well as on human mammary carcinoma MX-1 xenograft. Molecular modeling techniques were adopted to predict a possible location and interaction mode of the molecule into LBD. Lactandrate induced significantly high antitumor effect against all tested in vitro and in vivo models. The cell lines with positive ER expression found to be significantly more sensitive to lactandrate. Moreover, lactandrate found to be positioned inside the binding cavity with its steroidal moiety, whilst the alkylating moiety protrudes out of receptor's pocket. Lactandrate produced important anticancer activity on breast cancer in vitro and in vivo. Some correlation between ER and lactandrate effect was demonstrated. Docking studies provide the basis for the structure-based design of improved steroidal alkylating esters for the treatment of estrogen-related cancers.