EMP combination chemotherapy and low-dose monotherapy in advanced prostate cancer

Single nucleotide polymorphisms of 17beta-hydroxysteroid dehydrogenase type 7 gene: mechanism of estramustine-related adverse reactions?

OBJECTIVES

To investigate the influence of single nucleotide polymorphisms (SNP) on transcription of the 17beta-hydroxysteroid dehydrogenase (HSD17B7) gene.

METHODS

Luciferase reporter genes containing a 5'-flanking of the HSD17B7 gene, as well as the sequence around the SNP, were transfected into LNCaP and DU145 cells. Then, luciferase assays were carried out.

RESULTS

The presence of the G allele resulted in an increase of transcriptional activity derived from the 5'-flanking region of the HSD17B7 gene by 270% and 370% in LNCaP and DU145 cells, respectively. Transcriptional activity of the HSD17B7 gene containing the G allele was higher than that of the C allele.

CONCLUSIONS

The transcriptional activity of the HSD17B7 gene containing the G allele is higher than that of the C allele. This difference in HSD17B7 expression may regulate the risk of peripheral edema as an adverse reaction induced by estramustine phosphate sodium.

Tissue inhibitor of metalloproteinase-3 induces apoptosis in prostate cancer cells and confers increased sensitivity to paclitaxel

Prostate cancer is the most common cancer and the second leading cause of cancer-related death in American men. To investigate the possible usefulness of tissue inhibitor of metalloproteinase-3 (TIMP-3) in prostate cancer gene therapy, we used an adenovirus expressing TIMP-3 to assess its role as an apoptosis trigger in highly metastatic prostate cancer cell lines PC-3 and DU-145. We showed that TIMP-3 alone induced apoptotic cell death which was triggered by mitochondrion-mediated caspase-3 activation. In combination treatment, we found that adenovirus-mediated expression of TIMP-3 greatly sensitised prostate cancer cells to chemotherapeutic drug paclitaxel, indicating a superadditive or synergistic effect of TIMP-3 and cytostatic treatment on prostate cancer cell death. The proper combination of adenovirus-mediated expression of TIMP-3 with conventional chemotherapeutic drug(s) could have potential benefits in treating highly metastatic prostate cancer.

Docetaxel induces apoptosis in hormone refractory prostate carcinomas during multiple treatment cycles

Caspase-cleaved proteins are released from disintegrated apoptotic cells and can be detected in the circulation. We here addressed whether caspase-cleaved cytokeratin 18 (CK18-Asp396) can be used as a serum biomarker for assessment of the clinical efficiency of chemotherapy in hormone-refractory prostate cancer (HRPC). A total of 82 patients with HRPC were evaluated during 751 treatment cycles, either with estramustine (EMP)/vinorelbine or with EMP/docetaxel. The levels of CK18-Asp396 and of total CK18 were measured in patient serum before and during therapy by ELISA. Docetaxel induced significant increases in serum CK18-Asp396 (P<0.0001) and total CK18 (P<0.0002), suggesting induction of apoptosis. Similarly, vinorelbine induced increases in both CK18-Asp396 and CK18 (P<0.001 and 0.011). In contrast, EMP induced increases in total serum CK18 (P<0.0001), but not in CK18-Asp396 (P=0.13). The amplitudes of docetaxel-induced increases were associated with baseline prostate-specific antigen (PSA) and CK18 serum levels in these patients, consistent with tumoral origin of caspase-cleaved fragments. Docetaxel induced significant increases in CK18-Asp396 during second-, third- and fourth-line therapy and induced increased levels of CK18-Asp396 during treatment cycles 1–8. In contrast, vinorelbine induced significant increases only during cycles 1–3. In a subgroup of 32 patients that received EMP/vinorelbine in second line followed by EMP/docetaxel in third line, docetaxel induced stronger increases than vinorelbine (P=0.008). These results show that the CK18-Asp396 serum marker can be used to assess tumour apoptosis in vivo and suggest that the clinical efficiency of docetaxel in HRPC is due to induction of apoptosis during multiple treatment cycles.

New standards in the chemotherapy of metastatic hormone-refractory prostate cancer

Hormone-refractory prostate cancer (HRPC) is a major issue in Western countries and the second leading cause of cancer death in North American men. In the prostate-specific antigen era, most HRPCs are currently diagnosed in asymptomatic patients based on biochemical failure, with increasing demand for active treatment. Until recently, chemotherapy for HRPC patients was not considered a standard of care due to the absence of clear data evidencing an overall survival benefit. In fact, few Phase III studies conducted in the 1980s and early 1990s had documented a superiority over corticosteroids alone in terms of biochemical response (declines in serum prostate-specific antigen levels) and quality of life, but not survival. Due to their impact on pain control, mitoxantrone and prednisone were long considered the best regimen for symptomatic HRPC patients. In recent years, more chemotherapeutic agents have been tested, among which the microtubule inhibitors (vinca alkaloids and taxanes) have obtained the most promising results in Phase II trials and have entered Phase III testing. Two well-designed randomized trials have changed this scenario. Both compared docetaxel (with or without estramustine) against mitoxantrone and prednisone, and demonstrated a significant advantage not only in terms of response, pain control and quality of life, but also in terms of overall survival. Which patients need to be treated, the regimen of choice and duration of chemotherapy will be the next questions to be answered in the coming years in the field of HRPC, along with the role of new signal transduction inhibitors and other targeted therapies.

The Val158Met polymorphism of the catechol-O-methyltransferase gene is associated with the PSA-progression-free survival in prostate cancer patients treated with estramustine phosphate

OBJECTIVE

The aim of our study is to find out the good responders for estramustine phosphate (EMP) therapy in patients with prostate cancer. We have focused on the metabolism of EMP and studied the association between a functional single-nucleotide polymorphism in the catechol-O-methyltransferase gene (Val158Met of COMT) and PSA-progression-free survival in Japanese patients with prostate cancer treated by EMP.

METHODS

Seventy-two Japanese patients with previously untreated prostate cancer who were found to be eligible for low-dose EMP therapy were enrolled in the study. Genotyping of the Val158Met polymorphism of COMT was conducted by both the polymerase chain reaction-based restriction fragment length polymorphism method and TaqMan assay.

RESULTS

Patients with the Val/Val genotype of COMT had a significantly higher PSA-progression-free rate as compared to those with the Val/Met or Met/Met genotype (p=0.027). The adjusted hazard ratio of biochemical PSA failure for the Val158Met genotype of COMT was 2.164 (95% CI, 1.111 to 5.525).

CONCLUSIONS

The Val158Met polymorphism of COMT is associated with the PSA-progression-free rate of EMP-treated patients in prostate cancer.

Single-nucleotide polymorphisms in the 17beta-hydroxysteroid dehydrogenase genes might predict the risk of side-effects of estramustine phosphate sodium in prostate cancer patients

BACKGROUND

Estramustine phosphate sodium (EMP) frequently causes side-effects such as gastrointestinal discomfort, nausea, and edema in extremities. We analyzed single nucleotide polymorphisms (SNP) in the 17beta-hydroxysteroid dehydrogenase (HSD17B) genes, which are involved in the metabolism of EMP, to predict the risk of EMP side-effects in prostate cancer patients.

METHODS

We performed genotyping of SNP in the HSD17B genes of 44 Japanese patients with newly diagnosed prostate cancer. The association of SNP and individual EMP side-effects was evaluated.

RESULTS

Peripheral edema occurred more frequently in patients with C/C genotype of IMS-JST123219 than in those with C/G genotype (OR: 5.47, 95% CI: 1.27-23.64). Haplotype analysis showed that appetite loss was associated with the G allele of IMS-JST123219 and the T allele of IMS-JST123218 (OR: 9.13, 95% CI: 1.15-72.76).

CONCLUSIONS

These preliminary data demonstrated that analyses of SNP in the HSD17B genes might predict the occurrence of side-effects from EMP.

The Evolving Role of Chemotherapy and Other Systemic Therapies for Managing Localized Prostate Cancer

PURPOSE

The recent literature is reviewed regarding the use of neoadjuvant and adjuvant chemotherapy, and promising new molecular targeted agents in patients with high risk localized prostate cancer.

MATERIALS AND METHODS

A MEDLINE literature review was performed of studies evaluating chemotherapy and other systemic therapies for localized prostate cancer.

RESULTS

Patients with prostate cancer at high risk for recurrence despite local therapy include those with clinical stage T3 disease, biopsy Gleason scores of 8 to 10 or serum prostate specific antigen greater than 20 ng/ml. Although hormonal therapy has palliative benefit for the majority of patients with metastatic disease, randomized trials have not demonstrated a survival benefit from its administration before surgery for high risk localized disease. Recent trials have shown that cytotoxic chemotherapy has significant activity in hormone refractory prostate cancer, which has led to ongoing clinical trials that are investigating the use of chemotherapy in the neoadjuvant setting. Published and ongoing clinical trials in the use of systemic therapy for localized prostate cancer are reviewed.

CONCLUSIONS

Systemic therapy for advanced prostate cancer is improving. Efforts to use such therapies for managing localized disease are ongoing.