Shi Ming Tu

Phase I Trial of the Proteasome Inhibitor Bortezomib in Patients With Advanced Solid Tumors With Observations in Androgen-Independent Prostate Cancer

PURPOSE To determine the dose-limiting toxicity and maximum-tolerated dose of the proteasome inhibitor bortezomib administered intravenously weekly for 4 every 5 weeks; to determine the bortezomib pharmacokinetics and pharmacodynamics using plasma levels and an assay for 20S proteasome inhibition (PI) in whole blood; to correlate toxicity with bortezomib dose and degree of 20S PI; and to conduct a preliminary determination of the antitumor activity of bortezomib in patients with androgen independent prostate cancer (AIPCa). PATIENTS AND METHODS Fifty-three patients (48 with AIPCa) received 128 cycles of bortezomib in doses ranging from 0.13 to 2.0 mg/m(2)/dose, utilizing a careful escalation scheme with a continuous reassessment method. Pharmacokinetic and pharmacodynamic studies were performed in 24 patients (at 1.45 to 2.0 mg/m(2)). RESULTS A dose-related 20S PI was seen, with dose-limiting toxicity at 2.0 mg/m(2) (diarrhea, hypotension) occurring at an average 1-hour post-dose of >/= 75% 20S PI. Other side effects were fatigue, hypertension, constipation, nausea, and vomiting. No relationship was seen between body-surface area and bortezomib clearance over the narrow dose range tested. There was evidence of biologic activity (decline in serum prostate-specific antigen and interleukin-6 levels) at >/= 50% 20S PI. Two patients with AIPCa had prostate-specific antigen response and two patients had partial response in lymph nodes. CONCLUSION The maximum-tolerated dose and recommended phase II dose of bortezomib in this schedule is 1.6 mg/m(2). Biologic activity (inhibition of nuclear factor-kappa B-related markers) and antitumor activity is seen in AIPCa at tolerated doses of bortezomib. This agent should be further explored with chemotherapy agents in advanced prostate cancer.

Bone-targeted therapy for advanced androgen-independent carcinoma of the prostate: a randomised phase II trial

BACKGROUND Prostate carcinoma is linked to osteoblastic metastasis. We therefore investigated the value of bone-targeted consolidation therapy in selected patients with advanced androgen-independent carcinoma of the prostate. METHODS 103 patients received induction chemotherapy, consisting of ketoconazole and doxorubicin alternating with estramustine and vinblastine. After two or three cycles of induction chemotherapy, we randomly assigned 72 patients who were clinically stable or responders to receive doxorubicin with or without strontium-89 (Sr-89) every week for 6 weeks. FINDINGS Overall 62 of the 103 (60%, 95% CI 50-70) patients had a 50% or greater reduction in serum prostate-specific antigen concentration that was maintained for at least 8 weeks, and 43 (42%, 32-52) had an 80% or greater reduction. 49 (52%) patients with bone pain at registration had complete resolution of pain. After follow-up of 67 patients until death, the estimated median survival for all 103 patients was 17.5 months (range 0.5-37.7). For the 36 patients randomly assigned to receive Sr-89 and doxorubicin, the median survival time was 27.7 months (4.9-37.7), and for the 36 who received doxorubicin alone it was 16.8 months (4.4-34.2) (p=0.0014). The hazard ratio was 2.76 (95% CI 1.44-5.29). INTERPRETATION Bone-targeted consolidation therapy consisting of one dose of Sr-89 plus doxorubicin once a week for 6 weeks, when given to patients with stable or responding advanced androgen-independent carcinoma of the prostate after induction chemotherapy, improved overall survival.

Results of a Phase II Study With Doxorubicin, Etoposide, and Cisplatin in Patients With Fully Characterized Small-Cell Carcinoma of the Prostate

PURPOSE To determine the activity and toxicity of doxorubicin in combination with cisplatin and etoposide in patients with small-cell prostate carcinoma (SCPCa) and to characterize the clinicopathologic features of SCPCa. PATIENTS AND METHODS Patients with SCPCa (pure or mixed), measurable disease, good organ function, and no prior treatment with doxorubicin, etoposide, or cisplatin were treated every 4 weeks with doxorubicin 50 mg/m(2) as a 24-hour intravenous (IV) infusion followed by etoposide 120 mg/m(2)/d and cisplatin 25 mg/m(2)/d IV on days 2 to 4. RESULTS Thirty-eight patients (36 assessable for response) were treated for a median of four cycles. Twenty-nine (81%) of 36 patients had prior hormonal therapy. Study patients had visceral metastases, lytic bone disease, and relatively low serum prostate-specific antigen (PSA). We observed 22 partial responses (response rate, 61% in an intent-to-treat analysis); toxicity was severe (grade 3 or 4 neutropenia 100%, thrombocytopenia 66%, mucositis 21%, and infection 68%). Three patients died of toxicity. Median time to progression and overall survival time were 5.8 months and 10.5 months, respectively. Performance status, serum albumin, and number of organs involved (but not PSA, carcinoembryonic antigen, or neuroendocrine markers) were predictors of survival. CONCLUSION SCPCa presents unique clinicopathologic features. Addition of doxorubicin to the etoposide/cisplatin regimen caused higher toxicity in this patient population and failed to improve outcome. Given these results, we do not recommend further development of this regimen for patients with SCPCa. Improvement in therapy will come from understanding the biology of SCPCa progression and integrating new targeted therapies into the treatment of SCPCa.

Stem-cell origin of metastasis and heterogeneity in solid tumours

An explanation for the inherently metastatic and heterogeneous nature of cancers may be their derivation from distinct stem cells. The type of stem cell from which a neoplasm arises determines both the metastatic potential and the phenotypic diversity of that neoplasm. Hence, tumours originating from an early stem cell or its progenitor cells metastasise readily and have a more heterogeneous phenotype, whereas tumours originating from a later stem cell or its progenitor cells have limited metastatic potential and a more homogeneous phenotype. Further investigation of the role of stem cells in the development of cancer may lead to the discovery of novel diagnostic tools, prognostic markers, and therapeutic targets in the battle against cancer.

Patient survival after surgery for osseous metastases from renal cell carcinoma.

BACKGROUND Skeletal metastases from renal cell carcinoma are highly destructive vascular lesions. They pose unique surgical challenges due to the risk of life-threatening hemorrhage and resistance to other treatments. The goal of this retrospective study was to evaluate factors that may affect survival after surgical treatment of metastases of renal cell carcinoma. METHODS We performed a retrospective review of a series of 295 consecutive patients who had been treated for metastatic renal cell carcinoma at one institution between 1974 and 2004. There were 226 men and sixty-nine women. A total of 368 metastases of renal cell tumors to the extremities and pelvis were treated. The surgical procedures included curettage with cementing and/or internal fixation (214 tumors), en bloc resection (117), closed nailing (twenty-seven), amputation (four), and other measures (six). Overall survival was calculated with Kaplan-Meier analysis. The log-rank test was used to evaluate the effect of different variables on overall survival. RESULTS The overall patient survival rates at one and five years were 47% and 11%, respectively. The metastatic pattern had a significant effect on the survival rate (p < 0.0001): patients with a solitary bone metastasis had the most favorable overall survival rate. Patients with multiple bone-only metastases had a better survival rate than patients with pulmonary metastases (p = 0.009). A clear-cell histological subtype was also associated with better survival (p < 0.0001). The tumor grade did not predict survival (p = 0.17). Fifteen patients (5%) died within four weeks after surgery. The causes included acute pulmonary failure (seven patients), multiorgan failure (six), cerebrovascular accident (one), and hypercalcemia (one). There were no deaths attributable to intraoperative hemorrhage. DISCUSSION Survival beyond twelve months is possible for a substantial proportion of patients with metastatic renal cell carcinoma. Patients with a clear-cell histological subtype, bone-only metastases, and a solitary metastasis have superior survival rates. The presence of pulmonary metastases does not predict early death in a reliable manner, and some patients may survive for years with pulmonary and systemic disease. The data are important for surgeons to consider when choosing treatment for these patients. For example, local control of disease and implant stability are important issues for patients with a potential for a long duration of survival.

Molecular Characterization of Enzalutamide-treated Bone Metastatic Castration-resistant Prostate Cancer

BACKGROUND Enzalutamide is a novel antiandrogen with proven efficacy in metastatic castration-resistant prostate cancer (mCRPC). OBJECTIVE To evaluate enzalutamides effects on cancer and on androgens in blood and bone marrow, and associate these with clinical observations. DESIGN, SETTING, AND PARTICIPANTS In this prospective phase 2 study, 60 patients with bone mCRPC received enzalutamide 160mg orally daily and had transilial bone marrow biopsies before treatment and at 8 wk of treatment. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Androgen signaling components (androgen receptor [AR], AR splice variant 7 (ARV7), v-ets avian erythroblastosis virus E26 oncogene homolog [ERG], cytochrome P450, family 17, subfamily A, polypeptide 1 [CYP17]) and molecules implicated in mCRPC progression (phospho-Met, phospho-Src, glucocorticoid receptor, Ki67) were assessed by immunohistochemistry; testosterone, cortisol, and androstenedione concentrations were assessed by liquid chromatography-tandem mass spectrometry; AR copy number was assessed by real-time polymerase chain reaction. Descriptive statistics were applied. RESULTS AND LIMITATIONS Median time to treatment discontinuation was 22 wk (95% confidence interval, 19.9-29.6). Twenty-two (37%) patients exhibited primary resistance to enzalutamide, discontinuing treatment within 4 mo. Maximal prostate-specific antigen (PSA) decline ≥ 50% and ≥ 90% occurred in 27 (45%) and 13 (22%) patients, respectively. Following 8 wk of treatment, bone marrow and circulating testosterone levels increased. Pretreatment tumor nuclear AR overexpression (> 75%) and CYP17 (> 10%) expression were associated with benefit (p = 0.018). AR subcellular localization shift from the nucleus was confirmed in eight paired samples (with PSA decline) of 23 evaluable paired samples. Presence of an ARV7 variant was associated with primary resistance to enzalutamide (p = 0.018). Limited patient numbers warrant further validation. CONCLUSIONS The observed subcellular shift of AR from the nucleus and increased testosterone concentration provide the first evidence in humans that enzalutamide suppresses AR signaling while inducing an adaptive feedback. Persistent androgen signaling in mCRPC was predictive of benefit and ARV7 was associated with primary resistance. PATIENT SUMMARY We report a first bone biopsy study in metastatic prostate cancer in humans that searched for predictors of outcome of enzalutamide therapy. Benefit is linked to a pretreatment androgen-signaling signature. TRIAL REGISTRATION ClinicalTrials.gov identifier NCT01091103.

ADULT PROSTATE SARCOMA: THE M. D. ANDERSON CANCER CENTER EXPERIENCE

PURPOSE Sarcoma of prostate origin is rare. Historically, long-term survival rates for adult patients with prostate sarcoma are poor. We analyzed the experience of 1 institution with prostate sarcoma during the last 3 decades. MATERIALS AND METHODS The records of 21 patients with prostate sarcoma were reviewed to identify symptoms at presentation, diagnostic procedures, presence and development of metastases, staging evaluation, histological subtype, grade and size of the primary tumor, and treatment sequence, including surgery, and preoperative and postoperative therapies. Several clinicopathological variables were assessed for prognostic importance. RESULTS Most patients presented with urinary obstruction. The diagnosis of prostate sarcoma was usually established with ultrasound guided biopsy or transurethral resection. Histological subtypes were leiomyosarcoma in 12, rhabdomyosarcoma in 4, malignant fibrous histiocytoma in 1 and unclassified sarcoma in 4 patients. At last followup, 8 patients had no evidence of disease after a median of 81.5 months (range 10 to 197). The remaining 13 patients died of sarcoma (median survival 18 months, range 3 to 94). The 1, 3 and 5-year actuarial survival rates for all 21 patients were 81%, 43% and 38%, respectively. Factors predictive of long-term survival were negative surgical margins (p = 0.0005) and absence of metastatic disease at presentation (p = 0.0004). Tumor size and grade, and the histological subtype of prostate sarcoma had no significant influence on actuarial survival. CONCLUSIONS The long-term disease specific survival rate for adults with prostate sarcoma is poor. Early diagnosis and complete surgical resection offer patients the best chance for cure.

Paclitaxel, Cisplatin and Methotrexate Combination Chemotherapy is Active in the Treatment of Refractory Urothelial Malignancies

PURPOSE We investigated the activity of combination chemotherapy consisting of paclitaxel, cisplatin and methotrexate in patients with advanced urothelial cancers. MATERIALS AND METHODS A total of 25 consecutive patients with metastatic refractory urothelial malignancies was treated with a combination of 200 mg./m.2 paclitaxel, 30 mg./m.2 methotrexate and 70 mg./m.2 cisplatin in a pilot study. RESULTS There were no complete responses. Of 25 patients 10 (40%), including 3 of 7 with liver metastases, had a partial response. Hematological and nonhematological toxicity was tolerable. CONCLUSIONS The combination chemotherapeutic regimen of paclitaxel, cisplatin and methotrexate is active in patients with advanced urothelial cancer and warrants further study.

Platelet-Derived Growth Factor Receptor Inhibition and Chemotherapy for Castration-Resistant Prostate Cancer with Bone Metastases

Purpose: To further assess preclinical and early clinical evidence that imatinib mesylate, a platelet-derived growth factor receptor (PDGFR) inhibitor, modulates taxane activity in prostate cancer and bone metastases, a randomized study was conducted. Experimental Design: Men with progressive castration-resistant prostate cancer with bone metastases (n = 144) were planned for equal randomization to i.v. 30 mg/m2 docetaxel on days 1, 8, 15, and 22 every 42 days with 600 mg imatinib daily or placebo, for an improvement in median progression-free survival from 4.5 to 7.5 months (two-sided α = 0.05 and β = 0.20). Secondary end points included differential toxicity and bone turnover markers, tumor phosphorylated PDGFR (p-PDGFR) expression, and modulation of p-PDGFR in peripheral blood leukocytes. Results: Accrual was halted early because of adverse gastrointestinal events. Among 116 evaluable men (57 docetaxel + imatinib; 59 docetaxel + placebo), respective median times to progression were 4.2 months (95% confidence interval, 3.1-7.5) and 4.2 months (95% confidence interval, 3.0-6.8; P = 0.58, log-rank test). Excess grade 3 toxicities (n = 23) in the docetaxel + imatinib group were principally fatigue and gastrointestinal. Tumor p-PDGFR expression was observed in 12 of 14 (86%) evaluable bone specimens. In peripheral blood leukocytes, p-PDGFR reduction was more likely in docetaxel + imatinib–treated patients compared with docetaxel + placebo (P < 0.0001), as were reductions in urine N-telopeptides (P = 0.004) but not serum bone-specific alkaline phosphatase (P = 0.099). Conclusions: These clinical and translational results question the value of PDGFR inhibition with taxane chemotherapy in prostate cancer bone metastases and are at variance with the preclinical studies. This discordance requires explanation.

Prostate carcinoma with testicular or penile metastases: Clinical, pathologic, and immunohistochemical features

Despite the proximity, prostate carcinoma seldom metastasizes to the penis or testis.