Suramin: a novel growth factor antagonist with activity in hormone-refractory metastatic prostate cancer.

PURPOSE: Suramin is known to inhibit the growth of malignant prostate carcinoma cells in vitro. This led us to evaluate the effectiveness of suramin in the treatment of 38 patients with prostate carcinoma refractory to hormone therapy. PATIENTS AND METHODS: Suramin was administered by continuous infusion at a rate designed to reach a peak of 300 micrograms/mL at the end of 14 days. Patients were given 8 weeks to recover from any toxicity before beginning the second cycle. Subsequent cycles were administered in the same manner except the starting dose rate was 280 mg/m2. RESULTS: In 17 patients with measurable soft tissue disease, three had complete disappearance of soft tissue disease for 4, 5, and 11 months, whereas three patients had a greater than or equal to 50% decrease in the sum of the products of the diameters of all measurable disease for greater than or equal to 1 month. Of these 17 patients, pretreatment prostate-specific antigen (PSA) decreased by 75% or more in five (29%) and normalized in one (6%). The remaining 21 patients had disease limited to bone, and only one of these experienced resolution of more than 50% of all lesions on bone scan. Of these 21 patients, pretreatment PSA decreased by 75% or more in eight (38%) and normalized in five (25%). Median time to progression for all patients was 26.3 weeks, and median survival was 42.3 weeks. Patients with bone involvement alone exhibited a better survival than patients with soft tissue involvement (P2 = .02). Survival was strongly correlated (P2 = .0001) with a decline in the pretreatment PSA of greater than or equal to 75% by the eighth week on therapy, with nearly an 85% survival at 1 year compared with a 20% survival for those whose pretreatment PSA did not decline by that amount. CONCLUSION: We conclude that suramin is an active agent in hormone-refractory prostate carcinoma.

High-dose toremifene as a cisplatin modulator in metastatic non-small cell lung cancer: targeted plasma levels are achievable clinically.

PURPOSE: The triphenylethylenes tamoxifen and toremifene have been reported to enhance the cytotoxicity of cisplatin by inhibition of protein kinase C (PKC) signal transduction pathways. However, the concentrations of tamoxifen and toremifene required for chemosensitization in preclinical models are generally > or =5 microM, at least tenfold higher than plasma levels observed in patients receiving these agents as antiestrogenic therapy. As part of a translational phase II trial investigating the efficacy and potential molecular mechanism of high-dose toremifene as a cisplatin modulator in metastatic non-small-cell lung cancer, plasma concentrations of toremifene and its active metabolite N-desmethyltoremifene were measured to determine whether targeted levels could be achieved clinically. METHODS: Treatment consisted of toremifene, 600 mg orally on days 1-7, and cisplatin, 50 mg/m2 intravenously on days 4 and 11, repeated every 28 days. Toremifene and N-desmethyltoremifene were measured by reverse-phase HPLC assay on days 4 and 11 prior to cisplatin infusion. RESULTS: In the initial 14 patients, the mean total plasma concentrations of toremifene plus its N-desmethyl metabolite on days 4 and 11 were 14.04 (+/- 8.6) microM and 9.8 (+/- 4.4) microM, respectively. Variability in concentrations achieved did not correlate with renal or hepatic function, gender, or body surface area. Levels of N-desmethyltoremifene were higher on day 11 relative to toremifene concentrations. CONCLUSIONS: We conclude that plasma levels achieved compare favorably with the levels required for cisplatin chemosensitization and PKC modulation in vitro. Targeted toremifene levels can be achieved clinically with 600 mg orally daily in combination with cisplatin and are well tolerated.

Use of suramin in treatment of prostatic carcinoma refractory to conventional hormonal manipulation.

Suramin and related compounds, in view of their growth factor and enzyme binding properties, represent in many respects a novel approach to the treatment of cancer. Although in this preliminary analysis of suramin use in the treatment of metastatic prostate cancer, the objective response rate does not appear impressive, much work still needs to be done to optimize suramin's administration to patients and to elucidate its various postulated mechanisms of action. The development of related compounds with more specific enzyme and growth factor antagonist properties is under way.

Assessment of fatigue, monitor placement, and surgical experience during simulated laparoscopic surgery.

BACKGROUND: Laparoscopic surgery requires the surgeon to assume atypical postures for extended periods of time, potentially leading to fatigue and chronic injury. This study assessed the level of muscle activity and compared the effects of fatigue, monitor placement, and surgical experience during simulated laparoscopic surgery. METHODS: Four attending and four resident surgeons repeated a series of four tasks with a View site and a standard operating room monitor. Electromyography (EMG) activity and muscular discomfort scores were obtained before and after a "fatigue session." Two variables, the EMG amplitudes and discomfort scores, were analyzed. RESULTS: The EMG amplitudes generally exceed the recommended threshold limits of acceptable muscular load. EMG data and discomfort scores demonstrated a fatigue response in several muscle groups. Minimal differences between the two monitor positions were seen. Overall, the EMG data and discomfort scores showed less muscle activity and discomfort in the attending surgeons. CONCLUSION: Laparoscopic surgery required a relatively high muscular load, putting surgeons at risk for fatigue and injury. Altering the monitor placement did not reduce the surgeon's risk of fatigue. Experience slightly reduced the level of fatigue, but not enough to reduce the surgeon's risk category.

Preoperative gait comparisons between adults undergoing long spinal deformity fusion surgery (thoracic to L4, L5, or sacrum) and controls.

STUDY DESIGN: This investigation compared the gait of revision and primary spinal deformity patients about to undergo surgical reconstruction with that of a group of able-bodied controls. OBJECTIVES: The hypothesis of the study was that both patient groups would have significantly compromised gait, spine motion, and gait endurance compared with the able-bodied group. SUMMARY OF BACKGROUND DATA: There is a population of adults with degenerative changes superimposed on idiopathic scoliosis who present for reconstructive spinal surgery (primary patients). There is another group of adults who have already had spinal deformity surgery and present for revision surgery (revision patients). METHODS: Twenty-seven women were recruited (8 primary, 13 revision, 6 able-bodied controls). A typical gait analysis was performed. Walking endurance was estimated from a submaximal graded treadmill exercise test. Three motion variables describing the orientation of the shoulders with respect to the pelvis in the three principal planes of the body were determined. Also, gait speed, stride length, cadence, and step width were calculated. The variable for the endurance test was the length of time walked on the treadmill. RESULTS: Results for the revision group indicated a slower walking speed, greater sagittal plane trunk flexion, reduced range of motion in the coronal and transverse planes, and poorer endurance relative to age-matched controls. The primary group demonstrated a slower walking speed relative to age-matched controls. The revision group had poorer endurance scores relative to the primary group. CONCLUSION: This investigation is an objective report describing the compromised gait and walking endurance of adult patients with spinal deformity before spinal fusion surgery. Results supported subjective observations regarding the preoperative gait of these patients and presented results difficult to observe in a clinical setting. The techniques appear useful in providing objective information regarding the gait abilities of these patients.

A pilot study of suramin in the treatment of metastatic renal cell carcinoma.

Suramin sodium is an aromatic polysulfonated compound that was originally introduced as an antiparasitic agent in the 1920s. Recently, in view of its ability to bind and disrupt the function of multiple growth factors and cellular enzyme systems, the authors have been evaluating the role of suramin as an antitumor agent. In this study, 12 patients with metastatic renal cell carcinoma received parenteral suramin by continuous infusion to a peak plasma suramin level greater than 200 micrograms/ml. No objective radiographic responses were observed, although greater than 90% necrosis of multiple tumor sites was documented at autopsy in one patient and normalization of tumor-related hypercalcemia occurred in another patient. Two patients had stable disease of 10 and 28 weeks' duration, respectively. Significant toxicities included hypotension related to sepsis and resulting in renal insufficiency (one patient), development of liver function abnormalities (one patient) marked thrombocytopenia (one patient), prothrombin time prolongation (all patients), vortex keratopathy (two patients), and Grade 1 sensory neuropathy (two patients). On the basis of the current results, suramin does not appear to be an active single agent against metastatic renal cell carcinoma when administered by this dosing schedule.

Serotonergic blockade in the treatment of the cancer anorexia-cachexia syndrome.

BACKGROUND: Imbalanced amino acid diets in animals rapidly produce anorexia and weight loss. Blockade of type 3 serotonergic receptors (5HT(3)) can ameliorate anorexia in this animal model. Imbalanced plasma amino acid levels also have been documented in both animal models and human patients with cancer cachexia. Therefore a trial of the 5HT(3) receptor antagonist, ondansetron, was undertaken in the treatment of patients with cancer cachexia. METHODS: Patients with metastatic cancer who were not undergoing chemotherapy or radiotherapy and who had lost >5% of their body weight were eligible. Baseline physical examination; weight; anthropometric studies; levels of retinol binding protein, albumin, and prealbumin; and skin testing for anergy were obtained. The ability to enjoy food was assessed utilizing a seven-point hedonic category scale for specific foods. Therapy was comprised of oral ondansetron, 8 mg twice a day. RESULTS: Twenty-seven patients were enrolled; all were evaluable for toxicity and 20 patients were evaluable for response. Toxicity of ondansetron was minimal. Patients demonstrated significant weight loss prior to disease entry (mean baseline weight of 76.9 kg vs. 72. 1 kg; P < 0.000002). Patients continued to lose weight on study (Week 0: 72.5 kg vs. Week 4: 71.4 kg; P = 0.027); in addition, there was significant deterioration of midarm circumference and hand grip strength, all of which indicated worsening nutritional status. However, a significant improvement in food enjoyment was noted (P = 0.04). CONCLUSIONS: Although it apparently improved the ability of patients to enjoy food, the blockade of 5HT(3) receptors failed to prevent weight loss in patients with cancer cachexia or alter laboratory parameters of protein nutrition.

Phase I trial of edatrexate plus carboplatin in advanced solid tumors: amelioration of dose-limiting mucositis by ice chip cryotherapy.

PURPOSE: Edatrexate (10-Edam) is a methotrexate analog with improved intracellular transport, polyglutamation, and antitumor activity compared to the parent compound. Edatrexate shows schedule-dependent synergism with platinum compounds in preclinical studies. We performed a phase I trial to determine toxicities and establish the maximum tolerated dose (MTD) of edatrexate in combination with carboplatin. Based on the short initial plasma half-life of edatrexate, prophylactic ice chip cryotherapy was used to reduce the severity of mucositis. PATIENTS AND METHODS: Forty-six chemotherapy-naive patients with advanced solid tumors were treated. Edatrexate was given weekly for 5 doses (50% on day 8), and then every other week, followed by carboplatin at a fixed dose of 350 mg/m2 on day 1 and then every 4 weeks for 8 cycles. Edatrexate dose was increased at increments of 10 mg/m2/dose level beginning at 60 mg/m2/week (range 60-120 mg/m2). RESULTS: All patients were assessable for toxicity and response analysis. The median number of cycles administered per patients was 4. This combination chemotherapy regimen was well tolerated. Using ice chip cryotherapy, no grade IV mucositis was observed. Grade III mucositis occurred in only 7/46 pts and was not dose-related. Protocol-defined dose-limiting toxicity occurred at a edatrexate dose level of 120 mg/m2, yielding an MTD of 110 mg/m2. Responding tumor types included non-small cell and small lung cancer, head and neck cancer, and bladder cancer. CONCLUSIONS: 1 ) This phase I study demonstrated the safety and tolerability of this edatrexate and carboplatin combination. 2) Dose-limiting mucositis did not occur allowing escalation of edatrexate dose above levels previously achieved with this edatrexate dose schedule. This was most likely a result of prophylactic ice chip cryotherapy. 3) An edatrexate dose of 110 mg/m2 with ice chip cryotherapy is recommended for Phase II trials of this combination.

A pilot study of suramin in the treatment of progressive refractory follicular lymphomas.

Ten patients with progressive follicular lymphomas (seven with follicular mixed lymphomas, three with follicular, small cleaved cell lymphomas) with clinical indications for systemic therapy received parenteral suramin. Each had failed from one to six prior chemotherapeutic regimens and three had in addition received prior radiation therapy. All had measurable disease and nine of the ten had documented bone marrow involvement at the start of therapy. Suramin was administered at an initial infusion rate of 350 mg/m2/day, which was then modified on the basis of subsequent weekly plasma suramin concentrations in order to reach a final plasma concentrations of 250-350 micrograms/ml. Treatment cycles were repeated at eight week intervals. Nine of ten patients are evaluable for response. Five of nine evaluable patients achieved a partial remission as defined by a greater than 50% decrease in the sum of the product of all measurable lesions. Sites of response include: Peripheral (five patients) and central (four patients) adenopathy, disappearance of biopsy-proven skin involvement (one patient), malignant pleural effusions (one patient) and shrinkage of an enlarged spleen (two patients). Disappearance of B symptoms occurred in the one responder with these symptoms. Response duration varied from 3 to 9 months (mean 5.6 months) with time to subsequent systemic therapy varying from 5 to 12 months (mean 8 months). Drug related toxicity included the development of polyradiculopathy (one case), liver function abnormalities (three cases), thrombocytopenia (five cases), vortex keratopathy (two cases) and bacterial infection (two cases). We conclude that suramin has significant activity against follicular lymphomas refractory to standard chemotherapy and that its precise role in the treatment of lymphoproliferative neoplasms in general warrants further investigation.