Bo Lennernäs

Bone-targeted radium-223 in symptomatic, hormone-refractory prostate cancer: a randomised, multicentre, placebo-controlled phase II study

BACKGROUND The alpha-emitter radium-223 ((223)Ra) is a bone-seeking radionuclide studied as a new treatment for patients with bone metastases from hormone-refractory prostate cancer. We aimed to study mature outcomes from a randomised, multicentre, phase II study of (223)Ra. METHODS Patients with hormone-refractory prostate cancer and bone pain needing external-beam radiotherapy were assigned to four intravenous injections of (223)Ra (50 kBq/kg, 33 patients) or placebo (31 patients), given every 4 weeks. Primary endpoints were change in bone-alkaline phosphatase (ALP) concentration and time to skeletal-related events (SREs). Secondary endpoints included toxic effects, time to prostate-specific-antigen (PSA) progression, and overall survival. All tests were done at a 5% significance level, based on intention to treat. FINDINGS Median relative change in bone-ALP during treatment was -65.6% (95% CI -69.5 to -57.7) and 9.3% (3.8-60.9) in the (223)Ra group and placebo groups, respectively (p<0.0001, Wilcoxon ranked-sums test). Hazard ratio for time to first SRE, adjusted for baseline covariates, was 1.75 (0.96-3.19, p=0.065, Cox regression). Haematological toxic effects did not differ significantly between two groups. No patient discontinued (223)Ra because of treatment toxicity. Median time to PSA progression was 26 weeks (16-39) versus 8 weeks (4-12; p=0.048) for (223)Ra versus placebo, respectively. Median overall survival was 65.3 weeks (48.7-infinity) for (223)Ra and 46.4 weeks (32.1-77.4) for placebo (p=0.066, log rank). The hazard ratio for overall survival, adjusted for baseline covariates was 2.12 (1.13-3.98, p=0.020, Cox regression). INTERPRETATION (223)Ra was well tolerated with minimum myelotoxicity, and had a significant effect on bone-ALP concentrations. Larger clinical trials are warranted to study (223)Ra on the prevention of SREs and on overall survival in patients with hormone-refractory prostate cancer. Bone-targeting properties of (223)Ra could also potentially be used for treating skeletal metastasis from other primary cancers.

The anti-tumour effect of low-dose continuous chemotherapy may partly be mediated by thrombospondin

Background: Tumour growth is dependent on angiogenesis. Antiangiogenic chemotherapy, i.e. continuous or metronomic low-dose chemotherapy, is a method for administrating cytostatics at a low and well-tolerated concentration without prolonged breaks. The target is the genetically stable endothelial cells playing a pivotal role in angiogenesis within the tumour. Different mediators could mediate the antiangiogenic effect of metronomic chemotherapy. One of these mediators could be thrombospondin (TSP). TSP is a potent inhibitor of angiogenesis and might therefore be important in controlling tumour growth. This study was designed to evaluate the effects of low-dose continuous or moderate-dose bolus chemotherapy on tumour growth and on tumour expression of TSP. Materials and methods: Rats bearing a malignant prostate tumour (Dunning AT-1) not expressing TSP were treated systemically with cyclophosphamide, doxorubicin or paclitaxel and the combination of cyclophosphamide and doxorubicin. Tumour growth and body weight were measured during the treatment. CD36, one of TSP’s main receptors, was also analysed. The expression pattern of TSP-1, TSP-2 and CD36 was investigated using immunohistochemistry and Western blot analyses. Q-PCR was used to analyse TSP-1 mRNA expression. Results: Low-dose cyclophosphamide and paclitaxel re-induced the expression of TSP in the tumours. However, following a bolus dose of doxorubicin, tumours showed no expression of TSP. Both cyclophosphamide and doxorubicin treatments decreased the tumour weight by more than 60% compared with vehicle controls. When cyclophosphamide and doxorubicin were combined the tumour weight was reduced by 47%, while paclitaxel reduced the tumour weight by 18% compared to the vehicle controls. Conclusions: Systemic low-dose continuous treatment of a rat prostate cancer model with cyclophosphamide and paclitaxel induced the expression of TSP in tumour tissue and inhibited tumour growth. These findings support the hypothesis that the anti-tumour effect of low-dose metronomic chemotherapy, at least with certain chemotherapeutics, is partly mediated by induction of endogenous antiangiogenic factors.

Two-Year Survival Follow-Up of the Randomized, Double-Blind, Placebo-Controlled Phase II Study of Radium-223 Chloride in Patients With Castration-Resistant Prostate Cancer and Bone Metastases

BACKGROUND This phase II randomized, placebo-controlled study was conducted to evaluate efficacy and safety of radium-223 in patients with castration-resistant prostate cancer (CRPC) and painful bone metastases. Twelve- and 18-month survival results were reported previously. Here we report 24-month overall survival (OS) and safety data from the period 12 to 24 months after the first injection of study medication. METHODS Patients with CRPC and bone pain were randomized 1:1 to receive 4 injections of radium-223 (50 kBq/kg [n = 33]) or placebo (n = 31) after external-beam radiotherapy; each injection was given every 4 weeks. Endpoints for this report were 24-month OS, long-term safety, and treatment-related adverse events (AEs) occurring in the 12- to 24-month period. RESULTS After 24 months, 10 (30%) patients were alive in the radium-223 group compared with 4 patients (13%) in the placebo group. Patients who received at least 1 dose of study medication had a median OS of 65 weeks in the radium-223 group vs. 46 weeks in the placebo group (log-rank P = .056). The hazard ratio (HR) for OS, adjusted for baseline covariates, was 0.476 (95% confidence interval [CI], 0.258-0.877; Cox regression P = .017). The most frequent cause of death for both arms was disease progression. There were no reports of treatment-related AEs or long-term hematologic toxicity during the 12- to 24-month follow-up. CONCLUSION Radium-223 had a highly favorable safety profile, with no evidence of second malignancies at 24-month follow-up. The significant improvement in OS observed in patients receiving radium-223 vs. placebo suggests that treatment of bone disease with radium-223 has survival benefits.

Additive/synergistic antitumoral effects on prostate cancer cells in vitro following treatment with a combination of docetaxel and zoledronic acid

Once bone metastasized and androgen independent, prostate cancer is often associated with skeletal morbidity and disability. New treatment modalities that can palliate symptoms from the skeleton and inhibit further progression are warranted. In this study, the antitumoral effects following treatment with a combination of docetaxel and the new generation bisphosphonate, zoledronic acid, were investigated on two hormone-refractory prostate cancer cell lines: PC3 and DU145. The prostate cancer cells were treated with increasing concentrations of zoledronic acid in the absence or presence of docetaxel. Toxicity was measured using fluorometric microculture cytotoxic assay technique. A concentration of 25 µM, zoledronic acid reduced the viable cell number to 68% and 98% for PC3 and DU145 cells respectively. Docetaxel, on the other hand, at a concentration of 0.1 ng/ml, had no effect on the viability. However, a combination of zoledronic acid and docetaxel reduced the cell number to 60% and 81% respectively. Furthermore, zoledronic acid in the concentration range 12.5 µM–50 µM enhanced the antitumoral effects of docetaxel (0.01–1 ng/ml) in an additive and/or synergistic manner for both cell lines. These data support the hypothesis that zoledronic acid, in addition to having bone resorption inhibiting properties, also exhibits anti-tumoral effects. It also appears that combined treatment with docetaxel causes additive and/or synergistic cytostatic effects on prostate cancer cells.

Comparative treatment planning between proton and X-ray therapy in esophageal cancer

PURPOSE Conformal treatment planning with megavoltage x-rays and protons for five patients with esophageal cancer has been studied in an attempt to determine if there are advantages of using protons instead of x-rays. METHODS AND MATERIALS For each of the five patients, two different proton plans, one x-ray plan, and one mixed plan with x-rays and protons were made. A three-dimensional treatment planning system, TMS, was used. The evaluation of the different plans was made by applying the tumor control probability (TCP) model proposed by Nahum and Webb and the normal tissue complication (NTCP) model proposed by Lyman on the dose distributions in terms of dose-volume histograms (DVHs). RESULTS The comparison shows advantages of using protons instead of x-rays for all five patients. The dose-limiting organs at risk are the spinal cord, the lungs, and the heart, but the proton plans also spare the kidneys better than the x-ray plan does. At 5% NTCP in any risk organ, the calculated mean TCP value for the five patients is increased by an average of 20%-units (from 2 to 23%-units) with the best proton plan compared with x-rays only. However, if we assume maximally a 1% risk in the spinal cord and a total NTCP for the two lungs of 100%, the mean TCP value for the five patients is increased from 6 to 49% with the best proton plan compared with x-rays only. The corresponding figure for the mixed plan is 27%. These gains are relatively insensitive to variations within reasonable limits in the biological parameters. CONCLUSIONS Protons appear to have clear therapeutic advantages over conventional external radiotherapy when treating esophageal carcinoma.

On metronomic chemotherapy: Modulation of angiogenesis mediated by VEGF-A

Tumors are angiogenesis dependent. Preclinical studies have shown that well-tolerated continuous low dose, i.e. metronomic, chemotherapy can exert significant antiangiogenic effects pe rse and thereby a greater antitumor influence than conventional chemotherapy with high, spaced-out bolus doses. There are however, no means of quantitatively assessing the antiangiogenic effect of chemotherapy in tumors. We therefore used a surrogate tumor-free, non-surgical rat mesentery model and quantitatively studied the dose effect of metronomic treatment with cisplatin, cyclophosphamide, doxorubicin, fluorouracil and paclitaxel on VEGF-A-mediated angiogenesis, a characteristic of tumors. Cyclophosphamide and paclitaxel treatment exerted significant dose-dependent antiangiogenic effects, whereas doxorubicin treatment produced insignificant effects. By contrast, metronomic cisplatin and fluorouracil treatment occasionally significantly stimulated angiogenesis in a dose-dependent, non-linear manner. To our knowledge, this is the first report of metronomic chemotherapy stimulating angiogenesis in vivo. The data suggest that the angiogenic response to cisplatin, cyclophosphamide, fluorouracil and paclitaxel was significantly influenced by the presence of antioxidants in the vehicles or when co-treated with N-acetylcystein, a widely used free-radical scavenger. The data relating to the metronomic scheduling were compared with bolus treatment data for the identical agent formulations in the same experimental model. Cisplatin, cyclophosphamide and paclitaxel caused approximately the same overall, agent-specific angiogenesis-modulating effects following metronomic and bolus treatments. Moreover, apparently secondary delayed effects of chemotherapy affected capillary sprouting.

High precision transponder localization using a novel electromagnetic positioning system in patients with localized prostate cancer

BACKGROUND AND PURPOSE The Micropos 4DRT system is being developed to provide accurate, precise, objective, and continuous target localization during radiotherapy. This study involves the first in vivo use of the system, aiming to evaluate the localization accuracy of this electromagnetic positioning technique compared with radiographic localization and to assess its real-time tracking ability. MATERIAL AND METHODS An active positioning marker was inserted in the prostatic urethra of 10 patients scheduled to receive radiotherapy for localized prostate cancer. A receiving sensor plate (antennae system) was placed at a known position in the treatment tabletop. Initial in vivo system calibrations were performed in three subjects. Ten additional patients were then enrolled in a study arm that compared radiographic transponder location to radiotransponder location simultaneously acquired by the Micropos 4DRT system. Frontal and side radiographs were taken with the radiopaque transponder located at three different positions within the prostatic urethra. RESULTS The transponder insertions were all successful and without complications. Comparison of the transponder location as per the Micropos 4DRT system with the radiographic transponder localization showed an average (+/-SD) absolute and relative 3D difference of 2.7+/-1.2 and 1.7+/-1.0mm, respectively. Continuous transponder tracking capability was also demonstrated. CONCLUSIONS Electromagnetic positioning using the Micropos transponder system is feasible in vivo. Evaluation of this novel non-ionizing localization system, in this study using a transponder positioned in the prostatic urethra, indicates transponder localization accuracy to isocenter comparable with X-ray localization of a radiopaque marker.

Radical prostatectomy versus high-dose irradiation in localized/locally advanced prostate cancer: A Swedish multicenter randomized trial with patient-reported outcomes

Abstract Background. Treatment of localized prostate cancer (PC) is controversial. This is the first randomized study comparing an open surgery procedure (radical prostatectomy) with a combination of high-dose rate brachytherapy (2 × 10 Gy) and external beam radiotherapy (25 × 2 Gy) in PC patients in Sweden 1996–2001. The two randomization arms were compared regarding differences in patients-reported outcomes, such as complications and health-related quality of life (HRQoL). Material and methods. The patients had localized/locally advanced PC, clinical category T1b–T3a, N0, M0 and PSA ≤ 50 ng/ml. All underwent total androgen blockade (six months). Self-reported HRQoL and symptoms including urinary, bowel, and sexual side effects were investigated prospectively before randomization and 12 and 24 months after randomization. A total of 89 patients were randomized and completed the EORTC QLQ C-33 and EORTC PR-25 questionnaires. Results. Over the study period, there were no discernible differences in HRQoL, or complications between the two groups. Emotional functioning, however, improved statistically significantly over time, whereas Social functioning decreased, and financial difficulties increased. No statistically significant differences in group-by-time interactions were found. The survival rate was 76%. Only eight patients (9%) died of PC. Conclusion. Open radical prostatectomy and the combined high-dose rate brachytherapy with external beam radiation appeared to be comparable in the measured outcomes. It was not possible to draw any conclusion on the efficacy of the two treatments due to insufficient power of the study.

Zoledronic acid induces caspase-dependent apoptosis in renal cancer cell lines

Objective. To study and characterize the potential antitumoral effects of zoledronic acid (ZA) on renal cancer cell lines in vitro. Material and methods. Three different and well-characterized renal cancer cell lines were studied, namely ACHN, A-498 and CAKI-2. The cytotoxic potential of ZA was evaluated using a fluorometric microculture cytotoxic assay. The degree of M30 induction following ZA treatment was measured using an M30 enzyme-linked immunosorbent assay (ELISA), and the blockage of this effect was studied using a pan-caspase inhibitor. Immunofluorescence of the M30 neoepitope was performed to visualize the M30-inducing properties of ZA. Results. A significant reduction in viable cells was seen for all three cell lines following treatment with ZA, compared with untreated controls. This effect was most pronounced for the ACHN cells, as only 4% were viable following incubation with ZA for 72 h. A concomitant increase in the apoptosis significant caspase-dependent M30 antigen was demonstrated. This effect could be blocked by the pan-caspase inhibitor Z-VAD. Conclusions. ZA exerts cytotoxic effects on renal cancer cell lines in vitro. These include caspase-dependent induction of apoptosis, which can be quantified and visualized using M30 ELISA and immunofluorescence, respectively. The clinical relevance of this finding needs to be further investigated, but these results indicate that ZA may be a treatment alternative for selected patients with skeletal metastasized renal cell cancer, particularly for those with impaired performance status without other treatment options.

High-Dose Rate Brachytherapy of Prostatic Adenocarcinoma in Combination with External Beam Radiotherapy

Aim: To report the long-term follow-up of 50 patients with prostatic adenocarcinoma (PAC) treated by high-dose rate brachytherapy in combination with external beam radiotherapy. Patients and Methods: Between 1988 and 1995, 50 patients were treated with external beam radiotherapy delivered in 2 Gy fractions to a total dose of 50 Gy. Brachytherapy was delivered in two 10 Gy fractions. The mean follow-up time was 7.2 years. Results: 42 patients are alive and four patients have deceased of prostatic adenocarcinoma. Of the remaining patients, 40 have a PSA < 1 ng/l. 41 patients were interviewed during the year 2000 and 91% of these were satisfied with the treatment. Four (8%) patients reported grade III/IV side effects. Ten of the 41 patients reported that they still had an erection allowing intercourse. Half of those who developed an erectile dysfunction did so in direct connection with the treatment. In the others erectile dysfunction developed gradually during the first 48 months after the treatment. Conclusion: The combined treatment gave an exceptionally good local control (86%). The method represents a promising curative treatment, but the effect can be double edged. The small number of patients in this study restricts a more conclusive statement concerning this treatment modality.Ziel: Monoinstitutioneller Erfahrungsbericht zur Behandlung des Prostatakarzinoms mit kombinierter externer und HDR-Brachytherapie. Patienten und Methoden: Von 1988 bis 1995 wurden 50 Patienten mit einem Prostataadenokarzinom kombiniert extern und interstitiell behandelt. Die perkutane Radiotherapie erfolgte bei einer Einzeldosis von 2 Gy bis zu einer Gesamtreferenzdosis von 50 Gy. Die Brachytherapie folgte mittels zweier HDR-Fraktionen von je 10 Gy. Die mediane Nachbeobachtungszeit betrug 7,2 Jahre. Ergebnisse: 42 Patienten sind am Leben, vier starben am Prostataadenokarzinom. Von den überlebenden Patienten haben 40 einen PSA-Wert < 1 ng/l. 41 Patienten wurden während des Jahres 2000 interviewt, 91% waren mit der Behandlung zufrieden. Vier Patienten (8%) berichteten über Grad-3- bis -4-Nebenwirkungen. Zehn der 41 Patienten hatten keine erektile Dysfunktion: Bei der Hälfte derjenigen, die über eine erektile Dysfunktion klagten, stand diese in direktem Zusammenhang mit der Behandlung. Bei den anderen entwickelte sich die Dysfunktion während der ersten 48 Monate nach Behandlung. Schlussfolgerung: Die kombinierte Behandlung war mit einer hervorragenden lokalen Kontrolle (86%) verbunden. Die Behandlung stellt somit eine viel versprechende kurative Option dar, die bislang niedrige Patientenzahl lässt jedoch definitive Schlussfolgerungen noch nicht zu.