Combination hormonal therapy: a reassessment within advanced prostate cancer

Treatment pathways of Japanese prostate cancer patients - A retrospective transition analysis with administrative data

BACKGROUND

Limited availability of real-world data that describe treatment patterns of Japanese prostate cancer (PCA) patients.

METHODS

A biweekly transition analysis of PCA treatment was performed for patients with PCA diagnosis and a specific treatment between 2010 and 2015. To account for different cancer stages, two patient populations were analyzed. The first group consisted of patients on medication for hormone-sensitive prostate cancer (HSPC). The second group is comprised of patients who ended up receiving specific therapy for castration-resistant prostate cancer (CRPC). For each treatment, the average of treatment duration and the portion of patients transitioning to a consecutive treatment was calculated.

RESULTS

We identified 59,626 patients from the Japanese administrative database with a PCA diagnosis and specific treatment. In the first year of our observational study 786 patients commenced a HSPC treatment and 695 received a CRPC specific therapy Among the HSPC group, we found that combination hormonal therapy, comprised of a gonadotrophin releasing hormone agonist or antagonist with an antiandrogen was more common than monotherapy. The results of the CRPC group indicated that chemotherapy administration was for a shorter time period in a real-world setting as compared to published clinical studies.

CONCLUSION

Utilizing a novel method to visualize real-world treatment pathways for PCA patients we found that real treatment pathways are in line with international guidelines.

Anti-cancer effect of bee venom in prostate cancer cells through activation of caspase pathway via inactivation of NF-κB

BACKGROUND

Bee venom has been used as a traditional medicine to treat arthritis, rheumatism, back pain, cancerous tumors, and skin diseases. However, the effects of bee venom on the prostate cancer and their action mechanisms have not been reported yet.

METHODS

To determine the effect of bee venom and its major component, melittin on the prostate cancer cells, apoptosis is analyzed by tunnel assay and apoptotic gene expression. For xenograft studies, bee venom was administrated intraperitoneally twice per week for 4 weeks, and the tumor growth was measured and the tumor were analyzed by immunohistochemistry. To investigate whether bee venom and melittin can inactivate nuclear factor kappa B (NF-κB), we assessed NF-κB activity in vitro and in vivo.

RESULTS AND CONCLUSIONS

Bee venom (1-10 µg/ml) and melittin (0.5-2.5 µg/ml) inhibited cancer cell growth through induction of apoptotic cell death in LNCaP, DU145, and PC-3 human prostate cancer cells. These effects were mediated by the suppression of constitutively activated NF-κB. Bee venom and melittin decreased anti-apoptotic proteins but induced pro-apoptotic proteins. However, pan caspase inhibitor abolished bee venom and melittin-induced apoptotic cell death and NF-κB inactivation. Bee venom (3-6 mg/kg) administration to nude mice implanted with PC-3 cells resulted in inhibition of tumor growth and activity of NF-κB accompanied with apoptotic cell death. Therefore, these results indicated that bee venom and melittin could inhibit prostate cancer in in vitro and in vivo, and these effects may be related to NF-κB/caspase signal mediated induction of apoptotic cell death.

Androgen receptor abnormalities in castration-recurrent prostate cancer

The androgen receptor (AR) plays a critical role in prostate cancer (PCa) development and progression. Despite the success of androgen-deprivation therapy, remission occurs in almost all cases. This stage of the disease is called castration-recurrent PCa (CRPC). CRPC cells adapt to low circulating levels of androgens, and active AR is maintained by numerous cellular mechanisms. Some mutations in the AR make it more responsive to lower androgen levels or other steroids. Furthermore, in this advance stage of the disease, PCa cells express the enzymes necessary for de novo synthesis of androgens. AR is also activated in a ligand-independent manner. Therefore, it is important to understand the mechanisms of AR activation and its deregulation during CRPC. The purpose of this article is to discuss mechanisms that are involved in modulation of AR activity and specificity.

The efficacy and safety of degarelix: a 12-month, comparative, randomized, open-label, parallel-group phase III study in patients with prostate cancer

OBJECTIVE

To evaluate the efficacy and safety of degarelix, a new gonadotrophin-releasing hormone (GnRH) antagonist (blocker), vs leuprolide for achieving and maintaining testosterone suppression in a 1-year phase III trial involving patients with prostate cancer.

PATIENTS AND METHODS

In all, 610 patients with adenocarcinoma of the prostate (any stage; median age 72 years; median testosterone 3.93 ng/mL, median prostate-specific antigen, PSA, level 19.0 ng/mL) were randomized and received study treatment. Androgen-deprivation therapy was indicated (neoadjuvant hormonal treatment was excluded) according to the investigator's assessment. Three dosing regimens were evaluated: a starting dose of 240 mg of degarelix subcutaneous (s.c.) for 1 month, followed by s.c. maintenance doses of 80 mg or 160 mg monthly, or intramuscular (i.m.) leuprolide doses of 7.5 mg monthly. Therapy was maintained for the 12-month study. Both the intent-to-treat (ITT) and per protocol populations were analysed.

RESULTS

The primary endpoint of the trial was suppression of testosterone to <or=0.5 ng/mL at all monthly measurements from day 28 to day 364, thus defining the treatment response. This was achieved by 97.2%, 98.3% and 96.4% of patients in the degarelix 240/80 mg, degarelix 240/160 mg and leuprolide groups, respectively (ITT population). At 3 days after starting treatment, testosterone levels were <or=0.5 ng/mL in 96.1% and 95.5% of patients in the degarelix 240/80 mg and 240/160 mg groups, respectively, and in none in the leuprolide group. The median PSA levels at 14 and 28 days were significantly lower in the degarelix groups than in the leuprolide group (P < 0.001). The hormonal side-effect profiles of the three treatment groups were similar to previously reported effects for androgen-deprivation therapy. The s.c. degarelix injection was associated with a higher rate of injection-site reactions than with the i.m. leuprolide injection (40% vs <1%; P < 0.001, respectively). There were additional differences between the degarelix and leuprolide groups for urinary tract infections (3% vs 9%. P < 0.01, respectively), arthralgia (4% vs 9%, P < 0.05, respectively) and chills (4% vs 0%, P < 0.01, respectively). There were no systemic allergic reactions.

CONCLUSIONS

Degarelix was not inferior to leuprolide at maintaining low testosterone levels over a 1-year treatment period. Degarelix induced testosterone and PSA suppression significantly faster than leuprolide; PSA suppression was also maintained throughout the study. Degarelix represents an effective therapy for inducing and maintaining androgen deprivation for up to 1 year in patients with prostate cancer, and has a different mechanism of action from traditional GnRH agonists. Its immediate onset of action achieves a more rapid suppression of testosterone and PSA than leuprolide. Furthermore, there is no need for antiandrogen supplements to prevent the possibility of clinical 'flare'.

Optimal treatment of intermediate-risk prostate carcinoma with radiotherapy

The clinical heterogeneity of intermediate-risk prostate carcinoma presents a challenge to urologic oncology in terms of prognosis and management. There is controversy regarding whether patients with intermediate-risk prostate carcinoma should be treated with dose-escalated external beam radiotherapy (EBRT) (e.g., doses > 74 gray [Gy]), or conventional-dose EBRT (e.g., doses < 74 Gy) combined with androgen deprivation (AD). Data for this review were identified through searches for articles in MEDLINE and in conference proceedings, indexed from 1966 to 2004. Currently, the intermediate-risk prostate carcinoma grouping is defined on the basis of prostate-specific antigen (PSA), tumor classification (T classification), and Gleason score. Emerging evidence suggests that additional prognostic information may be derived from the percentage of positive core needle biopsies at the time of diagnosis and/or from the pretreatment PSA doubling time. Novel prognostic biomarkers include protein expression relating to cell cycle control, cell death, DNA repair, and intracellular signal transduction. Preclinical data support dose escalation or combined AD with radiation as a means to increase prostate carcinoma cell kill. There is Level I evidence that patients with intermediate-risk prostate carcinoma benefit from dose-escalated EBRT or AD plus conventional-dose EBRT. However, clinical evidence is lacking to support the uniform use of AD plus dose-escalated EBRT. Patients in the intermediate-risk group should be entered into well designed, randomized clinical trials of dose-escalated EBRT and AD with sufficient power to address biochemical failure and cause-specific survival endpoints. These studies should be stratified by novel prognostic markers and accompanied by strong translational endpoints to address clinical heterogeneity and to allow for individualized treatment.