Selecting treatment for high-risk, localized prostate cancer: the case for radiation therapy

Prostate cancers that clinically appear to be localized may nonetheless respond poorly to curative treatment. Pretreatment prostate-specific antigen (PSA) level, biopsy Gleason score, and percentage of positive biopsies are all at least as important as clinical stage in predicting treatment outcome. A patient with a nonpalpable tumor, stage T1c disease, serum PSA of 12 ng/mL, and a Gleason score of 8 to 10 in 2 of 12 biopsy cores has a relatively poor prognosis. In a high-risk patient such as this one, the recommended treatment strategy involves a combination of brachytherapy and conformal external beam radiotherapy. In studies comparing treatments in patients stratified according to a variety of risk measures, this combination has shown biochemical disease-free survival rates superior to those seen following radical prostatectomy. The role of androgen suppression remains unclear.     

Selecting candidates for radical prostatectomy

Men with clinically localized prostate cancer and their physicians are faced with the management decision of radical prostatectomy, radiation therapy, or watchful waiting. Who is the best candidate for radical prostatectomy? Is cure the only relevant outcomes parameter? Does age make a difference? Are imaging studies necessary? This review provides answers, step-by-step, in the decision-making process.     

Biochemical failure and toxicity in treatment with brachytherapy and external beam radiotherapy compared with radical prostatectomy in localized prostate cancer

BackgroundLocalized prostate cancer (T1–3N0M0) has therapeutic options such as radical prostatectomy (RP), external beam radiation therapy (EBRT) and brachytherapy (BT). However, the evidence of the outcome of these treatments is limited and no studies have been conducted comparing biochemical failure (BF) and toxicity associated with surgical treatment and EBRT + high-dose brachytherapy (HDBT) in the region.Materials and methodsRetrospective cohort study, clinical records of patients diagnosed with localized prostate cancer between 2014 and 2018 were reviewed at one of the main private neoplasm centers in Lima, Peru; Cox regression was used for both the BF outcome and the grade 2 toxicity outcome, calculating the hazard ratio (HR) with 95% confodence interval (CI).ResultsOf 549 patients, 76.3% (419) received RP as primary treatment, and 72% were between 50 and 70 years old at the time of diagnosis. The patients treated with EBRT + HDBT presented worse characteristics. The EBRT + HDBT group had a 40% lower risk of presenting BF (HR = 0.6; 95% CI: 0.4–0.9), and also a 50% greater risk of presenting toxicity greater than or equal to grade 2 (HR = 1.5; 95% CI: 1.0–2.0) than the group treated with RP.ConclusionOur results show that when comparing patients treated with EBRT + HDBT and RP, BF was greater in RP, and post-treatment toxicity was greater in EBRT + HDBT.     

Finding of no tumor (pT0) in patients undergoing radical retropubic prostatectomy for clinically localized prostate cancer

OBJECTIVE: To evaluate features and clinical outcome of patients with clinically localized prostate cancer graded pT0 following radical retropubic prostatectomy (RRP). STUDY DESIGN: Between 1974 and 2001 we performed 1,135 RRPs for cT1-T2 prostate cancer, of which 386 (34%) underwent 3-6 months of neoadjuvant endocrine treatment (NHT) before RRP. Median clinical follow-up was 53.8 months (range 24-251). Estimation of likelihood events for biochemical relapse was calculated according to the Kaplan-Meier method. Statistical differences between curves were calculated using the log-rank test. RESULTS: In 24 cases (2.12%) routine histologic workup failed to detect residual tumor. The pT0 group contained a higher proportion of cTla-b patients and a biopsy Gleason score < or =6. A tendency toward lower pre-operatory PSA levels in the pT0 group compared to the pT2-3 group was shown. PSA progression was observed in 3 pT0 patients, all of whom previously underwent NHT. CONCLUSION: Patients pT0 at RRP presented with lower preoperative PSA values and low preoperative Gleason score compared to the pT+ group. Absence of tumor at pathology examination has a different clinical meaning when it occurs following NHT or in untreated patients. Patients pT0 after NHT may have a worse clinical outcome than pT0 untreated patients.     

Androgen deprivation therapy in combination with radiotherapy for high-risk clinically localized prostate cancer

Androgen deprivation therapy (ADT) has remained the main therapeutic option for patients with advanced prostate cancer (PCa) for about 70 years. Several reports and our findings revealed that aggressive PCa can occur under a low dihydrotestosterone (DHT) level environment where the PCa of a low malignancy with high DHT dependency cannot easily occur. Low DHT levels in the prostate with aggressive PCa are probably sufficient to propagate the growth of the tumor, and the prostate with aggressive PCa can produce androgens from the adrenal precursors more autonomously than that with non-aggressive PCa does under the low testosterone environment with testicular suppression. In patients treated with ADT the pituitary-adrenal axis mediated by adrenocorticotropic hormone has a central role in the regulation of androgen synthesis. Several experimental studies have confirmed the potential benefits from the combination of ADT with radiotherapy (RT). A combination of external RT with short-term ADT is recommended based on the results of phase III randomized trials. In contrast, the combination of RT plus 6 months of ADT provides inferior survival as compared with RT plus 3 years of ADT in the treatment of locally advanced PCa. Notably, randomized trials included patients with diverse risk groups treated with older RT modalities, a variety of ADT scheduling and duration and, importantly, suboptimal RT doses. The use of ADT with higher doses of RT or newer RT modalities has to be properly assessed.     

Changes in prostate cancer at radical prostatectomy during the prostate specific antigen era: an Italian experience

OBJECTIVE: To assess changes in prostate cancer clinical and pathologic features by review of 15 years' experience with radical prostatectomy. STUDY DESIGN: A total of 596 consecutive patients who underwent open or laparoscopic radical prostatectomy (RP) between 1991 and 2006 were included. All had clinically localized prostate cancer. Surgical specimens were analyzed or blindly reviewed by a uropathologist, and whole-mount sections were prepared. Statistical analysis evaluated whether significant changes in clinical and pathologic variables occurred over time. RESULTS: Median prostate specific antigen (PSA) values at diagnosis significantly decreased over time. Definite stage migration was observed, with significant increase of organ-confined tumors. Incidence of seminal vesicle and lymph node involvement declined steadily. Median tumor volume decreased significantly over time (p<0.001). Incidence of nonsignificant cancers at RP increased significantly, reaching 25.6% in 2006. PSA value has progressively lost correlation with prostate cancer volume and today correlates only with prostate gland volume. CONCLUSION: Prostate cancer stage and volume at diagnosis have steadily decreased in the last 15 years, likely reflecting increasing use of PSA testing. In early prostate cancer, PSA level no longer correlates with tumor volume.     

A new paradigm for the treatment of high-risk prostate cancer: radiosensitization with docetaxel

Survival and biochemical outcome of patients with localized, high-risk prostate cancer treated with definitive three-dimensional conformal radiation therapy (3-D CRT) with or without hormonal therapy are poor. Other therapeutic strategies are needed to improve outcome in these poor-prognostic-group patients. One such strategy involves the use of chemotherapeutic agents to radiosensitize the effects of local 3-D CRT. Very few investigators have tested this novel concept of chemotherapeutic radiosensitization. Two studies evaluated the combination of estramustine phosphate and vinblastine (EV) with radiation therapy (RT). In both studies, the combination of EV and RT resulted in moderate to severe acute and late toxicity. A recently completed, phase I trial evaluated the maximally tolerated dose (MTD) of weekly docetaxel that could be concurrently delivered with 3-D CRT (70.2 Gy) in men with high-risk prostate cancer. The MTD of concurrent weekly docetaxel with 3-D CRT was determined to be 20 mg/m(2), and this combination was shown to be safe and well tolerated. This was the first trial to evaluate taxane radiosensitization in prostate cancer. Other phase I/II studies are needed to further assess chemotherapeutic radiosensitization in localized, high-risk prostate cancer.     

Therapeutic strategies for localized prostate cancer

Prostate-specific antigen determinations for prostate cancer screening have led to a dramatic increase in the number of men who are diagnosed with organ-confined and therefore potentially curable prostate cancer. Advances in predicting outcomes with artificial neural networks may help to recommend one therapy over another. Less invasive forms of treatment, such as high-intensity focused ultrasound, may ultimately give patients additional options for treatment. Furthermore, attempts to better define the role of both neoadjuvant hormonal therapy and chemotherapy may give higher-risk patients better outcomes than with current treatments. These advances as well as continued research will likely lead to a day when more and more men with organ-confined disease will be cured.     

Radiobiological comparison of two radiotherapy treatment techniques for high-risk prostate cancer

Background

To make a radiobiological comparison, for high risk prostate cancer (T3a, PSA > 20 ng/ml or Gleason > 7) of two radiotherapy treatment techniques. One technique consists of a treatment in three phases of the pelvic nodes, vesicles and prostate using a conventional fractionation scheme of 2 Gy/fraction (SIMRT). The other technique consists of a treatment in two phases that gives simultaneously different dose levels in each phase, 2 Gy/fraction, 2.25 Gy/fraction and 2.5 Gy/fraction to the pelvic nodes, vesicles and prostate, respectively (SIBIMRT).

Materials and methods

The equivalent dose at fractionation of 2 Gy (EQD₂), calculated using the linear quadratic model with α/β_prostate = 1.5 Gy, was the same for both treatment strategies. For comparison the parameters employed were D95, mean dose and Tumour Control Probabilities for prostate PTV and D15, D25, D35, D50, mean dose and Normal Tissue Complication Probabilities for the rectum and bladder, with physical doses converted to EQD₂. Parameters were obtained for α/β_prostate = 1.5, 3 and 10 Gy and for α/β_oar = 1, 2, 3, 4, 6 and 8.

Results

For prostate PTV, both treatment strategies are equivalent for α/β_prostate = 1.5 Gy but for higher α/β_prostate, EQD₂ and TCP, decrease for the SIBIMRT technique. For the rectum and bladder when α/β_oar ≤ 2 Gy, EQD₂ and NTCP are lower for the SIMRT technique or equal in both techniques. For α/β_oar ≥ 2–3 Gy, EQD₂ and NTCP increase for the SIMRT treatment.

Conclusions

A comparison between two radiotherapy techniques is presented. The SIBIMRT technique reduces EQD₂ and NTCP for α/β_oar from 2 to 8 Gy.     

Treatment of localized prostate cancer

This article provides an overview of treatment of localized prostate cancer, which was discussed in detail in the second scientific session of the 16th International Prostate Cancer Update. The role of radical prostatectomy in localized disease was presented by Bob Djavan, MD. Benefits and risks of radical prostatectomy were addressed by Gerald Chodak, MD. Robert E. Donohue, MD, presented the role of radical prostatectomy in Gleason grade 8, 9, and 10 tumors. Impact of positive margins on outcomes after radical prostatectomy was presented by James A. Eastham, MD. E. David Crawford, MD, provided an overview of the role of targeted therapy. Indications and results of brachytherapy were presented by Mack Roach, III, MD. Finally, Michael J. Manyak, MD, described the evolution of radioimmunoscintigraphy and clinical outcomes data.     

Evolution of the clinical presentation and outcomes after radical prostatectomy for patients with clinically localized prostate cancer--changing trends over a ten year period

We demonstrate the evolution of the clinical presentation and outcomes for patients with clinically localized prostate cancer (PC) treated with radical retropubic prostatectomy (RRP) at our department, emphasizing epidemiologic significance of changes during the 10-year period. We assessed the annual trends for changes in patients age, preoperative prostate specific antigen (PSA), preoperative versus postoperative stages and Gleason grades, organ confined status and surgical margin status. A total of 488 RRPs were performed from January 1996 to December 2005 with the annual frequency increased from 8 to 129 (1512.5%). Mean patient age increased from 61.5 to 66.12 years in 2005, with the percentage of men aged more than 70 years increased from 12.5 to 26.5%, respectively. The detection of PC based solely on pathological PSA levels (as indication for prostate biopsy) rose impressively from 25.5 to 70% and the rates of postoperative organ-confined disease also increased significantly from 25 to 74.7%. Mean preoperative PSA decreased from 16.7 to 9.89 ng/mL. On the contrary, there was an increase in percentage of patients with preoperative PSA values ranging from 4 to 10 ng/mL (from 20 to 65.4%). Positive surgical margin rate decreased from 49.4 to 25% and percent of patients receiving neoadjuvant therapy decreased from 78.5 to 5.4%. Proportion of patients who were undergraded decreased from 75.1 to 31.7%. The rates of understaging have remained relatively stable over the years. During the study period, PC was increasingly detected by prostate biopsy on the basis of a pathological PSA level only and shifted significantly to more organ-confined stages with more favourable outcomes for pathological variables due to a more accurate assessment of clinical stage prior to surgery, reduced use of neoadjuvant therapy and improved surgical technique. Our data also argue strongly that routine PSA testing should be expanded and not restricted.     

Dynamic thiol/disulphide homeostasis before and after radical prostatectomy in patients with prostate cancer

Abstract

Thiol groups are important anti-oxidants and essential molecules protecting organism against the harmful effects of reactive oxygen species (ROS). The aim of our study is to evaluate thiol–disulphide homeostasis with a novel recent automated method in patients with localized prostate cancer (PC) before and six months after radical prostatectomy (RP). 18 patients with PC and 17 healthy control subjects were enrolled into the study. Blood samples were collected from the controls subjects and patients before and six months after RP. Thiol–disulphide homeostasis was determined using a recently developed novel method. Prostate-specific antigen (PSA), albumin, total protein, total thiol, native thiol, disulphide and total antioxidant status (TAS) were measured and compared between the groups. Native thiol, total thiol and TAS levels were significantly higher in the control group than the patients before RP (p?<?.001). There was a non-significant increase in the native thiol, total thiol and TAS levels in the patients six months after RP in comparison to the levels before RP (p values .3, .3 and .09, respectively). We found a significant negative correlation between PSA and thiol levels. Our study demonstrated that the decreased thiol and TAS levels weakened anti-oxidant defence mechanism in the patients with PC as indicated. Increased oxidative stress in prostate cancer patients may cause metabolic disturbance and have a role in the aetiopathogenesis of prostate cancer.     

Tomotherapy-based moderate hypofractionation for localized prostate cancer: a mono-institutional analysis

BackgroundTo date, few studies have been published on image-guided helical tomotherapy (HT) in a moderate hypofractionation of localized PCa. We report outcome and toxicity of localized PCa patients treated with HT-based moderate hypofractionated radiotherapy.Materials and methods76 patients were retrospectively analyzed. A total dose of 60 Gy (20 × 3 Gy) or 67.5 Gy (25 × 2.7 Gy) was prescribed. The χ² test was used to analyze associations between toxicity and dosimetric and clinical parameters. The Cox proportional hazard regression model was used for multivariate analysis. Kaplan-Meier method was used for survival analysis.Resultsmedian follow-up was 42.26 months [interquartile (IQR), 23–76). At 4-year, overall survival (OS) and metastasis-free survival (MFS) were 91% and 89%, respectively. At multivariate analysis, smoking habitude was associated with MFS [hazard ratio (HR) 7.32, 95% CI: 1.57–34.16, p = 0.011]. Acute and late grade ≥ 2 gastro-intestinal (GI) toxicity was observed in 6.5% and 2.6% of patients, respectively. Acute and late grade ≥ 2 genito-urinary (GU) toxicity were 31.5% and 3.9%. Four-year late GI and GU grade ≥ 2 toxicity were 3% and 7%, respectively. Acute GI toxicity was associated with statins medication (p = 0.04) and androgen deprivation therapy (p = 0.013). Acute GU toxicity was associated with the use of anticoagulants (p = 0.029) and antiaggregants (p = 0.013).ConclusionsHT-based moderate hypofractionation shows very low rates of toxicity. Smoking habitude is associated with the risk of developing metastases after radical treatment for localized PCa.