Testosterone recovery after androgen deprivation therapy in localised prostate cancer: Long-term data from two randomised trials

BACKGROUND AND PURPOSE

To determine the rate and time of testosterone (T) recovery in patients (pts) with localised prostate cancer treated with radiotherapy plus 0-, 6-, 18- or 36-month of androgen deprivation therapy (ADT).

MATERIALS AND METHODS

In 1230 pts with prostate cancer randomised into two phase III trials, serum T was measured at baseline, then regularly. T recovery rate was compared between normal vs. abnormal baseline T and with ADT duration with Chi-square test or Fisher's exact test. A multivariable logistic regression model to predict the probability of recovering normal T was performed.

RESULTS

Overall, 87.4 % (167/191), 75.9 % (293/386), 54.8 % (181/330) and 43.2 % (80/185) of pts, recovered normal T on the 0-, 6-, 18- or 36-month schedule, respectively (p < 0.001). In patients recovering normal T, the median time to T recovery increased with ADT duration ranging from 0.31, 1.64, 3.06 to 5.0 years for the 0-, 6-, 18- or 36-month schedules, respectively (p < 0.001) and was significantly faster for those with a normal T at baseline (p < 0.001). On multivariable analysis, older age and longer ADT duration are associated with a lower T recovery.

CONCLUSIONS

Testosterone recovery rate after ADT depends on several factors including hormonal duration, normal baseline T, age and medical comorbidities. A longer ADT duration is the most important variable affecting T recovery. The data from this report might be a valuable tool to help physicians and patients in evaluating risks and benefits of ADT.

Hypofractionated, Dose Escalation Radiation Therapy for High-Risk Prostate Cancer: The Safety Analysis of the Prostate Cancer Study-5, a Groupe de Radio-Oncologie Génito-Urinaire de Quebec Led Phase 3 Trial

PURPOSE

The low α\β ratio of 1.2 to 2 for prostate cancer (PCa) suggests high radiation-fraction sensitivity and predicts a therapeutic advantage of hypofractionated (HF) radiation therapy (RT). To date, no phase 3 randomized clinical trial has compared moderately HF RT with standard fractionation (SF) exclusively in high-risk PCa patients. We are reporting the safety of moderate HF RT in high-risk PCa in an initially noninferiority-designed phase 3 clinical trial.

METHODS AND MATERIALS

From February 2012 to March 2015, 329 high-risk PCa patients were randomized to receive either SF or HF RT. All patients received neoadjuvant, concurrent, and long-term adjuvant androgen deprivation therapy. Standard fractionation RT consisted of 76 Gy in 2 Gy per fraction to the prostate, where 46 Gy was delivered to the pelvic lymph nodes. Hypofractionated RT included concomitant dose escalation of 68 Gy in 2.72 Gy per fraction to the prostate and 45 Gy in 1.8 Gy per fraction to the pelvic lymph nodes. The coprimary endpoints were acute and delayed toxicity at 6 and 24 months, respectively. The trial was originally designed as a noninferiority with a 5% absolute margin. Given the lower-than-expected toxicities in both arms, the noninferiority analysis was completely dropped.

RESULTS

Of the 329 patients, 164 were randomized to the HF and 165 to the SF arms. In total, there were more grade 1 or worse acute gastrointestinal (GI) events in the HF arm, 102 versus 83 events in the HF and SF arm, respectively (P = .016). This did not remain significant at 8 weeks of follow-up. There were no differences in grade 1 or worse acute GU events in the 2 arms, 105 versus 99 events in the HF and SF arm, respectively (P = .3). At 24 months, 12 patients in the SF arm and 15 patients in the HF arm had grade 2 or worse delayed GI-related adverse events (hazard ratio, 1.32; 95% CI, 0.62-2.83; P = .482). There were 11 patients in the SF arm and 3 patients in the HF arm with grade 2 or higher delayed genitourinary (GU) toxicities (hazard ratio, 0.26; 95% CI, 0.07-0.94; P = .037). There were 3 grade 3 GI and one grade 3 GU delayed toxicities in the HF arm and 3 grade 3 GU and no grade 3 GI toxicities in the SF arm. No grade 4-toxicities were reported.

CONCLUSIONS

This is the first study of moderate HF dose-escalated RT in exclusively high-risk patients with prostate cancer treated with long-term androgen deprivation therapy and pelvic RT. Although our data were not analyzed as a noninferiority, our results demonstrate that moderately HF RT is well-tolerated, similar to SF RT at 2 years, and could be considered an alternative to SF RT.

Biochemical Failure in Intermediate Risk Prostate Cancer: Then What? Long-Term Data from a Phase III Trial

PURPOSE/OBJECTIVE(S)

Aiming to determine long-term outcomes post biochemical failure (BF) in patients (pts) treated for intermediate-risk prostate cancer, we analyzed data from our prospective randomized trial (PCS III).

MATERIALS/METHODS

From December 2000 to September 2010, 600 pts with intermediate risk prostate cancer (IRPC) received prostate radiotherapy (RT) with or without short-term (6 months) androgen deprivation therapy (ADT) on a Phase III trial. We report death rate from prostate cancer, rate and timing of BF plus the final clinical outcome of patients, alive or dead, with BF. Chi-squared test was used to compare BF and prostate cancer progression (PCP) rates between patient with or without ADT.

RESULTS

Median age at randomization was 71 years (IQR 66-74). With a median follow-up (FU) of 13.5 years (IQR 11.2-17.0), 74.5% (447/600) were free from BF at last FU. Of these, 211 died, 79 stopped FU after 10 years, 9 were lost to FU, 6 withdrew from the study and 142 are still on FU, at a median follow-up of 13.2 years (IQR = 10.9 - 16.2). A total of 153 pts (25.5%) developed BF at a median time of 6.5 years post-randomization. Among BF pts, 82/153 died: we documented 32 deaths from prostate cancer (DPC) at a median time of 6 years post-BF and 50/153 pts died from other causes at a median time of 4.7 years from BF. 48/153 BF pts continue on FU: 34 show no clinical evidence of cancer, 9 developed a second cancer and 5 show clinical evidence of PCP. 20/153 pts stopped FU after 10 years: 3 of them with PCP. 3/153 pts were lost to FU: 1 after 3 years with prostate bone metastasis and 2 after 13 years of FU. In the first 5 years post-randomization, 47 pts (7.8%) presented BF with 1 (0.2%) DPC; between 6 and 10 years, there were another 84 (14%) BFs and 11 (1.8%) DPC. Finally, after 10 years and beyond, we recorded an additional 22 (3.7%) BFs and 20 (3.3%) DPC. The rate of patients who received ADT was significantly lower in patients with BF (74/153 = 48.4%) compared to patients without BF (324/447 = 72.5%), p<0.001. The rate of patients who received ADT was also significantly lower in patients with PCP (19/48 = 39.6%) compared to patients without PCP (379/552 = 68.7%), p<0.001.

CONCLUSION

In our trial for intermediate-risk prostate cancer, a quarter of the pts developed BF. Most of the BFs occurred between 5- and 10- year post-randomization. Deaths due to prostate cancer post-BF occurred at a median time of 6 years, justifying the need for long-term FU. BF and PCP were significantly higher in patients not receiving ADT.

Patient Reported Outcomes in High-Risk Prostate Cancer Patients with or without Testosterone Recovery after Androgen Deprivation Therapy

PURPOSE/OBJECTIVE(S)

In a previous report from a randomized trial of 630 patients (pts), we showed that 18 months of androgen deprivation therapy (18m ADT) appears to be equally effective as 36 months (36m ADT) in high-risk prostate cancer (HRPC) pts. We performed the current analysis to evaluate quality of life (QOL) using the 25 items of EORTC PR25 validated tool in pts with or without testosterone (T) recovery after ADT.

MATERIALS/METHODS

We selectedpts with no biochemical failure to avoid subsequent T variations due to reintroduction of ADT for recurrence. Patients receiving exactly 18 or 36m of ADT, survived more than one year (y) post randomization, had T measured at baseline and during follow-up and who completed QOL questionnaire entered this review. The 25 items were regrouped into 5 scales. All items and scales scores were linearly transformed to a 0-100 points scale. Serum T was measured at baseline then at each visit. We defined unrecovered testosterone as measured below the normal level. All items and scales scores were analyzed with general linear model and repeated measures to evaluate changes between pts with or without T recovery over time. T recovery was adjusted in a multivariable model including age, initial normal/unrecovered T and ADT (18 or 36m). P-value < 0.01 was considered statistically significant and a difference in mean scores of ≥10 points was considered clinically relevant. Patient-reported outcomes were filled out before treatments, every 6m during ADT, 4m after ADT and then once a year for 5y.

RESULTS

Two hundred sixty nine of 630 pts met the eligibility criteria and were retained for the analysis. At a median follow-up of 14 years, 140/269 (52.0%) pts recovered T to normal level: 94/166 (56.6%) in 18m ADT and 46/103 (44.7%) in 36m ADT, p = 0.056. The median time to recovered T was significantly lower in 18m vs. 36m ADT (3.04 vs. 5.06 y, p<0.001). The global adherence to QOL questionnaires was 83.9% (2649/3156) and was similar between arms. Pts recovering T compared to those who did not, had a better QOL. 6/20 items [difficult to get enough sleep: get up frequently at night to urinate, blood in stool, hot flushes, feel less man, interested in sex, sexually active (with or without intercourse)] and 2/4 scales (treatment and sexual activity) were statistically significant (all p<0.01). 2 items were also clinically relevant: hot flushes and interested in sex. Hot flushes were clinically relevant (more than 10 point of difference) between 3.5 to 5y inclusively with maximum difference of 19.4 point. Interest in sex was clinically relevant with 13.1 point of difference at 3 years.

CONCLUSION

T recoverypost long-term ADT is associated with a significantly improved QOL in patients with HRPC. Considering similar prostate cancer clinical outcomes and faster T recovery, our results suggest that 18m ADT may be the most appropriate ADT treatment duration for these patients.

Conventional vs. Hypo-Fractionated, Radiotherapy for High-Risk Prostate Cancer (PCS5), Randomized, Non-Inferiority, Phase 3 Trial: Posthoc Analysis of IMRT vs. 3D-CRT Radiation Therapy Associated Toxicities

PURPOSE/OBJECTIVE(S)

The Prostate Cancer Study number 5 (PCS5), is a multi-centric non-inferiority, phase 3, randomized controlled trial of high-risk prostate cancer patients of treated with either conventionally fractionated radiotherapy (CFRT) or hypofractionated radiotherapy (HFRT). The 7 years' pre-planned analysis showed that HFRT (68 Gy in 25 fractions) was as effective and well tolerated as CFRT (76 Gy in 38 fractions). In this posthoc analysis we aim to report the genitourinary (GU) and gastrointestinal (GI) toxicities associated with radiation therapy techniques: intensity-modulated radiotherapy (IMRT) and 3D-conformal radiotherapy (3D-CRT).

MATERIALS/METHODS

PCS5 randomized patients in a 1:1 ratio to receive either CFRT or HFRT. All patients received long term neoadjuvant, concurrent and adjuvant androgen suppression, with a median duration of 24 months. The toxicities were reported as per the Common Terminology Criteria for Adverse Events version 4. Acute toxicities were defined as presenting ≤ 180 days post-RT start and delayed > 180 days. The cumulative acute and delayed GI and GU toxicities were classified in grade groups: grade 1 or higher (G1+), G2+, and G3+. For each grade group, acute and delayed, we performed multivariable logistic regression analyses, adjusting for age, CTV volume, diabetes, fractionation (CRFT or HFRT), hypertension, and stage < T3b or ≥ T3b. For efficacy analyses cox-regression was utilized. A p-value < 0.05 was considered significant.

RESULTS

Three hundred twenty of the 329 patients enrolled in the trial were included in this posthoc analyses. The mean age was 71.4 ± 6.1 years, and the mean CTV volume (n = 219) was 47.25 ± 19.9 cc. IMRT was used in 195 (60.6%) patients and 3D-CRT in 125 (39.1%) patients. Multivariable logistic regression showed a significant difference in favor of IMRT for GI G2+ acute toxicity (OR = 0.285 [0.14-0.59]; CI: 95%; p<0.001) and GI G2+ delayed toxicity (OR = 0.202 [0.60-0.69]; CI: 95%; p = 0.01). There were no differences in G3+ GI or GU toxicities and there were no grade 4 toxicities. There were no differences in efficacy at 7 years between the two treatment technics. Outcomes for IMRT vs. 3D-CRT respectively, overall survival (81.5% vs 79.2%; HR: 0.92 [0.55-1.53]; CI: 95%; p-value: 0.74), distant metastasis free survival (90,7% vs 92.8%; HR: 1.4 [0.63-3.1]; CI: 95%; p-value: 0.42), prostate cancer mortality (95.8% vs. 92.2%; HR: 0.93 [0.32-2.67]; CI: 95%; p-value: 0.89), and biochemical failure (85.1% vs 88%; HR: 1.35 [0.72-2.52]; CI: 95%; p-value: 0.35).

CONCLUSION

This is the first phase 3 randomized controlled trial assessing the use of HFRT vs. CFRT, exclusively in high-risk prostate cancer patients. Given that our efficacy data at 7 years follow-up establishes moderate HFRT as a new standard of care and no difference between IMRT and 3D-CRT, we strongly recommend that patients who are treated with EBRT should receive IMRT, given the reduced acute and delayed grade 2 or higher GI toxicities.

Phase III Study of Hypofractionated, Dose Escalation Radiotherapy vs. Conventional Pelvic Radiation Therapy followed by High Dose Rate Brachytherapy Boost for High Risk Adenocarcinoma of the Prostate (PCS VI): Acute Toxicity Results

PURPOSE/OBJECTIVE(S)

The low α\β ratio of 1.2-2 for prostate cancer (PCa) suggests high radiation-fraction sensitivity and predicts a therapeutic advantage of lager fraction size. We have recently shown (PCS5) that high risk prostate cancer patients can safely and effectively be treated with moderate hypofractionated radiation therapy (HF-RT). To date there has been no phase-III randomized clinical-trial comparing moderately HF-RT with EBRT and HDR boost (HDRB). We are reporting the acute safety of EBRT+HDRB compared to moderate HF-RT in this phase III Canadian trial.

MATERIALS/METHODS

From January 2015-June 2022, 308 high-risk localized PCa patients were randomized to receive either HF-RT or EBRT+HDRB. All patients received neo-adjuvant, concurrent, and long-term adjuvant androgen deprivation therapy (ADT). EBRT+HDRB consisted of 46 Gy in 2 Gy per fraction to the pelvis and a 15 Gy in one fraction HDR boost within 3 weeks of EBRT. HF-RT include concomitant dose escalation of 68 Gy in 2.72 Gy per fraction to the prostate, and 45 Gy in 1.8 Gy per fraction to the pelvic lymph-nodes.

RESULTS

Of the 308 patients, 148 received HF-RT and 144 EBRT+ HDRB. The remainder either withdrew from the study or were treated with standard (2 Gy per fraction) fractionation for technical reasons. In both intention to treat and as treated analysis, using log-Rank, there were more grade 1 or worse (G1+) acute GI and GU events and more G2+ acute GI events in the HF-RT than EBRT+HDRB. As treated analysis the acute G1+ and G2+ GI events were 92 vs 77 (60.1% vs. 53.5%; p < 0.017) and 21 vs 10 (13.7% vs. 6.9%; p = 0.052), respectively for HF-RT and EBRT + HDRB. Similarly, the G1+ acute GU events were 123 vs. 101 (80.4% vs.70.1%; p < 0.001) respectively for HF-RT and EBRT+HDRB. There were only four G3 GI and one G3 GU acute toxicities in both arms. No grade 4 toxicities were reported.

CONCLUSION

This is the first study of EBRT+HDRB compared to moderate HF dose escalated RT in high-risk prostate cancer patients treated with long-term ADT and pelvic RT. Our results demonstrate that both treatment approaches are well-tolerated and that EBRT+HDRB carries less G2+ GI and G1+ GU acute toxicities.

Testosterone recovery in patients with prostate cancer treated with radiotherapy and different ADT duration: Long-term data from two randomized trials

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Background: To determine the rate and time of testosterone (T) recovery to normal level in patients (pts) with prostate cancer treated with radiotherapy plus 6, 18 or 36 months of androgen deprivation therapy (ADT) and considered cured from their disease. Methods: We randomized 1230 pts with prostate cancer, into two phase III trials: 600 with intermediate risk and 630 with high-risk. We selected those considered cured to avoid subsequent T variations due to reintroduction of ADT for recurrence. We excluded the following pts: no ADT at all (126) or not receiving exactly 6, 18 or 36 months of ADT (69), survival less than one year (21), no T measured at baseline or during follow-up (75), biochemical failure (195) or evidence of metastatic/recurrent disease (137).T recovery rate was compared between baseline normal/abnormal T (values below biochemical normal range) and by ADT duration with Chi-square test or Fisher's exact test. A multivariable logistic regression model to predict the probability of recovering normal T was performed by including normal/abnormal T at baseline, age, Zubrod, comorbidities and ADT duration. A second model was performed by replacing ADT duration with baseline PSA, Gleason score and stage. The median time to T recovery was calculated only on pts who recovered normal T. Results: Results are reported with a median follow-up of 14 years. 607 pts fit the criteria and are available for analysis: 309 pts in the 6 months ADT schedule, 185 in the 18 and 113 in the 36. Overall, 76.7%, 54.6% and 45.1% pts recovered normal T on the 6, 18 or 36 months schedule, respectively (p<0.001). The median time to T recovery was 1.5, 3.1, and 5.1 years for the 6, 18 or 36 months schedule, respectively (p<0.001). 79.7% presented with a normal T at baseline while 20.3% had an abnormal T level. By splitting pts between a normal vs. abnormal presenting T level, the T recovery rate was as follows: 82.1%, 63.3%, and 50% for the normal T cohort, compared to 53.4%, 28.3% and 21.1% for the abnormal T cohort at 6, 18 or 36 months, respectively. There was a significant difference in the overall recovery rate (p<0.001) between normal vs. abnormal T level and at all ADT duration lengths between the two cohorts. In multivariable model, baseline normal T was a strong predictor of T recovery. Older age, diabetes, longer ADT, higher clinical stage, higher PSA and higher Gleason score reduced significantly the chance for T recovery. In pts recovering T post-ADT, except for the 6 months duration (p=0.01), the median time for T recovery was not significantly different between normal or abnormal T at baseline in 18 and 36 months cohorts. Conclusions: Older age, longer ADT and poor disease features are associated with a lower T recovery. Even after adjusting for several variables and ADT duration, a higher T recovery post-ADT is significantly associated with a normal T at baseline.

Optimizing Treatment in Intermediate-Risk Prostate Cancer: Secondary Analysis of a Randomized Phase 3 Trial

PURPOSE

To identify patients with intermediate-risk prostate cancer (IRPC) benefiting from de-escalation of androgen deprivation therapy (ADT) and/or dose escalated radiation therapy (DERT), we performed a secondary analysis of a phase 3 trial by measuring biochemical failure (BF), distant metastases, prostate cancer-specific mortality, overall survival (OS), and distant metastases-free survival (DMFS) rates according to prognostic intermediate risk factors (IRF).

METHODS AND MATERIALS

The initial trial randomized 600 patients with IRPC to a 3-arm trial with 200 patients per arm, consisting of 6 months of ADT plus 70 Gy radiation therapy (ADT + RT70) versus ADT plus a DERT of 76 Gy (ADT + DERT76) versus DERT of 76 Gy alone (DERT76). We performed an analysis based on IRF: clinical stage, prostate-specific antigen level, Gleason score, percentage of positive biopsy cores (PBC) ≥50%, and Gleason pattern. Patients were allocated to 2 groups: favorable intermediate risk (FIR), defined as patients with only 1 IRF without Gleason pattern 4 + 3 or PBC ≥50%; and unfavorable intermediate risk (UIR), defined as all other patients. BF, distant metastases, prostate cancer-specific mortality, OS, and DMFS were compared between FIR and UIR.

RESULTS

The median follow-up was 11.3 years (interquartile range, 10.9-11.7). In the FIR cohort, BF and OS were not significantly different between arms. UIR patients had significantly worse DMFS (hazard ratio [95% confidence interval], 1.61 [1.20-2.15]; P = .026) and OS (1.51 [1.12-2.04]; P = .0495) and a nonsignificant higher cumulative incidence of BF rate (1.55 [0.98-2.47]; P = .08). In UIR patients, a significant improvement in BF was seen in the arms receiving ADT compared to DERT76 alone. On multivariable analysis, Gleason pattern 4 + 3 and prostate-specific antigen >10 ng/mL independently affected BF and OS, regardless of the treatment arm.

CONCLUSIONS

In IRPC, therapeutic optimization appears possible. To avoid ADT side effects, DERT76 alone appears sufficient in patients harboring only 1 risk factor without Gleason pattern 4 + 3 and PBC ≥50% (FIR). All other UIR patients seem to benefit from ADT + DERT76.

Hypofractionated, dose escalation radiotherapy for high-risk prostate cancer: The primary endpoint of a group led phase III trial. (PCS5)

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Background: The low α\β ratio of prostate cancer (PCa), 1.5-2, suggests high radiation-fraction sensitivity and predicts a therapeutic advantage of hypofractionated radiation treatment (HFRT). Most available data of moderate HFRT have focused on low, intermediate and/or mixed risk groups. We therefore conducted the first randomized trial of moderately HFRT in high-risk PCa patients and present the primary safety analysis of side effects at 2 years. Methods: We conducted a Canadian multi-centric phase III trial of conventional fractionated radiation therapy (CFRT) vs. intensity-modulated HFRT in men with high-risk PCa as per NCCN definition. From February 2012 to March 2015, 329 patients were randomized in a 1:1 ratio to receive either CFRT or HFRT. All patients received neo-adjuvant, concurrent and adjuvant androgen suppression, with a median duration of 24 months. CFRT consisted of 76 Gy in 2 Gy per fraction to the prostate where 46 Gy was delivered to the pelvic lymph nodes. HFRT consisted of concomitant dose escalation of 68 Gy in 2.72 Gy per fraction to the prostate and 45 Gy, in 1.8Gy per fraction to the pelvic lymph nodes. The primary endpoint was to compare the toxicities at 6 months and at 24 months using the CTCAE v.4. Results: Of the329 patients, 164 were randomized to HFRT and 165 to CFRT. The minimum, median and maximum follow-up were 24, 40 and 60 months respectively. At 24 months, 12 patients in the CFRT arm and 15 patients in the HFRT arm had grade 2 or worse gastrointestinal (GI)-related adverse events (HR:1.32 [0.62.2.83] 95% CI; P=NS). Similarly, 11 patients in the CFRT arm and 3 patients in HFRT arm had grade 2 or higher genitourinary (GU) toxicities (HR:0.26 [0.07-0.94] 95% CI; P=0.037). In the HFRT arm, there were 3 grade 3 GI and one grade 3 GU related toxicities. In the CFRT arm there were 3 grade 3 GU and no grade 3 GI related toxicities. There were no grade 4 toxicities in either arm. Conclusions: This is the first hypofractionated dose escalated radiotherapy study in high-risk PCa patients treated with contemporary radiation and androgen suppression. Our results indicate that moderate HFRT to high risk PCa patients is equally well tolerated as CFRT at 2 years. Clinical trial information: NCT01444820.

Duration of androgen deprivation therapy in high risk prostate cancer: Final results of a randomized phase III trial

5008

Background: Long-term androgen deprivation therapy (ADT) combined with radiotherapy (RT) is a standard treatment for patients with high-risk prostate cancer (HRPC). However, the optimal duration of ADT is not yet defined. The aim of this randomized trial (Clinical Trials.gov, #NCT00223171) was to compare outcomes of RT combined with either 36 or 18 months of ADT. Methods: Patients with HRPC were randomized to pelvic and prostate RT combined with 36 (arm 1) or 18 months (arm 2) of ADT. Overall survival (OS) and quality of life (QoL) were primary end points. OS rates were compared with Cox Regression model and QoL data were analyzed through mixed linear model. Results: 630 patients were randomized, 310 to arm 1 and 320 to arm 2. With a median follow-up of 9.4 years, 290 patients had died (147 arm 1 vs. 143 arm 2). The 10-year OS rate was 62.4% (95% confidence interval [CI] 56.4%, 67.8%) for arm 1 and 62.0% (95% CI 56.1%, 67.3%) for arm 2 (p = 0.8412) with a global hazard ratio (HR) of 1.024 (95% CI 0.813-1.289, p = 0.8411). QoL analysis showed a significant difference (p < 0.001) in 6 scales and 13 items favoring 18 months ADT with two of them presenting a clinically relevant difference in mean scores of ≥10 points. Conclusions: In HRPC, ADT combined with RT can be safely reduced from 36 to 18 months without compromising outcomes or QoL. 18 months of ADT represents a new standard of care in HRPC. Funded by AstraZeneca Pharmaceuticals Clinical trial information: NCT00223171.

Is there a relationship between testosterone levels at the end of short-term androgen deprivation therapy and outcomes in intermediate risk prostate cancer? Prospective data from a phase III trial

78

Background: The purpose of this analysis was to assess whether the testosterone level measured at the end of short term androgen deprivation therapy (STADT) and prostate radiotherapy (RT) has an impact on treatment outcomes in patients with intermediate risk prostate cancer (IRPC) treated on a randomized trial (PCS III ClinicalTrials.gov #NCT00223145). Methods: From December 2000 to September 2010, 400 patients with IRPC received 6 months of STADT (bicalutamide 50mg die and goserelin 10.8mg x 2) and RT. Castrate level of testosterone was defined as <1.7 nmol/L: lower level <0.7 and upper level 0.7-1.7. In 347/400 patients, testosterone levels were available at the end of STADT and were divided into 3 groups based on measured testosterone levels: <0.7, 0.7 to 1.7 and >1.7 nmol/L. Patient’s characteristics were compared with ANOVA and Fisher’s exact test. Biochemical failure, prostate cancer recurrence and death were compared with Cox regression. Results: Patient’s characteristics were well balanced between the 3 groups with no statistical difference for age, performance status, PSA at start, Gleason score and stage. At the end of STADT 55.3% (192/347) presented testosterone levels <0.7 and 38.9% (135/347) levels between 0.7 and 1.7 for a total of 94.2% (327/ 347) reaching castrate levels ≤1.7 nmol/L. In 5.8% of patients (20/347) a castrate testosterone level was not achieved. With a median follow-up of 8.1 years, outcomes are shown in the table. Conclusions: In IRPC patients treated with STADT and RT, the majority of patients (94.2%) achieve a castrate level of testosterone (<1.7 nmol/L). Although we could not show a difference in outcomes between castrate and non-castrate patients, these data have to be viewed with caution given the small number of non-castrate patients studied. Source of Funding: AstraZeneca Pharmaceuticals Grant. Clinical trial information: NCT00223145. [Table: see text]

Causes of death in intermediate- and high-risk prostate cancer treated with radiotherapy with or without androgen deprivation therapy: Analysis from two phase III trials

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Background: The purpose of this analysis was to establish causes of death in a population of intermediate-risk (IR) and high-risk (HR) prostate cancer treated on two phase III trials. Methods: From October 2000 to September 2010, 1,230 patients were randomized: 630 with HR (ClinicalTrials.gov, #NCT00223171) and 600 with IR (#NCT00223145). HR was defined as T3-4, PSA >20 g/ml, Gleason >7 (with at least one of these 3 factors). IR was defined as T1-T2, Gleason < 6 and PSA 10-20 ng/ml or T1-T2, Gleason 7 and PSA < 20 ng/ml. Causes of death were compiled until July 2015 and were established from data sent by the different investigators and centrally reviewed. Causes of death were mainly based on data from clinical records, then by family members, obituaries, death certificates and family physicians. Results: The median follow-up for the 1,230 patients was 7.5 years (HR 8 vs. IR 6.8 years, p<0.001). 30.2% (372/1,230) patients had died: (HR 37% vs. IR 23.2%, p<0.001). A total of 8% (99/1,230) patients developed local, regional, and metastatic prostate cancer recurrences: (HR 11.6% vs. IR 4.3%, p<0.001) and 4.4% (54/1,230) died from prostate cancer: (HR 7.3% vs. IR 1.3%, p<0.001). The most frequent cause of death was a second cancer (120/1,230, 9.8%): (HR 10.6% vs. IR 8.8%, p=NS). Cardiovascular deaths occurred in 6.3% (78/1,230) (HR 7.1% vs. IR 5.5%, p=NS) with no statistical difference between the different durations of androgen deprivation therapy (ADT) 0, 6, 18, or 36 months. Other causes of death were pulmonary (3.7%), digestive (1.1%), others (3.3%), and unknown (1.7%). Majority of deaths occurred between 3 and 9 years after randomization (HR 70% and IR 73%). Prostate cancer deaths were distributed over all the follow-up period. The 5/10 year overall survival between HR and IR were 88.6%, 91.8%, and 61.6%, 69.8%, respectively with significant differences (p=0.045 and p=0.016). Conclusions: In patients with localized HR and IR prostate cancer, the first cause of death was a second cancer and prostate cancer came as the third one after cardiovascular disease. There was no statistical difference in the incidence of cardiovascular deaths in patients treated with different durations of ADT. Clinical trial information: Clinical Trials, gov. #NCT00223145 - Clinical Trials, gov. #NCT00223171.

Place of short-term androgen deprivation therapy in intermediate-risk prostate cancer treated with radiotherapy: A phase III trial

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Background: The place of short term androgen deprivation therapy (STADT) in combination with radiation therapy (RT) for patients with intermediate risk prostate cancer (IRPC) remains controversial. The purpose of this prospective, randomized trial was to compare outcomes between patients with IRPC treated with different doses of RT with or without STADT, (PCS III trial, Clinical Trials.gov, NCT00223145). Methods: From December 2000 to September 2010, 600 patients with IRPC were randomized to 6 months of STADT and two levels of prostate RT doses of 70 (arm 1) or 76 Gy (arm 2) versus prostate dose-escalated RT alone at 76 Gy (arm 3). STADT consisted of bicalutamide and gosereline for six months. RT (2 Gy per fraction) started four months after the beginning of STADT. Biochemical failure and disease-free survival (DFS) were primary end-points, with overall survival (OS) as secondary endpoint. DFS and OS rates were estimated with Kaplan-Meier and compared with log rank test and Cox regression. Results: Patient’s characteristics were well balanced among the 3 arms (median age 71 years, median PSA 10 ng/ml, median Gleason score 7). At a median follow-up of 75.4 months, biochemical failure occurred in 84 (14%) patients (arms 1 to 3: 12.5%, 8.0%, 21.5%) with statistical difference between arm 1 and 3 (p = 0.023) and arm 2 and 3 (p < 0.001). There was no significant difference between arm 1 and 2. A total of 113 (19%) patients had died with only 6 deaths (1%) attributed to prostate cancer. The 5-/10-year DFS rates were 93%, 97.5% and 86%, and 77%, 90% and 64.5%, respectively. Significant differences in DFS between the treatment arms were observed at 5 years but at 10 years it was observed only between arm 1 and 3 (p=0.01) and arm 2 and 3 (p<0.001). The 5-/10-year OS rates were 91%, 95% and 93%, and 64%, 70% and 78%, respectively. There was no statistical difference in OS between arms at 5 and 10 years. Conclusions: In patients with IRPC, the use of STADT in association with RT, even at lower doses, leads to a superior biochemical control and DFS as compared to dose-escalated RT alone. These outcomes did not translate into an improved OS. Source of Funding: AstraZeneca Pharmaceuticals Grant. Clinical trial information: NCT00223145.

Long-term quality of life in high-risk prostate cancer: Results of a phase III randomized trial

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Background: To evaluate long-term quality of life (QOL) in 630 patients with high-risk prostate cancer (HRPC) treated in a prospective randomized phase III trial (PCS IV clinical trials, Gov. # NCT 00223171). Methods: Patients were randomized to radiotherapy (RT) plus 36 or 18 months of androgen deprivation therapy (ADT). QOL was assessed by two validated tools: EORTC30 (30 items) and PR25 (25 items). The 55 items were regrouped into 21 scales: 15 for EORTC30 and six for PR25. All items and scales scores were linearly transformed to a 0 to 100 points scale. A p value less than 0.01 was considered statistically significant and a difference between groups in mean scores of greater than or equal to 10 points as clinically relevant. Patient-reported outcomes were filled out before treatments, every six months during ADT, four months after and then once a year for five years. All items and scales scores were analysed with general linear model with repeated measures to evaluate changes between groups and over time periods. Results: Three hundred ten patients were randomized to 36 months and 320 to 18 months of ADT, with a median follow-up of 79 months, there was no difference in survival outcomes. The global adherence to QOL questionnaires was 72.4% (10,052 out of 13,880). When comparing the two groups, 6 out of 21 scales (physical, emotional, and social functioning, fatigue, hormonal treatment-related symptoms, and sexual active) and 14 out of 55 items (trouble with long walks, stay in bed during the day, weakness, tenseness, worry, irritable, depressed, close to a toilet, blood in stools, hot flushes, enlarged breasts, interested in sex, sexually active, enjoyable sex) were statistically significant (p< 0.01) in favor of the 18 months ADT group. None of the 21 scales reached clinical relevance (mean scores greater than or equal to 10 points) sexual active being the highest score with 9.0 points of difference. For the 14 statistically significant items, interest in sex with 9.9 points and sexually active with 8.1 points were close to clinical relevance and hot flushes with 24 points and enjoyable sex with 18 points had important clinical relevance at 42 months. Conclusions: In HRPC treated with RT and ADT, reducing the duration of ADT from 36 to 18 months improves QOL, without a negative impact on survival. Source of Funding: AstraZeneca Pharmaceuticals grant. Clinical trial information: PCS IV clinical trials, Gov. # NCT 00223171.

Duration of androgen deprivation therapy in high-risk prostate cancer: A randomized trial

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Background: Radiotherapy (RT) and long-term androgen deprivation therapy (ADT) is a standard treatment for patients with high-risk prostate cancer. However, the optimal duration of ADT is not yet defined. The purpose of this randomized trial was to compare outcomes between 36 and 18 months of ADT in high-risk prostate cancer treated with RT (PCS IV trial). Methods: PCS IV randomized patients with node-negative high-risk prostate cancer (T3-4, PSA >20 ng/ml or Gleason score >7), to pelvic RT (whole pelvis 44 Gy/4 ½ weeks, prostate 70 Gy/7 weeks) and 36 (arm 1) vs 18 months (arm 2) of ADT (neo- adjuvant, concomitant, adjuvant). ADT consisted of bicalutamide 50 mg for one month and goserelin 10.8 mg every three months for 36 vs 18 months. Overall survival was the primary end point. From randomization, overall and cancer-specific survival rates were compared between arms with Kaplan-Meier log rank test and Cox regression. Results: From October 2000 to January 2008, 310 patients were randomized to arm 1 and 320 to arm 2. Patients' characteristics were well balanced between the two arms (median age 71 years, median PSA 16 ng/ml, median Gleason score 8). Most patients had T2-T3 disease. At a median follow-up of 78 months, 80/310 patients (25.8%) in arm 1 and 85/320 (26.6%) in arm 2 had died (p=0.829). 113 patients died of causes other than prostate cancer. Overall and cancer-specific survival hazard ratios were 1.15 (0.85-1.56), p=0.366 and 1.07 (0.62-1.84), p=0.819, respectively. 5-year overall and disease-specific survival rates were 91.1% (87.9-94.3) vs. 86.1% (82.3-90.0), p=0.06 and 96.6% (94.5-98.7) vs. 95.3% (92.8-97.7), p=0.427 and 10-year overall and disease-specific survival rates were 61.9% (54.1-69.7) vs. 58.6% (49.8-67.4), p=0.275 and 84.1% (77.6-90.6) vs. 83.7% (76.3-91.1), p=0.819 for arm 1 and arm 2, respectively. There were no significant differences in the rates of biochemical, regional, or distant failure between arms. Conclusions: With a median follow-up of 6.5 years, our study shows that long-term ADT can be safely reduced from 36 to 18 months without compromising outcomes. Analysis of treatment impact on quality of life is now under review. Source of Funding: AstraZeneca Pharmaceuticals Grant. Clinical trial information: #NCT00223171.

Duration of androgen deprivation therapy in high-risk prostate cancer: A randomized trial

LBA4510

The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Monday, June 3, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Monday edition of ASCO Daily News.

High-risk prostate cancer treated with pelvic radiotherapy and 36 versus 18 months of androgen blockade: Results of a phase III randomized study

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Background: Radiotherapy (RT) and long term androgen blockade (AB) is standard treatment for patients with high risk prostate cancer. However, the optimal duration of AB is not yet defined. The purpose of this randomized study was to compare outcomes between 36 vs. 18 months of AB in high risk prostate cancer treated with RT (PCS IV trial, Clinical Trials.gov, #NCT00223171). Methods: PCS IV randomized patients with node negative high risk prostate cancer (T3-4, PSA >20 ng/ml or Gleason score >7), to pelvic RT (whole pelvis 44 Gy/4 ½ weeks, prostate 70 Gy/7 weeks) and 36 (arm 1) vs. 18 months (arm 2) of AB (neo adjuvant, concomitant, adjuvant). AB consisted of bicalutamide 50 mg for one month plus goserelin 10.8 mg every three months for 36 vs. 18 months. Overall survival was the primary end point. Overall and cancer specific survival rates were compared between arms with Kaplan-Meier log rank test and Cox regression. Results: From October 2000 to January 2008, 310 patients were randomized to arm 1 and 320 to arm 2. Patients’ characteristics were well balanced between the two arms (median age 71 years, median PSA 16 ng/ml, median Gleason score 8). Most patients had T2-3 disease. At a median follow-up of 77 months, 71/310 patients (22.9%) in arm 1 and 76/320 (23.8%) in arm 2 had died (p=0.802). Overall, 116 patients died of causes other than prostate cancer. Overall and cancer specific survival hazard ratios were 1.15 (0.83-1.59), p=0.398 and 1.13 (0.61-2.08), p=0.153, respectively. 5 year overall and disease specific survival rates were 92.1% (89.1-95.1) vs. 86.8% (83.0-90.6), p=0.052 and 97.6% (95.9-99.4) vs. 96.4% (94.2-98.6), p=0.473 and 10 year overall and disease specific survival rates were 63.6% (55.7-71.5) vs. 63.2% (54.7-71.7), p=0.429 and 87.2% (81.0-93.3) vs. 87.2% (80.9-93.6), p=0.838 for arm 1 and arm 2, respectively. There were no significant differences in the rates of biochemical, regional or distant failure between arms. Conclusions: Our study shows that long term AB can be safely reduced from 36 to 18 months without compromising outcomes. Analysis of treatment impact on quality of life is now under review. Source of Funding: AstraZeneca Pharmaceuticals Grant. Clinical trial information: Clinical Trials.gov, #NCT00223171.