Late Toxicity of Moderately Hypofractionated Intensity-Modulated Proton Therapy Treating the Prostate and Pelvic Lymph Nodes for High-Risk Prostate Cancer

PURPOSE

To evaluate late gastrointestinal (GI) and genitourinary (GU) toxicity of moderately hypofractionated intensity modulated proton therapy (IMPT) targeting the prostate and pelvic lymph nodes.

METHODS AND MATERIALS

A target accrual of 56 patients with high-risk or unfavorable intermediate risk prostate cancer were enrolled into a prospective study (ClinicalTrials.gov: NCT02874014) of moderately hypofractionated IMPT. IMPT with pencil beam scanning was used to deliver 6750 and 4500 cGy relative biological effectiveness in 25 daily fractions simultaneously to the prostate and pelvic lymph nodes, respectively. All received androgen deprivation therapy. Late GI and GU toxicity was prospectively assessed using Common Terminology Criteria for Adverse Events version 4.0, at baseline, weekly during radiation therapy, 3-month postradiation therapy, and then every 6 months. Actuarial rates of late GI and GU toxicity were estimated using Kaplan-Meier method.

RESULTS

Median age was 75.5 years. Fifty-four patients were available for late toxicity evaluation. Median follow-up was 43.9 months (range, 16-66). The actuarial rate of late grade ≥2 GI toxicity at both 2 and 3 years was 7.4% (95% confidence interval [CI], 0.2%-14.2%). The actuarial rate of late grade 3 GI toxicity at both 2 and 3 years was 1.9% (95% CI, 0%-5.4%). One patient experienced grade 3 GI toxicity with proctitis. The actuarial rate of late grade ≥2 GU toxicity was 20.5% (95% CI, 8.9%-30.6%) at 2 years, and 29.2 % (95% CI, 15.5%-40.7%) at 3 years. None had grade 3 GU toxicity. The presence of baseline GU symptoms was associated with a higher likelihood of experiencing late grade 2 GU toxicity.

CONCLUSIONS

A moderately hypofractionated IMPT targeting the prostate and regional pelvic lymph nodes was generally well tolerated. Patients with pre-existing GU symptoms had a higher rate of late grade 2 GU toxicity. A phase 3 study is needed to assess any therapeutic gain of IMPT, in comparison with photon-based radiation therapy.

Preliminary Analysis of a Phase II Trial of Stereotactic Body Radiation Therapy for Prostate Cancer With High-Risk Features After Radical Prostatectomy

Purpose

There are limited data regarding using stereotactic body radiation therapy (SBRT) in the postprostatectomy setting. Here, we present a preliminary analysis of a prospective phase II trial that aimed to evaluate the safety and efficacy of postprostatectomy SBRT for adjuvant or early salvage therapy.

Materials and Methods

Between May 2018 and May 2020, 41 patients fulfilled inclusion criteria and were stratified into 3 groups: group I (adjuvant), prostate-specific antigen (PSA) < 0.2 ng/mL with high-risk features including positive surgical margins, seminal vesicle invasion, or extracapsular extension; group II (salvage), with PSA ≥ 0.2 ng/mL but < 2 ng/mL; or group III (oligometastatic), with PSA ≥ 0.2 ng/mL but < 2 ng/mL and up to 3 sites of nodal or bone metastases. Androgen deprivation therapy was not offered to group I. Androgen deprivation therapy was offered for 6 months for group II and 18 months for group III patients. SBRT dose to the prostate bed was 30 to 32 Gy in 5 fractions. Baseline-adjusted physician reported toxicities (Common Terminology Criteria for Adverse Events), patient reported quality-of-life (Expanded Prostate Index Composite, Patient-Reported Outcome Measurement Information System), and American Urologic Association scores were evaluated for all patients.

Results

The median follow-up was 23 months (range, 10-37). SBRT was adjuvant in 8 (20%) patients, salvage in 28 (68%), and salvage with the presence of oligometastases in 5 (12%) patients. Urinary, bowel, and sexual quality of life domains remained high after SBRT. Patients tolerated SBRT with no grade 3 or higher (3+) gastrointestinal or genitourinary toxicities. The baseline adjusted acute and late toxicity grade 2 genitourinary (urinary incontinence) rate was 2.4% (1/41) and 12.2% (5/41). At 2 years, clinical disease control was 95%, and biochemical control was 73%. Among the 2 clinical failures, 1 was a regional node and the other a bone metastasis. Oligometastatic sites were salvaged successfully with SBRT. There were no in-target failures.

Conclusions

Postprostatectomy SBRT was very well tolerated in this prospective cohort, with no significant effect on quality of life metrics postirradiation, while providing excellent clinical disease control.

A Phase II prospective study of hypofractionated proton therapy of prostate and pelvic lymph nodes: Acute effects on patient-reported quality of life

BACKGROUND

The objective of this study was to report acute changes in patient-reported quality of life (PRQOL) using the 26-item Expanded Prostate Index Composite (EPIC-26) questionnaire in a prospective study using hypofractionated intensity-modulated proton beam therapy (H-IMPT) targeting the prostate and the pelvic lymph nodes for high-risk or unfavorable intermediate-risk prostate cancer.

METHODS

Fifty-five patients were enrolled. H-IMPT consisted of 45 GyE to the pelvic lymph nodes and 67.5 GyE to the prostate and seminal vesicles in 25 fractions. PRQOL was assessed with the urinary incontinence (UI), urinary irritative/obstructive symptoms (UO), and bowel function (BF) domains of EPIC-26 questionnaire. Mean changes in domain scores were analyzed from pretreatment to the end of treatment and 3 months posttreatment. A clinically meaningful change (or minimum important change) was defined as a score change > 50% of the baseline standard deviation.

RESULTS

The mean scores of UO, UI, and BF at baseline were 84.6, 91.1, and 95.3, respectively. At the end of treatment, there were statistically significant and clinically meaningful declines in UO and BF scores (-13.5 and -2.3, respectively), while the decline in UI score was statistically significant but not clinically meaningful (-13.7). A clinically meaningful decline in UO, UI, and BF scores occurred in 53.5%, 22.7%, and 73.2% of the patients, respectively. At 3 months posttreatment, all three mean scores showed an improvement, with fewer patients having a clinically meaningful decline in UO, UI, and BF scores (18.4%, 20.5%, and 45.0%, respectively). There was no significant reduction in the mean UO and UI scores compared to baseline, although the mean BF score remained lower than baseline and the difference was clinically meaningful.

CONCLUSIONS

UO, UI, and BF scores of PRQOL declined at the end of H-IMPT. UO and UI scores showed improvement at 3 months posttreatment and were similar to the baseline scores. However, BF score remained lower at 3 months posttreatment with a clinically meaningful decline.

The impact of genetic aberrations on response to radium-223 treatment for castration-resistant prostate cancer with bone metastases

BACKGROUND

Radium (Ra)-223 is an established treatment option for patients with metastatic castrate-resistant prostate cancer (mCRPC) who have symptomatic bone metastases without soft tissue disease. Studies have indicated genetic aberrations that regulate DNA damage response (DDR) in prostate cancer can increase susceptibility to treatments such as poly ADP-ribose polymerase inhibitors and platinum-based therapies. This study aims to evaluate mCRPC response to Ra-223 stratified by tumor genomics.

METHODS

This is a retrospective study of mCRPC patients who received Ra-223 and genetic testing within the Mayo Clinic database (Arizona, Florida, and Minnesota) and Tulane Cancer Center. Patient demographics, genetic aberrations, treatment responses in terms of alkaline phosphatase (ALP) and prostate-specific antigen (PSA), and survival were assessed. Primary end points were ALP and PSA response. Secondary end points were progression-free survival (PFS) and overall survival (OS) from time of first radium treatment.

RESULTS

One hundred and twenty-seven mCRPC patients treated with Ra-223 had germline and/or somatic genetic sequencing. The median age at time of diagnosis and Ra-223 treatment was 61.0 and 68.6 years, respectively. Seventy-nine (62.2%) had Gleason score ≥ 8 at time of diagnosis. 50.4% received prior docetaxel, and 12.6% received prior cabazitaxel. Notable alterations include TP53 (51.7%), BRCA 1/2 (15.0%), PTEN (13.4%), ATM (11.7%), TMPRSS2-ERG (8.2%), RB deletion (3.4%), and CDK12 (1.9%). There was no significant difference in ALP or PSA response among the different genetic aberrations. Patients with a TMPRSS2-ERG mutation exhibited a trend toward lower OS 15.4 months (95% confidence interval [CI] 10.0-NR) versus 26.8 months (95% CI 20.9-35.1). Patients with an RB deletion had a lower PFS 6.0 months (95% CI 1.28-NR) versus 9.0 months (95% CI 7.3-11.1) and a lower OS 13.9 months (95% CI 5.2-NR) versus 26.5 months (95% CI 19.8-33.8).

CONCLUSIONS

Among mCRPC patients treated with Ra-223 at Mayo Clinic and Tulane Cancer Center, we did not find any clear negative predictors of biochemical response or survival to treatment. TMPRSS2-ERG and RB mutations were associated with a worse OS. Prospective studies and larger sample sizes are needed to determine the impact of genetic aberrations in response to Ra-223.

A phase II trial of hypofractionated radiation therapy over five treatments for prostate cancer with high-risk features after radical prostatectomy: MC1754

248

Background: Hypofractionated prostate cancer radiation has showed similar results in several prior phase III studies (PCG GU 003, PACE-B, and Hypo PC RT). However, prospective phase II-III clinical trial data testing 5 tx after prostatectomy is scarce. Methods: Between 2018 and 2019, 41 patients were treated after postprostatectomy for high risk features. 5 patients were treated adjuvantly, 36 for salvage including 8 with oligometastatic disease. Indications for adjuvant RT included a PSA < 0.2 and +margins, SVI, or EPE. Salvage RT was offered for PSA ≥0.2. Oligometastatic RT for patients with ≤5 RT targets. Staging included C11 PET for all cases. Total dose to the prostate bed was 30-32 Gy in 5tx QOD with IMRT, conebeam IGRT, and MRI registration. All salvage patients received ADT for 6 months and oligometastatic patients for 18 months. Dose to the metastatic sites was 30 in 5tx QOD. Of the 41 patients 8 also received SBRT to the sites of oligometastatic disease. We looked at clinical outcomes defining biochemical failure as a PSA > 0.2 after treatment, baseline adjusted CTC AE V5.0, baseline adjusted patient reported toxicities (PRO CTC AE), QOL (EPIC, PROMIS), and AUA was used for all cases. Results: Median follow up was 23 months (range 10-37). Pre-RT T stage was T2-T3b, with 47% being T3a-b; Pre RT Median PSA of 0.4 (range < 0.1-1.9); Median GS 8 (6-9); and (+) margins in 48.8%. Sites of oligometastatic disease radiated included the LN and bone. Treatment related AE were grade 0-1 in all cases, except for one patient with G2 GU incontinence. Overall QOL remained high during follow including Promis 10 overall, mental, and physical scores; urinary bother, irritative/obstructive, and AUA scores; bowel overall, bowel bother, and bowel function scores; and overall sexual, sexual function, and sexual bother scores remained at baseline levels during follow up. Only hormonal overall, hormonal function, and hormonal bother had lower scores at 3 months that recovered by 12 months in patients treated with ADT for 6 months and by 24 months in patients treated with ADT for 18 months. A total of 3 clinical failure have been seen; 2 patients with regional failures alone; and one with axial skeleton bony failures for 93% clinical control at median follow up of 23 months. All 3 patients with clinical failure were salvaged successfully with SBRT and all patients remain disease free at last follow up. A total 5 patients with raising PSAs alone have been seen. All patients have been re-staged with C11 PET. No failures in the prostate bed or previously radiated sites have been seen. Conclusions: Toxicity for RT over 5tx is lower than expected with only one case of grade 2 urinary incontinence. QOL scores remained high during follow up, minor changes in hormonal scores were seen during ADT, but recovered after. 30-32 Gy over 5 tx provided 100% control in radiated targets and metastatic sites. Clinical trial information: NCT03570827.

Proton Therapy of Prostate and Pelvic Lymph Nodes for High Risk Prostate Cancer: Acute Toxicity

Purpose

To assess acute gastrointestinal (GI) and genitourinary (GU) toxicities of intensity-modulated proton therapy (IMPT) targeting the prostate/seminal vesicles and pelvic lymph nodes for prostate cancer.

Materials and Methods

A prospective study (ClinicalTrials.gov: NCT02874014), evaluating moderately hypofractionated IMPT for high-risk or unfavorable intermediate-risk prostate cancer, accrued a target sample size of 56 patients. The prostate/seminal vesicles and pelvic lymph nodes were treated simultaneously with 6750 and 4500 centigray radiobiologic equivalent (cGyRBE), respectively, in 25 daily fractions. All received androgen-deprivation therapy. Acute GI and GU toxicities were prospectively assessed from 7 GI and 9 GU categories of the Common Terminology Criteria for Adverse Events (version 4), at baseline, weekly during radiotherapy, and 3-month after radiotherapy. Fisher exact tests were used for comparisons of categorical data.

Results

Median age was 75 years. Median follow-up was 25 months. Fifty-five patients were available for acute toxicity assessment. Sixty-two percent and 2%, respectively, experienced acute grade 1 and 2 GI toxicity. Grade 2 GI toxicity was proctitis. Sixty-five percent and 35%, respectively, had acute grade 1 and 2 GU toxicity. The 3 most frequent grade 2 GU toxicities were urinary frequency, urgency, and obstructive symptoms. None had acute grade ≥ 3 GI or GU toxicity. The presence of baseline GI and GU symptoms was associated with a greater likelihood of experiencing acute GI and GU toxicity, respectively. Of 45 patients with baseline GU symptoms, 44% experienced acute grade 2 GU toxicity, compared with only 10% among 10 with no baseline GU symptoms (P = 0.07). Although acute grade 1 and 2 GI and GU toxicities were common during radiotherapy, most resolved at 3 months after radiotherapy.

Conclusion

A moderately hypofractionated IMPT targeting the prostate/seminal vesicles and regional pelvic lymph nodes was well tolerated with no acute grade ≥ 3 GI or GU toxicity. Patients with baseline GU symptoms had a higher rate of acute grade 2 GU toxicity.

Assessing concordance between patient-reported and investigator-reported CTCAE after proton beam therapy for prostate cancer

PURPOSE

We report acute patient-reported outcomes using CTCAE (PRO-CTCAE) of proton beam radiotherapy for high-risk or unfavorable intermediate-risk prostate cancer in a prospective clinical trial. PRO-CTCAE were correlated with investigator reported-CTCAE (IR-CTCAE) to assess the degree of concordance.

METHODS AND MATERIALS

11 PRO-CTCAE questions assessed gastrointestinal (GI), genitourinary (GU), or erectile function side effects. The correlation scheme between PRO-CTCAE and IR-CTCAE was independently developed by two physicians. Analyses of PRO-CTCAE and IR-CTCAE were conducted using both descriptive terms and the converted grade scores. The Kappa statistic described the degree of concordance.

RESULTS

55 patients were included. IR-CTCAE underestimated diarrhea compared to PRO-CTCAE at the end of treatment (EOT), with a 28% rate of underestimation (11% by ≥ 2 toxicity grades). Similarly, urinary tract pain was underestimated in 45% of cases (17% by ≥ 2 grades) at EOT. Differences were less pronounced at baseline or 3 months after radiotherapy. The incidence of urinary urgency and frequency tended to be overestimated prior to treatment (36% and 24%, respectively) but underestimated at EOT (35% and 31%, respectively). The degree of interference with daily activities was consistently overestimated by investigators (45%-85%). Finally, erectile dysfunction showed a 36-56% rate of discordance by ≥ 2 toxicity grades.

CONCLUSIONS

Our study shows a low agreement between IR-CTCAE and PRO-CTCAE in the setting of proton therapy for prostate cancer. Compared to patient-reported outcomes, physicians underestimated the frequency and severity of urinary symptoms and diarrhea at the end of treatment. Continued use of PROs should be strongly encouraged.

Elective pelvic nodal irradiation with a simultaneous hypofractionated integrated prostate boost for localized high risk prostate cancer: Long term results from a prospective clinical trial

BACKGROUND

To report on long-term results of elective pelvic nodal irradiation (EPNI) and a simultaneous hypofractionated prostate boost for high-risk prostate cancer.

MATERIALS AND METHODS

This was a prospective single-arm study. Patients with high-risk disease (cT3, PSA >20 ng/mL, or Gleason score 8-10) were eligible. Patients received 45 Gy in 25 fractions to the prostate and pelvic lymph nodes with a simultaneous intensity-modulated radiotherapy boost of 22.5 Gy to the prostate (total dose 67.5 Gy in 25 fractions), with androgen deprivation therapy (ADT) for 2-3 years. The primary endpoint was biochemical failure. Secondary endpoints included distant metastases and overall survival. Multivariable analysis was performed to look for predictive factors. Late toxicity was assessed using CTCAE v3.0.

RESULTS

230 patients enrolled. Median follow-up was 11.2 years (IQR 8.1-12.9). At 10 years, cumulative incidence of biochemical failure was 33.4%, distant metastasis was 16.5%, and overall survival was 76.3%. On multivariable analysis, PSA nadir ≥0.05 ng/mL was associated with biochemical failure (HR 6.8, 95% CI 4-11.8, p < 0.001) and distant metastases (HR 7.5, 95% CI 3.9-14.5, p < 0.0001). PSA nadir ≥0.1 ng/mL (HR 5.2, 95% 2.2-12, p = 0.0001) and ADT use ≤12 months (versus >24 months) (HR 2.3, 95% CI 1.3-3.9, p = 0.004) were associated with worse survival. The 5-year cumulative incidence of any late grade ≥3 gastrointestinal and genitourinary toxicity was 2.3% and 7.5%, respectively.

CONCLUSION

EPNI and a simultaneous hypofractionated prostate boost combined with long-term ADT for high-risk prostate cancer resulted in acceptable 10-year biochemical control and survival with low grade ≥3 toxicity.

Comparison of Multimodal Therapies and Outcomes Among Patients With High-Risk Prostate Cancer With Adverse Clinicopathologic Features

IMPORTANCE

The optimal management strategy for high-risk prostate cancer and additional adverse clinicopathologic features remains unknown.

OBJECTIVE

To compare clinical outcomes among patients with high-risk prostate cancer after definitive treatment.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included patients with high-risk prostate cancer (as defined by the National Comprehensive Cancer Network [NCCN]) and at least 1 adverse clinicopathologic feature (defined as any primary Gleason pattern 5 on biopsy, clinical T3b-4 disease, ≥50% cores with biopsy results positive for prostate cancer, or NCCN ≥2 high-risk features) treated between 2000 and 2014 at 16 tertiary centers. Data were analyzed in November 2020.

EXPOSURES

Radical prostatectomy (RP), external beam radiotherapy (EBRT) with androgen deprivation therapy (ADT), or EBRT plus brachytherapy boost (BT) with ADT. Guideline-concordant multimodal treatment was defined as RP with appropriate use of multimodal therapy (optimal RP), EBRT with at least 2 years of ADT (optimal EBRT), or EBRT with BT with at least 1 year ADT (optimal EBRT with BT).

MAIN OUTCOMES AND MEASURES

The primary outcome was prostate cancer-specific mortality; distant metastasis was a secondary outcome. Differences were evaluated using inverse probability of treatment weight-adjusted Fine-Gray competing risk regression models.

RESULTS

A total of 6004 men (median [interquartile range] age, 66.4 [60.9-71.8] years) with high-risk prostate cancer were analyzed, including 3175 patients (52.9%) who underwent RP, 1830 patients (30.5%) who underwent EBRT alone, and 999 patients (16.6%) who underwent EBRT with BT. Compared with RP, treatment with EBRT with BT (subdistribution hazard ratio [sHR] 0.78, [95% CI, 0.63-0.97]; P = .03) or with EBRT alone (sHR, 0.70 [95% CI, 0.53-0.92]; P = .01) was associated with significantly improved prostate cancer-specific mortality; there was no difference in prostate cancer-specific mortality between EBRT with BT and EBRT alone (sHR, 0.89 [95% CI, 0.67-1.18]; P = .43). No significant differences in prostate cancer-specific mortality were found across treatment cohorts among 2940 patients who received guideline-concordant multimodality treatment (eg, optimal EBRT alone vs optimal RP: sHR, 0.76 [95% CI, 0.52-1.09]; P = .14). However, treatment with EBRT alone or EBRT with BT was consistently associated with lower rates of distant metastasis compared with treatment with RP (eg, EBRT vs RP: sHR, 0.50 [95% CI, 0.44-0.58]; P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that among patients with high-risk prostate cancer and additional unfavorable clinicopathologic features receiving guideline-concordant multimodal therapy, prostate cancer-specific mortality outcomes were equivalent among those treated with RP, EBRT, and EBRT with BT, although distant metastasis outcomes were more favorable among patients treated with EBRT and EBRT with BT. Optimal multimodality treatment is critical for improving outcomes in patients with high-risk prostate cancer.

Predictors of Locoregional Recurrence and Delineation of Adjuvant Radiation Therapy Fields for Patients With Upper Tract Urothelial Carcinoma Receiving Nephroureterectomy

PURPOSE

To identify factors predictive of locoregional recurrence (LRR) in upper tract urothelial carcinoma (UTUC) treated with nephroureterectomy and to propose adjuvant radiation therapy (ART) fields.

METHODS AND MATERIALS

Clinical and pathologic variables for patients receiving nephroureterectomy for UTUC between 1995 and 2009 were analyzed for associations with outcomes. Sites of LRR from all patients with available imaging (39) were contoured on computed tomography image sets of patients with representative anatomy, and ART fields were proposed based on these distributions.

RESULTS

A total of 279 patients with a median follow-up of 13.0 years were analyzed. The 5-year cumulative incidence of LRR was 16.7% (95% CI, 12.2-21). Pathologic risk factors (PRFs) associated with increased risk of LRR included tumor in both the renal pelvis and ureter, T stage ≥2, lymph node involvement, grade 3 histology, and positive surgical margins (P < .05). Patients with an increased number of PRFs had a significantly greater risk of LRR. The 5-year cumulative incidence estimates of LRR were 5.3% (95% CI, 1.8%-16.0%), 15.6% (95% CI, 9.5%-25.7%), and 43.9% (95% CI, 31.1%-62.1%) for those with 1, 2, and ≥3 PRFs, respectively. ART fields covering the renal fossa and retroperitoneal lymph nodes from the superior border of L1 through the aortic bifurcation would encompass all sites of LRR for 33 of 46 patients (72%). Non-LRR bladder and distant failure occurred in 101 (36.2%) and 73 (26.2%) of the patients, respectively. The 5-year cumulative incidence estimate of distant failure was 22.5% (95% CI, 17.4%-27.3%).

CONCLUSIONS

In patients receiving nephroureterectomy for UTUC, LRR is significantly increased in patients with 2 or more PRFs. These data provide clinically valuable insight into the selection of candidates for ART and the design of ART fields.

Comparing bowel and urinary domains of patient-reported quality of life at the end of and 3 months post radiotherapy between intensity-modulated radiotherapy and proton beam therapy for clinically localized prostate cancer

PURPOSE

To prospectively assess acute differences in patient-reported outcomes in bowel and urinary domains between intensity-modulated radiotherapy (IMRT) and proton beam therapy (PBT) for prostate cancer.

METHODS AND MATERIALS

Bowel function (BF), urinary irritative/obstructive symptoms (UO), and urinary incontinence (UI) domains of EPIC-26 were collected in patients with T1-T2 prostate cancer receiving IMRT or PBT at a tertiary cancer center (2015-2018). Mean changes in domain scores were analyzed from pretreatment to the end of and 3 months post-radiotherapy for each modality. A clinically meaningful change was defined as a score change >50% of the baseline standard deviation.

RESULTS

A total of 157 patients receiving IMRT and 105 receiving PBT were included. There were no baseline differences in domain scores between cohorts. At the end of radiotherapy, there was significant and clinically meaningful worsening of BF and UO scores for patients receiving either modality. In the BF domain, the IMRT cohort experienced greater decrement (-13.0 vs -6.7, P < .01), and had a higher proportion of patients with clinically meaningful reduction (58.4% vs 39.5%, P = .01), compared to PBT. At 3 months post-radiotherapy, the IMRT group had significant and clinically meaningful worsening of BF (-9.3, P < .001), whereas the change in BF score of the PBT cohort was no longer significant or clinically meaningful (-1.2, P = .25). There were no significant or clinically meaningful changes in UO or UI 3 months post-radiotherapy.

CONCLUSIONS

PBT had less acute decrement in BF than IMRT following radiotherapy. There was no difference between the two modalities in UO and UI.

The impact of genetic mutations on response to radium-223 treatment for castration-resistant prostate cancer with bone metastases

e17587

Background: Radium (Ra)-223 has become the cornerstone treatment in patients with metastatic castrate-resistant prostate cancer (mCRPC) with bone metastases. Ra-223 has been shown to suppress abnormal bone formation by inducing DNA double-strand breaks in tumor cells. This can reduce skeletal-related events, as well as improve survival and quality of life. Studies have indicated mutations that regulate DNA damage response in prostate cancer as susceptible to PARP inhibitors and platinum-based therapies. This study aims to evaluate mCRPC response to Ra-223 stratified by tumor genomics. Methods: This is a retrospective study of mCRPC patients who received Ra-223 and genetic testing within the Mayo Clinic database (Arizona, Florida, and Minnesota). Patient demographics, genetic mutations, treatment responses in terms of alkaline phosphatase (ALP) and prostate-specific antigen (PSA), and survival were assessed. Primary end points were progression-free survival (PFS) and overall survival (OS) from time of first radium treatment. Results: 239 mCRPC patients treated with Ra-223 were identified. Germline and/or somatic genetic sequencing was available in 50 patients, who had a median age of 61 years at time of diagnosis and 68 years at time of Ra-223 treatment. Median Gleason score at time of diagnosis was 8.0. 100% of patients received prior androgen deprivation therapy. 72% received prior docetaxel, and 18% received prior cabazitaxel. Notable mutations included TP53 (45.2%), TMPRSS2-ERG (28.6%), PTEN (26.2%), BRCA1/2 (14.3%), ATM (9.3%), CDK12 (7.1%), and Rb (4.9%). TMPRSS2-ERG was the second most commonly found mutation, with median OS 12.7 mo versus 15.4 mo in patients without TMPRSS2-ERG mutations (p = 0.099). In patients with CDK12 mutations (2 of 28 tested positive), PFS was 10.4 mo versus 5.6 mo in patients without CDK12 mutations (p = 0.157). The assessment of ALP and PSA response to radium treatment stratified by genetic mutation did not reach statistical significance. Conclusions: Among mCRPC patients treated with Ra-223 at Mayo Clinic, TMPRSS2-ERG was the second most commonly found genetic mutation and had observed worse survival outcomes that approached statistical significance. Prospective studies and increased sample sizes are needed to determine the impact of genetic mutations in response to Ra-223.

Outcomes and Profiles of Older Patients Receiving Definitive Radiation Therapy for Muscle-Invasive Bladder Cancer at a Tertiary Medical Center

PURPOSE

Our purpose was to evaluate the outcomes and profiles of older patients with muscle-invasive bladder cancer (MIBC) treated with definitive radiation therapy (RT) with or without chemotherapy (CHT) at a tertiary medical center.

METHODS AND MATERIALS

A retrospective study was conducted for older patients with MIBC who were ≥70 years old and underwent RT with or without CHT between 2000 and 2016. Overall survival (OS) was estimated using the Kaplan-Meier method. Disease-specific survival (DSS), cumulative incidence of progression, patterns of recurrence, and toxicities were examined. Univariate analyses were performed to identify variables associated with OS, DSS, and cumulative incidence of progression, using the Cox proportional hazards model.

RESULTS

A total of 84 patients underwent definitive RT with or without CHT. Of these, only 29% were deemed medically fit to undergo radical cystectomy, and the remainder were medically unfit or had surgically unresectable disease. Median age was 81 years. Sixty-one percent, 29%, and 11% had clinical stage II, III, and IV disease, respectively. Eighty-six percent had maximal transurethral resection of bladder tumor before RT. Seventy-three percent received CHT with RT, and 27% had RT alone. Median follow-up was 5.7 years. Median OS was 1.9 years. OS was 42% and 25%, and DSS was 64% and 54% at 3 and 5 years, respectively. On univariate analysis, medical fitness to undergo radical cystectomy, receipt of CHT, lower T stage, and maximal transurethral resection of bladder tumor were associated with better OS; lower T stage was associated with better DSS. The cumulative incidence of progression was 44% and 49% at 3 and 5 years, respectively. Late grade 3 genitourinary and gastrointestinal toxicity were 15% and 4%, respectively. None had grade 4 or 5 toxicity.

CONCLUSIONS

Older patients with MIBC referred for RT were often medically unfit or had a surgically unresectable tumor. In these medically compromised patients, definitive RT with or without CHT was well tolerated and yielded encouraging treatment outcomes.

Acute patient-reported toxicities after proton therapy or intensity-modulated radiotherapy for prostate cancer

305

Background: Toxicity due to radiotherapy (RT) may differ in patients (pts) with prostate cancer who receive intensity-modulated radiotherapy (IMRT) or proton beam therapy (PBT). Methods: Patient-reported bowel function (BF), urinary incontinence (UI), and urinary irritative/obstructive symptoms (UO) domains of the Expanded Prostate Index Composite Questionnaire (EPIC-26) were prospectively collected in pts with localized prostate cancer receiving either IMRT (n=157) or PBT (n=105) to the prostate +/- proximal seminal vesicles for clinical stage T1-T2 N0 prostate cancer at a single tertiary cancer center between 2015 and 2018. Changes in domain scores were analyzed from pretreatment to the end of RT and 3 months post-RT, assessing the acute effects of each modality. A clinically relevant change was defined as a score change that exceeded 50% of the standard deviation of a baseline value. Results: At baseline there was no difference in the scores of BF, UI, and UO domains between IMRT and PBT cohorts. At the end of RT, pts treated with either modality had a statistically significant and clinically relevant worsening of BF and UO compared to baseline. Pts treated with IMRT experienced a significantly greater decrement in BF compared to the PBT cohort (-13 vs -9, p<0.01), including significantly more IMRT pts having a clinically relevant deterioration in BF compared to PBT pts (58% vs 40%, p=0.01). Though there was a statistically significant deterioration in UI in the IMRT cohort (-4, p<0.001), this did not reach the predefined threshold for clinical relevance. Three months following RT, the IMRT group continued to have statistically significant and clinically relevant worsening of BF (-9, p<0.001), whereas the change in BF domain score of the PBT cohort was no longer statistically significant or clinically relevant compared to baseline (-1, p=0.25). There were no statistically significant or clinically relevant changes in UO or UI in either cohort at three months when compared to baseline. Conclusions: Pts who received IMRT or PBT reported unique patterns of toxicity, and pts treated with IMRT had worse decrement in BF immediately after and three months following RT, compared to those treated with PBT.

Proton Therapy for Stage IIA-B Seminoma: A New Standard of Care for Treating Retroperitoneal Nodes

Currently there has been no published report describing the use of proton beam therapy for stage II testicular seminoma. A 31-year-old man presenting with a right testicular mass and a 2.7-cm aortocaval lymph node received a diagnosis of stage IIB testicular seminoma. He was treated with scanning proton beam therapy, as a means of improving the therapeutic ratio of radiation therapy over conventionally used x-ray radiation therapy. The patient achieved a complete response and remained free of relapse at 15 months post proton beam therapy. The advantageous dose deposition characteristics of proton beam, allowing much lower radiation doses to normal tissues, should be exploited when radiation therapy is applied for stage II testicular seminoma or for an isolated retroperitoneal lymph node relapse of stage I disease initially managed with surveillance.

Is there any benefit in adding postoperative adjuvant concurrent radiotherapy and chemotherapy for penile cancer with regional lymph node metastasis?

BACKGROUND

The aim of this study was to evaluate whether there is any benefit in adding postoperative adjuvant concurrent radiotherapy and chemotherapy (RT-CHT) for penile cancer with regional lymph node metastasis (RLNM).

METHODS

A single institution, retrospective study was conducted for a total of 23 patients with RLNM from penile squamous cell carcinoma. All underwent a definitive surgical intervention for both primary tumor and RLNM. Of these, 11 patients received adjuvant concurrent RT and CHT within 3 months after surgery (RT-CHT group), while 12 patients received no additional treatment (Surveillance Group). Overall survival was calculated with the Kaplan-Meier method. The difference in survival between the two groups was tested using the log-rank test. A potential prognostic factor for survival was evaluated using a univariate Cox-proportional hazards model.

RESULTS

Median follow-up for the entire group was 15.8 months (17.1 months for the RT-CHT group and 10.7 months for the Surveillance Group). Overall survival at 1 and 2 years were 54.5% and 27.2%, respectively, for the RT-CHT Group, compared to 57.1% and 28.4% for the Surveillance Group (log-rank=0.68). On a univariate analysis, the number of involved lymph nodes and the presence of pN3 disease were associated with poor prognosis (P>0.001 and P=0.049, respectively). The RT-CHT Group had more extensive RLNM with a higher median number of positive nodes (5 vs. 3) and more pN3 disease (72.7% vs. 16.7%) than the Surveillance Group. The rate of complications requiring hospitalization was higher in the RT-CHT Group (63.6% vs. 16.6%; P=0.02), as was the rate of systemic complications (34.7% vs. 0%; P<0.01).

CONCLUSIONS

Penile cancer with extensive RLNM carries a poor prognosis. Despite having more extensive RLNM, the RT-CHT group had a similar overall survival as the Surveillance Group. This suggests a potential benefit of postoperative adjuvant concurrent RT-CHT for patients with extensive RLNM, although it carries an increased risk of complications. Further study is warranted to assess the benefit-to-risk ratio of this combined adjuvant therapy.

IMPT versus VMAT for Pelvic Nodal Irradiation in Prostate Cancer: A Dosimetric Comparison

Purpose:

To compare dosimetric data of the organs at risk (OARs) and clinical target volumes (CTVs) between intensity-modulated proton therapy (IMPT) and volumetric-modulated arc therapy (VMAT) for patients undergoing prostate and elective, pelvic lymph node radiotherapy in the setting of unfavorable, intermediate and high-risk prostate carcinoma.

Methods and Materials:

A study of moderately hypofractionated proton therapy (6750 centigray [cGy] in 25 fractions) is in progress for unfavorable, intermediate and high-risk prostate cancer where treatment includes an elective pelvic nodal CTV (4500 cGy in 25 fractions). Ten consecutively accrued patients were the subjects for dose-volume histogram comparison between IMPT and VMAT. Two treatment plans (IMPT and VMAT) were prepared for each patient with predefined planning objectives for target volumes and OARs. The IMPT plans were prepared with 2 lateral beams and VMAT plans with 2 arcs.

Results:

The CTV coverage was adequate for both plans with 99% of CTVs receiving ≥ 100% of the prescription doses. Mean doses to the bladder, rectum, large bowel, and small bowel were lower with IMPT versus VMAT. Mean femoral head dose was greater with IMPT. The percentage of volumes of rectum receiving ≤ 47.5 Gy, large bowel receiving ≤ 27.5 Gy, small bowel receiving ≤ 30 Gy, and bladder receiving ≤ 37.5 Gy was less with IMPT versus VMAT, largely because of reduction in the low-dose “bath” associated with VMAT.

Conclusions:

In the setting of prostate and elective, pelvic nodal radiotherapy for prostate cancer, IMPT can significantly reduce the dose to OARs, in comparison to VMAT, and provide adequate target coverage.

Increased utilization of external beam radiotherapy relative to cystectomy for localized, muscle-invasive bladder cancer: a SEER analysis

OBJECTIVE

To assess recent utilization patterns of radiotherapy (RT) relative to cystectomy for muscle-invasive bladder cancer (MIBC) and evaluate survival trends over time in patients receiving RT.

MATERIALS AND METHODS

The surveillance, epidemiology, and end results program (SEER) was used to identify patients diagnosed between 1992 and 2013 with localized MIBC. Patients with a prior history of non-bladder malignancy, who received no treatment, or did not have available treatment information, were excluded. Treatment utilization patterns were assessed using Cochran-Armitage tests for trend, and patient characteristics were compared using chi-square tests. Overall survival (OS) and cause-specific survival (CSS) were estimated using the Kaplan-Meier method. All-cause (ACM) and cause-specific mortality (CSM) were evaluated with multivariable Cox proportional hazards regression.

RESULTS

Of 16175 patients analyzed, 11917 (74%) underwent cystectomy, and 4258 (26%) were treated with RT. Patients who received RT were older (median age 79 vs. 68, P < 0.01). Over time, the proportion of patients receiving RT relative to cystectomy increased (24% 1992–2002 vs. 28% 2003–2013, P < 0.01), despite median patient age throughout the study period remaining unchanged (71 for each 1992–2002 and 2003–2013, P = 0.41). For RT, compared with patients diagnosed earlier, those diagnosed from 2010–2013 showed improved OS (64% vs. 60% at 1 year, P < 0.01; 38% vs. 29% at 3 years, P < 0.01) and CSS (71% vs. 67% at 1 year, P = 0.01; 51% vs. 40% at 3 years, P < 0.01). On multivariable analysis, diagnosis from 2010–2013 was associated with a lower estimated risk of ACM (hazard ratio 0.77; 95% confidence interval 0.66–0.89, P < 0.001) and CSM (hazard ratio 0.81; 95% confidence interval 0.67–0.97, P = 0.02).

CONCLUSION

Utilization of RT for localized MIBC increased relative to cystectomy from 1992 to 2013, despite the median age of treated patients remaining unchanged. More recent survival outcomes for patients receiving RT were improved, supporting continued use of bladder preservation strategies utilizing RT.

Low dose rate prostate brachytherapy

Low dose rate (LDR) prostate brachytherapy is an evidence based radiation technique with excellent oncologic outcomes. By utilizing direct image guidance for radioactive source placement, LDR brachytherapy provides superior radiation dose escalation and conformality compared to external beam radiation therapy (EBRT). With this level of precision, late grade 3 or 4 genitourinary or gastrointestinal toxicity rates are typically between 1% and 4%. Furthermore, when performed as a same day surgical procedure, this technique provides a cost effective and convenient strategy. A large body of literature with robust follow-up has led multiple expert consensus groups to endorse the use of LDR brachytherapy as an appropriate management option for all risk groups of non-metastatic prostate cancer. LDR brachytherapy is often effective when delivered as a monotherapy, although for some patients with intermediate or high-risk disease, optimal outcome are achieved in combination with supplemental EBRT and/or androgen deprivation therapy (ADT). In addition to reviewing technical aspects and reported clinical outcomes of LDR prostate brachytherapy, this article will focus on the considerations related to appropriate patient selection and other aspects of its use in the treatment of prostate cancer.

Improved Metastasis-Free and Survival Outcomes With Early Salvage Radiotherapy in Men With Detectable Prostate-Specific Antigen After Prostatectomy for Prostate Cancer

Purpose To describe outcomes of salvage radiotherapy (SRT) for men with detectable prostate-specific antigen (PSA) after radical prostatectomy for prostate cancer and identify associations with outcomes. Patients and Methods A total of 1,106 patients received SRT between January 1987 and July 2013, with median follow-up 8.9 years. Outcomes were estimated using Kaplan-Meier for overall survival (OS) and cumulative incidence for biochemical recurrence (BcR), distant metastases (DM), and cause-specific mortality (CSM). Variable associations with outcomes used Cox or Fine-Gray methods, as appropriate. Multiple variable analyses used backward selection with P < .05 for retention. Results In multiple variable analyses, pathologic tumor stage, Gleason score, and pre-SRT PSA were associated with BcR, DM, CSM, and OS; androgen suppression and SRT doses > 68 Gy were associated with BcR; and age was associated with OS. Each pre-SRT PSA doubling increased significantly the relative risk of BcR (hazard ratio [HR], 1.30; P < .001), DM (HR, 1.32; P < .001), CSM (HR, 1.40; P < .001), and all-cause mortality (HR, 1.12; P = .02). Using a pre-SRT PSA cutoff ≤ 0.5 versus > 0.5 ng/mL, 5-year and 10-year cumulative incidences for BcR were 42% versus 56% and 60% versus 68% ( P < .001), DM 7% versus 14% and 13% versus 25% ( P < .001), CSM 1% versus 4% and 6% versus 13% ( P < .001), and OS of 94% versus 92% and 83% versus 73% ( P > .05). Conclusion SRT outcomes are in part affected by factors associated with prostatectomy findings but may be positively affected by using SRT at lower PSA levels, including reductions in BcR, DM, CSM, and all-cause mortality. These findings argue against prolonged monitoring of detectable postprostatectomy PSA levels that delay initiation of SRT.

Patterns of Recurrence After Postprostatectomy Fossa Radiation Therapy Identified by C-11 Choline Positron Emission Tomography/Computed Tomography

PURPOSE

To evaluate C-11 choline positron emission tomography/computed tomography (CholPET) in staging and determining patterns of recurrence in prostate cancer patients with rising prostate-specific antigen levels after prostatectomy radiation therapy (RT).

METHODS AND MATERIALS

The study includes patients with biochemical failure after postprostatectomy RT who underwent CholPET between 2008 and 2015. Patient and disease characteristics were examined in relation to sites of recurrence. All RT dosimetry records were reviewed, and recurrences were mapped on a representative computed tomography dataset with their relationship relative to the irradiated fossa field as out of field (OOF), edge of field (EOF; recurrence within <45-Gy isodose lines), or in field (IF; recurrence within ≥45-Gy isodose lines).

RESULTS

Forty-one patients were identified with 121 sites of recurrence (median 2 sites; interquartile range [IQR], 1-4). The median prostate-specific antigen level at CholPET was 3.1 (IQR, 1.9-5.6) ng/mL. Median interval from RT to biochemical failure was 24 (IQR, 10-46) months, with recurrence identified on CholPET at a median of 15 (IQR, 7-28) months from biochemical failure. Histologic confirmation of recurrence was obtained in 20 patients (49%), with the remainder confirmed by treatment response. Five patients (12%) had IF recurrences, 10 patients (24%) had EOF recurrences (median dose 10 Gy; IQR, 5-30 Gy), and 36 patients (88%) had OOF recurrences. Ten patients had combination failures: 6 (15%) EOF/OOF and 4 (10%) IF/OOF. Fifty-seven recurrences (47%) were pelvic nodal sites inferior to the L5-S1 interspace, of which 52 (43%) were within a pelvic RT field. Eighty-one recurrences (67%) were nodal and inferior to the aortic bifurcation.

CONCLUSIONS

Using CholPET, we found that the majority of patients evaluated for biochemical failure recurred outside of the postprostatectomy RT field. Furthermore, most recurrence sites were nodal and inferior to the aortic bifurcation. These results provide data that may be useful for examining strategies that include elective lymph node irradiation in postprostatectomy patients.

Stranded seed displacement, migration, and loss after permanent prostate brachytherapy as estimated by Day 0 fluoroscopy and 4-month postimplant pelvic x-ray

PURPOSE

The aim of the study was to determine the incidence of local displacement, distant seed migration to the chest, and seed loss after permanent prostate brachytherapy (PPB) with stranded seeds (SSs) using sequential two-dimensional fluoroscopic pelvic and chest x-rays.

METHODS AND MATERIALS

Between October 2010 and April 2014, a total of 137 patients underwent PPB and 4-month followup pelvic and chest x-ray imaging. All patients had exclusively SSs placed and an immediate postimplant fluoroscopic image of the seed cluster. Followup x-ray images were evaluated for the number, location, and displacement of seeds in comparison to Day 0 fluoroscopic images. Significant seed displacement was defined as seed displacement >1 cm from the seed cluster. Followup chest x-rays were evaluated for seed migration to the chest.

RESULTS

Seed migration to the chest occurred in 3 of the 137 patients (2%). Seed loss occurred in 38 of the 137 patients (28%), with median loss of one seed (range, 1-16), and total seeds loss of 104 of 10,088 (1.0%) implanted. Local seed displacement was seen in 12 of the 137 patients (8.8%), and total seeds displaced were 0.15% (15/10,088).

CONCLUSIONS

SS placement in PPB is associated with low rates of substantial seed loss, local displacement, or migration to the chest. Comparing immediate postimplant fluoroscopic images to followup plain x-ray images is a straightforward method to supplement quality assurance in PPB and was found to be useful in identifying cases where seed loss was potentially of clinical significance.

Second malignancies after radiotherapy for prostate cancer: systematic review and meta-analysis

OBJECTIVE

To determine the association between exposure to radiotherapy for the treatment of prostate cancer and subsequent second malignancies (second primary cancers).

DESIGN

Systematic review and meta-analysis of observational studies.

DATA SOURCES

Medline and Embase up to 6 April 2015 with no restrictions on year or language.

STUDY SELECTION

Comparative studies assessing the risk of second malignancies in patients exposed or unexposed to radiotherapy in the course of treatment for prostate cancer were selected by two reviewers independently with any disagreement resolved by consensus.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted study characteristics and outcomes. Risk of bias was assessed with the Newcastle-Ottawa scale. Outcomes were synthesized with random effects models and Mantel-Haenszel weighting. Unadjusted odds ratios and multivariable adjusted hazard ratios, when available, were pooled.

MAIN OUTCOME MEASURES

Second cancers of the bladder, colorectal tract, rectum, lung, and hematologic system.

RESULTS

Of 3056 references retrieved, 21 studies were selected for analysis. Most included studies were large multi-institutional reports but had moderate risk of bias. The most common type of radiotherapy was external beam; 13 studies used patients treated with surgery as controls and eight used patients who did not undergo radiotherapy as controls. The length of follow-up among studies varied. There was increased risk of cancers of the bladder (four studies; adjusted hazard ratio 1.67, 95% confidence interval 1.55 to 1.80), colorectum (three studies; 1.79, 1.34 to 2.38), and rectum (three studies; 1.79, 1.34 to 2.38), but not cancers of the hematologic system (one study; 1.64, 0.90 to 2.99) or lung (two studies; 1.45, 0.70 to 3.01), after radiotherapy compared with the risk in those unexposed to radiotherapy. The odds of a second cancer varied depending on type of radiotherapy: treatment with external beam radiotherapy was consistently associated with increased odds while brachytherapy was not. Among the patients who underwent radiotherapy, from individual studies, the highest absolute rates reported for bladder, colorectal, and rectal cancers were 3.8%, 4.2%, and 1.2%, respectively, while the lowest reported rates were 0.1%, 0.3%, and 0.3%.

CONCLUSION

Radiotherapy for prostate cancer was associated with higher risks of developing second malignancies of the bladder, colon, and rectum compared with patients unexposed to radiotherapy, but the reported absolute rates were low. Further studies with longer follow-up are required to confirm these findings.

Establishment of practice standards in nomenclature and prescription to enable construction of software and databases for knowledge-based practice review

INTRODUCTION

Establishment of standards within a practice and across disease site groups for nomenclatures, prescription formatting, and measured dose-volume histogram (DVH) metrics is a key enabling step for creating software and database solutions to make routine aggregation of dosimetric data for all patients treated in a practice, practical. A process of physician-driven, iterative dialogs coupled with development of technical tools is required to implement the cultural and procedural changes. The cumulative reward for this effort is a database that can be used for defining practice norms, benchmarking against national standards, and tracking dosimetric effects of longitudinal practice pattern changes.

METHODS AND MATERIALS

A 4-year project was carried out to develop and introduce standardizations, modify processes, and develop computer-based tools for reporting, aggregation, and analysis of prescription and DVH metrics. Physician disease site groups developed 42 target and 81 normal tissue templates. From the database of 32,002 DVH metrics, benchmarking was illustrated for a subgroup of breast (281) and prostate (324) patients treated with conventional fractionation over a 16-month period. Breast patients were segregated according to prescription template used: simple (S, tangents only) vs complex (C, tangents + supraclavicular ± intramammary nodes) and left (S-L or C-L) versus right (S-R or C-R).

RESULTS

Prostate patients' median and 50% confidence intervals (CIs) for bladder, stated according to the nomenclature: the percentage of bladder volume receiving doses of ≥40 Gy (V40[%]), V65Gy[%], V70Gy[%], V75Gy[%], and V80Gy[%] were 45.5 (24.9-57.0), 15.6 (9.0-23.8), 7.6 (3.3-13.6), 2.0 (0.0-7.9), and 0.0 (0.0-1.4), respectively. Values for rectum: V50Gy[%], V60 Gy[%], V65Gy[%], V70Gy[%], and V75Gy[%] were 37.1 (27.8-43.5), 21.8 (15.6-25.5), 14.6 (9.6-18.0), 7.7 (1.9-12.3), and 1.0 (0-7.0), respectively. For breast patients, heart:mean Gray values were 1.5 (1.0-2.0), 3.1 (2.2-4.8), 0.4 (0.3-0.7), and 1.1 (0.8-2.2) for S-L, C-L, S-R, and C-R, respectively. Longitudinal, moving window plots of median, 50% CI, and 90% CI for 6-month periods demonstrated the effect of practice changes to reduce heart doses.

CONCLUSIONS

Standardization was challenging as a practice change, but has resulted in significant improvements for both our clinical and research efforts.

Surgery Versus Radiotherapy for Clinically-localized Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

To date, there is no Level 1 evidence comparing the efficacy of radical prostatectomy and radiotherapy for patients with clinically-localized prostate cancer.

OBJECTIVE

To conduct a meta-analysis assessing the overall and prostate cancer-specific mortality among patients treated with radical prostatectomy or radiotherapy for clinically-localized prostate cancer.

EVIDENCE ACQUISITION

We searched Medline, EMBASE, and the Cochrane Library through June 2015 without year or language restriction, supplemented with hand search, using Preferred Reporting Items for Systematic Reviews and Meta-Analysis and Meta-analysis of Observational Studies in Epidemiology guidelines. We used multivariable adjusted hazard ratios (aHRs) to assess each endpoint. Risk of bias was assessed using the Newcastle-Ottawa scale.

EVIDENCE SYNTHESIS

Nineteen studies of low to moderate risk of bias were selected and up to 118 830 patients were pooled. Inclusion criteria and follow-up length varied between studies. Most studies assessed patients treated with external beam radiotherapy, although some included those treated with brachytherapy separately or with the external beam radiation therapy group. The risk of overall (10 studies, aHR 1.63, 95% confidence interval 1.54-1.73, p<0.00001; I(2)=0%) and prostate cancer-specific (15 studies, aHR 2.08, 95% confidence interval 1.76-2.47, p < 0.00001; I(2)=48%) mortality were higher for patients treated with radiotherapy compared with those treated with surgery. Subgroup analyses by risk group, radiation regimen, time period, and follow-up length did not alter the direction of results.

CONCLUSIONS

Radiotherapy for prostate cancer is associated with an increased risk of overall and prostate cancer-specific mortality compared with surgery based on observational data with low to moderate risk of bias. These data, combined with the forthcoming randomized data, may aid clinical decision making.

PATIENT SUMMARY

We reviewed available studies assessing mortality after prostate cancer treatment with surgery or radiotherapy. While the studies used have a potential for bias due to their observational design, we demonstrated consistently higher mortality for patients treated with radiotherapy rather than surgery.

Long-term results of a study using individualized planning target volumes for hypofractionated intensity-modulated radiotherapy boost for prostate cancer

Background

This is the final report of a prospective phase I study which evaluated the feasibility, toxicities, and biochemical control in prostate cancer patients treated with a hypofractionated boost utilizing a fiducial marker-based daily image guidance strategy and small patient-specific PTV margins.

Methods

Low- and intermediate-risk prostate cancer patients underwent transperineal ultrasound-guided implantation of three gold fiducial markers and were treated with three-dimensional conformal radiotherapy to 42 Gy (2 Gy/day). During the first nine fractions of treatment, pre- and post-treatment electronic portal imaging was performed to calculate intrafraction prostate motion. Patient-specific PTV margins were derived and a 30 Gy (3 Gy/day) intensity modulated radiotherapy boost was delivered (Total dose = 72 Gy in 31 fractions; EQD2 = 81 Gy, α/β = 1.4).

Results

Thirty-three patients completed treatment and were followed for a median of 7.2 years (range, 1.2 – 9.5). Seven patients (21%) developed Radiation Therapy Oncology Group (RTOG) late grade 2 GI toxicity and 1 patient (3%) developed late grade 2 GU toxicity. No patients developed late grade 3 GI or GU toxicity. To date, nine patients developed PSA relapse according to the Phoenix criteria. The actuarial five, seven and nine year biochemical control (BC) rates were 87% (95% confidence interval: 69–95), 77% (95% confidence interval: 56–89) and 66% (95% confidence interval: 42–82).

Conclusions

Our study demonstrates that the use of prostate fiducial markers in combination with a daily online image guidance protocol permits reduced, patient-specific PTV margins in a hypofractionated treatment scheme. This treatment planning and delivery strategy was well tolerated in the intermediate time frame. The use of very small PTV margins did not result in excessive failures when compared to other radiation regimens of similar radiobiological intensity.

Neuroendocrine differentiation in prostate cancer: a mechanism of radioresistance and treatment failure

Neuroendocrine differentiation (NED) in prostate cancer is a well-recognized phenotypic change by which prostate cancer cells transdifferentiate into neuroendocrine-like (NE-like) cells. NE-like cells lack the expression of androgen receptor and prostate specific antigen, and are resistant to treatments. In addition, NE-like cells secrete peptide hormones and growth factors to support the growth of surrounding tumor cells in a paracrine manner. Accumulated evidence has suggested that NED is associated with disease progression and poor prognosis. The importance of NED in prostate cancer progression and therapeutic response is further supported by the fact that therapeutic agents, including androgen-deprivation therapy, chemotherapeutic agents, and radiotherapy, also induce NED. We will review the work supporting the overall hypothesis that therapy-induced NED is a mechanism of resistance to treatments, as well as discuss the relationship between therapy-induced NED and therapy-induced senescence, epithelial-to-mesenchymal transition, and cancer stem cells. Furthermore, we will use radiation-induced NED as a model to explore several NED-based targeting strategies for development of novel therapeutics. Finally, we propose future studies that will specifically address therapy-induced NED in the hope that a better treatment regimen for prostate cancer can be developed.

Late gastrointestinal (GI) complications in patients with stage I-II testicular seminoma treated with radiotherapy (RT)

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Background: For stage I-II testicular seminoma, RT is highly effective at eradicating disease in the abdominopelvic lymph nodes, but results in unnecessary exposure to normal tissues including the GI tract. The purpose of this study was to define the incidence and risk factors for late GI complications in this patient population. Methods: A retrospective review was performed of 251 patients with stage I-II testicular seminoma treated with curative intent RT at our institution from 1974-2009. All patients underwent orchiectomy and postoperative external beam RT to the involved and/or at-risk nodal basins. Potential late GI complications that were assessed included endoscopically-confirmed gastric or duodenal ulceration, small bowel obstruction (SBO), and biopsy-confirmed malignancy of the GI tract. Risks were estimated using the Kaplan-Meier (KM) technique and univariate/multivariate analyses were performed using the Cox proportional hazards model. Results: Median age at diagnosis was 36 years (range 18 – 80). Clinical stage was I (n=199) or II (n=52). Median abdominopelvic RT dose was 26 Gy (interquartile range 25 – 30). Median follow-up was 15 years (range 0.1 – 38). KM estimates for any GI complication (ulcer, SBO, or GI malignancy) at 10, 20, and 30 years were 7, 10 and 24%, respectively. Four patients died as result of a GI complication. KM estimates for ulcer at 10, 20, and 30 years were 4, 7, and 9%, respectively. Age at RT (Hazard Ratio [HR] 1.05, 95% Confidence Interval [CI] 1.00 – 1.10, p=0.03) and RT total dose (per Gy, HR 1.20, 95% CI 1.09 – 1.31, p<0.01) were associated with risk of ulcer. KM estimates for SBO at 10, 20, and 30 years were 2%, 2%, and 3%, respectively. History of inflammatory bowel disease was associated with risk of SBO (HR 43, 95% CI 7-325, p<0.01). KM estimates for GI malignancy at 10, 20, and 30 years were 0.5, 3 and 16%, respectively. Age at RT was associated with risk of GI malignancy (HR 1.07, 95% CI 1.02-1.14, p=0.01). Conclusions: In patients with stage I-II testicular seminoma treated with RT, late GI complications were a relatively uncommon, but clinically significant source of late morbidity. Use of low dose, limited field, and/or proton RT may reduce these risks.

Long-term outcomes of radiotherapy for stage II testicular seminoma: The Mayo Clinic experience

327

Background: To report long-term outcomes of patients (pts) treated with radiotherapy (RT) for stage II testicular seminoma.

Methods: Between 1974 and 2007, 52 pts received RT for clinical stage II testicular seminoma after radical inguinal orchiectomy; 3 pts were excluded due to no clinical follow-up. CT staging was used for 46 pts (94%). Estimates of overall (OS), relapse-free (RFS), and cause-specific (CSS) survival were determined using the Kaplan-Meier technique. Major cardiac event (MCE) was defined as myocardial infarction, coronary artery bypass grafting or stenting, or valve replacement. Second malignancy (SM) was defined as biopsy-confirmed malignancy occurring in the RT field.

Results: The median pt age was 35 years. AJCC stage was IIA (n=23), IIB (n=7), IIC (n=15), and unknown (n=4). Three pts were treated for paraortic recurrence during surveillance for stage I seminoma. Four pts with IIB (n=1) or IIC (n=3) disease were treated with chemotherapy in addition to RT. The median total RT dose was 30.4 Gy. Prophylactic mediastinal/supraclavicular (MSCV) RT was given to 24 pts (49%). The median follow-up was 18 years (range 0.4-37). Estimates of OS, RFS, and CSS at 10 and 20 years were 94% and 81%, 79% and 70%, and 96% and 96%, respectively. OS, RFS, and CSS were not significantly different between stage groups. Recurrence occurred in 9 pts (18%); sites were MSCV (n=6), para-aortic (n=1), lung (n=1), and peritoneal cavity (n=1). Seven pts were successfully salvaged, while 2 pts died of seminoma. No patient with stage IIA/B that received prophylactic MSCV RT (n=11) experienced MSCV relapse. Among patients that did not receive prophylactic MSCV RT, 2 of 13 (15%) with stage IIA and 3 of 6 (50%) with stage IIB experienced MSCV relapse. MCE occurred in 10 pts (20%) at a median of 18 years (range 7-30) after RT. SM occurred in 5 pts (10%) at a median of 27 years (range 20-34) after RT.

Conclusions: Infradiaphragmatic RT alone was associated with a significant risk of MSCV failure, particularly in patients with stage IIB disease, suggesting that chemotherapy may be the optimal treatment in this patient cohort. Most MCE and SM events occurred more than 20 years after RT, highlighting the importance of vigilant long-term follow-up.

Quality of life after hypofractionated concomitant intensity-modulated radiotherapy boost for high-risk prostate cancer

PURPOSE

To evaluate the change in health-related quality of life (QOL) of patients with high-risk prostate cancer treated using hypofractionated radiotherapy combined with long-term androgen deprivation therapy.

METHODS AND MATERIALS

A prospective Phase I-II study enrolled patients with any of the following: clinical Stage T3 disease, prostate-specific antigen level ≥20 ng/mL, or Gleason score 8-10. Radiotherapy consisted of 45 Gy (1.8 Gy per fraction) to the pelvic lymph nodes with a concomitant 22.5 Gy intensity-modulated radiotherapy boost to the prostate, for a total of 67.5 Gy (2.7 Gy per fraction) in 25 fractions over 5 weeks. Daily image guidance was performed using three gold seed fiducials. Quality of life was measured using the Expanded Prostate Cancer Index Composite (EPIC), a validated tool that assesses four primary domains (urinary, bowel, sexual, and hormonal).

RESULTS

From 2004 to 2007, 97 patients were treated. Median follow-up was 39 months. Compared with baseline, at 24 months there was no statistically significant change in the mean urinary domain score (p = 0.99), whereas there were decreases in the bowel (p < 0.01), sexual (p < 0.01), and hormonal (p < 0.01) domains. The proportion of patients reporting a clinically significant difference in EPIC urinary, bowel, sexual, and hormonal scores at 24 months was 27%, 31%, 55%, and 60%, respectively. However, moderate and severe distress related to these symptoms was minimal, with increases of only 3% and 5% in the urinary and bowel domains, respectively.

CONCLUSIONS

Hypofractionated radiotherapy combined with long-term androgen deprivation therapy was well tolerated. Although there were modest rates of clinically significant patient-reported urinary and bowel toxicity, most of this caused only mild distress, and moderate and severe effects on QOL were limited. Additional follow-up is ongoing to characterize long-term QOL.