Comparisons of outcomes for patients with high-risk prostate cancer treated with brachytherapy, external beam radiation, or radical prostatectomy

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Background: There is no consensus on how to best treat patients (pts) with high-risk prostate cancer. Methods: The outcomes for 2,736 high-risk prostate cancer pts treated with radical prostatectomy (RP), external beam radiotherapy (RT), and I-125 brachytherapy (BT) at a single institution from 1996 to 2012 were reviewed. The majority of RT pts were treated prior to 2002 because of our preference for RP and BT over time. High-risk was defined per the NCCN criteria. The outcomes assessed were biochemical failure (bF), clinical failure (cF), and prostate cancer mortality (PCM). Results: The distribution by treatment was RP 54%, RT 27%, and BT 19%. The median follow up for all pts was 4.6 years (y) (range 0.1-19.5): 3.8 y (0.1-18.7) for RP, 7.7 y (0.1-19.4) for RT, and 4.1 y (0.1-16.8) for BT pts. No patient received RT+BT, and 44% received androgen deprivation therapy (ADT). On multivariable analysis (see table) RP pts were at higher risk for bF vs. RT; BT pts and RT pts were at higher risk for cF vs. RP; and RT pts were at higher risk for PCM vs. RP. All multivariable analyses were adjusted for clinical stage, biopsy Gleason score, pre-treatment PSA, and duration of ADT. Conclusions: RP is associated with worse bF but better cF and PCM. There is no difference between BT and RT for bF, cF, or PCM while BT and RP had similar PCM. These outcomes may be a result of selection bias or differences in follow up time among the three treatment arms so no demonstration of modality superiority is possible. [Table: see text]

Informed consent conversations and documents: A quantitative comparison

BACKGROUND

Informed consent for clinical research includes 2 components: informed consent documents (ICDs) and informed consent conversations (ICCs). Readability software has been used to help simplify the language of the ICD, but to the authors' knowledge is rarely used to assess the language used during the ICC, which may influence the quality of informed consent. The current analysis was performed to determine whether length and reading levels of transcribed ICCs are lower than their corresponding ICDs for selected clinical trials, and to assess whether investigator experience affected the use of simpler language and comprehensiveness.

METHODS

The current study was a prospective study in which ICCs were audiorecorded at 6 institutions when families were offered participation in pediatric phase I oncology trials. Word count, Flesch-Kincaid Grade Level (FKGL), and Flesch Reading Ease score (FRES) of the ICCs were compared with corresponding ICDs, including the frequency with which investigators addressed 8 prespecified critical consent elements during the ICC.

RESULTS

Sixty-nine unique physician/protocol pairs were identified. Overall, ICCs contained fewer words (4677 vs 6364 words; P = .0016) and had a lower FKGL (6 vs 9.7; P ≤ .0001) and a higher FRES (77.8 vs 56.7; P<.0001) compared with their respective ICDs, but were more likely to omit critical consent elements, such as voluntariness (55%) and dose-limiting toxicities (26%). Years of investigator experience was not correlated with reliably covering critical elements or decreased linguistic complexity.

CONCLUSIONS

Clinicians use more understandable language during ICCs than the corresponding ICD, but appear to less reliably cover elements critical to fully informed consent. Efforts focused at providing communication training for clinician-investigators should be made to optimize the synergy between the ICD and the ICC.

The Impact of Preoperative Radiation Therapy on Locoregional Recurrence in Patients with Stage IV Rectal Cancer Treated with Definitive Surgical Resection and Contemporary Chemotherapy

PURPOSE

Definitive resection of primary rectal cancers is frequently incorporated, with or without preoperative radiotherapy and perioperative chemotherapy, in the management of selected patients with metastatic rectal adenocarcinoma. This study reviews the impact of preoperative radiotherapy and perioperative chemotherapy on locoregional recurrence and overall survival in these patients.

METHODS AND MATERIALS

This retrospective study with an Institutional Review Board (IRB) waiver included 109 patients with metastatic rectal adenocarcinoma who underwent definitive primary resection between 1998 and 2011. In addition to resection, 64 patients were treated with preoperative radiotherapy and perioperative chemotherapy and 45 patients were treated with perioperative chemotherapy alone. Radiotherapy dose was typically 50.4 Gy. Baseline variables were compared using chi-square and unpaired t tests. Overall survival was calculated using Kaplan-Meier method. Univariate and multivariate analyses were performed using Cox proportional hazards regression.

RESULTS

There were no significant baseline differences between the two groups. There was no significant difference in locoregional recurrence (10.9 vs. 11.1%; p = 0.90) or overall survival (34.5 vs. 34.8 months; p = 0.89) for patients treated with preoperative radiotherapy compared to those treated with perioperative chemotherapy alone, respectively. Patients who underwent radiotherapy were less likely to have a positive margin (10.9 vs. 20.0%; p = 0.19), lymphovascular invasion (32.8 vs. 53.3%; p = 0.03), and pathologic stage N2 disease (25.0 vs. 42.2%; p = 0.02). Grade 2 postoperative complications were more common in the preoperative radiotherapy group (32.8 vs. 15.6%; p = 0.04). Multivariate analysis demonstrated that patients with poorly differentiated tumors (HR 2.19; p = 0.009) and those that did not undergo liver-directed therapy (HR 2.20; p = 0.005) had inferior survival.

CONCLUSIONS

Locoregional recurrence is modest in patients with metastatic rectal adenocarcinoma receiving definitive primary resection, irrespective of the use of radiotherapy. Preoperative radiotherapy may enhance pathologic downstaging at the expense of increased grade 2 postoperative complications. Its use should be reserved for patients at high risk for locoregional recurrence.

A Contemporary Prostate Cancer Grading System: A Validated Alternative to the Gleason Score

BACKGROUND

Despite revisions in 2005 and 2014, the Gleason prostate cancer (PCa) grading system still has major deficiencies. Combining of Gleason scores into a three-tiered grouping (6, 7, 8-10) is used most frequently for prognostic and therapeutic purposes. The lowest score, assigned 6, may be misunderstood as a cancer in the middle of the grading scale, and 3+4=7 and 4+3=7 are often considered the same prognostic group.

OBJECTIVE

To verify that a new grading system accurately produces a smaller number of grades with the most significant prognostic differences, using multi-institutional and multimodal therapy data.

DESIGN, SETTING, AND PARTICIPANTS

Between 2005 and 2014, 20,845 consecutive men were treated by radical prostatectomy at five academic institutions; 5501 men were treated with radiotherapy at two academic institutions.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Outcome was based on biochemical recurrence (BCR). The log-rank test assessed univariable differences in BCR by Gleason score. Separate univariable and multivariable Cox proportional hazards used four possible categorizations of Gleason scores.

RESULTS AND LIMITATIONS

In the surgery cohort, we found large differences in recurrence rates between both Gleason 3+4 versus 4+3 and Gleason 8 versus 9. The hazard ratios relative to Gleason score 6 were 1.9, 5.1, 8.0, and 11.7 for Gleason scores 3+4, 4+3, 8, and 9-10, respectively. These differences were attenuated in the radiotherapy cohort as a whole due to increased adjuvant or neoadjuvant hormones for patients with high-grade disease but were clearly seen in patients undergoing radiotherapy only. A five-grade group system had the highest prognostic discrimination for all cohorts on both univariable and multivariable analysis. The major limitation was the unavoidable use of prostate-specific antigen BCR as an end point as opposed to cancer-related death.

CONCLUSIONS

The new PCa grading system has these benefits: more accurate grade stratification than current systems, simplified grading system of five grades, and lowest grade is 1, as opposed to 6, with the potential to reduce overtreatment of PCa.

PATIENT SUMMARY

We looked at outcomes for prostate cancer (PCa) treated with radical prostatectomy or radiation therapy and validated a new grading system with more accurate grade stratification than current systems, including a simplified grading system of five grades and a lowest grade is 1, as opposed to 6, with the potential to reduce overtreatment of PCa.

Impact of timing of biochemical failure on the eventual development of clinical failure after definitive treatment with brachytherapy or external beam radiotherapy for prostate cancer

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Background: Late treatment failure is often considered to be a rare event. We will assess the influence of the timing of biochemical failure (bF) after definitive brachytherapy (BT) or external beam radiotherapy (EBRT) for prostate cancer on its frequency and association with clinical failure (cF). Methods: Patients with prostate cancer treated between 1996 and 2009 with at least 5 years of follow-up (N= 2,293; 1,060 EBRT, 1,233 BT) were studied in the context of an IRB-approved inception cohort study. Those with a bF were reviewed to determine the timing of bF [< 5 years after treatment (bF<5) vs. > 5 years after treatment (bF>5)] and occurrence of cF post-bF. The bF definition used was the nadir + 2.0 ng/mL version. Results: Of the total patient population, 477 (21%) were noted to have bF- 244 (11%) bF<5 vs. 233 (10%) bF>5. The median follow-up after bF for the bF< 5 group is 41 months while in the bF> 5 group it is 22 months. In the BT group, 94 (8%) failed < 5 years and 87 (7%) failed > 5 years. In the EBRT group, 150 (14%) failed < 5 years and 146 (14%) failed > 5 years. The median PSA value (ng/mL) at the time of bF for all patients, EBRT, and BT in the bF<5 group was 3.70, 3.65, and 3.80, respectively (p=not significant). The median PSA value (ng/mL) at the time of bF for all patients, EBRT, and BT in the bF>5 group was 3.01, 3.01, and 3.04, respectively (p=not significant). Overall, 53.3% of patients in the bF<5 group developed cF while 27% of patients in the bF>5 group developed a cF. The actuarial five year rate of cF for the bF <5 group was 50% vs. 38% for the bF>5 group (p= 0.028). The detection of bF and cF was closely linked to PSA testing frequency ( p < 0.0001). Conclusions: The risk of bF does not appear to decrease >5 years post treatment. Late bF (i.e. >5 years after treatment) may still result in eventual cF. While cF is less common after bF > 5 years post definitive therapy, it still affects 27% of those with bF and is strongly associated with PSA testing frequency. The lower rate of cF after 5 years may relate to the shorter follow-up time for this group.

HSD3B1 and resistance to androgen deprivation therapy in prostate cancer

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Background: The somatic mutation HSD3B1(1245A>C) has been mechanistically linked to castration-resistant prostate cancer by encoding a mutant enzyme that augments intratumoral dihydrotestosterone synthesis. Given the HSD3B1(1245C) allele is also frequently found in the germline, we hypothesized men inheriting this variant allele would exhibit resistance to androgen deprivation therapy (ADT), as manifested by worse clinical outcomes. Methods: We used a prospectively maintained prostate cancer registry to identify men treated with ADT for biochemical failure in the post-prostatectomy setting who were without evidence of metastatic disease at the time of ADT initiation. We analyzed progression-free survival, distant metastasis-free survival, and overall survival according to HSD3B1 genotype using Kaplan-Meier methods. Cox proportional hazards regression was performed to evaluate potential gene-dosage effects, with homozygous wild-type men serving as the reference group. Demographic and treatment characteristics were compared across genotypes to assess for possible confounders using Fisher’s exact test and Kruskal-Wallis analysis of variance. Results: Of 118 men genotyped, 37% were homozygous wild-type, 53% were heterozygous, and 10% were homozygous variant. Demographic and treatment characteristics did not differ across groups. Median progression-free survival diminished as a function of the number of variant alleles inherited (6.6 years in homozygous wild-type men, 4.1 years in heterozygotes, and 2.5 years in homozygous variant men; P=0.01). Median distant metastasis-free survival likewise decreased according to the number of variant alleles inherited (9.1 years in homozygous wild-type men, 6.8 years in heterozygotes, and 3.6 years in homozygous variant men; P=0.01). Finally, overall survival also diminished with the number of variant alleles inherited (5-year and 10-year overall survival: 82% and 55% in homozygous wild-type men, 74% and 35% in heterozygotes, and 58% and 0% in homozygous variant men; P=0.006). Conclusions: Inheritance of the variant HSD3B1(1245C) allele that enhances dihydrotestosterone synthesis may predict resistance to ADT for prostate cancer. These findings require validation.

Treatment of Large Brain Metastases With Stereotactic Radiosurgery

Introduction:

We report our series of patients with large brain metastases, >3 cm in diameter, who received stereotactic radiosurgery (SRS) as a component of their treatment, focusing on survival and intracranial recurrence rates.

Materials and Methods:

The brain tumor database was queried for patients treated with SRS for large brain metastases. Local recurrence (LR) and distant brain recurrence (DBR) rates were calculated using cumulative incidence analysis, and overall survival (OS) was calculated using Kaplan-Meier analysis. Patients were classified into 1 of the 4 groups based on treatment strategy: SRS alone, surgery plus SRS, SRS plus whole-brain radiation therapy (WBRT), and salvage SRS from more remote WBRT and/or surgery.

Results:

A total of 153 patients with 164 lesions were evaluated. The SRS alone was the treatment approach in 62 lesions, surgery followed by SRS to the resection bed (S + SRS) in 33, SRS + WBRT in 19, and salvage SRS in 50. There was no statistically significant difference in OS between the 4 treatment groups ( P = .06). Median survival was highest in patients receiving surgery + SRS (12.2 months) followed by SRS + WBRT (6.9 months), SRS alone (6.6 months), and salvage SRS (6.1 months). There was also no significant difference for LR rates between the groups at 12 months. No significant variables on univariate analysis were noted for LR. The 12-month DBR rates were highest in the S + SRS group (52%), followed by salvage SRS (31%), SRS alone (28%), and SRS + WBRT (13%; P = .03).

Conclusion:

There were no significant predictors for local control. Keeping in mind that patient numbers in the SRS + WBRT group are small, the addition of WBRT to SRS did not appear to significantly improve survival or local control, supporting the delayed use of WBRT for some patients to prevent potential side effects provided regular imaging surveillance and salvage therapy are utilized. Prospective studies are needed to optimize SRS treatment regimens for patients with large brain metastases.

Calvarial and skull base metastases: expanding the clinical utility of Gamma Knife surgery

OBJECT

Traditionally, the treatment of choice for patients with metastases to the calvaria or skull base has been conventional radiation therapy. Because patients with systemic malignancies are also at risk for intracranial metastases, the utility of Gamma Knife surgery (GKS) for these patients has been explored to reduce excess radiation exposure to the perilesional brain parenchyma. The purpose of this study was to report the efficacy of GKS for the treatment of calvarial metastases and skull base lesions.

METHODS

The authors performed a retrospective chart review of 21 patients with at least 1 calvarial or skull base metastatic lesion treated with GKS during 2001-2013. For 7 calvarial lesions, a novel technique, in which a bolus was placed over the treatment site, was used. For determination of local control or disease progression, radiation therapy data were examined and posttreatment MR images and oncology records were reviewed. Survival times from the date of procedure were estimated by using Kaplan-Meier analyses.

RESULTS

The median patient age at treatment was 57 years (range 29-84 years). A total of 19 (90%) patients received treatment for single lesions, 1 patient received treatment for 3 lesions, and 1 patient received treatment for 4 lesions. The most common primary tumor was breast cancer (24% of patients). Per lesion, the median clinical and radiographic follow-up times were 10.3 months (range 0-71.9 months) and 7.1 months (range 0-61.3 months), respectively. Of the 26 lesions analyzed, 14 (54%) were located in calvarial bones and 12 (46%) were located in the skull base. The median lesion volume was 5.3 cm(3) (range 0.3-55.6 cm(3)), and the median prescription margin dose was 15 Gy (range 13-24 Gy). The median overall survival time for all patients was 35.9 months, and the 1-year local control rate was 88.9% (95% CI 74.4%-100%). Local control rates did not differ between lesions treated with the bolus technique and those treated with traditional methods or between calvarial lesions and skull base lesions (p > 0.05). Of the 3 patients for whom local treatment failed, 1 patient received no further treatment and 2 patients responded to salvage chemotherapy. Subsequent brain parenchymal metastases developed in 2 patients, who then underwent GKS.

CONCLUSIONS

GKS is an effective treatment modality for patients with metastases to the calvarial bones or skull base. For patients with superficial calvarial lesions, a novel approach with bolus application resulted in excellent rates of local control. GKS provides an effective therapeutic alternative to conventional radiation therapy and should be considered for patients at risk for calvarial metastases and brain parenchymal metastases.

Adjuvant versus neoadjuvant androgen deprivation with radiotherapy for prostate cancer: does sequencing matter?

INTRODUCTION/BACKGROUND

Androgen deprivation therapy (ADT) is typically provided neoadjuvantly and concurrently with radiotherapy (RT) in the management of intermediate and high-risk prostate cancer. Our objective was to compare outcomes between patients who received adjuvant ADT (ADJ), ie, immediately after the completion of RT, to those who received a neoadjuvant and concurrent regimen (NEO).

MATERIALS AND METHODS

From 1995 to 2002, 515 patients with prostate cancer were definitively treated with RT and ADT. NEO was provided 2 to 3 months before the start of RT (n = 311). ADJ was initiated immediately after the completion of RT (n = 204). Kaplan-Meier analysis was used to calculate biochemical relapse-free survival (bRFS), distant metastasis-free survival (DMFS), and overall survival (OS). Cox proportional hazards regression was used to examine the impact of ADT timing on outcomes.

RESULTS

Ten-year bRFS, DMFS, and OS rates were 61%, 80%, and 66%, respectively. Ten-year bRFS rates for ADJ versus NEO were 63% versus 60% (P = .98). Ten-year DMFS rates for ADJ versus NEO were both 80% (P = .60). Ten-year OS rates for ADJ versus NEO were 65% versus 67% (P = .98).

CONCLUSION

There was no significant difference in bRFS, DMFS, or OS between neoadjuvant versus adjuvant ADT in the setting of dose-escalated RT for localized prostate cancer. This suggests that the synergy between RT and androgen deprivation is independent of the sequencing of both modalities and that the initiation of RT does not need to be delayed for a course of neoadjuvant ADT.

Are biochemical recurrence outcomes similar after radical prostatectomy and radiation therapy? Analysis of prostate cancer-specific mortality by nomogram-predicted risks of biochemical recurrence

BACKGROUND

Due to the protracted natural history of the clinical progression of prostate cancer, biochemical recurrence (BCR) is often used to compare treatment modalities. However, BCR definitions and posttreatment prostate-specific antigen kinetics vary considerably among treatments, calling into the question the validity of such comparisons.

OBJECTIVE

To analyze prostate cancer-specific mortality (PCSM) according to treatment-specific nomogram-predicted risk of BCR for men treated by radical prostatectomy (RP), external-beam radiation therapy (EBRT), and brachytherapy.

DESIGN, SETTING, AND PARTICIPANTS

A total of 13 803 men who underwent RP, EBRT, or brachytherapy at two US high-volume hospitals between 1995 and 2008.

INTERVENTION

RP, EBRT, and brachytherapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The 5-yr progression-free probability (5Y-PFP) was calculated for each patient based on the treatment received using a validated treatment-specific nomogram. Fine and Gray competing risk analysis was then used to estimate PCSM by a patient's predicted 5Y-PFP. Multivariable competing risk regression analysis was used to determine the association of treatment with PCSM after adjusting for nomogram-predicted 5Y-PFP.

RESULTS AND LIMITATIONS

Men receiving EBRT had higher 10-yr PCSM compared with those treated by RP across the range of nomogram-predicted risks of BCR: 5Y-PFP >75%, 3% versus 0.9%; 5Y-PFP 51-75%, 6.8% versus 5.9%; 5Y-PFP 26-50%, 12.2% versus 10.6%; and 5Y-PFP ≤25%, 26.6% versus 21.2%. After adjusting for nomogram-predicted 5Y-PFP, EBRT was associated with a significantly increased PCSM risk compared with RP (hazard ratio: 1.5; 95% confidence interval, 1.1-2.0; p=0.006). No statistically significant difference in PCSM was observed between patients treated by brachytherapy and RP, although patient selection factors and lack of statistical power limited this analysis.

CONCLUSIONS

EBRT patients with similar nomogram-predicted 5Y-PFP appear to have a significantly increased risk of PCSM compared with those treated by RP. Comparison of treatments using nomogram-predicted BCR end points may not be valid.

PATIENT SUMMARY

Biochemical recurrence (BCR) outcomes after external-beam radiation therapy and radical prostatectomy are associated with different risks of subsequent prostate cancer-specific mortality. Physicians and patients should cautiously interpret BCR end points when comparing treatments to make treatment decisions.

Evaluation of the current prostate cancer staging system based on cancer-specific mortality in the surveillance, epidemiology, and end results database

BACKGROUND

Prostate cancer is the most common noncutaneous malignancy diagnosed in men. From a large population-based database, this study aimed to report prostate cancer-specific mortality (PCSM) rates of men diagnosed with various presentations of prostate cancer and to examine the adequacy of the current American Joint Committee on Cancer (AJCC) staging system.

PATIENTS AND METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for all patients diagnosed with prostate cancer from 1997 to 2005. PCSM was reported by the classification of extent of disease provided by the SEER database, for clinically staged and pathologically staged cohorts.

RESULTS

Using the cumulative incidence method, PCSM at 10 years for all patients (n = 354,326) was 5% for clinically localized (CL) lesions, 7% for T3aN0M0, 14% for T3bN0M0, 26% for T4N0M0, 27% for TanyN1M0, and 66% for TanyNanyM1. Within the pathologically staged subgroup (n = 108,135), PCSM at 10 years was 1% for CL lesions, 4% for T3aN0M0, 9% for T3bN0M0, 9% for T4N0M0, and 19% for TanyN1M0.

CONCLUSION

Staging of any disease site aims to accurately communicate, prognosticate, and guide management for that particular level of disease. Stage IV prostate cancer is a diverse group, with PCSM in the subgroups ranging from 9% to 68% in this study. Considering the favorable outcomes of those with T4 or N1 nonmetastatic prostate cancer relative to those with M1 disease, the authors propose that T4 or N1 M0 prostate cancer should be reclassified into a new stage IIIB and that patients with such disease should be offered curative-intent therapy whenever possible.

Using Higher Isodose Lines for Gamma Knife Treatment of 1 to 3 Brain Metastases Is Safe and Effective

BACKGROUND:

Higher isodose lines (IDLs) in Gamma Knife (GK) Perfexion treatment of brain metastases (BMet) could result in lower local control (LC) or higher radiation necrosis (RN) rates, but reduce treatment time.

OBJECTIVE:

To assess the impact of the heterogeneity index (HI) and conformality index (CFI) ion local failure (LF) for patients treated with GK for 1 to 3 BMet.

METHODS:

From an institutional review board—approved database, 320 patients with 496 BMet were identified, treated for 1 to 3 BMet from July 2007 to April 2011 on GK Perfexion. Cox proportional hazards regression was used to analyze significance of HI, CFI, IDL, dose, tumor diameter, recursive partitioning analysis class, tumor radioresistance, primary, smoking history, metastasis location, and whole-brain radiation therapy (WBRT) history with LF and RN.

RESULTS:

Median follow-up by lesion was 6.8 months (range, 0-49.6). The series median survival was 14.2 months. Per RECIST, 9.5% of lesions failed, 33.9% were stable, 38.3% partially responded, 17.1% responded completely, and 1.2% could not be assessed. The 12-month LC rate was 87.3%. On univariate analysis, a dose less than 20 Gy (hazard ratio [HR]: 2.940, P &lt; .001); tumor size (HR: 1.674, P &lt; .001); and cerebellum/brainstem location vs other (HR: 1.891, P = .043) were significant for LF. Non-small cell lung cancer (HR: 0.333, P = .0097) was associated with better LC. On multivariate analysis, tumor size (HR: 1.696, P &lt; .001) and cerebellum/brainstem location vs other (HR: 1.959, P = .033) remained significant for LF. Variables not significant for LF included CI, IDL, and HI.

CONCLUSION:

Our study of patients with 1 to 3 BMet treated with GK demonstrated no difference in LC or RN with varying HI, indicating that physicians can treat to IDL at 70% or higher IDL to reduce treatment time without increased LF or RN.

Risk for developing myelodysplastic syndromes in prostate cancer patients definitively treated with radiation

BACKGROUND

Exposure to ionizing radiation has been linked to myelodysplastic syndromes (MDS); it is not clear whether therapeutic radiation doses used for prostate cancer pose an increased MDS risk.

METHODS

We performed a retrospective cohort study of prostate cancer patients diagnosed between 1986 and 2011 at Cleveland Clinic, comparing those who underwent definitive treatment with radical prostatectomy (RP) to radiotherapy either external beam radiotherapy (EBRT) or prostate interstitial brachytherapy (PI) and to population-based registries. Competing risk regression analyses were used to determine the cumulative risk of developing MDS. All statistical tests were two-sided.

RESULTS

Of 10924 patients, 5119 (47%) received radiation (n = 2183 [43%] in EBRT group and n = 2936 [57%] in PI group) and 5805 (53%) were treated with RP. Overall, 31 cases of MDS were observed, with age-adjusted incidence rates no higher than in population-based registries. In univariate analyses, advancing age (hazard ratio [HR] = 1.14; 95% confidence interval [CI] = 1.09 to 1.20; P < .001) and radiotherapy exposure (HR = 3.44; 95% CI = 1.41 to 8.37; P = .007) were statistically significantly associated with development of MDS. In multivariable analyses, although advanced age (HR = 1.13; 95% CI = 1.06 to 1.19; P < .001) remained statistically associated with MDS, radiation did not, although a small non-statistically significant trend existed for PI-treated patients. MDS rates were no higher than in population-based registries.

CONCLUSIONS

With relatively short follow-up, prostate cancer patients definitively treated with radiation did not appear to have a statistically increased risk of subsequent MDS.

Long-term clinical and toxicity outcomes of hypofractionated intensity-modulated radiation therapy for clinically localized prostate cancer

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Background: As an alternative to dose-escalated conventionally fractionated radiotherapy, hypofractionation capitalizes on the unique radiobiology of prostate cancer cells. This study reports the long-term clinical outcomes and late treatment-related toxicities in patients with clinically localized prostate adenocarcinoma treated with hypofractionated radiation therapy at a single tertiary-care institution. Methods: Between 1996 and 2008, 822 patients were treated with hypofractionated intensity modulated radiation therapy (IMRT) (70 Gy in 2.5 Gy/fraction) directed to the prostate gland with or without coverage of the seminal vesicles over a 5.5 week period. Actuarial rates of biochemical relapse free survival by the nadir + 2 definition (bRFS), distant metastasis free survival (DMFS), and overall survival (OS) were calculated using the Kaplan-Meier method. Acute and late genitourinary (GU) and gastrointestinal (GI) toxicity outcomes were available and measured according to the National Cancer Institute Common Toxicity Criteria (v3) in 773 (94%) of the patients. Results: The median follow-up was 8.5 years (range: 0-14.2 years). The overall 10-year bRFS, DMFS, and OS rates were 69.6%, 86.4%, and 71.7%, respectively. By National Comprehensive Cancer Network (NCCN) low-, intermediate-, and high-risk groups, the 10-year bRFS rates were 86.9%, 74.1%, and 41.3%, respectively. The rate of grade 2 or worse late genitourinary (GU) and gastrointestinal (GI) toxicity rates were 17.2% and 5.6 %. Only 1.4% of patients experienced late equal to or greater than grade 3 GU toxicity and 1.0% experienced late greater than or equal to grade 3 GI toxicity. Of those who had any toxicity during the follow-up period, 47% and 65% of patients experienced resolution or improvement in their GU and GI symptoms, respectively. Conclusions: Hypofractionated IMRT for localized prostate cancer provides excellent long-term relapse-free survival rates that are comparable to historical studies using conventional fractionation. With modern IMRT and image guidance, HFRT has an acceptably low incidence of late GU and GI toxicities, and appears to be a suitable treatment alternative to conventional fractionation.

Does up-front definitive surgical resection with delayed chemotherapy in patients with stage IV rectal cancer compromise overall survival?

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Background: Definitive resection of the primary is frequently part of the management of patients (pts) with stage IV rectal cancer with good performance status and low volume of systemic metastases. It is unclear whether delaying systemic therapy for up front surgical management of the primary compromises overall survival (OS). Methods: Pts with metastatic rectal adenocarcinoma who received definitive surgical resection between 1998-2011 were identified in an IRB approved registry. The sequencing of CT and surgery, and the use of perioperative radiation therapy (RT), was at the discretion of treating physicians. Preoperative chemotherapy (Pre-CT) regimens included 5-fluorouracil (5-FU) +/- leukovorin (LV), capecitabine, 5-FU/LV/oxaliplatin +/- avastin, or 5-FU/LV/irinocetan. RT dose was typically 50.4 Gy. OS was measured from the date of diagnosis. Baseline variables were compared using the Chi-square and unpaired t-tests. OS was calculated using the Kaplan Meier method. Univariate (UVA) and multivariate analysis (MVA) were performed using Cox proportional hazards regression to identify variables associated with OS. Results: In this study of 115 pts, 75 (65%) were treated with pre-CT, while 40 (35%) were treated with up front surgery. Of the pts who received surgery up front, 3 (8%) received RT and of the pts who received pre-CT, 62 (83%) received RT. The cohort was predominantly male (70%) with a median age of 57, median KPS of 80, and median follow-up of 24.1 months. 94% of pts had T3/T4 tumors, 80% had N+ disease, and 33% had poorly differentiated tumors. Liver directed therapy (LDT) was performed in 61% of pts. There was no significant difference in OS (32.3 vs. 32 months; p = 0.24) between pts treated with pre-CT and those who received surgery up front, respectively. UVA demonstrated that pre-CT was not associated with OS (HR 1.26; p = 0.544). MVA demonstrated that pts with poorly differentiated tumors (HR 2.04; p = 0.007) and those that did not undergo LDT (HR 2.45; p = 0.001) had inferior survival. Conclusions: Delaying systemic chemotherapy in order to achieve local control with surgical resection up front does not appear to impact OS in pts with stage IV rectal cancer.