Clinical utility of the percentage of positive prostate biopsies in predicting prostate cancer-specific and overall survival after radiotherapy for patients with localized prostate cancer

Machine-Learning Models for Multicenter Prostate Cancer Treatment Plans

Clinical factors, including T-stage, Gleason score, and baseline prostate-specific antigen, are used to stratify patients with prostate cancer (PCa) into risk groups. This provides prognostic information for a heterogeneous disease such as PCa and guides treatment selection. In this article, we hypothesize that nonclinical factors may also impact treatment selection and their adherence to treatment guidelines. A total of 552 patients with intermediate- and high-risk PCa treated with definitive radiation with or without androgen deprivation therapy (ADT) between 2010 and 2017 were identified from 34 medical centers within the Veterans Health Administration. Medical charts were manually reviewed, and details regarding each patient's clinical history and treatment were extracted. Support Vector Machine and Random forest-based classification was used to identify clinical and nonclinical predictors of adherence to the treatment guidelines from the National Comprehensive Cancer Network (NCCN). We created models for predicting both initial treatment intent and treatment alterations. Our results demonstrate that besides clinical factors, the center in which the patient was treated (nonclinical factor) played a significant role in adherence to NCCN guidelines. Furthermore, the treatment center served as an important predictor to decide on whether or not to prescribe ADT; however, it was not associated with ADT duration and weakly associated with treatment alterations. Such center-bias motivates further investigation on details of center-specific barriers to both NCCN guideline adherence and on oncological outcomes. In addition, we demonstrate that publicly available data sets, for example, that from Surveillance, Epidemiology, and End Results (SEERs), may not be well equipped to build such predictive models on treatment plans.

Survival after radiotherapy vs. radical prostatectomy for unfavorable intermediate-risk prostate cancer

BACKGROUND

The optimal treatment for unfavorable intermediate-risk prostate cancer is unknown. Given the lack of randomized evidence, large comparative studies may be useful in guiding clinical decision-making.

METHODS

We queried the National Cancer Database for patients with unfavorable intermediate-risk prostate cancer, as defined by the National Comprehensive Cancer Network. We compared overall survival between patients treated with radical prostatectomy (RP), external beam radiation therapy (EBRT), brachytherapy, and EBRT plus brachytherapy (EBRT+BT) using Cox proportional hazards models and propensity score matching.

RESULTS

A total of 10,439 patients were analyzed. There was no statistically significant difference in overall survival between RP and EBRT+BT (hazard ratio [HR] = 1.24; 95% confidence interval [CI] 0.58-2.65). RP was associated with higher survival when compared to EBRT (HR = 2.30, 95% CI 1.70-3.20) and brachytherapy (HR = 2.90, 95% CI 1.40-6.20). When accounting for androgen deprivation therapy (ADT), there was no statistically significant difference in survival between RP and brachytherapy with ADT (HR = 3.08; 95% CI 0.62-15.27) or EBRT to a dose of ≥7920 cGy with ADT (HR = 2.6, 95% CI 0.50-13.20).

CONCLUSION

We found no statistically significant difference in survival between RP and EBRT+BT. EBRT and brachytherapy had higher mortality, respectively, compared to RP. When including only radiotherapy patients who received ADT and, in the case of EBRT, a total dose ≥ 7920 cGy, there was no statistically significant difference in survival when comparing RP to EBRT or brachytherapy. These findings should be prospectively studied.

Mutant Kras-induced upregulation of CD24 enhances prostate cancer stemness and bone metastasis

Prostate cancer (PCA), one of the most common malignant tumors in men, is the second leading cause of cancer deaths in males worldwide. We report here that PCA models harboring conditional LSL/KrasG12D or BRAFF-V600E allele with prostate-specific abrogated p53 function recapitulate human PCA precursor lesions, histopathology, and clinical behaviors. We found that the development of reprogrammed EMT-like phenotypes and skeleton metastatic behavior requires concurrent activated Kras and p53 depletion in PCA. Microarray analyses of primary PCA cells derived from these models identified several cancer stemness genes including CD24, EpCAM, and CD133 upregulated by KRASG12D. Among these stemness markers, we identified CD24 as a key driver of tumorigenesis and metastasis in vivo. These data demonstrate that specific factors involved in cancer stemness are critical for metastatic conversion of PCA and may be ideal targets for therapeutic intervention.

Prostate cancer reporting and staging: needle biopsy and radical prostatectomy specimens

Prostatic adenocarcinoma remains the most common cancer affecting men. A substantial majority of patients have the diagnosis made on thin needle biopsies, most often in the absence of a palpable abnormality. Treatment choices ranging from surveillance to radical prostatectomy or radiation therapy are largely driven by the pathologic findings in the biopsy specimen. The first part of this review focuses on important morphologic parameters in needle biopsy specimens that are not covered in the accompanying articles. This includes tumor quantification as well as other parameters such a extraprostatic extension, seminal vesicle invasion, perineural invasion, and lymphovascular invasion. For those men who undergo radical prostatectomy, pathologic stage and other parameters are critical in prognostication and in determining the appropriateness of adjuvant therapy. Staging parameters, including extraprostatic extension, seminal vesicle invasion, and lymph node status are discussed here. Surgical margin status is also an important parameter and definitions and reporting of this feature are detailed. Throughout the article the current reporting guidelines published by the College of American Pathologists and the International Collaboration on Cancer Reporting are highlighted.

The dog prostate cancer (DPC-1) model: a reliable tool for molecular imaging of prostate tumors and metastases

Background

Clinical applicability of newly discovered reagents for molecular imaging is hampered by the lack of translational models. As the dog prostate cancer (DPC-1) model recapitulates in dogs the natural history of prostate cancer in man, we tested the feasibility of single-photon emission computed tomography (SPECT)/CT imaging in this model using an anti-prostate-specific membrane antigen (PSMA)/17G1 antibody as the radiotracer.

Methods

Immunoblots and immunohistochemistry (IHC) with 17G1 were performed on canine and human prostate cancer cell lines and tissues. Five dogs with DPC-1 tumors were enrolled for pelvic and, in some instances, thoracic SPECT/CT procedures, also repeated over time. Controls included ¹¹¹indium (In)-17G1 prior to DPC-1 implantation and ¹¹¹In-immunoglobulins (IgGs) prior to imaging with ¹¹¹In-17G1 in dogs bearing prostatic DPC-1 tumors.

Results

17G1 cross-reactivity with canine PSMA (and J591) was confirmed by protein analyses on DPC-1, LNCaP, and PC-3 cell lines and IHC of dog vs. human prostate tissue sections. 17G1 stained luminal cells and DPC-1 cancer cells in dog prostates similarly to human luminal and cancer cells of patients and LNCaP xenografts. SPECT/CT imaging revealed low uptake (≤2.1) of both ¹¹¹In-17G1 in normal dog prostates and ¹¹¹In-IgGs in growing DPC-1 prostate tumors comparatively to ¹¹¹In-17G1 uptake of 3.6 increasing up to 6.5 values in prostate with DPC-1 lesions. Images showed a diffused pattern and, occasionally, a peripheral doughnut-shape-like pattern. Numerous sacro-iliac lymph nodes and lung lesions were detected with contrast ratios of 5.2 and 3.0, respectively. The highest values were observed in pelvic bones (11 and 19) of two dogs, next confirmed as PSMA-positive metastases.

Conclusions

This proof-of-concept PSMA-based SPECT/CT molecular imaging detecting primary prostate tumors and metastases in canines with high cancer burden speaks in favor of this large model’s utility to facilitate technology transfer to the clinic and accelerate applications of new tools and modalities for tumor staging in patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13550-015-0155-6) contains supplementary material, which is available to authorized users.

The development of nomograms for stratification of men at risk of prostate cancer prior to prostate biopsy

A main limitation of early prostate cancer (PCa) detection due to elevated PSA levels is caused by the low specificity of PSA, which is associated with a high proportion of men detected with nonmalignant findings at first or subsequent prostate biopsy (PBX). Multivariate prediction models, such as nomograms, have been developed, providing a more accurate method to prospectively determine the risk of a positive PBX. Combining established clinical risk factors with novel diagnostic markers of PCa appears promising to further improve predictive accuracy estimates. Ideally, these nomograms should be capable of identifying PCa at PBX without missing men with high-grade PCa, and preventing a significant proportion of men without, or with insignificant, PCa from undergoing PBX. The intention is to reduce disease morbidity and mortality by detecting significant PCa at an early stage, and at the same time to avoid overdiagnosis as well as overintervention.

Prognostic factors for newly diagnosed prostate cancer and their role in treatment selection

Adenocarcinoma of the prostate is extremely heterogeneous, ranging from an indolent chronic illness to an aggressive rapidly fatal systemic malignancy. The classic prognostic factors of tumor stage, prostate specific antigen level, and Gleason score have been used for over a decade to categorize patients at the time of diagnosis into broad risk groups that help to determine appropriate management. Although the grouping of patients into favorable, intermediate, and high-risk categories has become standard, and the categories continue to define distinct prognostic subgroups, considerable heterogeneity exists within each risk group. As a range of management options are available, additional prognostic factors can be considered when determining the treatment approach for an individual patient. We review these additional prognostic variables under the headings of patient-related, tumor-related, and treatment-related. The influence of each of these factors may vary depending on treatment factors such as dose, the radiation modality, or the use of concomitant androgen ablation.

Age and Racial Differences among PSA-Detected (AJCC Stage T1cN0M0) Prostate Cancer in the U.S.: A Population-Based Study of 70,345 Men

Purpose: Few studies have evaluated the risk profile of prostate-specific antigen (PSA)-detected T1cN0M0 prostate cancer, defined as tumors diagnosed by needle biopsy because of elevated PSA levels without other clinical signs of disease. However, some men with stage T1cN0M0 prostate cancer may have high-risk disease (HRD), thus experiencing inferior outcomes as predicted by a risk group stratification model.

Methods: We identified men diagnosed with stage T1cN0M0 prostate cancer from 2004 to 2008 reported to the surveillance, epidemiology, and end results (SEER) program. Multivariate logistic regression was used to model the probability of intermediate-risk-disease (IRD) (PSA ≥ 10 ng/ml but <20 ng/ml and/or GS 7), and high-risk-disease (HDR) (PSA ≥ 20 ng/ml, and/or GS ≥ 8), relative to low-risk disease (LRD) (PSA < 10 ng/ml and GS ≤ 6), adjusting for age, race, marital status, median household income, and area of residence.

Results: A total of 70,345 men with PSA-detected T1cN0M0 prostate cancer were identified. Of these, 47.6, 35.9, and 16.5% presented with low-, intermediate-, and high-risk disease, respectively. At baseline (50 years of age), risk was higher for black men than for whites for HRD (OR 3.31, 95% CI 2.85–3.84). The ORs for age (per year) for HRD relative to LRD were 1.09 (95% CI 1.09–1.10) for white men, and as 1.06 (95% CI 1.05–1.07) for black men. Further, among a subgroup of men with low PSA (<10 ng/ml) T1cN0M0 prostate cancer, risk was also higher for black man than for white men at baseline (50 years of age) (OR 2.70, 95% CI 2.09–3.48). The ORs for age (per year) for HRD relative to LRD were 1.09 (95% CI 1.09–1.10) for white men, and as 1.06 (95% CI 1.05–1.07) for black men.

Conclusion: A substantial proportion of men with PSA-detected prostate cancer as reported to the SEER program had HRD. Black race and older age were associated with a greater likelihood of HRD.

La Radioterapia Nel Trattamento Del Carcinoma Della Prostata: Indicazioni, Evoluzione Tecnologica e Approcci Integrati

Prostate cancer is a heterogeneous, indolent or sometimes aggressive tumor. Treatment options are various and without proved superiority. Radiotherapy (RT) plays a key role in the disease history. Technological evolution with Intensity Modulate Radiation Therapy (IMRT) and Image Guided Radiation Therapy (IGRT) allowed improvement, with significant results on local control and survival. Hypofractionation, Stereotactic Body RT (SBRT) and new brachytherapy approachs are still under investigation, with promising opportunities. Adjuvant vs salvage postoperative RT, hormone association, prophylactic pelvic irradiation are still under debate, but guidelines express overlapping indications.

Multidisciplinary managements will be the future for care optimization, providing the best tool for holistic and informed patients' choice.

The impact of dose-escalated radiotherapy plus androgen deprivation for prostate cancer using 2 linked nomograms

BACKGROUND

Randomized trials have demonstrated that escalated-dose external-beam radiotherapy (EDRT) is better than standard-dose radiotherapy (SDRT) for patients with prostate cancer and that adding androgen-deprivation therapy (ADT) to SDRT is better than SDRT alone; however, no trials have compared EDRT versus SDRT plus ADT or EDRT versus EDRT plus ADT. The authors designed a model to estimate the results of various doses of radiotherapy (RT) combined with various durations of ADT.

METHODS

From 1989 to 2007, 3215 men consecutively received definitive EDRT with or without ADT. In total, 2012 patients had complete records available for creating the nomogram. The duration of ADT varied for patients who received no RT (n = 1562), ≤6 months of RT (n = 145), from >6 months to <24 months of RT (n = 140), and ≥24 months of RT (n = 165) with a median follow-up of 65.7 months, 66.2 months, 60.1 months, and 63 months, respectively. The model included the following covariates: palpation T-category, biopsy Gleason score, the percentage of tumor cells with a Gleason pattern of 4 or 5, the percentage of tumor tissue, initial pretreatment prostate-specific antigen (PSA) level, ADT duration, and RT dose. Two nomograms, for outcomes with and without ADT, were created from a single competing-risks model. Biochemical failure was defined as a rise in serum PSA of 2 ng/mL over the post-treatment PSA nadir.

RESULTS

According to the results from analyzing representative intermediate-risk to high-risk patient parameters, the gains from increasing the RT dose from 70 Gray (Gy) to 80 Gy were far less than the gains from adding ≥3 months of ADT.

CONCLUSIONS

The nomograms provided unique patient-specific estimates of the effects of various doses and durations of RT and ADT. The results indicated that adding ADT to treatment for intermediate-risk and high-risk prostate cancer is far more beneficial than a modest RT dose escalation.

Critical review of prostate cancer predictive tools

Prostate cancer is a very complex disease, and the decision-making process requires the clinician to balance clinical benefits, life expectancy, comorbidities and potential treatment-related side effects. Accurate prediction of clinical outcomes may help in the difficult process of making decisions related to prostate cancer. In this review, we discuss attributes of predictive tools and systematically review those available for prostate cancer. Types of tools include probability formulas, look-up and propensity scoring tables, risk-class stratification prediction tools, classification and regression tree analysis, nomograms and artificial neural networks. Criteria to evaluate tools include discrimination, calibration, generalizability, level of complexity, decision analysis and ability to account for competing risks and conditional probabilities. The available predictive tools and their features, with a focus on nomograms, are described. While some tools are well-calibrated, few have been externally validated or directly compared with other tools. In addition, the clinical consequences of applying predictive tools need thorough assessment. Nevertheless, predictive tools can facilitate medical decision-making by showing patients tailored predictions of their outcomes with various alternatives. Additionally, accurate tools may improve clinical trial design.

Inventory of prostate cancer predictive tools

PURPOSE OF REVIEW

We created an inventory of current predictive tools available for prostate cancer. This review may serve as an initial step toward a comprehensive reference guide for physicians to locate published nomograms that apply to the clinical decision in question. Using MEDLINE a literature search was performed on prostate cancer predictive tools from January 1966 to November 2007. We describe the patient populations to which they apply and the outcomes predicted, and record their individual characteristics.

RECENT FINDINGS

The literature search generated 111 published prediction tools that may be applied to patients in various clinical stages of disease. Of the 111 prediction tools, only 69 had undergone validation. We present an inventory of models with input variables, prediction form, number of patients used to develop the prediction tools, the outcome being predicted, prediction tool-specific features, predictive accuracy, and whether validation was performed.

SUMMARY

Decision rules, such as nomograms, provide evidence-based and at the same time individualized predictions of the outcome of interest. Such predictions have been repeatedly shown to be more accurate than those of clinicians, regardless of their level of expertise. Accurate risk estimates are also required for clinical trial design, to ensure homogeneous high-risk patient groups for whom new cancer therapeutics will be investigated.

Staging for prostate cancer: time to incorporate pretreatment prostate-specific antigen and Gleason score?

BACKGROUND

The American Joint Committee on Cancer (AJCC) staging system for prostate cancer is based primarily based on clinical tumor (T) classification. In this article, the authors summarize arguments for incorporating additional pretreatment parameters and creating a new staging system for prostate cancer.

METHODS

Men with localized prostate cancer who received treatment with external beam radiation alone were analyzed using the 1997 AJCC staging system compared with a system that included pretreatment prostate-specific antigen (pPSA) level and Gleason score (GS). Multivariate analyses using a Cox proportional-hazards model were carried out to evaluate T classification, GS, and pPSA as predictors of overall survival (OS), disease-specific survival (DSS), and freedom from PSA failure (FFPF). RESULTS.: Based on pretreatment characteristics in a series of contemporary patients, only 0.6% of patients were classified with AJCC stage I disease, 16.0% were classified with AJCC stage III disease, and 83.4% were classified with AJCC stage II disease. Multivariate analyses indicated the independent statistical significance of T classification, GS, and pPSA in predicting OS, DSS, and FFPF (model chi-square value, P < .0001 for each). Using these 3 predictors, subsets of patients who had similar outcomes were combined to provide examples of the insensitivity of the AJCC system for predicting outcomes. Incorporating pPSA and GS allowed the identification of differences in OS, DSS, and FFPF for subsets of patients with AJCC stage II disease (P < .0001, P = .005, and P < .0001, respectively).

CONCLUSIONS

The current AJCC staging system does not divide contemporary patients with prostate cancer into prognostic subgroups and does not identify patients who have comparable biochemical control and survival. The AJCC staging system for prostate cancer should be changed to incorporate pPSA, GS, and risk stratification.

Defining High Risk Prostate Cancer With Risk Groups and Nomograms: Implications for Designing Clinical Trials

PURPOSE

Death from prostate cancer is usually preceded by metastases and it usually occurs in men with high risk disease who experienced biochemical failure with a short prostate specific antigen doubling time. We developed a model for determining disease specific survival in prostate cancer.

MATERIALS AND METHODS

We used the model for defining high risk prostate cancer that was developed by the Radiation Therapy Oncology Group and combined it with the Kattan nomogram for predicting the risk of metastases. We selected 414 Radiation Therapy Oncology Group intermediate and high risk patients who were treated with external beam radiotherapy alone. Excluded were patients with low risk disease. The Kaplan-Meier product limit method was used to estimate the probability of freedom from biochemical failure, overall survival and disease specific survival.

RESULTS

A significant difference was observed in freedom from biochemical failure, disease specific survival and overall survival among the 3 tertiles created by the nomogram using the cutoff points less than 8.5%, 8.5% to 15% and greater than 15% (p <0.001, 0.0002 and 0.0003, respectively). Only the risk of metastases using the categorized nomogram score (less than 8.5% and 8.5% to 15% vs greater than 15%), not preradiotherapy prostate specific antigen or Radiation Therapy Oncology Group risk (Radiation Therapy Oncology Group 2 vs 3), was a significant predictor of disease specific and overall survival for intermediate/high risk patients and intermediate/high risk with 15% or less risk for metastases.

CONCLUSIONS

We combined a risk group stratification scheme for disease specific survival with a nomogram predicting the risk of metastases and created a model that may be useful for designing phase III trials with metastases and disease specific survival as study end points.

Reliability of small amounts of cancer in prostate biopsies to reveal pathologic grade

OBJECTIVES

To examine grade reliability when biopsies contain very small amounts of prostate cancer. Prostate biopsy findings are known to undergrade prostate cancer compared with the pathologic specimens yet remain the only grade guiding disease management.

METHODS

The presence of a clinically significant grade change from biopsy cores to matched prostatectomy specimens was examined in 371 patients. The biopsies were characterized for primary and secondary Gleason grade, number of positive cores, and total linear length of cancer. The pathologic specimens were characterized for cancer volume and relative percentage by grade. The rates of upgrading or downgrading were tested against all clinical and biopsy information for any significant predictive value.

RESULTS

The overall rate of upgrading was 40.7% and downgrading was 16.1%. Upgrading was constant and independent of any clinical or biopsy tumor volume indexes. Specifically, when cancer was present in only one biopsy core and measured 2 mm or less (n = 48), it was just as predictive of the pathologic grade as that from any greater number of positive cores and any greater extent of cancer length present. Downgrading was less frequent for biopsies with small amounts of cancer.

CONCLUSIONS

Histologic grading from small amounts of cancer in prostate biopsies is reliable and not more prone to grading errors. A repeat biopsy for these patients may not be indicated.

[Prostate cancer: Diagnosis and staging]

The discovery and the use of serum prostate specific antigen (PSA) has considerably improved the diagnosis of prostate cancer during the past 20 years. Before PSA era, early diagnosis was only based on the digital rectal examination (DRE) of which the Limitations have been evidenced; over half of the tumours diagnosed by such means had already spread out of the prostate and were incurable. Assessment of serum PSA has allowed the diagnosis to be made at an earlier stage of the disease, curable by current treatments. Whichever the diagnostic tools, transrectal ultrasound (TRUS) prostatic biopsies remain necessary for diagnosis ascertainment, taking into account the low specificity of PSA assessment. The feasibility of a diagnosis at an early and curable stage of the disease has logically resulted in screening procedures aimed at reducing the high mortality related to prostate cancer. The numerous publications on prostate cancer screening provide precise information on the accuracy of available diagnostic means (PSA, DRE, TRUS, combined PSA and DRE), on the characteristics of screened tumours (stage and differentiation), and also on the population of men likely to benefit from the screening (age at beginning and end of the screening, frequency of PSA testing, identification of the men with ethnic and/or genetic predisposition). In those early diagnosed prostate cancers, the assessment of loco-regional cancer extension (extracapsular and/or, microscopic nodal involvement), remains unsatisfactory because no imaging technique (ultrasonography, CT scan, MRI,...) allows visualising the tumour itself or microscopic metastases. Nevertheless, the combination of multiple parameters such as DRE data, PSA level, biopsy data and tumour differentiation helps approaching with an increasing precision (nomograms) the true pathologic stage of the disease. Such advances allow distinguishing, among the very heterogeneous group of prostate cancers, tumours that differ from one to another in terms of disease stage, progression and prognosis, which is helpful for the determination of an adapted therapeutic strategy.

Association of percent positive prostate biopsies and perineural invasion with biochemical outcome after external beam radiotherapy for localized prostate cancer

PURPOSE

Few studies have evaluated the significance of the percentage of positive biopsies (PPB) and perineural invasion (PNI) for patients treated with external beam radiotherapy (EBRT) for localized prostate cancer. Our goal was to investigate the value of these factors in predicting biochemical control (bNED) after EBRT.

METHODS AND MATERIALS

The study cohort consisted of 331 patients who received EBRT between 1993 and 1999 for clinically localized prostate cancer. The median follow-up was 4.4 years (range, 3 months to 9.6 years). The distribution by clinical T stage was as follows: T1 in 55 (17%), T2a in 94 (28%), T2b in 76 (23%), T2c in 74 (22%), T3a in 27 (8%), and T3b in 5 (2%). The pretreatment prostate-specific antigen (iPSA) level was < or =10 ng/mL in 224 patients, 10.1-20 ng/mL in 72 patients, and >20 ng/mL in 35 patients. The biopsy Gleason score was < or =6 in 216 patients and > or =7 in 115 patients. On the basis of the pathology report, the PPB was calculated for 239 patients and was < or =33% in 109, 34-66% in 72, and > or =67% in 58 patients. PNI was present in 30 patients. The median dose of EBRT was 68.4 Gy (range, 64-71 Gy). Patients were categorized into three risk groups: 142 patients were low risk (T1-T2, iPSA < or =10 ng/mL, and Gleason score < or =6), 137 were intermediate risk (increase in the value of one of the risk factors); and 52 patients were high risk (increase in value of two or more of the risk factors). Biochemical failure was defined as three consecutive rises in the PSA level.

RESULTS

The 5-year bNED rate for the entire cohort was 62%. The 5-year bNED rate for the low-, intermediate, and high-risk group was 79%, 51%, and 47%, respectively (p <0.0001). On univariate analysis (log-rank test), clinical stage (p = 0.0073), grade (p <0.0001), iPSA (p = 0.0043), risk group (p <0.0001), PPB (p = 0.0193), and presence of PNI (p = 0.0137) correlated with bNED. For T1-T2a, T2b-T2c, and T3 patients, the 5-year bNED rate was 71%, 59%, and 40%, respectively. The 5-year bNED rate was 68% for those with an iPSA level of < or =10 ng/mL and 49% for those with an iPSA level of >10 ng/mL. For patients with PPB < or =33%, 34-66%, and > or =67%, the 5-year bNED rate was 75%, 67%, and 51%, respectively. Within the intermediate-risk group, the PPB was significantly associated with the bNED rate: 67%, 52%, and 30% for those with PPB < or =33%, 34-66%, and > or =67%, respectively (p = 0.0046). This association was not seen in the low- or high-risk group. The 5-year bNED rate was 64% for patients without PNI and 48% for those with PNI. On multivariate analysis (Cox proportional hazards model), the statistically significant predictive factors for bNED were risk group (p = 0.0032) and PPB (p = 0.044). Using the chi-square test, statistically significant associations between T stage, PSA level, Gleason score, and risk group with PPB were found; PNI was significantly associated with T stage and PSA level only.

CONCLUSION

Our results showed that PPB and PNI have a statistically significant impact on the bNED rate in patients treated with conventional dose of EBRT (< or =71 Gy). Within the intermediate-risk group, the PPB was predictive of bNED, suggesting that patients with < or =33% PPB had a statistically significant better treatment outcome compared with those with a greater PPB. PNI was not significant for bNED in multivariate analysis. The effects of these two prognostic factors in patients who have been treated with higher doses of RT (> or =75.6 Gy) should be studied.

Avaliação da resposta bioquímica no câncer inicial de próstata: experiência uninstitucional comparando teleterapia exclusiva ou associada à braquiterapia de alta taxa de dose

OBJETIVO: Análise comparativa da resposta bioquímica em pacientes submetidos à teleterapia exclusiva ou associada à braquiterapia de alta taxa de dose para tumores localizados da próstata. MATERIAIS E MÉTODOS: De novembro de 1997 a janeiro de 2000, 74 pacientes foram submetidos à teleterapia com 45 Gy e reforço com braquiterapia de alta taxa de dose com irídio-192 e dose de 16 Gy em quatro inserções (BT). Estes foram comparados a 29 pacientes submetidos à teleterapia com 45 Gy e reforço com arcoterapia e dose mediana de 24 Gy (RT) entre outubro de 1996 e fevereiro de 2000. Nos dois grupos houve associação ocasional de hormonioterapia neoadjuvante. Sobrevida atuarial livre de doença em três anos (SB3) e fatores prognósticos pré-tratamento da resposta bioquímica, como o antígeno prostático-específico inicial (PSAi), escore de Gleason da biópsia de próstata (EG) e estádio clínico (EC), foram analisados. RESULTADOS: O seguimento mediano foi de 25 meses para o grupo RT e 37 meses para o BT. Na análise atuarial, a SB3 foi de 51% e 73% (p = 0,032) para RT e BT, respectivamente. Na análise estratificada pelo PSAi, a SB3 para RT e BT foi de 85,7% e 79,1% (p = 0,76) para PSAi < 10 ng/mL e de 38% e 68% (p = 0,023) para PSAi > 10 ng/mL, respectivamente. Quando estratificado pelo EG, a SB3 para RT e BT foi de 37% e 80% (p = 0,001) para EG < 6 e 78% e 55% para EG > 6 (p = 0,58); estratificando-se pelo EC, a SB3 para RT e BT foi de 36% e 74% (p = 0,018) para EC < T2a e 73% e 69% para EC > T2a (p = 0,692), respectivamente. O risco relativo bruto de recidiva bioquímica foi de 2,3 (95% IC: 1,0-5,1) para os pacientes tratados com RT, em relação à BT; quando ajustado pelo PSAi e EG, o risco relativo de recidiva bioquímica foi de 2,4 (95% IC: 1,0-5,7). CONCLUSÃO: A modalidade de tratamento foi fator prognóstico independente de recidiva bioquímica, com maior controle bioquímico associado à BT. Nossos resultados preliminares sugerem que o maior benefício com BT foi obtido nos pacientes com PSAi > 10 ng/mL, EC < T2a e EG < 6.

The use of hormonal therapy with radiotherapy for prostate cancer: analysis of prospective randomised trials

In 1901, Wilhelm Conrad Röntgen won the Nobel prize in Physics for his discovery of the Röntgen rays or, as he himself called them, X-rays. In 1966, Dr Charles Brenton Higgins won the Nobel Prize in Medicine for his breakthroughs concerning hormonal treatment of prostatic cancer. After 31 years, in 1997, the first prospective randomised trials of the combination of hormonal therapy and radiation therapy were published, showing increased survival when compared to radiation therapy alone for patients with prostate cancer. Since 1997, many investigators have published trials combining hormonal and radiation therapy for prostate cancer. This minireview will address the largest and most influential of these trials, and attempt to guide physicians in selecting the appropriate patients for this combined approach.

Hormonal Therapy and Radiotherapy for Localized Prostate Cancer: Who, Where and How Long?

PURPOSE

The results from recent randomized trials were used to identify subpopulations of patients most likely to benefit from long versus short-term hormonal therapy with external beam radiotherapy.

MATERIALS AND METHODS

Radiation Therapy Oncology Group study 9413 included 1,323 men with prostate cancer and a risk of lymph node involvement greater than 15%. In this study the hypotheses tested were that whole pelvis radiotherapy would improve progression-free survival (PFS) compared to prostate only radiotherapy and that neoadjuvant and concurrent hormone therapy (N&CHT) with radiotherapy would improve PFS compared to radiotherapy with adjuvant hormone therapy. The conclusions of this study were compared to other studies using long-term hormonal therapy.

RESULTS

At a median followup of almost 5 years, when all 4 treatment arms from study 9413 were compared, the group receiving whole pelvis radiotherapy plus N&CHT had a significant PFS advantage (p = 0.008).

CONCLUSIONS

Intermediate risk patients should receive N&CHT in combination with external beam radiotherapy while high risk patients require the addition of long-term adjuvant hormone therapy.

Prostate cancer update

Research has yielded important insights into the impact of radical prostatectomy in patients with localized prostate cancer. Other recent research has focused on the role of nutrition in prostate cancer development and progression, improved prognostication for patients with both early and advanced prostate cancer, efficacy of adjuvant and neoadjuvant hormonal therapy, and development of novel agents. In addition, the role of bisphosphonates in patients with bone metastasis was established.

Multiple measures of carcinoma extent versus perineural invasion in prostate needle biopsy tissue in prediction of pathologic stage in a screening population

The capacity of perineural invasion by carcinoma in prostate needle biopsy tissue to independently predict pathologic stage in radical prostatectomy tissues remains uncertain. We sought to determine, in a prostate specific antigen-based screening population, the ability of needle biopsy histologic grade, tumor extent, and perineural invasion to independently predict pathologic stage and margin status in the whole prostate gland. Perineural invasion, Gleason grade, percentage Gleason pattern 4/5 carcinoma, and multiple measures of needle biopsy tumor extent, including number of positive cores, percentage of positive cores, total percentage of carcinoma, greatest percentage of carcinoma in a single core, and total carcinoma length in millimeters, were captured for 215 men from a prostate specific antigen-based screening program diagnosed with prostate cancer in a median of six procured needle biopsy cores. Pathologic stage and surgical margin status were evaluated in corresponding completely embedded radical prostatectomy specimens. A logistic regression model was used to relate the endpoints of extraprostatic extension by carcinoma and/or positive margins to needle biopsy tissue findings. In univariate analyses, total percentage of carcinoma (p = 0.003), greatest percentage of carcinoma in a single core (p = 0.004), total tumor length in millimeters (p = 0.009), and fraction of positive cores (p = 0.02) were all significantly associated with extraprostatic (pT3) carcinoma, whereas all five measures of carcinoma extent in needle biopsy tissue were related to positive margins. Correlation coefficient determinations showed that all five measures of needle biopsy carcinoma extent were highly interrelated. In multivariate analyses, total percentage of carcinoma was significantly related to pathologic T stage (p = 0.003) and positive margins (p = 0.0002). In a multivariate model with the radical prostatectomy whole gland endpoint of either pT3 disease or positive margins, fraction of positive cores (p = 0.00001) was the only variable with significant predictive value. Perineural invasion by carcinoma in needle biopsy tissue was detected in 11% of cases. Neither presence nor absence of perineural carcinoma nor number nor percentage of positive nerves related to pathologic stage in univariate or multivariate analyses. Amount of carcinoma in prostate needle biopsy tissue, using multiple measurements but not perineural invasion, is a significant histologic attribute predictive of pathologic stage and margin status for men with prostate specific antigen screening detected prostatic carcinoma. Reporting of several measures of carcinoma extent in needle biopsy tissue is recommended.