Histopathologic effects of three-dimensional conformal external beam radiation therapy on benign and malignant prostate tissues

Prostate Cancer: Update on Grading and Reporting

The Gleason scoring system and Grade Group systems facilitate accurate grading and reporting of prostate cancer, which are essential tasks for surgical pathologists. Gleason Pattern 4 is critical to recognize because it signifies a risk for more aggressive behavior than Gleason Pattern 3 carcinoma. Prostatic adenocarcinoma with radiation or androgen therapy effect, with aberrant P63 expression, or with Paneth cell-like differentiation represent pitfalls in prostate cancer grading because although they display architecture associated with aggressive behavior in usual prostatic adenocarcinoma, they do not behave aggressively and using conventional Gleason scoring in these tumors would significantly overstate their biologic potential.

Eosinophilic metaplasia in transurethral resection of the prostate

Background

To investigate prostatic eosinophilic metaplasia (EM) in a large series of cases and their relationship with the basic prostate pathology in TURP-material: benign prostatic hyperplasia (BPH), National Institutes of Health category IV prostatitis (also called histologic prostatitis or HP), and prostatic adenocarcinoma (PCa).

Aim

The relation between EM and basic prostate pathology: BPH, PCa, and HP.

Materials and Methods

Around 61 consecutive TURP-specimens were reviewed for the presence of EM. The tissue sections were stained routinely with hematoxylin-eosin (HE), hematoxylin-phloxine-saffron (HPS), and periodic acid-Schiff's procedure. Simultaneously BPH, HP, and PCa were evaluated.

Results

We found EM in 55.7% of TURP-specimens. EM is located more often in the ductal epithelium (58.8%) and is usually focal (73.5%) and in small groups (88.2%) of secretory luminal cells. They are associated with BPH and with a variable degree of HP in all cases. However, there is no association with PCa. Eosinophilic cytoplasmic granules in EM are better visualized with HPS. Zones induced by tissue electrocoagulation which mimic EM, are seen in the periphery of TURP-fragments.

Conclusion

EM in prostate is presented by the presence of eosinophilic cytoplasmic granules in benign secretory epithelium. The study presents the first attempt to investigate EM in a large series of patients. Our results enrich the available information about the histoepidemiology of prostatic EM. Moreover, EM is more common in a focal lesion, found in small groups of ductal secretory epithelial cells while EM in TURP-specimens is associated with BPH and HP in all the cases.

Low-Dose-Rate Brachytherapy Combined With Ultrahypofractionated Radiation Therapy for Clinically Localized, Intermediate-Risk Prostate Cancer: Results From a Prospective Trial

PURPOSE

To report early toxicity and tumor control outcomes of Pd-103 brachytherapy with ultrahypofractionated stereotactic radiation therapy (RT) for intermediate-risk prostate cancer.

METHODS AND MATERIALS

This prospective trial included 40 patients with intermediate-risk prostate cancer who underwent low-dose-rate (Pd-103) brachytherapy (prescription dose, 100 Gy), followed 1 month later with ultrahypofractionated stereotactic RT (25 Gy in 5 fractions) to the prostate and seminal vesicles. The primary endpoint was the rate of grade 2+ genitourinary toxicity at 12 months using Common Terminology Criteria for Adverse Events v 4.0. Secondary endpoints included patient-reported quality-of-life metrics (International Prostate Scoring System [IPSS], International Index of Erectile Function, and Expanded Prostate Cancer Index Composite-bowel). Biochemical failure was defined as prostate-specific antigen nadir +2 ng/mL. Posttreatment biopsies were performed at between 24 and 36 months; median follow-up was 36 months.

RESULTS

The rate of grade 2 urinary toxicity at 12 months was 25% with no grade 3 urinary toxicity noted. Mean IPSS at baseline and 12 and 24 months was 5, 10, and 6.2, respectively. Mean change in IPSS from baseline at 12 months was +5.5 (interquartile range, 1-9.75) and +1.05 (interquartile range, -3 to 3.25) at 24 months. Grade 2 bowel toxicity was 5% at 12 months with no grade 3 bowel toxicity noted. Mean Expanded Prostate Cancer Index Composite-bowel domain scores at baseline and 12 months were 92.8 and 90.3, respectively. Of patients who were potent (International Index of Erectile Function ≥21) at baseline, 75% remained potent at 12 months. Of 40 patients, 28 underwent posttreatment prostate biopsy (PPB), which was negative (n = 20) or demonstrated severe treatment effect (n = 8). No patient had a positive PPB or developed biochemical failure during the follow-up period. One patient without a PPB developed osseous metastases at 18 months posttreatment in the absence of biochemical failure.

CONCLUSION

Low-dose-rate brachytherapy in combination with ultrahypofractionated stereotactic RT was safe and effective for intermediate-risk prostate cancer in early results of this trial.

Long-Term Implications of a Positive Posttreatment Biopsy in Patients Treated with External Beam Radiotherapy for Clinically Localized Prostate Cancer

PURPOSE

We determined the prognostic importance of a positive posttreatment biopsy after prostate radiotherapy.

MATERIALS AND METHODS

A total of 382 patients underwent a posttreatment biopsy after external beam radiotherapy for clinically localized prostate cancer. Posttreatment biopsies were classified as positive (prostatic adenocarcinoma without typical radiation induced changes), negative (no evidence of carcinoma) or adenocarcinoma with a severe treatment effect. Median followup in survivors was 9 years. Competing risks regression was used to assess relationships between prognostic predictors and cause specific mortality, distant metastasis and prostate specific antigen failure.

RESULTS

The prevalence of positive biopsy, treatment effect and negative biopsy was 30%, 22% and 48%, respectively. Androgen deprivation therapy omission and high risk disease were associated with a 2.6 and 1.8-fold increase, respectively, in the odds of positive posttreatment biopsy. The 15-year PSA relapse rate associated with negative, severe treatment effect and positive posttreatment biopsies was 34%, 36% and 79%, respectively (p <0.001). After controlling for known predictors the risk of distant metastasis was 2.6-fold higher in patients with a positive biopsy (p <0.001) and cause specific mortality was twice as high in patients with a positive biopsy compared to those with negative and severe treatment effect biopsy outcomes (HR 2.00, p = 0.022).

CONCLUSIONS

A positive posttreatment biopsy after external beam radiotherapy was associated with a higher risk of distant metastasis and prostate cancer related death. Patients with severe treatment effect classified biopsies have biological characteristics more like patients with a negative biopsy than a positive biopsy. Posttreatment biopsies were more often positive in the setting of external beam radiotherapy alone without androgen deprivation therapy or in the presence of high risk disease.

[Pathogenesis of urological complications after radiation therapy]

Radiation therapy is a treatment modality that is often used in the uro-oncological setting. The common indication for the radiation therapy in the urological sphere is prostate cancer, whether it is used primarily as a radical approach, or postoperatively as adjuvant or salvage therapy. All urological organs are sensitive to radiation injury with the urinary bladder being the most susceptible with a typical cascade including acute and late changes, arising in the dose-dependent manner. The common indication for radiation therapy in urology is prostate cancer, which collaterally affects the urinary bladder and rarely urethra (especially the bulbo-membranous urethra). Ureteral damage and stricture formation is almost always restricted to the cases of intraoperative therapy and external beam radiation therapy for other urological malignancies (gynecological organs, rectum, retroperitoneal soft tissue tumors) and should not be underestimated. Postradiotherapeutic tissue changes, especially of the prostate, can cause difficulties for pathologists and urologists with regard to diagnosis of prostate cancer recurrence and salvage therapy.

18F-FECH PET/CT to Assess Clinically Significant Disease in Prostate Cancer: Correlation With Maximum and Total Cancer Core Length Obtained via MRI-Guided Template Mapping Biopsies

OBJECTIVE

The objective of this study was to detect clinically significant and insignificant prostate cancer on 18F-fluoroethylcholine (FECH) PET/CT and to correlate findings with transperineal template-guided prostate mapping (TPM) biopsy.

SUBJECTS AND METHODS

Fifty-six lobes of the prostate were analyzed in 28 men who underwent FECH PET/CT and TPM. Whole-body images and pelvic images were acquired at 60 and 90 minutes after tracer administration. FECH PET/CT findings were correlated with TPM. Sensitivity, specificity, positive predictive values, negative predictive values, and AUC of dual phase FECH PET/CT were calculated.

RESULTS

Mean age of the patients was 68.8 years (range, 53-79 years), and mean prostate-specific antigen level was 12.1 ng/mL (range, 0.6-45 ng/mL). Mean maximum cancer core length was 4.4 mm (median, 4 mm; range, 1-14 mm) and mean total cancer core length, 14.6 mm (median, 14.6 mm; range, 1-82 mm). Prostate cancer was identified in 38 lobes with a Gleason score of 6 in five lobes (13%), 7 in 27 lobes (71%), 8 in four lobes (11%), and 9 in two lobes (5%). FECH PET/CT showed findings of prostate cancer in 46/56 lobes (82%). The ranges for maximum standardized uptake value for 60- and 90-minute FECH PET/CT were 1.3-11.4 and 1.2-10.9, respectively. Clinically significant cancer was seen in 30 of 38 positive lobes; eight had clinically insignificant disease. For 60-minute imaging, the sensitivity, specificity, and ROC AUC were 75%, 75%, and 0.746 (95% CI, 0.612-0.853). For 90-minute imaging, the sensitivity, specificity, and ROC AUC were 73.7%, 58.3%, and 0.646 (95% CI, 0.498-0.776). Overall sensitivity, specificity, positive predictive value, and negative predictive value were 95%, 50%, 82.6%, and 80%, respectively.

CONCLUSION

FECH PET/CT can detect prostate cancer and localizes TPM biopsy-proven clinically significant prostate cancer with sensitivity of greater than 89.7%. Of the two imaging durations, 60-minute imaging is more sensitive and specific than 90-minute imaging.

The benign mimickers of prostatic acinar adenocarcinoma

As the most frequent malignant histological subtype in prostatic cancer, prostatic acinar adenocarcinoma (PAA) has a series of benign mimickers including prostatic or non-prostatic lesions and normal structures, which may lead to an erroneous diagnosis and inappropriate treatment. It is very important to be aware of the existence of these mimickers and to recognize their histological features. The differential diagnosis should be based on a comprehensive evaluation of clinical history, histological structure, cytological morphology and the results of immunohistochemistry (IHC) staining, rather than on single criteria (e.g., the presence of prominent nucleoli or basal cell layer).

Predictive factors for urinary toxicity after iodine-125 prostate brachytherapy with or without supplemental external beam radiotherapy

PURPOSE

We examined the factors associated with urinary toxicities because of brachytherapy with iodine-125 with or without supplemental external beam radiotherapy (EBRT) for prostate cancer.

METHODS AND MATERIALS

We investigated 1313 patients with localized prostate cancer treated with iodine-125 brachytherapy with or without supplemental EBRT between 2003 and 2009. The International Prostate Symptom Score (IPSS) and Common Terminology Criteria for Adverse Events data were prospectively determined. Patients, treatment, and implant factors were investigated for their association with urinary toxicity or symptoms.

RESULTS

IPSS resolution was not associated with biologically effective dose (BED). Baseline IPSS, total needles, and the minimal dose received by 30% of the urethra had the greatest effect according to multivariate analysis (MVA). Urinary symptom flare was associated with baseline IPSS, age, BED, and EBRT on MVA. Urinary symptom flare and urinary Grade 2 or higher (G2+) toxicity occurred in 51%, 58%, and 67% (p = 0.025) and 16%, 22%, and 20% (p = 0.497) of the <180, 180-220, and >220 Gy BED groups, respectively. Urinary G2+ toxicity was associated with baseline IPSS, neoadjuvant androgen deprivation therapy (NADT), and seed density on MVA. When we divided patients into four groups according to prostate volume (<30 cc or ≥30 cc) and NADT use, urinary G2+ toxicity was most commonly observed in those patients with larger prostates who received NADT, and least in the patients with smaller prostates and no NADT.

CONCLUSIONS

NADT was associated with urinary G2+ toxicity. Higher dose and supplemental EBRT did not appear to increase moderate to severe urinary toxicities or time to IPSS resolution; however, it influenced urinary symptom flare.

A Domain Constrained Deformable (DoCD) Model for Co-registration of Pre- and Post-Radiated Prostate MRI

External beam radiation treatment (EBRT) is a popular method for treating prostate cancer (CaP) involving destroying tumor cells with ionizing radiation. Following EBRT, biochemical failure has been linked with disease recurrence. However, there is a need for methods for evaluating early treatment related changes to allow for an early intervention in case of incomplete disease response. One method for looking at treatment evaluation is to detect changes in MRI markers on a voxel-by-voxel basis following treatment. Changes in MRI markers may be correlated with disease recurrence and complete or partial response. In order to facilitate voxel-by-voxel imaging related treatment changes, and also to evaluate morphologic changes in the gland post treatment, the pre- and post-radiated MRI must first be brought into spatial alignment via image registration. However, EBRT induces changes in the prostate volume and distortion to the internal anatomy of the prostate following radiation treatment. The internal substructures of the prostate, the central gland (CG) and peripheral zone (PZ), may respond to radiation differently, and their resulting shapes may change drastically. Biomechanical models of the prostate that have been previously proposed tend to focus on how external forces affect the surface of the prostate (not the internals), and assume that the prostate is a volume-preserving entity. In this work we present DoCD, a biomechanical model for automatically registering pre-, post-EBRT MRI with the aim of expressly modeling the (1) changes in volume, and (2) changes to the CG and PZ. DoCD was applied to a cohort of 30 patients and achieved a root mean square error of 2.994 mm, which was statistically significantly better a traditional biomechanical model which did not consider changes to the internal anatomy of the prostate (mean of 5.071 mm).

Radiotherapy before and after radical prostatectomy for high-risk and locally advanced prostate cancer

OBJECTIVES

Men with localized high-risk prostate cancer carry significant risk of prostate cancer-specific mortality. The best treatment approach to minimize this risk is unclear. In this review, we evaluate the role of radiation before and after radical prostatectomy.

METHODS AND MATERIALS

A critical review of the literature was performed regarding the application of external radiation therapy (RT) in combination with prostatectomy for high-risk localized prostate cancer.

RESULTS

Up to 70% of men with high-risk localized disease may require adjuvant therapy because of adverse pathologic features or biochemical recurrence in the absence of systemic disease. The utility of adjuvant RT among men with adverse pathologic features are well established at least regarding minimizing biochemical recurrence risk. The optimal timing of salvage radiation is the subject of ongoing studies. Neoadjuvant RT requires further study but is a potentially attractive method because of decreased radiation field sizes and potential radiobiologic benefits of delivering RT before surgery. Salvage prostatectomy is effective at treating local recurrence after radiation but is associated with significant surgical morbidity.

CONCLUSIONS

Combining local therapies including radical prostatectomy and RT can be a reasonable approach. Care should be taken at the initial presentation of high-risk localized prostate cancer to consider and plan for the likelihood of multimodality care.

Preneoplasia in the prostate gland with emphasis on high grade prostatic intraepithelial neoplasia

There are a variety of morphological patterns and processes that have been implicated in the pathogenesis of prostate cancer. Prostatic intraepithelial neoplasia (PIN), inflammation with or without atrophy, and adenosis (atypical adenomatous hyperplasia) have all been given candidate status as precursor lesions of prostatic adenocarcinoma. Based on decades of research, high grade prostatic intraepithelial neoplasia (HPIN), a proliferative lesion of prostatic secretory cells, has emerged as the most likely morphological pre-invasive lesion involved in the evolution of many but not all prostatic adenocarcinomas. In this manuscript, we briefly discuss other proposed precursors of prostatic adenocarcinoma and then focus on the history, diagnostic criteria and morphology of HPIN. The incidence of HPIN and its relationship to prostate cancer is reviewed. The differential diagnosis of large glandular patterns in the prostate is discussed in depth. Finally, we summarise the recent clinicopathological studies evaluating the clinical significance of HPIN and discuss follow-up strategies in men diagnosed with HPIN.

Variants and unusual patterns of prostate cancer: clinicopathologic and differential diagnostic considerations

Beyond the typical acinar morphology observed in the majority of prostatic adenocarcinomas, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be classified as: (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features and/or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details a number of variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Outcomes following negative prostate biopsy for patients with persistent disease after radiotherapy for prostate cancer

PURPOSE

When faced with biochemical recurrence after definitive radiotherapy for prostate cancer, clinicians must determine whether the recurrence is local or systemic. Post radiotherapy prostate biopsies to detect persistent local disease are difficult to interpret histopathologically and are subject to sampling error. Our study examines outcomes for patients with a negative prostate biopsy performed for rising prostate-specific antigen (PSA) levels after prostate radiation.

MATERIALS AND METHODS

We performed a retrospective review of 238 prostate cancer patients with a negative biopsy following definitive radiotherapy. Seventy-five of these patients had biochemical recurrence at the time of biopsy. A negative biopsy was defined as the absence of prostate cancer without radiation-treatment effect in the specimen.

RESULTS

Patients underwent biopsy at a mean of 41 months after the completion of radiation. They had a mean PSA of 6. Patients were followed for an average of 63 months. Thirty-two patients (43%) developed metastasis, and 11 (15%) died of prostate cancer despite a negative post-radiation biopsy. Five of nine patients (56%) with sequential biopsies had a positive second biopsy.

CONCLUSIONS

Patients with PSA recurrence and a negative post-radiation biopsy have a high chance of persistent local disease, progression, and death from prostate cancer. Furthermore, an initial negative biopsy does not rule-out local recurrence. Patients with biochemical recurrence after radiotherapy for prostate cancer need to be evaluated earlier for local recurrence.

Histopathologic effects of hypofractionated robotic radiation therapy on malignant and benign prostate tissue

We describe the first histopathologic analysis of prostatic tissue following hypofractionated robotic radiation therapy. A 66 year-old man presented with stage II, low risk adenocarcinoma of the prostate and underwent elective conformal hypofractionated radiation therapy. His pretreatment evaluation revealed T1c adenocarcinoma, Gleason's grade 3 + 3 = 6 and a prostate specific antigen (PSA) level of 4.87 ng/ml. Hypofractionated radiation therapy (37.5 Gy in five daily fractions of 7.5 Gy) was completed on an Internal Review Board approved protocol. One year later, he developed progressive urinary retention. Transurethral prostatic resection was performed to alleviate obstructive symptoms. Bilobar hypertrophy was observed without evidence of stricture. Histolopathologic analyses of resected prostate tissues revealed changes consistent with radiation treatment, including cellular changes, inflammation, glandular atrophy and hyperplasia. There was no evidence of residual cancer, fibrosis or necrosis. The patient's postoperative course was uneventful with post-treatment PSA of 0.5 ng/ml and residual grade 1 stress incontinence.

Variants and Unusual Patterns of Prostate Cancer

Beyond the typical acinar morphology observed in most prostatic adenocarcinoma, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be further classified into (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details several variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Post-treatment prostate biopsies in the era of three-dimensional conformal radiotherapy: what can they teach us?

BACKGROUND

The ability to discriminate between therapeutic success and failure after radiotherapy (RT) for prostate cancer (PCa) remains a clinical challenge. Post-treatment biopsies would seem ideal for evaluating innovations such as dose escalation protocols or combination treatments involving brachytherapy or hormones.

OBJECTIVE

Correlate post-treatment biopsy results with prostate-specific antigen (PSA) and clinical outcome in PCa patients treated with three-dimensional conformal radiotherapy (3DCRT) in a dose-escalation study.

DESIGN, SETTING, AND PARTICIPANTS

This study included 160 patients with clinical stage T1c to T3b PCa treated between 1995 and 2005 in Hospital Universitario la Princesa with 3DCRT who consented to and underwent a transrectal ultrasound (TRUS)-guided prostate biopsy 24-36 mo after RT. The median follow-up was 78 mo (range 27-171 mo).

INTERVENTION

The median radiation dose was 74 gray (Gy; range 66.0-84.1). Risk-adapted short-term androgen deprivation (STAD) and long-term androgen deprivation (LTAD) were associated in 25 and 106 patients, respectively. Right and left systematic biopsies were carried out by the same urologist and were examined by a genitourinary pathologist.

MEASUREMENTS

Biochemical disease-free survival (bDFS) according to American Society for Therapeutic Radiology and Oncology (ASTRO) 1997 and Phoenix definition criteria as well as histologic control using post-treatment prostate biopsies.

RESULTS

Twenty-one percent of patients (34 of 160) had post-treatment-positive biopsies (PB). The 5-yr bDFS according to the Phoenix definition was 87%, 65%, and 92% for the whole series (PB and negative biopsies [NB] patients, respectively [p<0.001]). Multivariate analysis showed that biopsy status at 24-36 mo was an independent predictor of bDFS (p<0.0005) and of clinical failure-free survival (p=0.043).

CONCLUSION

The results of the present study show a strong correlation between a post-treatment PB and the 5-yr probability of bDFS, confirming that PSA control can be an adequate surrogate for local control, as assessed by post-treatment biopsies.

Influence of local tumor control on distant metastases and cancer related mortality after external beam radiotherapy for prostate cancer

PURPOSE

We report local control outcomes, as assessed by posttreatment biopsies in patients who underwent 3-dimensional conformal radiotherapy for clinically localized prostate cancer. In addition, we report the influence of local tumor control on long-term distant metastases and cause specific survival outcomes.

MATERIALS AND METHODS

Posttreatment prostate biopsies were performed in 339 patients who underwent 3-dimensional conformal radiotherapy for clinically localized prostate cancer. The histological outcome of prostate biopsy was classified as positive-prostatic adenocarcinoma without typical radiation induced changes or negative-no evidence of carcinoma or severe treatment effect. Median followup in this group of 339 patients was 10 years after the completion of treatment and 6.25 years after posttreatment biopsy.

RESULTS

Overall biopsy outcomes in these patients were positive in 32%, severe treatment effect in 21% and negative in 47%. A higher radiation dose in the intermediate and high risk subgroups was associated with a lower incidence of positive biopsy. Of patients at intermediate risk who received a dose of 75.6 or greater 24% had a positive biopsy compared to 42% who received 70.2 Gy or less (p = 0.03). In the high risk group positive treatment biopsies were noted in 51% of patients who received 70.2 Gy or less, 33% of those who received 75.6 Gy and 15% of those who received 81 Gy or greater (70.2 or less vs 75.6 Gy p = 0.07 and 75.6 vs 81 Gy or greater p = 0.05). Short course neoadjuvant androgen deprivation therapy before 3-dimensional conformal radiotherapy had a significant impact on the posttreatment biopsy outcome. Of patients who did not receive androgen deprivation therapy 42% had a positive biopsy compared to 16% who received androgen deprivation therapy (p <0.0001). Patients with negative and severe treatment effect biopsies had similar 10-year prostate specific antigen relapse-free survival outcomes that were markedly different from outcomes in those with positive treatment biopsies. Multivariate analysis indicated that the strongest predictor of biochemical failure was posttreatment biopsy status (positive vs severe treatment effect or negative p <0.001), followed by pretreatment prostate specific antigen (p = 0.05) and clinical T stage (p = 0.09). Similarly multivariate analysis revealed that a positive posttreatment biopsy was one of the strongest predictors of distant metastasis and prostate cancer death in this cohort of patients.

CONCLUSIONS

As assessed by posttreatment prostate biopsies, local control is improved with higher radiation doses. Long-term biochemical outcomes in patients with posttreatment biopsies demonstrating severe treatment effect changes were not different than those in patients with negative biopsies. We also noted that local tumor control was associated with a decrease in distant metastases and prostate cancer mortality, further highlighting the importance of achieving optimal tumor control in patients with clinically localized disease.

Residual prostate cancer after radiotherapy: a study of radical cystoprostatectomy specimens

OBJECTIVES

The incidence of histologic prostate cancer (CaP) after definitive radiation therapy (RT) for localized disease is rarely quantitated. We investigated the relationship between prostate-specific antigen (PSA) and histologically residual CaP after definitive RT in patients undergoing radical cystoprostatectomy (RCP) for unrelated indications.

METHODS

We reviewed our prostate cancer database to identify patients undergoing RCP who previously received definitive RT for localized CaP. Pre-radiation variables examined include PSA, Gleason score, radiation modality, and dose. Post-radiation variables reviewed include PSA, time to RCP, the presence of histologically proven prostate cancer, and Gleason score.

RESULTS

We identified 21 patients who underwent RCP at a median of 60 months after RT for localized CaP. Pre-radiation Gleason scores were low (6 or less) to intermediate risk (3+4) in 82% (14 of 17), intermediate (4+3) to high (8 or greater) in 18% (3 of 17), and unavailable in 4 patients. Median pre-radiation PSA was 9 ng/mL. Median PSA before RCP in all patients was 0.8 ng/mL. A total of 52% (11 of 21) of patients demonstrated active CaP in the RCP specimen. Although 89% (16 of 18) of patients met the Phoenix definition of biochemical freedom from disease, 50% (8 of 16) of these patients had histologically residual CaP at the time of RCP. Median PSA was not significantly different between patients with and without active CaP.

CONCLUSIONS

Histologic evidence of CaP was noted in 50% of patients demonstrating biochemical freedom from disease at the time of RCP. Although the biological significance of active CaP in this select population is uncertain, our findings demonstrate the limitations of PSA in monitoring CaP disease activity after definitive RT.

Diagnosis of prostatic carcinoma after therapy

CONTEXT

Prostate cancer is the most common cancer of men in the United States and is third only to lung and colon cancer as a cause of cancer death. In 2006, 27,350 Americans will die of prostate cancer, and 234,460 new cases will be diagnosed. Treatment changes in the benign and cancerous prostate create diagnostic challenges in pathologic interpretation, particularly in needle biopsy specimens and in evaluation of extraprostatic metastases.

OBJECTIVE

To summarize therapy-related pathologic findings in the prostate with emphasis on recognition of treated adenocarcinoma.

DATA SOURCES

Extensive review of published literature and the authors' experience.

CONCLUSIONS

Following therapy for prostate cancer, it is critical that the clinician provide the pertinent history of androgen deprivation or radiation therapy to assist the pathologist in rendering the correct diagnosis.

Natural history of prostatic carcinoma: the pathologist's perspective

The stem (basal) cells of prostate acini are considered the origin of prostate cancer. Between these cells and the final secretory cells, different intermediate or transit cells can be observed, and every one of them can evolve into malignant cells, explaining the biological variability of prostatic cancer. The exact changes between normal gland and prostatic intraepithelial neoplasia (PIN) are not yet known, but a post-inflammatory atrophy lesion is being studied in this respect. The PIN lesion is considered the pre-invasive change of prostatic cancer and its presence in needle biopsy is clinically used for follow-up of the patient. The progressive knowledge of the stromal invasion in prostate cancer (loss of some cell-cell adhesion molecules and expression of others) can be correlated with the Gleason grading system, and the molecular changes in the progression to androgen-independent carcinoma can be used as a prognostic marker in conjunction with the classical pathological markers.

Nonspecific granulomatous prostatitis with calculous ductal ectasia and extensive Paneth cell-like epithelial metaplasia. Case report

We present a case of nonspecific granulomatous prostatitis in combination with calculous ductal ectasia and extensive epithelial Paneth cell-like metaplasia in a TURP-specimen. Our report highlights the importance of calculous ductal obstruction and stasis of secretions in the etiopathogenesis of this type of prostatitis. The observed extensive Paneth cell-like metaplastic change in adjacent epithelial cells most likely represents a phenotypic adaptive mechanism directed against foreign antigens and nondegradable lipids in the stagnant intraluminal debris.

Do all patients with high-grade prostatic intraepithelial neoplasia on initial prostatic biopsy eventually progress to clinical prostate cancer?

OBJECTIVE

To assess the clinical outcome of patients with a diagnosis of high-grade prostatic intraepithelial neoplasia (PIN) on initial prostatic biopsy, with a minimum of 5 years of follow-up, as such patients are at greater risk of having prostate cancer on subsequent biopsy.

PATIENTS AND METHODS

Between November 1992 and October 1998, 21 patients were identified as having PIN on their initial transrectal ultrasonography-guided prostate biopsy. None of these patients had a focus of cancer on the initial biopsy. Their medical data were reviewed retrospectively to determine the natural history of PIN in these patients. Patients who were not identified as having cancer were followed every 6-12 months with prostate-specific antigen (PSA) testing and digital rectal examinations (DRE).

RESULTS

A mean (range) of 7 (2-8) cores were taken at initial biopsy; the mean age of the patients was 63 (53-77) years and mean PSA level 9.1 (4.9-17.6) ng/mL. Six patients had an abnormal DRE at presentation. A mean of 8 (7-10) cores were obtained on the second biopsy; six patients were diagnosed with cancer, with a mean Gleason score of 6 (5-7), while three were diagnosed with persistent PIN. These three patients had a third prostate biopsy which showed cancer of Gleason score 6 in one and benign prostatic hyperplasia in two. After a mean follow-up of 72.2 (60-84) months, none of the remaining 12 patients was diagnosed with clinically significant cancer. Five of these patients went on to a third prostate biopsy, with no evidence of cancer. One patient died from unrelated causes during this period.

CONCLUSION

This study affirms our current practice of following patients with PIN conservatively if a second or third subsequent prostate biopsy is negative. Whether PIN is a premalignant lesion or merely a lesion associated with cancer needs to be addressed in multicentre studies with a follow-up of > 10 years.

Evidence-based review of three-dimensional conformal radiotherapy for localized prostate cancer: An ASTRO outcomes initiative

PURPOSE

To perform a systematic review of the evidence to determine the efficacy and effectiveness of three-dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer; provide a clear presentation of the key clinical outcome questions related to the use of 3D-CRT in the treatment of localized prostate cancer that may be answered by a formal literature review; and provide concise information on whether 3D-CRT improves the clinical outcomes in the treatment of localized prostate cancer compared with conventional RT.

METHODS AND MATERIALS

We performed a systematic review of the literature through a structured process developed by the American Society for Therapeutic Radiology and Oncology's Outcomes Committee that involved the creation of a multidisciplinary task force, development of clinical outcome questions, a formal literature review and data abstraction, data review, and outside peer review.

RESULTS

Seven key clinical questions were identified. The results and task force conclusions of the literature review for each question are reported.

CONCLUSION

The technological goals of reducing morbidity with 3D-CRT have been achieved. Randomized trials and follow-up of completed trials remain necessary to address these clinical outcomes specifically with regard to patient subsets and the use of hormonal therapy.

Effects of Pd-bacteriopheophorbide (TOOKAD)-mediated photodynamic therapy on canine prostate pretreated with ionizing radiation

The aim of this study was to evaluate the effects of photodynamic therapy (PDT) using a novel palladium bacteriopherophorbide photosensitizer TOOKAD (WST09) on canine prostate that had been pretreated with ionizing radiation. To produce a physiological and anatomical environment in canine prostate similar to that in patients for whom radiotherapy has failed, canine prostates (n = 4) were exposed to ionizing radiation (54 Gy) 5 to 6 months prior to interstitial TOOKAD-mediated PDT. Light irradiation (763 nm, 50-200 J/cm at 150 mW/cm from a 1-cm cylindrical diffusing fiber) was delivered during intravenous infusion of TOOKAD at 2 mg/kg over 10 min. Interstitial measurements of tissue oxygen profile (pO(2)) and of local light fluence rate were also measured. The prostates were harvested for histological examination 1 week after PDT. The baseline pO(2) of preirradiated prostate was in the range 10-44 mmHg. The changes in relative light fluence rate during PDT ranged from 12 to 43%. The acute lesions were characterized by hemorrhagic necrosis, clearly distinguishable from the radiotherapy-induced pre-existing fibrosis. The lesion size was correlated with light fluence and comparable to that in unirradiated prostate treated with a similar TOOKAD-PDT protocol. There was no noticeable damage to the urethra, bladder or adjacent colon. The preliminary results obtained from a small number of animals indicate that TOOKAD-PDT can effectively ablate prostate pretreated with ionizing radiation, and so it may provide an alternative modality for those prostate cancer patients for whom radiotherapy has failed.

High-grade prostatic intraepithelial neoplasia

High-grade prostatic intraepithelial neoplasia (PIN) is now accepted as the most likely preinvasive stage of adenocarcinoma, almost two decades after its first formal description. PIN has a high predictive value as a marker for adenocarcinoma, and its identification warrants repeat biopsy for concurrent or subsequent invasive carcinoma. The only method of detection is biopsy; PIN does not significantly elevate serum prostate-specific antigen (PSA) concentration or its derivatives and cannot be detected by current imaging techniques, including ultrasound. Most patients with PIN will develop carcinoma within 10 years. PIN is associated with progressive abnormalities of phenotype and genotype, which are similar to cancer rather than normal prostatic epithelium, indicating impairment of cell differentiation with advancing stages of prostatic carcinogenesis. Androgen deprivation therapy decreases the prevalence and extent of PIN, suggesting that this form of treatment may play a role in chemoprevention.

Cell death in irradiated prostate epithelial cells: role of apoptotic and clonogenic cell kill

Dose-escalated conformal radiotherapy is increasingly being used to radically treat prostate cancer with encouraging results and minimal long-term toxicity, yet little is known regarding the response of normal or malignant prostate cells to ionizing radiation (IR). To clarify the basis for cell killing during prostate cancer radiotherapy, we determined the IR-induced expression of several apoptotic- (bax, bcl-2, survivin and PARP) and G1-cell cycle checkpoint- (p53 and p21(WAF1/Cip1)) related proteins, in both normal (PrEC-epithelial and PrSC-stromal) and malignant (LNCaP, DU-145 and PC-3; all epithelial) prostate cells. For these experiments, we chose doses ranging from 2 to 10 Gy, to be representative of the 1.8-2 Gy daily clinical fractions given during curative radiotherapy and the 8-10 Gy single doses given in palliative radiotherapy. We observed that IR-induced bax and p21(WAF1/Cip1) protein expression were attenuated selectively in normal stromal and epithelial cell cultures, yet maintained their p53-dependency in malignant cell lines. For each cell culture, we also determined total apoptotic and overall radiation cell kill using a short-term nuclear morphologic assay and a long-term clonogenic survival assay, respectively. Clonogenic survival, as measured by the surviving fraction at 2 Gy (SF2), ranged from 0.05 (PrEC) to 0.55 (DU-145), suggesting that malignant prostate cells are more radioresistant than normal prostate cells, for this series. IR-induced apoptotic cell kill was minimal (less than 6% cell after a dose of 10 Gy at times of 24-96 h) and was not dose-dependent. Furthermore, apoptotic kill was not correlated with either molecular apoptotic response or clonogenic cell kill. Using a flow cytometric proliferation assay with the PrSC (stromal) and DU-145 (epithelial) representative cultures, we observed that a senescent-like phenotype (SLP) emerges within a sub-population of cells post-irradiation that is non-clonogenic. Terminal growth arrest was dose-responsive at 96 h following irradiation and associated with long-term expression of both p21(WAF1/Cip1) and p16(INK4a) genes. Future strategies for prostate radiotherapy prediction or novel treatments should additionally focus on terminal growth arrest as an important endpoint in prostate cancer therapy.

Basal cell hyperplasia in the peripheral zone of the prostate

Basal cell hyperplasia in the prostate is often viewed as a transition zone proliferation, related to usual, nodular glandular, and stromal hyperplasia. Basal cell hyperplasia in the prostatic peripheral zone, the most common site for development of prostatic intraepithelial neoplasia and carcinoma, has not been previously characterized. We characterized the incidence and histomorphological attributes of basal cell hyperplasia in a series of 500 consecutive sextant needle core biopsy samples and in 26 completely embedded prostate glands from radical prostatectomy specimens. Comparative proliferation indices (by MIB-1 staining) and apoptotic indices (by TUNEL labeling) were quantitated for peripheral zone versus transition zone basal cell hyperplasia versus normal basal cells. The incidence of basal cell hyperplasia in prostate needle biopsy tissue was 10.2% (51 of 500 cases). Usual basal cell hyperplasia was detected in 8.2% of the 500 cases, and basal cell hyperplasia with prominent nucleoli, in 2.0% of cases. Basal cell hyperplasia in needle biopsy tissue was typically focal and associated with inflammation, which was usually lymphocytic, in 84% of cases. Peripheral zone basal cell hyperplasia was found in 23% of whole prostate glands. Peripheral zone basal cell hyperplasia was not observed to be in direct physical continuity with intraepithelial or invasive neoplasia. Peripheral zone and transition zone basal cell hyperplasia exhibited similar mean proliferation and apoptotic indices, at 1% and 0.07%, respectively. This proliferation index was elevated, and apoptotic index was decreased, relative to normal basal cells (P = 1 x 10(-7)). Basal cell hyperplasia in the peripheral zone is present in a significant minority of prostate needle biopsy samples and whole prostate glands. The presence of prominent nucleoli in basal cell hyperplasia may cause diagnostic concern for a neoplastic proliferation. The increase in cell number in basal cell hyperplasia appears to be due to a coordinate increase in proliferation index coupled with a diminished apoptotic index. The presence of inflammation in the majority of basal cell hyperplasia foci suggests that peripheral zone basal cell hyperplasia in untreated patients may represent a stereotyped response to injury such as that sustained because of inflammation.

Contemporary pathology of prostate cancer

In less than 20 years since the introduction of serum PSA and the spring-loaded 18-gauge prostatic biopsy needle, pathologists have adjusted to the limited tissue requirements of narrow needle specimens to apply criteria for diagnosis and grading of prostate cancer, borrowing from lessons learned from radical prostatectomies. Substantial gains have been made during this period in the understanding of precancerous lesions, mimics of malignancy, the criteria for minimal cancer, variants of cancer, and treatment-induced changes. The light microscopic findings remain the criterion standard for diagnosis against which all new techniques should be measured. Numerous findings have proven to be of value, including simple quantitation of histopathologic features, cancer volume, perineural invasion, and others.

Atypia in nonneoplastic prostate glands after radiotherapy for prostate cancer: duration of atypia and relation to type of radiotherapy

It is unknown how long postradiation atypia of benign prostate glands persists and whether the type of radiation is a factor. Forty-four cases consisting of 37 needle biopsies and 7 transurethral resections of the prostate seen in consultation (January 1997 to September 2000) were studied. In two men (5%), the cases were initially sent without a history of radiotherapy. Thirteen patients had minimal cancer (one core) with the remaining showing no residual tumor. Twenty patients were treated with interstitial radiotherapy (brachytherapy) (IRT), 17 with external beam radiation (XRT), and 7 with a combination of both (CT). The time interval between the treatment and tissue sampling ranged from 8 to 72 months (mean 3 months). Slides were reviewed blindly to the type of radiation and the time interval. Radiation-induced atypia in nonneoplastic glands, stromal fibrosis, and vascular changes was scored separately 0-3, with 0 showing no radiation injury and grade 3 showing prominent nuclear atypia, stromal fibrosis, and vascular hyalinization. We derived a combined score for the epithelial atypia from 0 to 300 (% of glands x grade) for each biopsy. For each case, an overall grade from 0 to 3 was given separately for the stromal and vascular changes. Cases were divided into three groups based on time between treatment and biopsy: <24 months (n = 14), between 24 and 48 months (n = 19), and >48 months (n = 11). Because the scores for epithelial atypia with IRT and CT were the same, we combined them into one group. There was more atypia in cases treated with IRT/CT (mean score 190) than XRT (mean score 105) (p <0.00001). There was also a greater degree of stromal fibrosis with IRT/CT than XRT (p <0.04). There was no correlation between the type of treatment and the effect on vessels. There was no change over time in epithelial atypia in men treated with IRT/CT. With XRT, there was less epithelial atypia in cases biopsied >48 months after treatment (mean score 57) compared with those with a shorter interval between biopsy and treatment (mean score 132) (p = 0.02). Radiation atypia in benign prostate glands may persist for a long time after the initial treatment, resulting in a significant pitfall in evaluating prostate biopsies. Prominent radiation effect (100% of the glands showing grade 2 and 3 atypia) was detected up to 72 months in one of the patients treated with IRT. In some cases, the clinician may not be aware of a prior remote history of radiation or does not relay this history to the pathologist. The pathologist must recognize radiation atypia without relying on the clinician to provide this history. The type of radiation therapy (IRT/CT vs XRT) is a major factor in the degree and duration of postradiation epithelial atypia.

Pathologic evidence of dose-response and dose-volume relationships for prostate cancer treated with combined external beam radiotherapy and high-dose-rate brachytherapy

PURPOSE

The clinical significance of postradiotherapy (RT) prostate biopsy characteristics is not well understood relative to the known prognostic factors. We performed a detailed pathologic review of posttreatment biopsy specimens in an attempt to clarify their relationship with clinical outcome and radiation dose.

METHODS AND MATERIALS

Between 1991 and 1998, 78 patients with locally advanced prostate cancer were prospectively treated with external beam RT in combination with high-dose-rate brachytherapy at William Beaumont Hospital and had post-RT biopsy material available for a complete pathologic review. Patients with any of the following characteristics were eligible for study entry: pretreatment prostate-specific antigen level > or =10.0 ng/mL, Gleason score > or =7, or clinical Stage T2b-T3cN0M0. Pelvic external beam RT (46.0 Gy) was supplemented with three (1991-1995) or two (1995-1998) ultrasound-guided transperineal interstitial (192)Ir high-dose-rate implants. The brachytherapy dose was escalated from 5.50 to 10.50 Gy per implant. Post-RT prostate biopsies were performed per protocol at a median interval of 1.5 years after RT. All pre- and post-RT biopsy specimen slides from each case were reviewed by a single pathologist (N.S.G.). The presence and amount of residual cancer, most common RT-effect score, and least amount RT-effect score were analyzed. The median follow-up was 5.7 years. Biochemical failure was defined as three consecutive prostate-specific antigen rises.

RESULTS

Forty patients (51%) had residual cancer in the post-RT biopsies. The 7-year biochemical control rate was 79% for patients with negative biopsies vs. 62% for those with positive biopsies with marked RT damage vs. 33% for those with positive biopsies with no or minimal RT damage. A greater percentage of positive pre-RT biopsy cores (p = 0.01), lower total RT dose (p = 0.001), lower dose per implant (p = 0.001), and greater percentage of positive post-RT biopsy cores (p = 0.01) were each associated with biochemical failure (Cox regression, univariate analysis). For patients with <25% positive post-RT biopsy cores, the 7-year biochemical control rate was 81% vs. a 62% biochemical control rate for those with 25-49% positive cores and only 32% for those with > or =50% positive cores (p = 0.01). On Cox multiple regression analysis, only the percentage of positive pre-RT biopsy cores and RT dose remained significantly associated with biochemical failure. Of all the factors analyzed, only the pretreatment cancer volume and lower RT dose were significantly associated with residual cancer and/or residual cancer with no or minimal RT damage. A greater percentage of positive pre-RT biopsy cores was associated with both a positive post-RT biopsy (p = 0.08) and a greater percentage of positive post-RT biopsy cores (p = 0.04). A lower total RT dose was associated with both a positive post-RT biopsy (p = 0.08) and a greater percentage of positive post-RT biopsy cores (p = 0.02). For patients who received <80 Gy (equivalent in 2-Gy fractions), 73% had positive post-RT biopsies vs. a 56% biopsy positivity rate for those who received 84-90 Gy and only 39% for those who received > or =92 Gy (p = 0.07).

CONCLUSION

Patients with positive post-RT biopsies are more likely to experience biochemical failure, especially when the RT damage is minimal. Patients who have a larger pretreatment tumor volume or receive a lower RT dose are more likely to demonstrate post-RT biopsy positivity and biochemical failure.

The influence of percentage of preradiation needle biopsies with adenocarcinoma and total radiation dose on the pathologic response of unfavorable prostate adenocarcinoma

We studied relationships among clinicopathologic factors in 78 patients with unfavorable prostate adenocarcinoma treated in a dose-escalation radiation therapy (RT) study using pre- and 18-month protocol post-RT biopsy specimens. Pre-RT factors analyzed were serum prostate-specific antigen (PSA) level, Gleason score, and percentage of needle cores with adenocarcinoma; post-RT factors were percentage of needle cores with adenocarcinoma and amount of radiation effect on the adenocarcinoma. Of 78 patients, 42 (54%) had residual adenocarcinoma in the post-RT biopsy specimen. Lower total RT dose and dose per implant and greater serum PSA level were associated with an increasing percentage of needle cores with residual post-RT adenocarcinoma. Lower RT dose, an increasing percentage of pre-RT needle cores with adenocarcinoma, and a greater serum PSA level were associated with an increasing percentage of post-RT needle cores with no to moderate RT effect scores in adenocarcinoma. The mean percentage of pre-RT and post-RT needle cores with adenocarcinoma was greater in patients with post-RT biopsy specimens with no to moderate RT effect. The percentage of pre-RT needle cores with adenocarcinoma (a surrogate marker of adenocarcinoma volume), serum PSA level, and RT dose are the key components in the dose-response relationship. Gleason score and gland volume did not contribute significantly to this relationship.