Pathologic features from prostate needle biopsy and prognosis after I-125 brachytherapy

Target Volume Optimization for Localized Prostate Cancer

Historically, the treatment of prostate cancer has required little anatomic information beyond the location of the prostate gland and adjacent seminal vesicles. Radiation therapy has classically been prescribed to the whole prostate due to the high frequency of multifocal cancer in surgical specimens and the inability to localize the precise boundaries of individual tumor foci on imaging. The development of prostate magnetic resonance imaging (MRI) and positron emission tomography (PET) using prostate-specific radiotracers has ushered in an era in which radiation oncologists are able to localize and focally dose-escalate high-risk volumes in the prostate gland. Recent phase III data have demonstrated that incorporating focal dose escalation improves biochemical control without significantly increasing toxicity. However, many questions remain regarding the optimal target volume definition and prescription strategy to implement this practice. In this review we summarize the currently available literature on image-based focal target delineation with MRI and PET. Our review includes a summary of the available data on anatomic patterns of spread to inform clinical judgement for the definition of clinical target volumes. Key knowledge gaps are identified and suggestions for novel implementation strategies are provided.

Tumor burden and location as prognostic factors in patients treated by iodine seed implant brachytherapy for localized prostate cancers

Background

Iodine seed implant brachytherapy is indicated for low risk and selected favorable intermediate risk prostate cancers. A percentage of positive biopsies > 50% is usually considered as a contra-indication, and the tumor location could also influence the treatment efficacy. We studied the association of the percentage of positive biopsy cores, and tumor location, with progression-free survival.

Methods

Among the 382 patients treated at our center by permanent implant iodine seed brachytherapy for a localized prostate cancer between 2006 and 2013, 282 had accessible detailed pathology reports, a minimum follow-up of 6 months, and were included. Progression was defined as a biochemical, local, nodal, or distant metastatic relapse. We studied cancer location on biopsies (base, midgland or apex of the prostate) and percentage of positive biopsy cores, as well as potential confounders (pre-treatment PSA, tumor stage, Gleason score, risk group according to D’Amico’s classification modified by Zumsteg, adjunction of androgen deprivation therapy, and dosimetric data).

Results

Most patients (197; 69.9%) had a low risk, 67 (23.8%) a favorable intermediate risk, 16 (5.7%) an unfavorable intermediate risk, and 1 (0.3%) a high-risk prostate cancer. An involvement of the apex was found for 131 patients (46,5%), of the midgland for 149 (52,8%), and of the base for 145 (51,4%). The median percentage of positive biopsy cores was 17% [3–75%]. The median follow-up was 64 months [12–140]. Twenty patients (7%) progressed: 4 progressions (20%) were biochemical only, 7 (35%) were prostatic or seminal, 6 (30%) were nodal, and 3 (15%) were metastatic. The median time to failure was 39.5 months [9–108]. There were more Gleason scores ≥7 among patients who progressed (40% vs 19%; p = 0.042). None of the studied covariates (including tumor location, and percentage of positive biopsy cores), were significantly associated with progression-free survival. The risk group showed a trend towards an association (p = 0.055).

Conclusions

Brachytherapy is an efficient treatment (5-year control rate of 93%) for patients carefully selected with classical criteria. The percentage and location of positive biopsies were not significantly associated with progression-free survival. A Gleason score ≥ 7 was more frequent in case of progression.

The impact of perineural invasion on biochemical outcome after permanent prostate iodine-125 brachytherapy

PURPOSE

Perineural invasion (PNI) in prostate biopsies is associated with increased risk of higher Gleason score and worse pathologic stage. We report the influence of PNI in biochemical no evidence of disease (bNED) survival after (125)I prostate brachytherapy (BT).

METHODS AND MATERIALS

Pathology reports of 700 men with localized prostate cancer who underwent (125)I prostate BT in 1999-2008 were reviewed. The presence or absence of PNI in the biopsy was documented in 339 men. Clinical, treatment, and dosimetric parameters, along with PNI status, were evaluated for bNED survival, defined by "nadir+2" definition.

RESULTS

Of the 339 patients, 87% had favorable risk and 13% intermediate risk. PNI was present in 89 patients (26%). After a median followup of 32 months, there were five biochemical failures (4: +PNI and 1: -PNI), of which one was local failure (+PNI). Actuarial 5-year bNED survival for the entire group was 97.0% (92.9% for +PNI; 99.2% for -PNI). In univariate analysis age, pretreatment prostate-specific antigen, Gleason score 7, and intermediate risk group predicted for worse biochemical outcome, whereas the presence of PNI showed a trend toward significance (p=0.06). Some of the regression algorithms failed to converge because of low event rates.

CONCLUSIONS

We report excellent biochemical control in 339 men treated with (125)I prostate BT. The presence of PNI showed a trend toward significance in predicting 5-year bNED survival but did not impact on local control and should not influence the decision to recommend BT for localized prostate cancer.

Perineural invasion affects biochemical recurrence-free survival in patients with prostate cancer treated with definitive external beam radiotherapy

OBJECTIVES

To assess the prognostic effect of perineural invasion (PNI) for patients undergoing external beam radiotherapy for prostate cancer.

METHODS

We evaluated 657 consecutive patients who had undergone external beam radiotherapy for clinically localized prostate cancer. The clinical/treatment parameters used for analysis included PNI, clinical stage, biopsy Gleason score, pretreatment prostate-specific antigen, radiation dose, and androgen deprivation. The primary endpoint was biochemical recurrence defined by the Radiation Therapy Oncology Group-American Society for Therapeutic Radiology Oncology Phoenix consensus; the secondary endpoint was prostate cancer death.

RESULTS

Of 586 men with a minimum of 24 months of follow-up, 112 (19.1%) had PNI present in the biopsy specimen. When patients were stratified into risk groups using the National Comprehensive Cancer Network criteria, PNI was more prevalent in patients within higher risk groups (6.8% in low-risk versus 18.3% in intermediate-risk versus 30.1% in high-risk groups; P <0.001). The presence of PNI was associated with lower biochemical recurrence-free (P = 0.003) and cancer-specific (P = 0.040) survival rates by Kaplan-Meier analysis. Cox regression analysis showed that PNI was a statistically significant prognostic factor of biochemical recurrence on both univariate (hazard ratio [HR] 1.71, 95% confidence interval [CI] 1.19 to 2.46, P = 0.004) and multivariate (HR 1.57, 95% CI 1.06 to 2.32, P = 0.025) analyses. Regression analysis after stratification by risk group and adjustment for treatment covariates demonstrated a significant association between PNI and the risk of biochemical recurrence for low-risk (HR 4.14, 95% CI 1.55 to 11.02, P = 0.005) and intermediate/high-risk patients (HR 1.53, 95% CI 1.02 to 2.29, P = 0.040).

CONCLUSIONS

The results of our study have shown that the presence of PNI is an independent risk factor associated with an increased risk of biochemical recurrence in patients with prostate cancer undergoing external beam radiotherapy.

The prognostic significance of perineural invasion in prostatic cancer biopsies: a systematic review

Men with clinically localized prostate cancer are faced with a wide range of treatment options, and only Gleason grading is universally used as a histopathological prognostic factor for this disease. The significance of perineural invasion in diagnostic biopsies is controversial. Opinion about whether or not it should influence treatment decisions is currently almost equally divided. To address this, the authors performed a systematic review of studies that examine the association between perineural invasion and prostate cancer recurrence. MEDLINE, Embase, and the Web of Knowledge were searched from January 1990 to December 2005. Outcomes analyzed were the development of biochemical or clinical recurrence. Twenty-one articles on the association of perineural invasion in biopsies and prostate cancer recurrence after radical prostatectomy (n = 10) or radiotherapy (n = 11) were found but none on its significance in the context of watchful waiting. Structured data extraction was performed to allow comparisons between articles and to identify sources of heterogeneity to explain discrepancies in results. The considerable variation in study design, execution, and reporting precluded meta-analysis and quantitative risk estimation, but the weight of evidence suggested that perineural invasion in biopsies was a significant prognostic indicator, particularly in specific patient groups defined by presenting serum prostate-specific antigen levels and biopsy Gleason scores. Immediate treatment rather than watchful waiting may be more appropriate for patients with localized prostatic cancer and perineural invasion. However, the data are limited, and well-designed studies that use predefined stringent protocols are required to provide robust estimates of risk to aid in treatment planning.

Treatment of intermediate-risk prostate cancer with brachytherapy without supplemental pelvic radiotherapy: A review of the H. Lee Moffitt Cancer Center experience

PURPOSE

To determine the biochemical outcomes of patients with intermediate-risk prostate cancer treated at the H. Lee Moffitt Cancer Center with an I-125 permanent seed implant without supplemental pelvic radiotherapy.

METHODS AND MATERIALS

Under an institutional review board approved protocol, the charts of 88 patients with intermediate-risk prostate cancer and a minimum follow-up of 36 months treated with brachytherapy without supplemental pelvic radiotherapy were reviewed. Median follow-up for the whole cohort was 57 months (range 37-121). Biochemical failure was defined using the American Society for Therapeutic Radiology and Oncology definition.

RESULTS

The 5-year biochemical failure-free survival for the cohort was 83%. Patients with perineural invasion had a worse biochemical outcome, which was statistically significant (perineural invasion vs. no perineural invasion, 5-year biochemical failure-free survival 64% vs. 89%, P = 0.004). None of the following factors were found significant in this subset of patients: Gleason scores 6 versus 7, primary Gleason grades 3 versus 4, percentage of core positive <20% versus >20%, number of cores positive <2 versus 2 versus >2, hormonal therapy versus no hormonal therapy, T1 versus T2, prostate-specific antigen <10 versus >10, or > or =2 intermediate risk factors versus 1 intermediate risk factor.

CONCLUSIONS

Our data suggest that patients with intermediate-risk prostate cancer may be treated effectively with brachytherapy without supplemental pelvic radiotherapy. However, because of the limited nature of our study, we cannot exclude that patients with intermediate-risk prostate cancer may benefit from supplemental external beam radiotherapy.

Perineural invasion on prostate needle biopsy does not predict biochemical failure following brachytherapy for prostate cancer

PURPOSE

To determine if the presence of perineural invasion (PNI) predicts biochemical recurrence in patients who underwent low-dose-rate brachytherapy for the treatment of localized prostate cancer.

METHODS AND MATERIALS

A retrospective case control matching study was performed. The records of 651 patients treated with brachytherapy between 1996 and 2003 were reviewed. Sixty-three of these patients developed biochemical failure. These sixty-three patients were then matched in a one-to-one ratio to patients without biochemical failure, controlling for biopsy Gleason score, clinical stage, initial prostate-specific antigen, age, and the use of androgen deprivation. The pathology of the entire cohort was then reviewed for evidence of perineural invasion on initial prostate biopsy specimens. The biochemical relapse free survival rates for these two groups were compared.

RESULTS

Cases and controls were well matched, and there were no significant differences between the two groups in age, Gleason grade, clinical stage, initial prostate-specific antigen, and the use of androgen deprivation. PNI was found in 19 (17%) patients. There was no significant difference in the rates of PNI between cases and controls, 19.6% and 14.3% respectively (p = 0.45). PNI did not correlate with biochemical relapse free survival (p = 0.40).

CONCLUSION

Perineural invasion is not a significant predictor of biochemical recurrence in patients undergoing brachytherapy for prostate cancer.

Prognostic significance of perineural invasion on biochemical progression-free survival after prostate brachytherapy

OBJECTIVES

To evaluate the influence of perineural invasion (PNI) in the biopsy specimen on biochemical progression-free survival in hormone-naive patients with prostate cancer undergoing brachytherapy.

METHODS

A total of 512 consecutive hormone-naive patients (173 low risk, 212 intermediate risk, and 127 high risk) underwent brachytherapy for clinical Stage T1b-T2cNxM0 (2002 American Joint Committee on Cancer staging system) prostate cancer. No patient underwent seminal vesicle or pathologic lymph node staging. All patients had undergone brachytherapy at least 3 years before analysis. The median follow-up was 5.3 years. Biochemical progression-free survival was defined by a prostate-specific antigen (PSA) cutpoint of 0.4 ng/mL or less after nadir and by the American Society for Therapeutic Radiology and Oncology consensus definition. PNI was defined as carcinoma tracking along, or around, a nerve within the perineural space.

RESULTS

PNI was documented in 133 patients (26.0%). For both biochemical progression-free definitions, 94.0% and 94.9% of patients with and without PNI, respectively, remained free of biochemical progression. The median time to failure in patients with and without PNI was 17.2 and 17.9 months, respectively. For the biochemically disease-free cohort, the median posttreatment PSA level was less than 0.1 ng/mL. On univariate Cox regression analysis, the pretreatment PSA level, percentage of positive biopsies, prostate volume, and Gleason score predicted for biochemical outcome. PNI did not approach statistical significance (P = 0.671). On multivariate analysis, only pretreatment PSA (P < 0.001) and the percentage of positive biopsies (P < 0.001) maintained statistical significance.

CONCLUSIONS

In hormone-naive brachytherapy patients implanted with generous periprostatic treatment margins, the presence of PNI in the biopsy specimen did not adversely affect 8-year biochemical progression-free survival.

Myths and fallacies in permanent prostate brachytherapy

Because there are competing modalities to treat early-stage prostate cancer, the constraints or deficiencies of one modality may be erroneously applied to others. Some valid concerns arising from surgery and external beam therapy, which have been falsely transferred to brachytherapy, are constraints based on patient age, clinical and pathological parameters, patient weight, and size of prostate. Although the constraints have a valid basis in one modality, knowledge of the origin and mechanism of the constraint has provided a means to circumvent or overcome it in brachytherapy. Failures as measured by biochemical no-evidence of disease (bNED) survival may be attributed to extracapsular disease extension. Such extension often expresses itself in surrogate parameters such as a high percentage of positive biopsies, perineural invasion, or the dominant pattern in Gleason score histology. Failures due to such factors may be prevented by implanting with consistent extracapsular dosimetric margins. Some presumed limitations on prostate brachytherapy originated from data on patients implanted in the first few years the procedure was being developed. Most of the urinary morbidity and a significant part of the decrease in sexual function observed may be avoided by controlling the dosimetry along the prostatic and membranous urethra and at the penile bulb.

Carcinoma extent in prostate needle biopsy tissue in the prediction of whole gland tumor volume in a screening population

Increasing prostate tumor volume has been shown to correlate with numerous adverse prognostic indicators for patients with prostate carcinoma The ability to predict tumor volume from pretreatment parameters is potentially critical in the stratification of patients for different management strategies. We assessed the capacity of preoperative variables to predict tumor volume in 100 men diagnosed with prostate cancer in a prostate-specific antigen (PSA)-based screening program. Preoperative information included total serum PSA concentration and needle biopsy tissue variables, including Gleason score, number of positive cores, linear extent of carcinoma in millimeters, greatest percentage of carcinoma (in a single core), total percentage of carcinoma (all cores), presence of perineural invasion, and percentage of high-grade carcinoma. The postoperative end point was total tumor volume in radical prostatectomy tissue, calculated by image analysis. We determined independently significant factors and generated a predictive modelfor whole gland tumor volume. Total tumor volume was related significantly in multivariate analysis to 3 preoperative variables: linear extent of carcinoma, exponential number of positive cores, and serum PSA. A predictive model generated based on these 3 variables accounted for only 65% of the natural deviance of the data owing to data-point scatter for individual patients, suggesting that additional variables are needed to more accurately predict tumor volume. Findings highlight the importance of reporting quantitative measures of tumor amount in prostate needle biopsy specimens; several measures of tumor extent (vs 1 measure) provide maximal information on prostate cancer size.

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.

Radiation therapy for prostate cancer

OBJECTIVES

To review the advances in radiation therapy for prostate cancer and the nursing care of patients with prostate cancer.

DATA SOURCES

Peer-reviewed journal articles, including research studies and review articles.

CONCLUSIONS

Radiation therapy is used to cure early stage prostate cancer, control locally advanced disease, and effectively palliate symptoms of metastasis. The three forms of treatment used include external beam radiation therapy, brachytherapy; and radiopharmaceutical treatments.

IMPLICATIONS FOR NURSING PRACTICE

Nursing care of patients receiving radiation therapy for prostate cancer includes managing the symptoms associated with the disease and treatment, educating patients and families about self-care measures, and providing support throughout the course of the disease.