Permanent radioactive seed implantation in the treatment of prostate cancer

New Developments in Breast Cancer and Their Impact on Daily Practice in Pathology

Advances in research have transformed our understanding of breast cancers and have altered the daily practice of pathology. Theranostic evaluations performed by pathologists are now critical in triaging the patients into appropriate treatment groups, as are new guidelines that were recently established for the evaluation of HER2/neu gene amplification. Emerging molecular classifications of breast cancers bring novel perspectives to the assessment of individual cases, and opportunities for better treatments. Molecular studies have particularly shed light on distinct biological subsets of triple-negative breast cancers, for which new targeted therapies are being developed. The prognostic and therapeutic utility of new histopathologic parameters, such as tumor-infiltrating lymphocytes, are also being elucidated, and new protocols have been devised for the pathologic evaluation of breast specimens that have undergone neoadjuvant treatment. Novel clinical practices, such as radioactive seed localization, also affect the way breast specimens are processed and evaluated. In this brief review, we highlight the developments that are most relevant to pathology and are changing or could potentially impact our daily practice.

Transcription Factor HBP1 Enhances Radiosensitivity by Inducing Apoptosis in Prostate Cancer Cell Lines

Radiotherapy for prostate cancer has been gradually carried out in recent years; however, acquired radioresistance often occurred in some patients after radiotherapy. HBP1 (HMG-box transcription factor 1) is a transcriptional inhibitor which could inhibit the expression of dozens of oncogenes. In our previous study, we showed that the expression level of HBP1 was closely related to prostate cancer metastasis and prognosis, but the relationship between HBP1 and radioresistance for prostate cancer is largely unknown. In this study, the clinical data of patients with prostate cancer was compared, and the positive correlation was revealed between prostate cancer brachytherapy efficacy and the expression level of HBP1 gene. Through research on prostate cancer cells in vitro, we found that HBP1 expression levels were negatively correlated with oncogene expression levels. Furthermore, HBP1 overexpression could sensitize prostate cancer cells to radiation and increase apoptosis in prostate cancer cells. In addition, animal model was employed to analyze the relationship between HBP1 gene and prostate cancer radiosensitivity in vivo; the result showed that knockdown of HBP1 gene could decrease the sensitivity to radiation of xenograft. These studies identified a specific molecular mechanism underlying prostate cancer radiosensitivity, which suggested HBP1 as a novel target in prostate cancer radiotherapy.

Haematuria after prostate brachytherapy

OBJECTIVE

To characterize the incidence and clinical history of gross haematuria after prostate brachytherapy. To identify treatment risk factors for the development of gross haematuria in this setting.

PATIENTS AND METHODS

We reviewed haematuria outcomes collected prospectively in 2454 patients treated with transperineal prostate brachytherapy over a 20-year period at a single institution. Patients were followed for a median of 5.9 years. The association of haematuria with age, pretreatment PSA, ethnicity, clinical tumour stage, Gleason score, prostate volume, isotope (iodine 125 or palladium 103), biologically effective dose (BED), external beam radiation, androgen deprivation, development of urinary retention and occurrence of biochemical failure was investigated.

RESULTS

A total of 218 men (8.9%) reported gross haematuria at a median time of 772.2 days after implantation. Haematuria was associated with prostate volume >40 cm(3) (P < 0.01), use of external beam radiation (P < 0.01), Gleason score >7 (P = 0.037), Asian ethnicity (P < 0.001), BED >200 Gy (P = 0.01), and freedom from biochemical failure (P = 0.004). On multivariate analysis, prostate volume >40 cm(3) (P = 0.002), external beam radiation, (P = 0.001), and freedom from biochemical failure (P = 0.035) were predictors of haematuria.

CONCLUSIONS

Late gross haematuria was observed in a small proportion of men after brachytherapy and may occur with considerable latency. Larger prostate glands, freedom from biochemical failure and external beam radiation are risk factors.

Brachytherapy for prostate cancer

The use of prostate brachytherapy for the treatment of early-stage, low-grade, low-volume carcinoma of the prostate continues to rise. Given the prolonged natural history of these early lesions, treatment failures may take many years or even a decade or more before becoming clinically evident. It is therefore likely that as the brachytherapy data mature, clinicians will be asked to help manage a potentially large cohort of men who have failed this local therapy--a scenario that will provide a number of unique challenges for the treatment of the disease and the management of the lower urinary tract. This article offers a contemporary review and suggestions with regard to the follow-up of patients who have undergone prostate brachytherapy, including low-dose rate permanent implants and high-dose rate temporary implants for the management of localized prostate cancer. In addition, current controversies in defining biochemical failure following radioactive implantation--including important data regarding the "prostate-specific antigen bounce" phenomenon--are discussed. Finally, a comprehensive review of the management of local recurrence following brachytherapy is offered.

3D visualization, analysis, and treatment of the prostate using trans-urethral ultrasound

In the year 2000, it is estimated that over 20,000 men underwent transperineal interstitial permanent prostate brachytherapy (TIPPB) for treatment of prostate cancer. Trans-urethral ultrasound (TUUS) is a new interactive, real-time 3D imaging method that may be effective in therapy-guidance during and after TIPPB. TUUS provides higher resolution than trans-rectal ultrasound (TRUS). TUUS can be used to accurately localize radioactive seeds and therefore contribute to more accurate determination of radiation dose distribution throughout the tissue after the completion of the procedure, similar to information currently provided by expensive and offline CT scans. A TUUS catheter can be used to acquire 2D section images or 3D volume images for detailed analyses of the prostate and associated tissue. Initial development of TUUS imaging was carried out on an ultrasound-equivalent prostate phantom with cylindrical dummy radiation sources. This was followed by preliminary studies in animals and then in patients. Both CT and TRUS data were acquired in these studies for comparative purposes. Segmentation of the prostate capsule and radioactive seeds was carried out using several semi-automated 3D algorithms and image processing techniques. Presentation of the data to the clinician is provided by a variety of complementary 2D and 3D display methods. In comparison with the CT data, TUUS data provided both greater spatial resolution and better soft tissue differentiation. In comparison to the TRUS data, TUUS data provided greater resolution and better seed localization. Combining these advantages suggests the possibility of TUUS becoming the exclusive imaging method in prostate cancer brachytherapy.

Perspectives on prostate cancer diagnosis and treatment: a roundtable

This roundtable was held September 30, 2000. It addressed, first of all, the accuracy and proper interpretation of the available prostate-specific antigen assays. Dr. Brawer presented data to demonstrate the specificity of the complexed prostate-specific antigen assay. Dr. Stamey counterpoised evidence that pretreatment prostate-specific antigen levels less than 9 ng/mL are attributable to benign prostatic hyperplasia and therefore are of little value as an indicator of when to initiate treatment for prostate cancer. The other roundtable participants offered reviews and new data regarding hormonal therapy as primary or adjunctive treatment of prostate cancer. Dr. Fowler presented a large retrospective series of men with locally advanced prostate cancer for whom androgen ablation was the primary therapy. Dr. Droller discussed his center's experience in integrating hormonal therapy with brachytherapy. Finally, Dr. Messing reviewed and critiqued the evidence that the combination of hormonal and radiation therapy improves survival.

Rectourethral Fistula and Massive Rectal Bleeding from Iodine-125 Prostate Brachytherapy: A Case Report

Iodine-125 brachytherapy is an effective well-tolerated treatment for localized prostate cancer. Gastrointestinal complications of brachytherapy (minor rectal bleeding or tenesmus) are uncommon. Rectal ulceration or rectourethral fistulas after prostate brachytherapy are rare. We present a case of massive refractory rectal bleeding and rectourethral fistula, a complication of prostate brachytherapy never before reported. As a result of the patient's life-threatening symptoms aggressive surgical therapy was necessary.