Detection of occult micrometastases in the bone marrow of patients with prostate carcinoma

Safety of androgen therapy in men with prostate cancer

Prostate cancer is one of the most frequently diagnosed malignancies in men worldwide and the life expectancy for men with prostate cancer is improving due to advancements in diagnostics and treatment. Male hypogonadism is associated with obesity, diabetes, and other comorbidities and also has been linked with increasing age; the primary therapy modality for this condition is testosterone replacement therapy (TRT). There are concerns that testosterone therapy may cause prostate cancer disease progression. However, contemporary evidence suggests that testosterone replacement therapy may be safe in specific groups of patients with prostate cancer. This chapter will summarise the contemporary literature regarding TRT use in hypogonadal men with prostate cancer, including limitations and future research goals.

Development of a Bacterial Macroarray for the Rapid Screening of Targeted Antibody-Secreted Hybridomas

Hybridoma screening is a key step for the successful generation of high-affinity analyte-specific monoclonal antibodies (MAbs). This work presents an innovative screening method, known as a bacterial macroarray, generated by contact printing of hybridoma cell supernatant samples on a nitrocellulose (NC) membrane initially coated with fluorescein isothiocyanate (FITC)-labeled bacteria. Given that bacterial fixation will be influenced by complex bacterial surface structures, we selected both gram-positive bacteria ( Staphylococcus aureus and Listeria monocytogenes) and gram-negative bacteria ( Escherichia coli O157:H7 and Cronobacter sakazakii) to optimize the fixation conditions for binding to the NC membrane, such as the aperture of the NC membrane, the concentration of bacteria, the dosage of glycerin in the spotting buffer, and the fixation time and temperature. As a result, we found that a better bacterial macroarray could be developed when the spotting buffer, containing 10¹¹ CFU mL^-1 of FITC-labeled bacteria and 15% (V/V) glycerol, was spotted onto a 0.45 µm NC membrane with an incubation of 2 h at 37 °C. Finally, we verified the stability and specificity of the prepared bacterial macroarray by detecting cell cultures with the addition of two MAbs ( Escherichia coli O157:H7 MAb E7 and Cronobacter sakazakii MAb 1E9) to simulate the screening experiments. Here, we describe a bacterial macroarray to efficiently screen the targeted antibody-secreted hybridomas.

Minimal residual disease in prostate cancer patients after primary treatment: theoretical considerations, evidence and possible use in clinical management

Minimal residual disease is that not detected by conventional imaging studies and clinically the patient remains disease free. However, with time these dormant cells will awaken and disease progression occurs, resulting in clinically and radiological detectable metastatic disease. This review addresses the concept of tumor cell dissemination from the primary tumor, the micrometastatic niche and tumor cell survival and finally the clinical utility of detecting and characterizing these tumor cells in order to guide management decisions in treating patients with prostate cancer.

B4 androgen ablation: attacking the prostate cancer stem cell

There is increasing evidence that prostate cancers in rodent models and in men contain a cellular subpopulation that displays stem cell properties. These prostate cancer stem cells (PCSCs) lack androgen receptor expression and are increased in castration-resistant disease. In this issue of the JCI, a study from Yoshioka et al. demonstrates that PCSCs are regulated by a pathway in which α6β4 integrin amplifies signaling through ErbB2 and c-Met receptors. Targeting this pathway provides a novel therapeutic strategy for hormone refractory prostate cancer.

Urokinase-plasminogen-activator receptor expression in disseminated tumour cells in the bone marrow and peripheral blood of patients with clinically localized prostate cancer

OBJECTIVE To evaluate the expression of urokinase-plasminogen-activator receptor (uPA-R) in disseminated tumour cells (DTC) in bone marrow (BM) and peripheral blood (PB) of patients with clinically localized prostate cancer before radical prostatectomy (RP), and to assess the associations with pathological variables and prognosis. PATIENTS AND METHODS In all, 52 patients (47 with clinically localized cancer and five with benign prostatic hyperplasia, BPH, as controls) were prospectively enrolled. BM and PB samples were drawn before surgery. DTC were enriched using a commercial system, cytokeratin (CK) 8/18 was used to detect DTC, and uPA-R expression was detected by dual-immunostaining of the DTC. The final pathology of the RP specimen was compared with the results of immunostaining. Follow-up was initiated to detect tumour relapse (defined as a prostate-specific antigen (PSA) level of > or =0.2 ng/mL). RESULTS Overall, there was expression of 'CK + uPA-R' in 60% of the BM and in 19% of the PB specimens. Expression of this marker in BM was most significantly increased in those with unfavourable Gleason scores (P = 0.004), followed by high-risk cancer (P = 0.005). The relative risk for CK + uPA-R expression in the BM was 3.1 times higher in high-risk than in low-risk prostate cancer. No relevant expression rates were detected for PB. In the control group, no patient showed CK or uPA-R expression in BM or PB. The PSA-recurrence free survival was significantly lower in patients with CK + uPA-R-positive BM cells (P = 0.01). CONCLUSION In this pilot study, the preoperative detection rate of CK + uPAR expression in BM of patients with prostate cancer increased with Gleason score and in those with high-risk disease. All patients with a later PSA relapse had had uPA-R expression in their DTC from the BM. DTC with uPA-R expression was an adverse prognostic factor for prostate cancer.

Detection of occult metastasis in patients with breast cancer

The most important factor affecting the outcome of patients with invasive cancer is whether the tumor has spread, either regionally (to regional lymph nodes) or systemically. However, a proportion of patients with no evidence of systemic dissemination will develop recurrent disease after primary "curative" therapy. Clearly, these patients had occult systemic spread of disease that was undetectable by routinely employed methods (careful pathological, clinical, biochemical, and radiological evaluation). In addition, the success of adjuvant therapy is assumed to stem from its ability to eradicate occult metastases before they become clinically evident. Therefore, methods for the detection of occult metastases in patients with the earliest stage of cancer, i.e., prior to detection of metastases by any other clinical or pathological analysis, have received a great deal of attention.

Occult metastasis

The most important factor affecting the outcome of patients with invasive cancers is whether the tumor has spread, either regionally (to regional lymph nodes) or systemically. However, a proportion of patients with no evidence of systemic dissemination will develop recurrent disease after primary 'curative' therapy. Clearly, these patients had occult systemic spread of disease that was undetectable by methods routinely employed (careful pathological, clinical, biochemical and radiological evaluation). In addition, the success of adjuvant therapy is assumed to stem from its ability to eradicate occult metastases before they become clinically evident [1]. Therefore, methods for the detection of occult metastases in patients with the earliest stage of cancer, i.e., prior to detection of metastases by any other clinical or pathological analysis, have received a great deal of attention.

Detection of occult metastases in lung carcinomas: progress and implications for lung cancer staging

The ability to detect occult regional and systemic metastases in patients with operable lung carcinoma could have a significant impact on the management of the disease. Here, we review the literature, including studies from our own laboratory, regarding the clinical significance of the presence of occult metastases in patients with lung cancer. The accumulated evidence strongly suggests that the detection of occult regional and systemic metastases is an important predictor of disease progression. The use of this method should be considered in the future design of lung cancer clinical trials, at the very least. The detection of occult metastases should have an impact on lung cancer management; to reflect this, we propose a change in the TNM staging system to indicate the presence or absence of occult regional (lymph node) and systemic (bone marrow) metastases. The proposed change is TNnMm, where n and m are occult nodal and bone marrow metastases status.

Focal therapy for prostate cancer 1996: maximizing outcome

OBJECTIVES

To summarize improvements in patient selection and the results of focal therapy for the management of localized prostate cancer.

METHODS

A contemporary series of patients managed with wide surgical excision, radiation therapy (three-dimensional conformal radiation, interstitial radiation, and charged-particle or proton therapy), and cryo-therapy were reviewed.

RESULTS

We used preoperative cancer grade, transrectal ultrasound, and serum prostate-specific antigen (PSA) in all patients, and cross-sectional imaging and bone scans in selected patients to allow for reasonably accurate cancer staging and selection of patients most likely to be cured by radical prostatectomy or radiation. In patients with extracapsular extension of prostate cancer, wide surgical excision and achievement of a clear surgical margin had therapeutic value. Newer radiation techniques resulted in a higher likelihood of prostate cancer control than previous techniques. Cryotherapy for patients with stages T1 through 3 prostate cancer was associated with a posttreatment undetectable PSA rate of 48% and a positive biopsy rate of 23%.

CONCLUSIONS

Patients with organ-confined and, therefore, curable prostate cancer can be identified. Well-performed radical prostatectomy, radiation, and cryotherapy are alternative treatments for the management of localized prostate cancer.

Prostate-specific antigen-producing cells in the bone marrow of a patient with early-stage prostate cancer

This report describes a clinical case that supports the hypothesis that occult bone marrow disease may exist even in early-stage and low prostate-specific antigen (less than 10 ng/mL) prostate cancer. The concept of adding androgen suppression to definitive local therapy in these patients is discussed.

Sensitivity of frozen section examination of pelvic lymph nodes for metastatic prostate carcinoma

BACKGROUND

A Total Quality Improvement review of frozen section diagnoses yielded four sequential false-negative frozen section diagnoses in lymph nodes in the evaluation of metastases from prostate carcinoma. Because these results appeared to differ from the department's overall frozen section experience, frozen section diagnoses of pelvic lymph nodes in patients with prostate carcinoma were reviewed to benchmark the department's performance.

METHODS

All 220 pelvic lymph node frozen section samples from 110 patients with prostate carcinoma from January, 1986 to July, 1993 at Bridgeport Hospital (BH) were reviewed, and the department's frozen section diagnostic efficiency was compared with: (1) all BH frozen section procedures performed during the same period; (2) pelvic lymph node frozen section analysis and (3) imaging techniques for prostate carcinoma from other institutions found in MEDLARS literature searches from 1973 to 1993.

RESULTS

Frozen section diagnostic efficiency for patients with prostate carcinoma from BH was 93.6% (sensitivity 63.2%, specificity 100%) compared with (1) 98% for all BH frozen section analyses (sensitivity 99%, specificity 98%); (2) 90.1% for MEDLARS search pelvic lymph node frozen section prostate carcinoma analyses (sensitivity 66.5%, specificity 100%); and (3) 88% for MEDLARS search magnetic resonance imaging (MRI) pelvic lymph node prostate carcinoma (sensitivity 41%, specificity 97%).

CONCLUSIONS

Frozen section diagnosis of pelvic lymph nodes approaches the overall diagnostic efficiency of frozen section analysis and is more sensitive for the diagnosis of prostate carcinoma in pelvic lymph nodes than is MRI because more than half of the metastases are smaller than the 1.0-cm resolution limit of the MRI. False-negative frozen section diagnoses (67% sensitivity) occur because of errors in sampling microscopic metastases.

Incidence of occult lymph node metastases in pathological stage C (pT3N0) prostate cancer

PURPOSE

To determine the incidence of occult lymph node metastases in patients with stage pT3N0 prostate cancer.

MATERIALS AND METHODS

Lymph nodes from 95 patients with stage pT3N0 prostate cancer were analyzed by immunohistochemistry for extrinsic epithelial cells using epithelial-specific monoclonal antibodies. The extrinsic epithelial cells were also tested for prostate specific antigen expression.

RESULTS

Occult lymph node metastases were identified in 15 cases (16%) and were more frequent in patients with high primary Gleason grade tumors and seminal vesicle invasion (p = 0.03). In all cases the extrinsic cells were of prostate origin based on prostate specific antigen expression.

CONCLUSIONS

Occult lymph node metastases can be detected in a substantial proportion of patients with stage pT3N0 prostate cancer, are associated with known predictors of disease progression, and may be useful in identifying patients at risk for recurrence and progression.