Search for residual prostate cancer on pT0 radical prostatectomy after positive biopsy

Reported incidence of no residual prostate cancer (i.e. pathological stage pT0) on radical prostatectomy ranges from 0.07 to 4.2%. The incidence is higher after neoadjuvant endocrine treatment. The aim of this study was to search for residual cancer on radical prostatectomy (RP) specimens when an initial sampling failed to find the cancer in patients with positive biopsy. Our database of 1,328 consecutive patients whose biopsies and RP specimen were both examined at the Polytechnic University-United Hospitals of the Marche Region between March 1995 and June 2006 was reviewed. The radical prostatectomies were grossly completely sampled and examined with the whole mount technique. We identified eight patients (i.e. 0.6%; three untreated and five hormonally treated preoperatively, i.e. 0.3 and 0.8%, respectively, of the total number of RPs included in the study) with positive biopsy and with no residual cancer in the initial routine histological examination of the RP. The RP of this group of eight was subjected to additional sectioning and evaluation of the paraffin blocks of the prostatectomy, also after block-flipping, immunostaining with an antibody against CAM 5.2, p63, PSA, and alpha-methylacyl-CoA racemase, and DNA specimen identity analysis. There were no cases with a false positive biopsy diagnosis, and cancer was not overlooked or missed in the initial routine histological examination of any of the 8 pT0 RPs. A minute focus of cancer (the diameter was always below 2.0 mm) was found on the additional sections in five. In particular, cancer was found after block-flipping in one of them. In an additional case, cancer was eventually discovered after immunostaining tissue sections for cytokeratin CAM 5.2, for p63 and PSA. In the remaining two cases (one untreated and the other hormonally treated), cancer was not found (0.15% of the 1,328 RPs included in the study); the review of the description of the macroscopic appearance of the RP and of its slides revealed that part of the peripheral zone corresponding to the site of the positive biopsy was missing, i.e. not removed from the patient at the time of the operation at least in one of the two. DNA specimen analysis confirmed the identity of the biopsy and prostatectomy in both. An extensive search for residual cancer reduces the number of pT0 RPs after a positive biopsy from 0.6 to 0.15%. It is recommended to have the needle biopsy reviewed, carefully look again at the radical prostatectomy, do deeper sections and then flip certain paraffin blocks. In addition, atypical foci should be stained for basal cell markers and often AMACR, especially in hormone-treated cases. If a block is missing part of the peripheral zone (capsular incision), this should be commented on. DNA analysis for tissue identity should be performed when the other steps have been taken without finding cancer

Impact of hormonal therapy on the detection of promoter hypermethylation of the detoxifying glutathione-S-transferase P1 gene (GSTP1) in prostate cancer

BACKGROUND: In spite of excellent cure rates for prostate cancer patients with favorable tumor characteristics, patients with unfavorable characteristics after radical prostatectomy are still at a significantly increased risk of tumor progression. Early adjuvant hormonal therapy (AHT) has been shown to be of prognostic benefit in these patients. Unfortunately initiation and duration of early AHT in the individual patient is based on statistic data. PSA, as the standard prostate marker is neither able to reliably indicate minimal residual tumor disease in the early postoperative phase, nor can it be used for therapy monitoring due to the suppressive effect of hormonal therapy on PSA production. Promoter hypermethylation of the detoxifying glutathione-S-transferase P1 gene (GSTP1-HM) has been shown to be the most common DNA alteration of primary prostatic carcinoma which, when used as a marker, is supposed to be able to overcome some of the disadvantages of PSA. However until now information on the impact of hormonal therapy on the detection of GSTP1-HM is lacking. The purpose of our study was to assess the impact of endocrine therapy on the detection of GSTP1-HM by methylation-specific PCR (MSP) in prostate cancer. METHODS: Paraffin embedded tumor samples from the radical prostatectomy (RP) specimens from 15 patients after hormonal therapy (HT) (mean 8 months) were assessed by MSP. In 8 of the patients the GSTP-1 status of the tumors before HT was assessed on the corresponding initial diagnostic biopsies. RESULTS: Following HT MSP showed GSTP1-HM in 13/15 of the RP specimens. In two patients analysis of the RP specimens failed to show GSTP1-HM. All initial tumor samples (8/8 biopsy specimens) showed GSTP1-HM, including both patients negative for GSTP1 HM in the corresponding RP specimen. CONCLUSION: In most cases hormonal therapy appears to not alter GSTP1 HM detection. However the change from a positive to a negative GSTP1 HM status in a subset of the patients may point to an, at least partial androgen dependency. Further studies on a larger cohort of patients are necessary to assess its frequency and the exact hormonal interactions

Quantitative real-time RT-PCR of CD24 mRNA in the detection of prostate cancer

BACKGROUND: Gene expression profiling has recently shown that the mRNA for CD24 is overexpressed in prostate carcinomas (Pca) compared to benign or normal prostate epithelial tissues. Immunohistochemical studies have reported the usefulness of anti-CD24 for detecting prostate cancer over the full range of prostate specimens encountered in surgical pathology, e.g. needle biopsies, transurethral resection of prostate chips, or prostatectomies. It is a small mucin-like cell surface protein and thus promises to become at least a standard adjunctive stain for atypical prostate biopsies. We tested the usefulness of real-time RT-PCR for specific and sensitive detection of CD24 transcripts as a supplementary measure for discriminating between malignant and benign lesions in prostatic tissues. METHODS: Total RNA was isolated from snap-frozen chips in 55 cases of benign prostatic hyperplasia (BPH) and from frozen sections in 59 prostatectomy cases. The latter contain at least 50% malignant epithelia. Relative quantification of CD24 transcripts was performed on the LightCycler instrument using hybridization probes for detection and porphobilinogen deaminase transcripts (PBGD) for normalization. RESULTS: Normalized CD24 transcript levels showed an average 2.69-fold increase in 59 Pca-cases (mean 0.21) when compared to 55 cases of BPH (mean 0.08). This difference was highly significant (p < 0.0001). The method has a moderate specificity (47.3%) but a high sensitivity (86.4%) if the cutoff is set at 0.0498. CD24 expression levels among Pca cases were not statistically associated with the tumor and lymph-node stage, the grading (WHO), the surgical margins, or the Gleason score. CONCLUSION: The present study demonstrates the feasibility of quantitative CD24 RNA transcript detection in prostatic tissues even without previous laser microdissection

Heterogeneous proliferative potential of occult metastatic cells in bone marrow of patients with solid epithelial tumors

Bone marrow is a major homing site for circulating epithelial tumor cells. The present study was aimed to assess the proliferative capacity of occult metastatic cells in bone marrow of patients with operable solid tumors especially with regard to their clinical outcome. We obtained bone marrow aspirates from 153 patients with carcinomas of the prostate (n = 46), breast (n = 45), colon (n = 33), and kidney (n = 29). Most of the patients (87%) had primary disease with no clinical signs of overt metastases [tumor-node-metastasis (TNM)-stage UICC (Union Internationale Contre le Cancer) I-III]. After bone marrow was cultured for 21–102 days under special cell culture conditions, viable epithelial cells were detected by cytokeratin staining in 124 patients (81%). The cultured epithelial cells harbored Ki-ras2 mutations and numerical chromosomal aberrations. The highest median number of expanded tumor cells was observed in prostate cancer (2,619 per flask). There was a significant positive correlation between the number of expanded tumor cells and the UICC-stage of the patients (P = 0.03) or the presence of overt metastases (P = 0.04). Moreover, a strong expansion of tumor cells was correlated to an increased rate of cancer-related deaths (P = 0.007) and a reduced survival of the patients (P = 0.006). In conclusion, the majority of cancer patients have viable tumor cells in their bone marrow at primary tumor diagnosis, and the proliferative potential of these cells determines the clinical outcome

2′-Hydroxyflavanone inhibits proliferation, tumor vascularization and promotes normal differentiation in VHL-mutant renal cell carcinoma

Renal cell carcinoma (RCC) is one of the top ten cancers prevalent in USA. Loss-of-function mutations in the von Hippel–Lindau (VHL) gene constitute an established risk factor contributing to 75% of total reported cases of RCC. Loss-of-VHL leads to a highly vascularized phenotype of renal tumors. Intake of citrus fruits has been proven to reduce the risk of RCC in multicenter international studies. Hence, we studied the effect of 2′-hydroxyflavanone (2HF), an active anticancer compound from oranges, in RCC. Our in vitro investigations revealed that 2HF suppresses VHL-mutant RCC to a significantly greater extent than VHL-wild-type RCC by inhibiting epidermal growth factor receptor signaling, which is increased due to VHL mutations in RCC. Our results also revealed for the first time, that 2HF inhibits glutathione S-transferase pi activity. 2HF reduced cyclin B1 and CDK4 levels and induced G2/M phase arrest in VHL-mutant RCC. Importantly, 2HF inhibited the angiogenesis in VHL-mutant RCC by decreasing vascular endothelial growth factor expression. Our in vivo studies in mice xenografts confirmed our in vitro results as evident by decreased levels of proliferation marker, Ki67 and angiogenic marker, CD31, in 2HF-treated mice xenografts of VHL-mutant RCC. 2HF also increased the expression of E-cadherin in VHL-mutant RCC, which would be of significance in restoring normal epithelial phenotype. Collectively, our in vitro and in vivo results revealed the potent antiproliferative, anti-angiogenic and prodifferentiation properties of 2HF in VHL-mutant RCC, sparing normal cells, which could have significant implications not only in the specific management of VHL-mutant RCC but also towards other VHL syndromes

Epigenetic targets in the diagnosis and treatment of prostate cancer

Prostate cancer (PC) is one of leading cause of cancer related deaths in men. Various aspects of cancer epigenetics are rapidly evolving and the role of 2 major epigenetic changes including DNA methylation and histone modifications in prostate cancer is being studied widely. The epigenetic changes are early event in the cancer development and are reversible. Novel epigenetic markers are being studied, which have the potential as sensitive diagnostic and prognostic marker. Variety of drugs targeting epigenetic changes are being studied, which can be effective individually or in combination with other conventional drugs in PC treatment. In this review, we discuss epigenetic changes associated with PC and their potential diagnostic and therapeutic applications including future areas of research