Wael Sakr

The frequency of carcinoma and intraepithelial neoplasia of the prostate in young male patients

The incidence of clinically detected prostate cancer is increasing with more frequent diagnosis in younger male patients. Whether this represents a genuine increase in incidence or earlier detection is not clear. To understand better the evolution and early changes of prostate cancer we evaluated 152 prostate glands from young male patients 10 to 49 years old. Of the prostates 98 were from African-Americans and 54 were from white patients. Prostatic intraepithelial neoplasia was identified in 0%, 9%, 20 and 44%, and small foci of histological cancer in 0%, 0%, 27% and 34% of the male patients in the second, third, fourth and fifth decades of age, respectively. The majority of the cases of prostatic intraepithelial neoplasia were of low grade. High grade prostatic intraepithelial neoplasia, found in 5 prostates, was first identified in the fifth decade. All 5 cases occurred in prostates containing histological carcinoma. Incidental carcinoma was detected with a similar frequency in white and black patients. The cancerous foci were of similar size with a tendency for cancer in black patients to be multifocal, particularly in those in the fifth decade. We conclude that prostatic intraepithelial neoplasia and histological cancers are surprisingly common in young male patients of both races. The evolution of prostatic intraepithelial neoplasia and focal histological cancers is not clear but it appears to present several decades earlier than clinically detected carcinoma. The natural history of prostate cancer must encompass many more years (decades) than has been previously realized. In addition, the initiating events leading to clinically relevant prostate cancers likely occur at a remarkably young age.

Age and racial distribution of prostatic intraepithelial neoplasia

AIMS To study the prevalence, extent and evolution of high-grade prostatic intraepithelial neoplasia (HGPIN) in African-American and Caucasian men of a wide age range in order to help clarify the role this lesion may play in the racial differences of prostate cancer. METHODS The lesion was documented in step-sectioned, entirely submitted prostates of two study populations: 525 autopsied men who died of trauma and 1,000 patients who had retropubic radical prostatectomy for clinically localized carcinoma of the prostate. RESULTS We found that HGPIN starts in young individuals and increases progressively with advancing age in both races but is more prevalent in African-Americans. Additionally, the more extensive form of HGPIN with multifocal or diffuse involvement of the gland appears at a younger age in African-Americans. CONCLUSIONS Microscopic foci of HGPIN can be documented in males in the 3rd and 4th decades with the lesion becoming more extensive in older men. The finding that HGPIN is both more prevalent and its more diffuse form appears earlier in African-Americans, indicates a potentially important role for this lesion in the race-related discrepancies associated with this disease.

Limited role of radionuclide bone scintigraphy in patients with prostate specific antigen elevations after radical prostatectomy

PURPOSE Bone scintigrams of patients with increasing serum prostate specific antigen (PSA) after radical prostatectomy are only rarely positive. We identify clinical parameters that would improve our ability to select patients for this imaging study. MATERIALS AND METHODS We reviewed all bone scintigrams done at our institution between 1991 and 1996 in patients with persistently increasing serum PSA after radical prostatectomy. What prompted the clinician to obtain the bone scintigram was trigger PSA (tPSA). The rate of increase in PSA to tPSA was measured by tPSA/time from radical prostatectomy (slope 1) and tPSA/time from last undetectable PSA (slope 2). These parameters were evaluated together with standard clinicopathological data in univariate and multivariate analyses to determine the ability to predict the bone scintigram result. RESULTS In univariate analysis tPSA (p = 0.003), slope 1 (p = 0.005) and slope 2 (p = 0.004) were useful in predicting the bone scintigram result but pathological stage, Gleason score, preoperative PSA and time to recurrence were not. In multivariate analysis the single most useful parameter in predicting the bone scintigram result was tPSA (p = 0.01). Based on a logistic regression model the probability of a positive bone scintigram was less than 5% until tPSA increased to 40 to 45 ng./ml. CONCLUSIONS In patients with increasing serum PSA after radical prostatectomy current serum PSA is the best predictor of the bone scintigram result. Furthermore, there is limited usefulness of bone scintigraphy until PSA increases above 30 to 40 ng./ml.

Epidemiology of Prostate Cancer

Malignant transformation of the prostate and progression of carcinoma appear to be the consequence of a complex series of initiation and promotional events under genetic and environmental influences. Increased incidence of the condition may be the result of improved detection, greater awareness of the condition, and possibly an increased life expectancy accompanied by a decrease in competing causes of death rather than a true increase in the prevalence of the disease. The marked racial and geographic differences are probably multifactorial, with genetic, environmental, and possibly social influences affecting progression of the disease. Among several risk factors, evidence for the familial inheritance of some prostate cancers is compelling. Dietary influences, hormonal milieu, and the role of environmental carcinogens are currently under intense investigation. As further risk factors are identified, it will become increasingly important to identify individuals at increased risk for the disease. These men should undergo regular evaluation with state-of-the-art methods.

Prognostic factors and reporting of prostate carcinoma in radical prostatectomy and pelvic lymphadenectomy specimens

This paper, based on the activity of the Morphology-Based Prognostic Factors Committee of the 2004 World Health Organization-sponsored International Consultation, describes various methods of handling radical prostatectomy specimens for both routine clinical use and research purposes. The correlation between radical prostatectomy findings and postoperative failure is discussed in detail. This includes issues relating to pelvic lymph node involvement, detected both at the time of frozen section and in permanent sections. Issues of seminal vesicle invasion, including its definition, routes of invasion and relationship to prognosis, are covered in detail. The definition, terminology and incidence of extra-prostatic extension are elucidated, along with its prognostic significance relating to location and extent. Margins of resection are covered in terms of their definition, the etiology, incidence and sites of positive margins, the use of frozen sections to assess the margins and the relationship between margin positivity and prognosis. Issues relating to grade within the radical prostatectomy specimen are covered in depth, including novel ways of reporting Gleason grade and the concept of tertiary Gleason patterns. Tumor volume, tumor location, vascular invasion and perineural invasion are the final variables discussed relating to the prognosis of radical prostatectomy specimens. The use of multivariate analysis to predict progression is discussed, together with proposed modifications to the TNM system. Finally, biomarkers to predict progression following radical prostatectomy are described, including DNA ploidy, microvessel density, Ki-67, neuroendocrine differentiation, p53, p21, p27, Bcl-2, Her-2/neu, E-cadherin, CD44, retinoblastoma proteins, apoptotic index, androgen receptor status, expression of prostate-specific antigen and prostatic-specific acid phosphatase and nuclear morphometry.

Ixabepilone (Epothilone B Analogue BMS-247550) Is Active in Chemotherapy-Naive Patients With Hormone-Refractory Prostate Cancer: A Southwest Oncology Group Trial S0111

PURPOSE The epothilones are a new class of tubulin-polymerizing agents with activity in taxane-sensitive and resistant tumor models. We evaluated ixabepilone (BMS-247550) in patients with metastatic hormone-refractory prostate cancer (HRPC). METHODS Eligible patients had chemotherapy-naive metastatic HRPC, a Zubrod performance status of 0 to 2, and adequate organ function. All patients received BMS-247550 at 40 mg/m2 over 3 hours every 3 weeks. The primary end point was proportion of patients achieving a prostate-specific antigen (PSA) response. RESULTS Forty-eight patients with metastatic HRPC were registered. Forty-two patients were eligible, with a median age of 73 years and a median PSA level of 111 ng/mL; 78% had bone-only or bone and soft tissue metastases, and 88% had objective radiologic disease progression at registration. Grade 3 and 4 adverse events (AEs) occurred in 16 and three patients, respectively. All grade 4 toxicities were neutropenia or leukopenia. The most frequent grade 3 AEs were neuropathy (eight patients), hematologic toxicity (seven patients), flu-like symptoms, and infection (five patients each). There were no grade 3/4 thrombocytopenia or grade 5 AEs. There were 14 confirmed PSA responses (33%; 95% CI, 20% to 50%); 72% of PSA responders had declines greater than 80%, and two patients achieved an undetectable PSA. The estimated median progression-free survival is 6 months (95% CI, 4 to 8 months), and the median survival is 18 months (95% CI, 13 to 24 months). CONCLUSION Ixabepilone has demonstrated activity in patients with chemotherapy-naive metastatic HRPC. Major toxicities were neutropenia and neuropathy. Further testing to define its activity relative to standard therapy is warranted.

Evidence Supports a Faster Growth Rate and/or Earlier Transformation to Clinically Significant Prostate Cancer in Black Than in White American Men, and Influences Racial Progression and Mortality Disparity

PURPOSE The incidence of prostate cancer is approximately 60% higher and the mortality rate is 2 to 3 times greater in black than in white American men. We propose that a more rapid prostate cancer growth rate and/or earlier transformation from latent to aggressive prostate cancer in black than in white men contribute to this disparity. MATERIALS AND METHODS We evaluated entirely embedded prostate glands on autopsy from 1,056 black and white men who died of causes other than prostate cancer. We also reviewed data from our radical prostatectomy database and from the Detroit Surveillance, Epidemiology and End Results database. RESULTS Autopsy data indicated that subclinical prostate cancer in black and white men starts at early age and clinical characteristics do not differ by race at early ages. Radical prostatectomy specimen data revealed that prostate cancer volume and Gleason grade were greater in black than in white men. Advanced or metastatic prostate cancer occurred at a 4:1 ratio in black and white men, respectively, in the Detroit Surveillance, Epidemiology and End Results registry database. CONCLUSIONS Results showed that age at prostate cancer initiation and clinical characteristics did not differ by race in our autopsy series, prostate cancer volume after radical prostatectomy was greater in black than in white men and disease became distant disease at a ratio of 4 black men to 1 white man in the Detroit Surveillance, Epidemiology and End Results population. These findings support the concept that prostate cancer grows more rapidly in black than in white men and/or earlier transformation from latent to aggressive prostate cancer occurs in black than in white men.

Elevated 12-lipoxygenase mRNA expression correlates with advanced stage and poor differentiation of human prostate cancer.

OBJECTIVES Prostate cancer is the most frequently diagnosed cancer and the second leading cause of cancer death in males in the United States. The mortality is due mainly to distant metastasis. Therefore, predicting the prognosis of prostate cancer patients is an important clinical problem. Previously, we demonstrated that a 12-lipoxygenase (12-LOX) metabolite of arachidonic acid, 12(S)-hydroxyeicosatetraenoic acid, enhances the invasiveness of prostate cancer cells and that a 12-LOX-selective inhibitor [N-benzyl-N-hydroxy-5-phenylpentanamide] reduces experimental metastasis in animal model systems. In this study, we investigated the potential of 12-LOX as a predictor for the aggressiveness of prostate cancer. METHODS The mRNA expression level of 12-LOX in 122 matching prostate normal and cancerous tissues were measured by quantitative reverse transcription- polymerase chain reaction. Possible association between 12-LOX expression and histologic grade, pathologic and clinical stage, margin positivity, age, and race was analyzed. RESULTS 12-LOX mRNA levels were elevated in cancer cells and the expression associated with poor differentiation and invasiveness of prostate cancer. Overall, 46 (38%) of 122 evaluable patients showed elevated levels of 12-LOX mRNA in prostate cancer tissues compared with the matching normal tissues. A statistically significantly greater number of cases were found to have an elevated level of 12-LOX among T3, high grade, and surgical margin-positive than T2, intermediate, and low grade, and surgical margin-negative prostatic adenocarcinomas. CONCLUSIONS Our data suggest that elevation of 12-LOX mRNA expression occurs more frequently in advanced stage, high-grade prostate cancer and that 12-LOX may serve as an indicator for progression and prognosis of prostate cancer. This enzyme also may be a novel target for the development of anti-invasive and antimetastatic agents.

Loss of Let-7 Up-Regulates EZH2 in Prostate Cancer Consistent with the Acquisition of Cancer Stem Cell Signatures That Are Attenuated by BR-DIM

The emergence of castrate-resistant prostate cancer (CRPC) contributes to the high mortality of patients diagnosed with prostate cancer (PCa), which in part could be attributed to the existence and the emergence of cancer stem cells (CSCs). Recent studies have shown that deregulated expression of microRNAs (miRNAs) contributes to the initiation and progression of PCa. Among several known miRNAs, let-7 family appears to play a key role in the recurrence and progression of PCa by regulating CSCs; however, the mechanism by which let-7 family contributes to PCa aggressiveness is unclear. Enhancer of Zeste homolog 2 (EZH2), a putative target of let-7 family, was demonstrated to control stem cell function. In this study, we found loss of let-7 family with corresponding over-expression of EZH2 in human PCa tissue specimens, especially in higher Gleason grade tumors. Overexpression of let-7 by transfection of let-7 precursors decreased EZH2 expression and repressed clonogenic ability and sphere-forming capacity of PCa cells, which was consistent with inhibition of EZH2 3′UTR luciferase activity. We also found that the treatment of PCa cells with BR-DIM (formulated DIM: 3,3′-diindolylmethane by Bio Response, Boulder, CO, abbreviated as BR-DIM) up-regulated let-7 and down-regulated EZH2 expression, consistent with inhibition of self-renewal and clonogenic capacity. Moreover, BR-DIM intervention in our on-going phase II clinical trial in patients prior to radical prostatectomy showed upregulation of let-7 consistent with down-regulation of EZH2 expression in PCa tissue specimens after BR-DIM intervention. These results suggest that the loss of let-7 mediated increased expression of EZH2 contributes to PCa aggressiveness, which could be attenuated by BR-DIM treatment, and thus BR-DIM is likely to have clinical impact.

Effects of Lycopene Supplementation in Patients with Localized Prostate Cancer

Epidemiological studies have shown an inverse association between dietary intake of lycopene and prostate cancer risk. We conducted a clinical trial to investigate the biological and clinical effects of lycopene supplementation in patients with localized prostate cancer. Twenty-six men with newly diagnosed prostate cancer were randomly assigned to receive a tomato oleoresin extract containing 30 mg of lycopene (n = 15) or no supplementation (n = 11) for 3 weeks before radical prostatectomy. Biomarkers of cell proliferation and apoptosis were assessed by Western blot analysis in benign and cancerous prostate tissues. Oxidative stress was assessed by measuring the Peripheral blood lymphocyte ONA oxidation product 5-hydroxymethyl-deoxyuridine (5-OH-mdU). Usual dietary Intake of nutrients was assessed by a food frequency questionnaire at baseline. Prostatectomy specimens were evaluated for pathologic stage, Gleason score, volume of cancer, and extent of high-grade prostatic intraepithelial neoplasia. Plasma levels of lycopene, insulin-like growth factor-1, insulin-like growth factor binding protein-3, and prostate-specific antigen were measured at baseline and after 3 weeks of supplementation or observation. After intervention, subjects in the intervention group had smaller tumors (80% vs 45%, less than 4 ml), less involvement of surgical margins and/or extra-prostatic tissues with cancer (73% vs 18%, organ-confined disease), and less diffuse involvement of the prostate by high-grade prostatic intraepithelial neoplasia (33% vs 0%, focal involvement) compared with subjects in the control group. Mean plasma prostate-specific antigen levels were lower in the intervention group compared with the control group. This pilot study suggests that lycopene may have beneficial effects in prostate cancer. Larger clinical trials are Warranted to investigate the potential preventive and/or therapeutic role of lycopene in prostate cancer.