Linda Sugar

Pre-natal and peri-natal exposures and risk of testicular germ-cell cancer

The present case‐control study was undertaken to investigate the association between exposure to maternal hormones and risk of testicular germ‐cell cancer by histologic subgroups. Cases were males, aged 16 to 59 years, diagnosed with testicular germ‐cell cancer in Ontario between 1987 and 1989. Histologic review was performed on all eligible cases for the purpose of categorizing cases as seminoma or non‐seminoma (the latter classified 2 ways, with and without tumors containing seminoma). Risk factor data were collected on 502 cases, 346 case mothers, 975 age‐matched controls, and 522 control mothers. Exogenous hormone exposure was associated with elevated risk (OR = 4.9, 95% CI 1.7–13.9). Several additional risk factors were associated with risk of testicular cancer: bleeding and threatened miscarriage (OR = 0.6, 95% CI 0.3–1.0), maternal cigarette smoking (12+ cigarettes/day OR = 0.6, 95% CI 0.4–1.0). pre‐term birth (OR = 1.6, 95% CI 1.0–2.5), and treatment for undescended testicle (OR = 8.0, 95% CI 3.2–20.0). First births were associated with elevated risk (OR = 1.7, 95% CI 1.0–2.8) among mothers below the age of 24 years at conception. There was little evidence that risk factors differed by histologic subgroup. We found evidence that exposure to maternal hormones, particularly estrogens, is associated with testicular germ‐cell cancer risk. Not only does exposure to elevated levels (exogenous hormone use, pre‐term birth, and first births among young mothers) increase risk but also exposure to relatively lower levels (heavy cigarette consumption and, perhaps, bleeding and threatened miscarriage) may decrease cancer risk. Int. J. Cancer 87:438–443, 2000.

Radical Radiotherapy for Muscle Invasive Transitional Cell Carcinoma of the Bladder: Failure Analysis

Patients with muscle invasive carcinoma of the bladder treated with radical radiation were prospectively documented and followed in an attempt to identify prognostic factors predictive of the response to treatment. Data on 121 consecutive patients treated with radical radiation between 1981 and 1985 are presented. Over-all actuarial survival of the patient population (median age 70 years) was 31.6% at 5 years and cause-specific survival was 44.8%. At analysis 33 of 121 patients (27.3%) were alive with preserved bladder function. Independent prognostic factors for cause-specific survival and for complete response with radical radiation were tumor configuration, hemoglobin level and clinical stage. The rate free of local relapse was significantly influenced by stage and presence of coexistent carcinoma in situ. The study suggests that factors other than stage and grade influence prognosis in invasive bladder cancer and should be considered in interpreting treatment results.

Assessing individual risk for prostate cancer.

PURPOSE To construct a clinical nomogram instrument to estimate individual risk for having prostate cancer (PC) for patients undergoing prostate specific antigen (PSA) screening, using all risk factors known for PC. PATIENTS AND METHODS We conducted a cross-sectional study of 3,108 men who underwent a prostate biopsy, including a subset of 408 volunteers with normal PSA levels. Factors including age, family history of PC (FHPC), ethnicity, urinary symptoms, PSA, free:total PSA ratio, and digital rectal examination (DRE) were incorporated in the model. A nomogram was constructed to assess risk for any and high-grade PC (Gleason score >or= 7). RESULTS Of the 3,108 men, 1,304 (42.0%) were found to have PC. Among the 408 men with a normal PSA (< 4.0 ng/mL), 99 (24.3%) had PC. All risk factors were important predictors for PC by multivariate analysis (P, .01 to .0001). The area under the curve (AUC) for the nomogram in predicting cancer, which included age, ethnicity, FHPC, urinary symptoms, free:total PSA ratio, PSA, and DRE, was 0.74 (95% CI, 0.71 to 0.81) and 0.77 (95% CI, 0.74 to 0.81) for high-grade cancer. This was significantly greater than the AUC that considered using the conventional screening method of PSA and DRE only (0.62; 95% CI, 0.58 to 0.66 for any cancer; 0.69; 95% CI, 0.65 to 0.73 for high-grade cancer). From receiver operating characteristic analysis, risk factors including age, ethnicity, FHPC, symptoms, and free:total PSA ratio contributed significantly more predictive information than PSA and DRE. CONCLUSION In a PC screening program, it is important to consider age, family history of PC, ethnicity, urinary voiding symptoms, and free:total PSA ratio, in addition to PSA and DRE.

Expression of TMPRSS2:ERG gene fusion in prostate cancer cells is an important prognostic factor for cancer progression

The prostate-specific gene, TMPRSS2, is fused with the transcription factor gene, ERG in a high proportion of prostate cancers. However, the clinical significance of TMPRSS2:ERG gene fusion among prostate cancer patients is unknown. We assayed for the presence of the TMPRSS2:ERG gene fusion product among 26 patients who underwent surgery for clinically localized prostate cancer using RT-PCR and direct DNA sequencing, and evaluated its prognostic significance. All 26 patients had cancers of the same histologic grade (Gleason score 7). The fusion protein was present within prostate cancer tumor cells in eleven patients (42.3%). Nine patients experienced biochemical disease relapse (elevated PSA) after a mean follow-up of 12 months (range 1 to 48 months). Patients with the fusion protein had a significantly higher rate of recurrence (5-year recurrence rate 79.5%) compared to patients who lacked the fusion protein (5-year recurrence rate 37.5%, p=0.009). The adjusted hazard ratio for disease relapse for patients with the fusion protein was 7.1 (95% C.I.: 1.1 - 45, p = 0.03) compared to patients without the fusion protein. In multivariate analysis, the presence of gene fusion was the single most important prognostic factor. Our study indicates that the expression of TMPRSS2:ERG fusion gene among prostate cancer patients treated with surgery is a strong prognostic factor for disease relapse, and may have important clinical implications.

Prognostic Factors for Relapse in Stage I Testicular Seminoma Treated With Surveillance

PURPOSE We sought to identify prognostic factors predictive of disease progression in patients with clinical stage I seminoma on surveillance following orchiectomy. MATERIALS AND METHODS Between January 1981 and December 1993, 201 patients 20 to 86 years old (median age 34) with clinical stage I seminoma were placed on surveillance following orchiectomy. The potential prognostic factors studied included age, tumor size, mitotic count, S phase fraction, ploidy, presence of small vessel invasion, syncytiotrophoblasts and tumor infiltrating lymphocytes, expression of beta-human chorionic gonadotropin and low molecular weight keratin on immunohistochemistry. RESULTS With a median followup of 6.1 years (range 1.3 to 12.3) 31 patients had relapse for an actuarial 5-year relapse-free rate of 84.9%. The 5-year actuarial survival rate was 97.1% and the cause specific survival rate was 99.5%. On univariate analysis factors predictive of relapse were tumor size (5-year relapse-free rate 88 and 67% for tumors 6 cm. or less and greater than 6 cm., respectively, p = 0.004), age (5-year relapse-free rate 79 and 91% for age 34 years or younger versus older than 34 years, respectively, p = 0.009) and presence of small vessel invasion (5-year relapse-free rate 86 versus 69%, p = 0.01). On multivariate analysis age and tumor size were predictive of relapse, while small vessel invasion approached statistical significance. The risk of relapse in 57 patients with none of the 3 adverse prognostic factors (age greater than 34 years, tumor 6 cm. or smaller and no small vessel invasion) was 6%. CONCLUSIONS We identified age, size of the primary tumor and small vessel invasion as important prognostic factors for relapse in patients with stage I seminoma treated with surveillance. Further followup and assessment of biological factors are needed to optimize selection of patients at a high risk for relapse who should receive immediate postoperative therapy.

Antioxidants Block Prostate Cancer in Lady Transgenic Mice

The development of chemopreventive agents against prostate cancer would benefit from conclusive evidence of their efficacy in animal models that emulate human disease. To date there has been little in vivo evidence supporting their preventive capabilities. The 12T-10 Lady transgenic model spontaneously develops localized prostatic adenocarcinoma and neuroendocrine cancer followed by metastases, recapitulating the natural history of human prostate cancer in many respects. Using male Lady version of the transgenic adenocarcinoma of the mouse prostate mice, we show that administration of antioxidants (vitamin E, selenium, and lycopene) in the diet dramatically inhibits prostate cancer development and increases the disease free survival. Treatment of animals with the antioxidants resulted in a 4-fold reduction in the incidence of prostate cancer compared with the untreated animals. Prostate cancer developed in 73.68% (14 of 19) and 100% (19 of 19) of the animals from the standard and high fat diet, respectively. In contrast, only 10.53% (2 of 19) and 15.79% (3 of 19; P < 0.0001) of the animals in the standard and high fat diets supplemented with antioxidants developed tumors. The micronutrients were well tolerated with no evidence of antioxidant-related toxicity. Histopathological analysis confirmed absence of cancer in the additive treated groups. Immunohistochemistry demonstrated a strong correlation between disease-free state and increased levels of the prognostic marker p27Kip1 and a marked decrease in proliferating cell nuclear antigen expression. These observations provide support for the chemopreventive effect of these micronutrients and some clues as to their mechanism of action.

Prospective Multi-Institutional Study Evaluating the Performance of Prostate Cancer Risk Calculators

PURPOSE Prostate cancer risk calculators incorporate many factors to evaluate an individuals risk for prostate cancer. We validated two common North American-based, prostate cancer risk calculators. PATIENTS AND METHODS We conducted a prospective, multi-institutional study of 2,130 patients who underwent a prostate biopsy for prostate cancer detection from five centers. We evaluated the performance of the Sunnybrook nomogram-based prostate cancer risk calculator (SRC) and the Prostate Cancer Prevention Trial (PCPT) -based risk calculator (PRC) to predict the presence of any cancer and high-grade cancer. We examined discrimination, calibration, and decision curve analysis techniques to evaluate the prediction models. RESULTS Of the 2,130 patients, 867 men (40.7%) were found to have cancer, and 1,263 (59.3%) did not have cancer. Of the patients with cancer, 403 (46.5%) had a Gleason score of 7 or more. The area under the [concentration-time] curve (AUC) for the SRC was 0.67 (95% CI, 0.65 to 0.69); the AUC for the PRC was 0.61 (95% CI, 0.59 to 0.64). The AUC was higher for predicting aggressive disease from the SRC (0.72; 95% CI, 0.70 to 0.75) compared with that from the PRC (0.67; 95% CI, 0.64 to 0.70). Decision curve analyses showed that the SRC performed better than the PRC for risk thresholds of more than 30% for any cancer and more than 15% for aggressive cancer. CONCLUSION The SRC performed better than the PRC, but neither one added clinical benefit for risk thresholds of less than 30%. Further research is needed to improve the AUCs of the risk calculators, particularly for higher-grade cancer.

The Clinical Utility of miR-21 as a Diagnostic and Prognostic Marker for Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common neoplasm of the kidney. Increasing evidence suggests that microRNAs are dysregulated in RCC and are important factors in RCC pathogenesis. miR-21 is a known oncogene with tumor-promoting effects in many types of cancer. In this study, we analyzed miR-21 in 121 cases of healthy kidney and different RCC subtypes, including clear cell (ccRCC), papillary (pRCC), chromophobe (chRCC), and oncocytoma. Total RNA was extracted, and the expression of miR-21 was measured with real-time quantitative RT-PCR using miR-21-specific probes. The expression of miR-21 was significantly up-regulated in RCC compared with healthy kidney. There was a significant difference in the expression levels between RCC subtypes, with the highest levels of expression in ccRCC and pRCC subtypes. miR-21 expression distinguished ccRCC and pRCC from chRCC and oncocytoma with 90% specificity (95% CI, 63.9% to 98.1%) and 83% sensitivity (95% CI, 53.5% to 97.6%). Significantly higher miR-21 levels were associated with higher stage and grade. Patients who were miR-21 positive had statistically significant shorter disease-free and overall survival rates. Thus, miR-21 is up-regulated in RCC, and its expression levels can be used as a diagnostic marker to distinguish ccRCC and pRCC from chRCC and oncocytoma. Moreover, it has potential as a prognostic marker in RCC, although it is not independent of tumor stage and grade.

Metformin enhances the antiproliferative and apoptotic effect of bicalutamide in prostate cancer

Background:Prostate cancer incidence and mortality vary dramatically by geographical location. Both are higher in developed countries. Some attribute this to westernized lifestyles of high-energy diets and limited physical activity with consequent obesity. Obesity and obesity-related diseases like diabetes cause hyperinsulinaemia, which upregulates pro-survival cell signalling. Previous work revealed diet-induced hyperinsulinaemia enhances prostate cancer xenograft growth in vivo. Metformin, an antidiabetic medication, reduces hyperinsulinaemia and also exhibits antineoplastic properties. Herein, we assess the potential additive benefit of combining bicalutamide antiandrogen therapy with metformin, in vitro and in vivo.Methods:Using clonogenic assays, we assessed the effect of bicalutamide and/or metformin on clonogenicity in prostate cancer cell lines. Western blot and cell cycle analyses were used to elucidate mechanisms of interaction between the drugs in androgen receptor (AR)-positive (LNCaP) and AR-negative (PC3) cell lines. The combination treatment regimen was assessed in vivo using an LNCaP murine xenograft model.Results:Micromolar bicalutamide or millimolar metformin caused a significant dose-dependent reduction in clonogenicity (P<0.001). Combination treatment further significantly reduced clonogenicity (P<0.005) with greater effects in AR-positive cells. Western blot and cell cycle analyses suggested differing mechanisms of interaction in AR-positive and -negative cell lines. Following combination treatment, LNCaP cells exhibited an altered cell proliferation (decreased phospho mammalian target of rapamycin expression) and perturbed cell cycle kinetics (G1/S cell cycle arrest). PC3 cells showed evidence of enhanced apoptosis (increased Bcl-2-associated X protein and decreased total caspase 3 expression). Markedly diminished tumour growth occurred following combination treatment in vivo (P<0.001).Conclusions:Combining bicalutamide and metformin significantly reduces prostate cancer cell growth further than either monotherapy. In AR-positive cells, this effect appeared to be mediated by reducing proliferation rates, whereas in AR-negative cells the combination treatment appeared to promote apoptosis. This combination drug regimen may improve prostate-cancer-specific survival by the direct antineoplastic properties outlined.

A Novel Serum Marker, Total Prostate Secretory Protein of 94 Amino Acids, Improves Prostate Cancer Detection and Helps Identify High Grade Cancers at Diagnosis

PURPOSE New biomarkers for prostate cancer are needed. We determined whether a novel serum marker, total PSP94 can be used to accomplish these goals. MATERIALS AND METHODS We conducted a case-control study of 1,212 men with no previous history of prostate cancer and who underwent a prostate biopsy from 1998 to 2000 because of an increased PSA or an abnormal DRE. Serum PSP94 levels were assessed using a sandwich enzyme-linked immunosorbent assay technique. Cases were patients with prostate cancer, and controls were patients who had no evidence of cancer. Multivariate logistic regression analysis was used to determine whether or not PSP94 levels improved the predictive value for prostate cancer. RESULTS Of the 1,212 men 596 (49.2%) had cancer detected. The median PSP94 level was significantly lower among cases (2.60 ng/ml) than among controls (3.40 ng/ml, p <0.0001). The adjusted odds ratios for the presence of prostate cancer for patients with the lowest quartile of PSP94, compared to patients in the highest quartile was 2.70 (95% CI 1.8 - 4.0, p <0.0001). Among a subgroup of 649 men in whom PSA had a low predictive value (PSA less than 20 ng/ml, normal DRE and less than 70 years), 260 (40.1%) were found to have cancer. In this subgroup total PSP94 levels helped discriminate between patients with high grade disease (Gleason score 8 or more, median 1.90 ng/ml), moderate grade disease (Gleason score 7, median 2.34 ng/ml) and low grade disease (Gleason score 6 or less, median 2.60 ng/ml, p = 0.007). PSA and the FTPSA were not able to distinguish between patients with different grades in this group. CONCLUSIONS Patients with low total PSP94 levels had a high probability for having prostate cancer detected at biopsy. The total PSP94 level was able to help identify patients with high grade disease among a subset of patients in whom PSA and FTPSA are least informative.