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Background: Circulating tumour cells (CTCs) offer a non-invasive approach to obtain and characterise metastatic tumour cells, but their usefulness has been limited by low CTC yields from conventional isolation methods.Methods: To improve CTC yields and facilitate their molecular characterisation we compared the Food and Drug Administration-approved CellSearch Epithelial Kit (CEK) to a simplified CTC capture method, CellSearch Profile Kit (CPK), on paired blood samples from patients with metastatic breast (n=75) and lung (n=71) cancer. Molecular markers including Human Epidermal growth factor Receptor 2 (HER2) were evaluated on CTCs by fluorescence in situ hybridisation (FISH) and compared to patients' primary and metastatic cancer.Results: The median cell count from patients with breast cancer using the CPK was 117 vs 4 for CEK (P<0.0001). Lung cancer samples were similar; CPK: 145 cells vs CEK:4 cells (P<0.0001). Recovered CTCs were relatively pure (60-70%) and were evaluable by FISH and immunofluorescence. A total of 10 of 30 (33%) breast cancer patients with HER2-negative primary and metastatic tissue had HER2-amplified CTCs.Conclusion: The CPK method provides a high yield of relatively pure CTCs, facilitating their molecular characterisation. Circulating tumour cells obtained using CPK technology demonstrate that significant discordance exists between HER2 amplification of a patient's CTCs and that of the primary and metastatic tumour. [ABSTRACT FROM AUTHOR]

Background: Men engaged in high physical activity have lower risks of advanced and fatal prostate cancer. Mechanisms underlying this association are not well understood but may include systemic and tumor-specific effects. We investigated potential mechanisms linking physical activity and gene expression in prostate tissue from men with prostate cancer., Methods: We included a subset of 118 men in the Health Professionals Follow-up Study diagnosed with prostate cancer between 1986 and 2005 with whole-transcriptome gene expression profiling on tumor and adjacent normal prostate tissue and physical activity data. Long-term vigorous physical activity was self-reported as the average time spent engaged in various forms of recreational physical activity at baseline and biennially until prostate cancer diagnosis. Gene set enrichment analysis was performed among KEGG and Hallmark gene sets to identify pathways with differential expression based on vigorous physical activity., Results: In adjacent normal tissue, we identified 25 KEGG gene sets enriched (downregulated) in the highest compared with lowest quintile of vigorous physical activity at an FDR <0.10, including a number of cancer- and immune-related pathways. Although no gene sets reached statistical significance in tumor tissue, top gene sets differentially expressed included TGF beta, apoptosis, and p53 signaling pathways., Conclusions: These findings suggest that physical activity may influence the tumor microenvironment. Future studies are needed to confirm these findings and further investigate potential mechanisms linking physical activity to lethal prostate cancer., Impact: Identification of gene expression alterations in the prostate associated with physical activity can improve our understanding of prostate cancer etiology., (©2021 American Association for Cancer Research.)

Background: Overexpression of prostate-specific membrane antigen (PSMA) in tumor tissue and serum has been linked to increased risk of biochemical recurrence in surgically treated prostate cancer patients, but none of the studies have assessed its association with disease-specific mortality., Methods: We examined whether high PSMA protein expression in prostate tumor tissue was associated with lethal disease, and with tumor biomarkers of progression, among participants of two U.S.-based cohorts (n = 902, diagnosed 1983-2004). We used Cox proportional hazards regression to calculate multivariable HRs and 95% confidence intervals (CI) of lethal prostate cancer, defined as disease-specific death or development of distant metastases (n = 95). Partial Spearman rank correlation coefficients were used to correlate PSMA with tumor biomarkers., Results: During an average 13 years of follow-up, higher PSMA expression at prostatectomy was significantly associated with lethal prostate cancer (age-adjusted HRQuartile(Q)4vs.Q1 = 2.42; Ptrend < 0.01). This association was attenuated and nonsignificant (multivariable-adjusted HRQ4vs.Q1 = 1.01; Ptrend = 0.52) after further adjusting for Gleason score and prostate-specific antigen (PSA) at diagnosis. High PSMA expression was significantly (P < 0.05) correlated with higher Gleason score and PSA at diagnosis, increased tumor angiogenesis, lower vitamin D receptor and androgen receptor expression, and absence of ets-related gene (ERG) expression., Conclusions: High tumor PSMA expression was not an independent predictor of lethal prostate cancer in the current study. PSMA expression likely captures, in part, malignant features of Gleason grade and tumor angiogenesis., Impact: PSMA is not a strong candidate biomarker for predicting prostate cancer-specific mortality in surgically treated patients., (©2013 AACR.)

Protein expression of p63 is used to differentiate prostate cancer from benign mimickers. Recent studies suggest that it may also distinguish aggressive prostate cancer with down-regulated expression occurring in men with more advanced disease. We conducted a prospective study among 298 men ages 51 to 84 years who were diagnosed with prostate cancer in the Physicians' Health Study in 1983 to 2004 and whose tissue was available for immunohistochemical staining. We used Cox proportional hazards regression to evaluate the association of p63 protein expression with fatal prostate cancer. We correlated p63 expression with tumor cell proliferation (Ki-67) and apoptosis (TUNEL staining). The predominant location of tumor p63 staining occurred in the cytoplasm, an uncommon departure from the strong nuclear staining usually observed in nonneoplastic basal cells. Increasing expression of cytoplasmic p63 (tertiles) was associated with prostate cancer mortality (n = 19 deaths); the hazard ratios (95% confidence intervals) were 1.0 (reference), 4.0 (0.9-18.9), and 5.9 (1.3-27.5; P(trend) = 0.03). The positive trend remained significant (P = 0.047) after multivariable adjustment for age, year of diagnosis, and Gleason score. Higher tertiles of cytoplasmic p63 were also associated with reduced levels of apoptosis (P(trend) = 0.0408) and increased cellular proliferation (P(trend) = 0.0026). We found aberrant expression of p63 in the cytoplasm to be associated with increased prostate cancer-specific mortality up to 20 years after diagnosis. The mislocalized expression was associated with reduced apoptosis and higher proliferative activity and may suggest an oncogenic role in prostate cancer progression and survival.