Hypercalcemia in Prostate Cancer with Positive Neuron‐Specific Enolase Stain

Severe hypercalcaemia in metastatic prostate cancer with biallelic BRCA2 mutations and lytic bone lesions

Molecular genetics is increasingly used to define the course and prognosis of prostate cancer. Hypercalcaemia of malignancy is a rare complication of metastatic prostate cancer associated with poor outcomes. However, no associations have yet been made in literature between pathogenic genetic mutations and hypercalcaemia in patients with prostatic malignancy.We report of a patient with bone-metastatic prostate cancer. He received sequential genetic tests for pathogenic mutations. A somatic BRCA2 truncation mutation was identified at diagnosis and suppressed on olaparib. Six months after stopping olaparib, several pathogenic mutations, including biallelic BRCA2 mutations, were identified. The patient developed large lytic bone lesions and a severe symptomatic hypercalcaemia. He was hospitalised and treated aggressively for hypercalcaemia but died shortly thereafter. To our knowledge, this is the first case of hypercalcaemia in metastatic prostate cancer to be contextualised within complex genetic mutations.

Compressed Prostate Cancer Cells Decrease Osteoclast Activity While Enhancing Osteoblast Activity In Vitro

Once prostate cancer cells metastasize to bone, they perceive approximately 2 kPa compression. We hypothesize that 2 kPa compression stimulates the epithelial-to-mesenchymal transition (EMT) of prostate cancer cells and alters their production of paracrine signals to affect osteoclast and osteoblast behavior. Human DU145 prostate cancer cells were subjected to 2 kPa compression for 2 days. Compression decreased expression of 2 epithelial genes, 5 out of 13 mesenchymal genes, and increased 2 mesenchymal genes by DU145 cells, as quantified by qPCR. Conditioned medium (CM) of DU145 cells was added to human monocytes that were stimulated to differentiate into osteoclasts for 21 days. CM from compressed DU145 cells decreased osteoclast resorptive activity by 38% but did not affect osteoclast size and number compared to CM from non-compressed cells. CM was also added to human adipose stromal cells, grown in osteogenic medium. CM of compressed DU145 cells increased bone nodule production (Alizarin Red) by osteoblasts from four out of six donors. Compression did not affect IL6 or TNF-α production by PC DU145 cells. Our data suggest that compression affects EMT-related gene expression in DU145 cells, and alters their production of paracrine signals to decrease osteoclast resorptive activity while increasing mineralization by osteoblasts is donor dependent. This observation gives further insight in the altered behavior of PC cells upon mechanical stimuli, which could provide novel leads for therapies, preventing bone metastases.

Endocrine and paracrine characteristics of neuroendocrine prostate cancer

Prostate cancer is a common malignancy affecting men worldwide. While the vast majority of newly diagnosed prostate cancers are categorized as adenocarcinomas, a spectrum of uncommon tumor types occur including those with small cell and neuroendocrine cell features. Benign neuroendocrine cells exist in the normal prostate microenvironment, and these cells may give rise to primary neuroendocrine carcinomas. However, the more common development of neuroendocrine prostate cancer is observed after therapeutics designed to repress the signaling program regulated by the androgen receptor which is active in the majority of localized and metastatic adenocarcinomas. Neuroendocrine tumors are identified through immunohistochemical staining for common markers including chromogranin A/B, synaptophysin and neuron specific enolase (NSE). These markers are also common to neuroendocrine tumors that arise in other tissues and organs such as the gastrointestinal tract, pancreas, lung and skin. Notably, neuroendocrine prostate cancer shares biochemical features with nerve cells, particularly functions involving the secretion of a variety of peptides and proteins. These secreted factors have the potential to exert local paracrine effects, and distant endocrine effects that may modulate tumor progression, invasion, and resistance to therapy. This review discusses the spectrum of factors derived from neuroendocrine prostate cancers and their potential to influence the pathophysiology of localized and metastatic prostate cancer.

Serum calcium is not predictive of aggressive prostate cancer after radical prostatectomy

OBJECTIVES

To investigate the effect of preoperative total serum calcium on disease progression after radical prostatectomy (RP). Elevated total serum calcium has been linked to death from prostate cancer in the National Health and Nutrition Examination Surveys I and II. However, these findings have not been studied in a large cohort of patients with prostate cancer.

METHODS

We identified 10,532 consecutive patients who had undergone RP from 1990 to 2004 for prostate cancer. Total serum calcium levels were available for 7648 (72.6%) of these patients within 90 days before RP. Postoperative survival was estimated using the Kaplan-Meier method and compared using the log-rank test. Cox proportional hazard regression models were used to analyze the ability of serum calcium to predict biochemical recurrence, systemic progression, and cancer-specific survival.

RESULTS

The median patient age at surgery was 64 years. The median total serum calcium level was 9.4 mg/dL (range 6.8-11.2). On univariate analysis, the total serum calcium level was not significantly associated with any clinical or pathologic variables, including tumor stage, preoperative prostate-specific antigen, Gleason score, tumor volume, surgical margins, or lymph node status. Furthermore, the serum calcium level was not significantly associated with biochemical failure, systemic progression, or prostate cancer death on univariate or multivariate analysis.

CONCLUSIONS

The total serum calcium level was not predictive of cancer outcomes in patients who had undergone RP. Additional investigations of the preoperative disease predictors after RP for patients with nonmetastatic disease might be better directed toward other markers.