Isolated Metastasis to the Brain From Upper Tract Urothelial Carcinoma.

Isolated brain metastasis from cancers of urothelial origin are rare, especially after a long recurrence-free interval with few reports in the literature. We herein present the case of a 62 year old male with history of recurrent bladder cancers treated in 2004 and 2005 and a left distal ureteral high grade pT3aN1M0 urothelial cancer treated with distal ureterectomy and reimplant followed by adjuvant chemotherapy in 2014 who presented after a 5 year recurrence-free interval with tonic-clonic seizure. Further workup revealed an isolated 12.0 mm x 18.0 mm x 8.0 mm mass overlying the left parietal lobe with no other metastatic sites. The patient was treated with resection of the mass and adjuvant radiation therapy with pathology confirming metastatic carcinoma of urothelial origin. Though prognosis for patients with such a presentation remains poor, we provide a review of the current literature with respect to incidence, presentation and therapeutic considerations for such patients.

Is repeat biopsy for isolated high-grade prostatic intraepithelial neoplasia necessary?

Numerous studies have cited the positive predictive value of isolated highgrade prostatic intraepithelial neoplasia (HGPIN) to the detection of cancer. Epidemiological, morphological, and molecular data support the potential for malignant transformation of HGPIN, yet no current method can discriminate which lesions will progress to clinically significant prostate cancer versus more latent lesions. Recent analyses of multiple retrospective studies have found similar rates of cancer detection following either diagnosis of isolated HGPIN or an initial negative biopsy. This may reflect increased use of extended biopsy techniques involving 10 or more cores rather than the true ability of HGPIN to undergo malignant transformation. This article discusses controversies surrounding management of an isolated diagnosis of HGPIN and whether repeat biopsy of HGPIN should be mandatory or selective in the context of other predictive values such as rising prostate-specific antigen or lesion on digital rectal examination.

Is the testis a chemo-privileged site? Is there a blood-testis barrier?

The incidence of testicular cancer, primarily seminoma, has been increasing in many countries, including the United States. The testis is often the site of residual cancer after adequate treatment with systemic chemotherapy. The blood-testis barrier is commonly cited as the explanation for residual tumor within the gonad after chemotherapy and as the indication for delayed orchiectomy. Conversely, complete eradication of viable tumor from the primary site is common and argues against the testis as a "tumor sanctuary." Residual tumor is also demonstrated within metastatic foci, and the disparity between the histopathologic response of the primary tumor and metastatic sites may be best explained by tumor heterogeneity and multiple tumor clones. Regardless of the scientific and academic arguments, delayed radical orchiectomy remains an important part of treatment for patients undergoing primary chemotherapy.

Elevated expression of 12/15-lipoxygenase and cyclooxygenase-2 in a transgenic mouse model of prostate carcinoma.

Changes in expression of arachidonic acid (AA) metabolizing enzymes are implicated in the development and progression of human prostate carcinoma (Pca). Transgenic mouse models of Pca that progress from high-grade prostatic intraepithelial neoplasia (HGPIN) to invasive and metastatic carcinoma could facilitate study of the regulation and function of these genes in Pca progression. Herein we characterize the AA-metabolizing enzymes in transgenic mice established with a prostate epithelial-specific long probasin promoter and the SV40 large T antigen (LPB-Tag mice) that develop extensive HGPIN and invasive and metastatic carcinoma with neuroendocrine (NE) differentiation. Murine 8-lipoxygenase (8-LOX), homologue of the 15-LOX-2 enzyme that is expressed in benign human prostatic epithelium and reduced in Pca, was not detected in wild-type or LPB-Tag prostates as determined by enzyme assay, reverse transcription-PCR, and immunohistochemistry. The most prominent AA metabolite in mouse prostate was 12-HETE. Wild-type prostate (dorsolateral lobe) converted 1.6 +/- 0.5% [(14)C]AA to 12-HETE (n = 7), and this increased to 8.0 +/- 4.4% conversion in LPB-Tag mice with HGPIN (n = 13). Quantitative real-time reverse transcription-PCR and immunostaining correlated the increased 12-HETE synthesis with increased neoplastic epithelial expression of 12/15-LOX, the leukocyte-type (L) of 12-LOX and the murine homologue of human 15-LOX-1. Immunostaining showed increased L12-LOX in invasive carcinoma and approximately one-half of metastatic foci. COX-2 mRNA was detectable in neoplastic prostates with HGPIN but not in wild-type prostate. By immunostaining, COX-2 was increased in the neoplastic epithelium of HGPIN but was absent in foci of invasion and metastases. We conclude that (a) AA metabolism in wild-type mouse prostate differs from humans in the basal expression of LOXs (15-LOX-2 in human, absence of its 8-LOX homologue in mouse prostate); (b) increased expression of 12/15-LOX in HGPIN and invasive carcinoma of the LPB-Tag model is similar to the increased 15-LOX-1 in high-grade human Pca; and (c) the LPB-Tag model shows increased COX-2 in HGPIN, and therefore, it may allow additional definition of the role of this enzyme in the subset of human HGPINs or other precursor lesions that are COX-2 positive, as well as investigation of its contribution to neoplastic cell proliferation and tumor angiogenesis in Pca.