Liang Cheng

Bladder cancer remains a leading cause of cancer death worldwide and is associated with substantial impacts on patient quality of life, morbidity, mortality, and cost to the healthcare system. Gross hematuria frequently precedes the diagnosis of bladder cancer. Non-muscle-invasive bladder cancer (NMIBC) is managed initially with transurethral resection of a bladder tumor (TURBT), followed by a risk stratified approach to adjuvant intravesical therapy (IVe), and is associated with an overall survival of 90%. However, cure rates remain lower for muscle invasive bladder cancer (MIBC) owing to a variety of factors. NMIBC and MIBC groupings are heterogeneous and have unique pathological and molecular characteristics. Indeed, The Cancer Genome Atlas project identified genetic drivers and luminal and basal molecular subtypes of MIBC with distinct treatment responses. For NMIBC, IVe immunotherapy (primarily BCG) is the gold standard treatment for high grade and high risk NMIBC to reduce or prevent both recurrence and progression after initial TURBT; novel trials incorporate immune checkpoint inhibitors. IVe gene therapy and combination IVe chemotherapy have recently been completed, with promising results. For localized MIBC, essential goals are improving care and reducing morbidity following cystectomy or bladder preserving strategies. In metastatic disease, advances in understanding of the genomic landscape and tumor microenvironment have led to the implementation of immune checkpoint inhibitors, targeted treatments, and antibody-drug conjugates. Defining better selection criteria to identify the patients most likely to benefit from a specific treatment is an urgent need.

PURPOSE: Human urothelial carcinoma is thought to arise from a field change that affects the entire urothelium. Multifocality of urothelial carcinoma is a common finding at endoscopy and surgery. Whether these coexisting tumors arise independently or are derived from the same tumor clone is uncertain. Molecular analysis of microsatellite alterations and X-chromosome inactivation status in the cells from each coexisting tumor may further our understanding of urothelial carcinogenesis. EXPERIMENTAL DESIGN: We examined 58 tumors from 21 patients who underwent surgical excision for urothelial carcinoma. All patients had multiple separate foci of urothelial carcinoma (two to four) within the urinary tract. Genomic DNA samples were prepared from formalin-fixed, paraffin-embedded tissue sections using laser-capture microdissection. Loss of heterozygosity (LOH) assays for three microsatellite polymorphic markers on chromosome 9p21 (IFNA and D9S171), regions of putative tumor suppressor gene p16, and on chromosome 17p13 (TP53), the p53 tumor suppressor gene locus, were done. X-chromosome inactivation analysis was done on the urothelial tumors from 11 female patients. RESULTS: Seventeen of 21 (81%) cases showed allelic loss in one or more of the urothelial tumors in at least one of the three polymorphic markers analyzed. Concordant allelic loss patterns between each coexisting urothelial tumor were seen in only 3 of 21 (14%) cases. A concordant pattern of nonrandom X-chromosome inactivation in the multiple coexisting urothelial tumors was seen in only 3 of 11 female patients; of these 3 cases, only one displayed an identical allelic loss pattern in all of the tumors on LOH analysis. CONCLUSION: LOH and X-chromosome inactivation assays show that the coexisting tumors in many cases of multifocal urothelial carcinoma have a unique clonal origin and arise from independently transformed progenitor urothelial cells, supporting the "field effect" theory for urothelial carcinogenesis.

BACKGROUND: Urothelial carcinoma of the bladder often contains areas with different histologic grades. The influence of cancer heterogeneity on grading and its relation to patient outcome is uncertain. METHODS: The study group consisted of 164 patients with Ta urothelial carcinoma diagnosed at the Mayo Clinic between 1985 and 1986. None had previous or coexistent urothelial carcinoma in situ or invasive carcinoma. The primary (most common) and secondary (second most common if at least 5% of the cancer) patterns of cancer growth were graded by the newly proposed World Health Organization and International Society of Urological Pathology (WHO/ISUP) grading system. Scores of 1, 2, and 3 were assigned to urothelial neoplasms of low malignant potential (LMP), low grade urothelial carcinoma, and high grade urothelial carcinoma, respectively. The mean follow-up was 7.7 years (range, 0-13.3 years; median, 9.2 years). Progression was defined as the development of invasive carcinoma, distant metastasis, or death due to bladder carcinoma. RESULTS: Patient ages ranged from 36 to 96 years (mean, 69 years), and the male-to-female ratio was 4:1. Disease progression developed in 32 patients during a mean follow-up of 7.7 years. The mean interval from diagnosis to progression was 3.1 years (range, 0.01-8.7 years). Progression free survival was 82%, 77%, and 76% at 5, 7, and 10 years, respectively. Primary and secondary grades were different for 52 patients (32%). Based on the worst grade, 19 patients (12%) had urothelial neoplasms of low malignant potential (LMP), 92 (56%) had low grade carcinoma, and 53 (32%) had high grade carcinoma. Histologic grades based on worst, primary, secondary, and combined primary and secondary grades were all significant for predicting progression (P = 0.0009, 0.0004, 0.001, and 0.0001, respectively). Seven-year progression free survival rates for patients with LMP, low grade, and high grade carcinoma (based on worst grade) were 93%, 82%, and 61%, respectively; for patients with combined scores of 2, 3, 4, 5, and 6, survival rates were 93%, 80%, 82%, 68%, and 40%, respectively. The difference between patients with combined scores of 5 or 6 was statistically significant (P = 0.02). CONCLUSIONS: Histologic grade of urothelial carcinoma based on the newly proposed WHO/ISUP grading system stratifies patients into prognostically significant groups. Grading should also take cancer heterogeneity into consideration, and prognostic accuracy appears to be increased when the combined primary and secondary grades are applied. [See editorial counterpoint on pages 1509-12 and reply to counterpoint on pages 1513-6, this issue.]

PURPOSE: OCT4 (POU5F1, OCT3) immunostaining highlights pluripotent cells (embryonal carcinoma and seminoma) in primary testicular germ cell tumors, but its relative usefulness in diagnosing intratubular germ cell neoplasia, unclassified (IGCNU) is not well established. The present study aimed to establish OCT4 as a sensitive and specific maker for IGCNU, a putative precursor for adult germ cell tumors. EXPERIMENTAL DESIGN: We evaluated OCT4 immunostaining in 44 cases of IGCNU from patients who had testicular germ cell tumors. In addition, 27 of the 44 IGCNU sections were also examined with antibodies to placenta-like alkaline phosphatase, the most frequently used immunohistochemical marker for intratubular germ cell neoplasia. Sections from the testes of 10 patients who had undergone orchiectomy for hormonal treatment of prostate cancer and from autopsies of 10 patients without histories of germ cell tumors were also examined for OCT4 immunostaining. The immunoreactivity of the autopsy tissues was determined with vimentin staining, and all were reactive. RESULTS: In all 44 of the cases, antibody to OCT4 marked the nuclei of nearly all of the dysplastic cells of intratubular germ cell neoplasia but not non-neoplastic testicular cells. The staining intensity was strong in every case, and there was little or no background staining. All 20 of the control specimens (10 orchiectomy specimens from prostate cancer patients and 10 testes from autopsies) were completely negative for OCT4. The 27 cases that were stained with antiplacenta-like alkaline phosphatase antibodies showed staining of variable intensity in the areas of intratubular germ cell neoplasia, and there was a high level of background staining artifact. CONCLUSIONS: OCT4 is a sensitive and specific maker for intratubular germ cell neoplasia.