Khaled Hafez

Testis cancer is one of the few solid organ malignancies for which reliable serum tumor markers are available to help guide disease management. Human chorionic gonadotropin, alpha fetoprotein, and lactate dehydrogenase play crucial roles in diagnosis, staging, prognosis, monitoring treatment response, and surveillance of seminomatous and nonseminomatous germ cell tumors. Herein we discuss the clinical applications of germ cell tumor markers, the limitations of these markers in the management of this disease, and additional serum molecules that have been identified with potential roles as novel germ cell tumor markers.

PURPOSE: We explored the diagnostic use of circulating tumor cells in patients with neoadjuvant bladder cancer using enumeration and next generation sequencing. MATERIALS AND METHODS: A total of 20 patients with bladder cancer who were eligible for cisplatin based neoadjuvant chemotherapy were enrolled in an institutional review board approved study. Subjects underwent blood draws at baseline and after 1 cycle of chemotherapy. A total of 11 patients with metastatic bladder cancer and 13 healthy donors were analyzed for comparison. Samples were enriched for circulating tumor cells using the novel IsoFlux™ System microfluidic collection device. Circulating tumor cell counts were analyzed for repeatability and compared with Food and Drug Administration cleared circulating tumor cells. Circulating tumor cells were also analyzed for mutational status using next generation sequencing. RESULTS: Median circulating tumor cell counts were 13 at baseline and 5 at followup in the neoadjuvant group, 29 in the metastatic group and 2 in the healthy group. The concordance of circulating tumor cell levels, defined as low-fewer than 10, medium-11 to 30 and high-greater than 30, across replicate tubes was 100% in 15 preparations. In matched samples the IsoFlux test showed 10 or more circulating tumor cells in 4 of 9 samples (44%) while CellSearch® showed 0 of 9 (0%). At cystectomy 4 months after baseline all 3 patients (100%) with medium/high circulating tumor cell levels at baseline and followup had unfavorable pathological stage disease (T1-T4 or N+). Next generation sequencing analysis showed somatic variant detection in 4 of 8 patients using a targeted cancer panel. All 8 cases (100%) had a medium/high circulating tumor cell level with a circulating tumor cell fraction of greater than 5% purity. CONCLUSIONS: This study demonstrates a potential role for circulating tumor cell assays in the management of bladder cancer. The IsoFlux method of circulating tumor cell detection shows increased sensitivity compared with CellSearch. A next generation sequencing assay is presented with sufficient sensitivity to detect genomic alterations in circulating tumor cells.

BACKGROUND: Cystectomy delay >90 days after a diagnosis of muscle-invasive bladder cancer (MIBC) adversely affects pathologic stage and survival outcomes in patients who undergo primary surgery. After neoadjuvant chemotherapy (NAC), the impact of the timing of cystectomy delivery on these outcomes is uncertain. Poor communication between urologic and medical oncologists can result in cystectomy delay after systemic treatment. The authors of this report hypothesized that a delay in cystectomy delivery after NAC is associated with adverse survival outcomes. METHODS: An eligible cohort of 153 patients with MIBC received NAC and underwent radical cystectomy between 1990 and 2007. At the authors' institution, the genitourinary team strives to schedule patients for surgery at the time of initial evaluation or after their first chemotherapy cycle. Clinicopathologic characteristics, including timing of cystectomy, chemotherapy delivery, vital status, and reasons for excessive surgical delay, were analyzed retrospectively using an institutional database. A Cox proportional regression model was used to test the association between the timing of cystectomy delivery and survival. RESULTS: The median follow-up for all patients was 3.6 years. The median time to cystectomy was 16.6 weeks and 6.9 weeks from the first and last day of NAC, respectively. In multivariate analyses, the timing of cystectomy delivery from the termination of NAC did not significantly alter the risk of survival. The most common reason for cystectomy delivery beyond 10 weeks (28 patients; 18%) was procedural scheduling. CONCLUSIONS: Cystectomy delivery within 10 weeks after NAC did not compromise patient survival and, thus, provided a reasonable window for patient recovery and surgical intervention.