Circulating Tumor Cells as Potential Biomarkers in Bladder Cancer

Abstract

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.

The functions of circulating tumor cells in early diagnosis and surveillance during cancer advancement

“…In September 2015, Alva et al explored the application of CTCs analysis in evaluating the outcome of neoadjuvant chemotherapy using cisplatin by recruiting patients undergoing neoadjuvant chemotherapy, patients undergoing tumor metastasis, and healthy adult volunteers and determining the CTC concentration on the course of treatment at different phases. [12] In the article "Circulating Tumor Cells as Potential Biomarkers in Unauthenticated Download Date | 5/12/18 10:34 AM Bladder Cancer," Alva et al divided 30 human volunteers into neoadjuvant group, metastatic group, and healthy group. The blood samples of the volunteers were then analyzed using the IsoFlux CTC Enrichment Kit, which was a selection apparatus based on the principles of negative enrichment by a CD45-negative and cytokeratin-positive filtrator.…”

“…Upon the ultimate CTC assay through NGS, the number of CTCs declined viably. [12] Despite progressive improvements in the management of patients with locoregionally confined, advanced-stage solid tumors, distant metastasis remains a very common -and usually fatal -mode of failure after attempted curative treatment. [13] Surgery and radiotherapy are the primary curative modalities for these patients, often combined with each other and/or with chemotherapy.…”

An improved CTC isolation scheme for pairing with downstream genomics: Demonstrating clinical utility in metastatic prostate, lung and pancreatic cancer

“…NGS was done at the UCSF Genome Core. Final variants were filtered using Ion Reporter software and a specialized set of filters as published in our previous paper [17] which included strand bias, homopolymer length, and exclusion of common germline mutations with the exception of allele ratio and allele read counts which were both increased since the purity of this CTC isolation was considerably higher. The final variant lists were verified by both manual filtration and with QIAGEN's Ingenuity Variant Analysis software (www.qiagen.com/ingenuity).…”

The biological complexity of urothelial carcinoma: Insights into carcinogenesis, targets and biomarkers of response to therapeutic approaches

“…According to a study [35], CTC were detected in 5 out of 30 patients with patients. All 8 cases had a medium/high CTC count with a CTC fraction of > 5% purity [36]. including long non-coding RNAs, have been described [38][39][40][41].…”

“…However, the survival between CTC-positive and CTC-negative patients with localized disease after two years was the same. A recent study evaluated the diagnostic use of CTC in patients with bladder cancer using CTC enumeration and next generation sequencing comparing two platforms[36].The median CTC count was 13 at baseline and 5 at follow-up in patients receiving neoadjuvant cisplatinbased chemotherapy, 29 in patients with metastasis, and 2 in healthy controls. In 9 matched samples the IsoFlux TM platform showed ≥10 CTC in 44% of samples while CellSearch® showed 0%.…”