Usefulness of monitoring circulating tumor cells as a therapeutic biomarker in melanoma with BRAF mutation

Abstract Background While molecularly targeted therapies and immune checkpoint inhibitors have improved the prognosis of advanced melanoma, biomarkers are required to monitor drug responses. Circulating tumor cells (CTCs) are released from primary and/or metastatic tumors into the peripheral blood. We examined whether CTCs have potential as biomarkers by checking the number of CTCs, as well as the BRAF genotype of individual CTCs, in melanoma patients undergoing BRAF/MEK inhibitor treatment. Methods CTCs were isolated from peripheral blood using a high-density dielectrophoretic microwell array, followed by labeling with melanoma-specific markers (MART-1 and/or gp100) and a leukocyte marker (CD45). The numbers of CTCs were analyzed in fifteen patients with stage 0–III melanoma. Furthermore, changes in CTC numbers were assessed in five patients with stage IV melanoma at four time points during BRAF/MEK inhibitor treatment, and the BRAF genotype was analyzed in CTCs isolated from one patient. Results We examined CTCs in patients with stage 0–III (five samples per stage: stage 0–I, stage II, and stage III), and detected CTCs even in patients with early disease (stage 0 and I). Interestingly, recurrence occurred in the lymph nodes of one stage I patient 2 years after the detection of a high number of CTCs in the patient’s blood. The total number of CTCs in four of five patients with stage IV melanoma fluctuated in response to BRAF/MEK inhibitor treatment, suggesting that CTC number has potential for use as a drug response marker in advanced disease patients. Interestingly, one of those patients had CTCs harboring seven different BRAF genotypes, and the mutated CTCs disappeared upon BRAF/MEK inhibitor treatment, except for those harboring BRAFA598V. Conclusions CTCs are present even in the early stage of melanoma, and the number of CTCs seems to reflect patients’ responses to BRAF/MEK inhibitor treatment. Furthermore, genetic heterogeneity of BRAF may contribute to resistance to BRAF/MEK inhibitors. Our findings demonstrate the usefulness of CTC analysis for monitoring responses to targeted therapies in melanoma patients, and for understanding the mechanism of drug resistance.

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Circulating Tumor Cells in Stage IV Melanoma Patients

Journal of the American College of Surgeons ◽

10.1016/j.jamcollsurg.2018.04.026 ◽

2018 ◽

Vol 227 (1) ◽

pp. 116-124 ◽

Cited By ~ 5

Author(s):

Carolyn S. Hall ◽

Merrick Ross ◽

Jessica B. Bowman Bauldry ◽

Joshua Upshaw ◽

Mandar G. Karhade ◽

...

Keyword(s):

Tumor Cells ◽

Circulating Tumor Cells ◽

Stage Iv ◽

Melanoma Patients ◽

Stage Iv Melanoma

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Usefulness of Monitoring Circulating Tumor Cells as a Therapeutic Biomarker in Melanoma with BRAF Mutation

10.21203/rs.3.rs-88937/v1 ◽

2020 ◽

Author(s):

Ryuhei Okuyama ◽

Yukiko Kiniwa ◽

Kenta Nakamura ◽

Asuka Mikoshiba ◽

Atsuko Ashida ◽

...

Keyword(s):

Drug Resistance ◽

Tumor Cells ◽

Circulating Tumor Cells ◽

Drug Response ◽

Early Stage ◽

Stage Iv ◽

Mek Inhibitor ◽

Disease Stage ◽

Mek Inhibitors ◽

Non Invasive

Abstract Background: Circulating tumor cells (CTCs) are non-invasive biomarkers that could be used to characterize changes in tumors. In this study, we monitored the number of CTCs, as well as the BRAF genotype of individual CTCs. Methods: CTCs were isolated from peripheral blood using a high-density dielectrophoretic microwell array, followed by labeling with melanoma-specific markers (MART-1 and/or gp100) and a leukocyte marker (CD45). Results: Examination of patients with stage 0–III melanoma detected CTCs even in patients with early disease (stage 0 or I). Next, we analyzed CTCs in five patients with stage IV melanoma during treatment with BRAF/MEK inhibitors. The number of CTCs fluctuated in association with the drug response in four of the five patients, suggesting that the total number of CTCs usually reflected the drug response. Interestingly, one of those patients had CTCs with seven different BRAF genotypes, and the mutated CTCs disappeared upon treatment with BRAF/MEK inhibitors, except for those harboring BRAFA598V.Conclusions: CTCs are present even in the early stage of melanoma, and the number of CTCs seems to reflect drug response during treatment with BRAF/MEK inhibitors. Furthermore, genetic heterogeneity of BRAF may contribute to drug resistance of BRAF/MEK inhibitor. Our findings demonstrate the usefulness of CTC analysis in melanoma for monitoring targeted therapies and understanding mechanism of drug resistance.

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Abstract 2847: Quantitative assessment of circulating BRAF DNA in stage IV melanoma patients undergoing BRAF inhibitor treatment

10.1158/1538-7445.am2014-2847 ◽

2014 ◽

Author(s):

David Polsky ◽

Jyothi Sakuntala Tadepalli ◽

Gregory Chang ◽

Nathaniel Fleming ◽

Yongzhao Shao ◽

...

Keyword(s):

Quantitative Assessment ◽

Braf Inhibitor ◽

Stage Iv ◽

Melanoma Patients ◽

Inhibitor Treatment ◽

Stage Iv Melanoma

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Gene expression patterns in CD4+ peripheral blood cells in healthy subjects and stage IV melanoma patients

Cancer Immunology Immunotherapy ◽

10.1007/s00262-015-1745-x ◽

2015 ◽

Vol 64 (11) ◽

pp. 1437-1447 ◽

Cited By ~ 3

Author(s):

Sara J. Felts ◽

Virginia P. Van Keulen ◽

Adam D. Scheid ◽

Kathleen S. Allen ◽

Renee K. Bradshaw ◽

...

Keyword(s):

Gene Expression ◽

Peripheral Blood ◽

Blood Cells ◽

Healthy Subjects ◽

Expression Patterns ◽

Stage Iv ◽

Gene Expression Patterns ◽

Peripheral Blood Cells ◽

Melanoma Patients ◽

Stage Iv Melanoma

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Mobilization of tumor cells and hematopoietic progenitor cells into peripheral blood of patients with solid tumors [see comments]

Blood ◽

10.1182/blood.v83.3.636.636 ◽

1994 ◽

Vol 83 (3) ◽

pp. 636-640 ◽

Cited By ~ 323

Author(s):

W Brugger ◽

KJ Bross ◽

M Glatt ◽

F Weber ◽

R Mertelsmann ◽

...

Keyword(s):

Breast Cancer ◽

Bone Marrow ◽

Tumor Cell ◽

Tumor Cells ◽

Circulating Tumor Cells ◽

Peripheral Blood ◽

Stage Iv ◽

Breast Cancer Patients ◽

Cell Recruitment ◽

Stage Iv Breast Cancer

Abstract Peripheral blood progenitor cells (PBPCs) are increasingly used for autografting after high-dose chemotherapy. One advantage of PBPCs over the use of autologous bone marrow would be a reduced risk of tumor-cell contamination. However, the actual level of tumor cells contaminating PBPC harvests is poorly investigated. It is currently not known whether mobilization of PBPCs might also result in mobilization of tumor cells. We evaluated 358 peripheral blood samples from 46 patients with stage IV or high-risk stage II/III breast cancer, small cell (SCLC) or non- small cell (NSCLC) lung cancer, as well as other advanced malignancies for the detection of epithelial tumor cells. Monoclonal antibodies against acidic and basic cytokeratin components and epithelial antigens (HEA) were used in an alkaline phosphatase-anti-alkaline phosphatase assay with a sensitivity of 1 tumor cell within 4 x 10(5) total cells. Before initiation of PBPC mobilization, circulating tumor cells were detected in 2/7 (29%) patients with stage IV breast cancer and in 2/10 (20%) patients with extensive-disease SCLC, respectively. In these patients, an even higher number of circulating tumor cells was detected after chemotherapy with VP16, ifosfamide, and cisplatin (VIP) followed by granulocyte colony-stimulating factor (G-CSF). This approach has previously been shown to be highly effective in mobilizing PBPCs. In the 42 patients without circulating tumor cells during steady state, tumor cells were mobilized in 9/42 (21%) patients after VIP+G-CSF induced recruitment of PBPCs. The overall incidence of tumor cells varied between 4 and 5,600 per 1.6 x 10(6) mononuclear cells analyzed. All stage IV breast cancer patients and 50% of SCLC patients were found to concomitantly mobilize tumor cells and PBPCs. Kinetic analyses showed two patterns of tumor cell recruitment depending on the presence or absence of bone marrow disease: (1) early after chemotherapy (between days 1 and 7) in patients without marrow infiltration, and (2) between days 9 and 16 in patients with marrow infiltration, ie, within the optimal time period for the collection of PBPCs. We show that there is a high proportion of patients with circulating tumor cells under steady-state conditions, and in addition a substantial risk of concomitant tumor cell recruitment upon mobilization of PBPCs, particularly in stage IV breast cancer patients with bone marrow infiltration. The biologic and clinical significance of this finding is unknown at present.

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