The CellSearch system (Veridex, Warren, NJ) is designed to enrich and enumerate circulating tumor cells (CTCs) from peripheral blood. Here, we validated the analytic performance of this system for ...clinical use in patients with metastatic breast cancer.
This prospective multicenter study conducted at three independent laboratories involved samples from 92 patients with metastatic breast cancer. Intra- and inter-assay variability using controls containing defined numbers of cells (average, 50 and 1,000, respectively), cell stability based on varying storage and shipment conditions, recovery precision from samples spiked with 4 to 12 tumor cells, inter-instrument variability, and positivity of samples from metastatic breast cancer patients were tested.
Intra- and inter-assay precision for two sites were high: All eight positive controls analyzed in the same run and >95% of the run to run control values (n=299) were within the specified ranges. Recovery rate of spiked samples averaged between 80% and 82%. CTCs were detected in approximately 70% of metastatic breast cancer patients. CTC values of identical samples processed either immediately after blood drawing or after storage for 24, 48, or 72 h at room temperature or at 4 degrees C did not differ significantly. Shipment of samples had no influence on CTC values. When analyzing identical samples in different centers, inter-instrument accordance was high.
The CellSearch system enables the reliable detection of CTCs in blood and is suitable for the routine assessment of metastatic breast cancer patients in the clinical laboratory. Blood samples should be shipped at room temperature and CTC counts are stable for at least 72 h.
The use of neoadjuvant systemic therapy (NST) for the treatment of primary breast cancer has constantly increased, especially in trials of new therapeutic regimens. In the 1980 s, NST was shown to ...substantially improve breast-conserving surgery rates and was first typically used for patients with inoperable locally advanced or inflammatory breast cancer. Investigators have since also used NST as an in vivo test for chemosensitivity by assessing pathologic complete response. Today, by using pathologic response and other biomarkers as intermediate end points, results from trials of new regimens and therapies that use NST are aimed to precede and anticipate the results from larger adjuvant trials. In 2003, a panel of representatives from various breast cancer clinical research groups was first convened in Biedenkopf to formulate recommendations on the use of NST. The obtained consensus was updated in two subsequent meetings in 2004 and 2006. The most recent conference on recommendations on the use of NST took place in 2010 and forms the basis of this report.
Circulating tumor cells (CTCs) are tumor cells shed from either primary tumors or its metastases that circulate in the peripheral blood of patients with metastatic cancers. The molecular ...characterization of the CTCs is critical to identifying the key drivers of cancer metastasis and devising therapeutic approaches. However, the molecular characterization of CTCs is difficult to achieve because their isolation is a major technological challenge.
CTCs from two triple negative breast cancer patients were enriched using CellSearch and single cells selected by DEPArray™. A TP53 R110 fs*13 mutation identified by next generation sequencing in the breast and chest skin biopsies of both patients was studied in single CTCs.
From 6 single CTC isolated from one patient, 1 CTC had TP53 R110 delC, 1 CTC showed the TP53 R110 delG mutation, and the remaining 4 single CTCs showed the wild type p53 sequence; a pool of 14 CTCs isolated from the same patient also showed TP53 R110 delC mutation. In the tumor breast tissue of this patient, only the TP53 R110 delG mutation was detected. In the second patient a TP53 R110 delC mutation was detected in the chest wall skin biopsy; from the peripheral blood of this patient, 5 single CTC and 6 clusters of 2 to 6 CTCs were isolated; 3 of the 5 single CTCs showed the TP53 R110 delC mutation and 2 CTCs showed the wild type TP53 allele; from the clusters, 5 showed the TP53 R110 delC mutation, and 1 cluster the wild type TP53 allele. Single white blood cells isolated as controls from both patients only showed the wild type TP53 allele.
We are able to isolate uncontaminated CTCs and achieve single cell molecular analysis. Our studies showed the presence of different CTC sub-clones in patients with metastatic breast cancer. Some CTCs had the same TP53 mutation as their matching tumor samples although others showed either a different TP53 mutation or the wild type allele. Our results indicate that CTCs could represent a non-invasive source of cancer cells from which to determine genetic markers of the disease progression and potential therapeutic targets.
Circulating tumor cells (CTCs) are isolated tumor cells disseminated from the site of disease in metastatic and/or primary cancers, including breast cancer, that can be identified and measured in the ...peripheral blood of patients. As recent technical advances have rendered it easier to reproducibly and repeatedly sample this population of cells with a high degree of accuracy, these cells represent an attractive surrogate marker of the site of disease. Currently, CTCs are being integrated into clinical trial design as a surrogate for phenotypic and genotypic markers in correlation with development of molecularly targeted therapies. As CTCs play a crucial role in tumor dissemination, translational research is implicating CTCs in several biological processes, including epithelial to mesenchymal transition. In this mini-review, we review CTCs in metastatic breast cancer, and discuss their clinical utility for assessing prognosis and monitoring response to therapy. We will also introduce their utility in pharmacodynamic monitoring for rational selection of molecularly targeted therapies and briefly address how they can help elucidate the biology of cancer metastasis.
Small cell carcinoma of the prostate (SCCP) is an aggressive disease that can arise
or by transdifferentiation from prostate adenocarcinoma. Alterations in anaplastic lymphoma kinase (
) gene are ...involved in neuroblastoma, lung cancer, and other malignancies, but its role in SCCP has not been documented. We describe a patient with refractory
SCCP with
F1174C-activating mutation who obtained clinical benefit from treatment with ALK inhibitor.
Next-generation sequencing (NGS) was used to analyze primary and circulating tumor DNA (ctDNA). Prostate cancer databases were queried for alterations in
gene, mRNA, and its impact in clinical outcomes.
prostate cell line/organoid models were generated by lentiviral-mediated expression of ALK and ALK F1174C and assessed for response to ALK inhibitors crizotinib and alectinib.
NGS analysis of the primary tumor and ctDNA of a 39-year-old patient with refractory SSCP identified
F1174C mutation. Treatment with second-generation ALK inhibitor alectinib resulted in radiographic stable disease for over 6 months, symptomatic improvement, and significant molecular response as reflected by declining ctDNA allele fraction. Analysis of prostate cancer datasets showed that
amplification was associated with poor outcome. In prostate cancer cells and organoids,
F1174C expression enhanced growth and induced expression of the neuroendocrine marker neuron-specific enolase. Alectinib was more effective than crizotinib in inhibiting
F1174C-expressing cell growth.
These findings implicate
-activating mutations in SCCP pathogenesis and suggest the therapeutic potential of targeting
molecular alterations in some patients with SCCP.
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Liquid biopsies, including circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs), can be used to understand disease prognosis, tumor heterogeneity, and dynamic response to treatment in ...metastatic breast cancer (MBC). We explored a novel, 180-gene ctDNA panel and the association of this platform with CTCs and CTC clusters.
A total of 40 samples from 22 patients with MBC were included in the study. For the primary analysis, all patients had ctDNA sequencing using the PredicinePLUS™ platform. CTCs and CTC clusters were examined using the CellSearch™ System. Clinical and pathological variables were reported using descriptive analyses. Associations between CTC count and specific genomic alterations were tested using the Mann-Whitney U test.
Of 43 sequenced patients, 40 (93%) had at least one detectable genomic alteration with a median of 6 (range 1-22). Fifty-seven different genes were altered, and the landscape of genomic alterations was representative of MBC, including the commonly encountered alterations TP53, PTEN, PIK3CA, ATM, BRCA1, CCND1, ESR1, and MYC. In patients with predominantly hormone-receptor-positive MBC, the number of CTCs was significantly associated with alterations in ESR1 (P < 0.005), GATA3 (P < 0.05), CDH1 (P < 0.0005), and CCND1 (P < 0.05) (Mann-Whitney U test). Thirty-six percent of patients had CTC clusters, which were associated with alterations in CDH1, CCND1, and BRCA1 (all P < 0.05, Mann-Whitney U test). In an independent validation cohort, CTC enumeration confirmed significant associations with ESR1 and GATA3, while CTC clusters were significantly associated with CDH1.
We report on a novel ctDNA platform that detected genomic alterations in the vast majority of tested patients, further indicating potential clinical utility for capturing disease heterogeneity and for disease monitoring. Detection of CTCs and CTC clusters was associated with particular genomic profiles.
Palbociclib improves outcomes for women with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer (HR+/HER2- ABC). Dose reductions are recommended for ...the management of hematologic toxicities. A previous pooled analysis from the PALOMA clinical trials showed that 36.9% of patients required dose reduction, predominantly during the first 6 months of treatment and with decreasing frequency during subsequent 28-day treatment cycles (C). Previous data have shown that palbociclib dose reductions do not affect efficacy. This pooled, post hoc analysis evaluated the frequency of hematologic adverse events (AEs) before and after palbociclib dose reduction in PALOMA-1, PALOMA-2, and PALOMA-3.
This analysis evaluated the frequency of hematologic AEs 30 days before dose reduction and during each subsequent treatment from C1 to C6 among patients who required palbociclib dose reduction. Data were pooled from 3 randomized studies. PALOMA-1 was a phase 2, open-label study of postmenopausal patients untreated for ABC receiving palbociclib plus letrozole or letrozole alone. PALOMA-2 was a phase 3, double-blind study of postmenopausal patients untreated for ABC receiving palbociclib plus letrozole or placebo plus letrozole. PALOMA-3 was a phase 3, double-blind study of pre/perimenopausal or postmenopausal patients, whose disease progressed on prior endocrine therapy, receiving palbociclib plus fulvestrant or placebo plus fulvestrant.
A total of 311 (35.5%) patients with HR+/HER2- ABC required a palbociclib dose reduction (93.6% due to AEs) from 125 to 100 mg. Mean patient age was 59.9 years, and 46.9% of patients had visceral disease. Median time to dose reduction was 70 days. The majority of dose reductions occurred within 3 months of starting palbociclib treatment. Incidences of all-grade and grades 3/4 hematologic AEs were lower following dose reduction.
A decrease in frequency and severity of hematologic AEs, including febrile neutropenia, following palbociclib dose reduction was observed, supporting the recommended use of dose reduction in AE management.
These studies were sponsored by Pfizer. ClinicalTrials.gov: NCT00721409; registration date July 24, 2008. ClinicalTrials.gov: NCT01740427; registration date December 4, 2012. ClinicalTrials.gov: NCT01942135; registration date September 13, 2013.
The presence of >or=5 circulating tumor cells (CTC) in 7.5 mL blood from patients with measurable metastatic breast cancer before and/or after initiation of therapy is associated with shorter ...progression-free and overall survival. In this report, we compared the use of CTCs to radiology for prediction of overall survival.
One hundred thirty-eight metastatic breast cancer patients had imaging studies done before and a median of 10 weeks after the initiation of therapy. All scans were centrally reviewed by two independent radiologists using WHO criteria to determine radiologic response. CTC counts were determined approximately 4 weeks after initiation of therapy. Specimens were analyzed at one of seven laboratories and reviewed by a central laboratory.
Interreader variability for radiologic responses and CTC counts were 15.2% and 0.7%, respectively. The median overall survival of 13 (9%) patients with radiologic nonprogression and >or=5 CTCs was significantly shorter than that of the 83 (60%) patients with radiologic nonprogression and <5 CTCs (15.3 versus 26.9 months; P=0.0389). The median overall survival of the 20 (14%) patients with radiologic progression and <5 CTCs was significantly longer than the 22 (16%) patients with >or=5 CTCs that showed progression by radiology (19.9 versus 6.4 months; P=0.0039).
Assessment of CTCs is an earlier, more reproducible indication of disease status than current imaging methods. CTCs may be a superior surrogate end point, as they are highly reproducible and correlate better with overall survival than do changes determined by traditional radiology.
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