In conclusion, CTC detection may be a promising early marker of disease progression potentially enhancing the difficult therapeutic decisions. Further studies should, however, clearly demonstrate its utility for both the prediction of outcome and monitoring the effect of treatment.

Background and Aims. Metastases are a severe complication in cancer patients and biomarkers predicting their progression are still lacking for specific groups of patients. HER2 positive breast cancer (HER2 BC) patients on trastuzumab therapy are at risk of the development of unpredictable and often fatal central nervous system (CNS) metastases and castration resistant prostate cancer (CRPC) patients urgently need a marker of disease progression during therapy. Proposed metastatic markers: circulating tumor cells (CTC), serum levels of matrix metalloproteinase 2 (MMP-2), 9 (MMP-9) and vascular endothelial growth factor (VEGF) were prospectively studied to confirm their utility in these two narrowly defined groups of cancer patients. Patients and Methods. The groups comprised 44 advanced HER2 BC, 24 CRPC patients and 42 healthy controls. An immunomagnetic separation method followed by PCR and electrophoretic detection (AdnaGen, Germany) were used for CTC determination. Serum marker levels were determined by the ELISAs (R&D System, USA). Results. MMP-2 serum level was significantly higher in HER2 BC patients who developed CNS metastases, especially if there were also bone metastases. CTCs were a negative predictive marker for overall survival in HER2 BC patients. MMP-9 serum level was significantly higher in CRPC patients in whom disease progression occurred. CTC vanished from the blood of most of the CRPC patients (from 88% to 37%) during chemotherapy. Conclusion. MMP-2 serum level and CTCs show the potential to predict CNS metastases and overall survival in BC patients. CTCs and MMP-9 serum level could be a promising therapy response marker in CRPC patients.

BACKGROUND: Breast cancer (BC) patients still harbor a considerable risk of metastatic relapse caused by minimal residual disease (MRD) despite of complete removal of primary tumor. The aim of this study was to identify single disseminated tumor cells (DTC) in the bone marrow and circulating tumor cells (CTC) in the peripheral blood as potential biomarkers for therapy response monitoring and metastatic relapse risk prediction. Finally, the gene expression profiles of CTCs have been analyzed. METHODS: A total of 87 patients with diagnosed BC at stage I to III and 115 metastatic patients were enrolled into a prospective study between years 2008 - 2010. Peripheral blood (5ml) for CTC-detection was collected from primary BC patients before chemotherapy (CHT), after 2 cycles of CHT and after the CHT. Metastatic BC patients have been examined for CTCs before starting a new line of the treatment. Bone marrow aspirates from 16 premenopausal BC patients (mean age 31) with primary tumor were analyzed for the presence of DTC by immunocytochemistry using the pan-cytokeratin antibody A45-B/B3 (Epimet™, AS Diagnostik, Germany) before surgery. CTC detection in blood was performed by AdnaTest BreastCancerTM(AdnaGen AG, Germany), which is based on the detection of EpCAM, HER2 and MUC1 specific transcripts in enriched CTC-lysates. cDNA from isolated CTCs has been further pre-amplified and used for multimarker qPCR gene expression profiling using Biomark® microfluidic 48x48 GE Dynamic arrays (Fluidigm, USA). qPCR results have been analyzed by GENEX vs. 5.2 software (MultiD Analysis). RESULTS: 286 CTC samples have been analyzed in total. The analysis has shown that the expression profiles of CTCs from primary BC patients have been significantly different comparing them to the CTC-profiles from metastatic BC patients for several of tested genes (e.g., CK19, GA7332, MLFIP1, SATB1, PTEN). Interestingly, before surgery of primary tumor DTCs were found in 5/16 patients (31 %) and CTCs in 7/16 (43 %). Both DTCs and CTCs together were found in 4/16 (25%) patients. In 18% of the primary BC patients no dissemination markers were found CONCLUSIONS: Information based on the CTCs-gene expression profiles could provide an additional support for therapy management. Metastatic potential of enriched CTCs will be further evaluated on the single cell level. This work has been supported by Grant Agency of Ministry of Health, Czech Republic (IGA NS9976) and Grant Agency of Charles University in Prague, Czech Republic no. 7709 and 59410. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-03-01.

BackgroundRituximab (RTX) and ocrelizumab (OCR), B cell-depleting therapy targeting CD20 molecules, affect the humoral immune response after vaccination. How these therapies influence T-cell-mediated immune response against SARS-CoV-2 after immunization remains unclear. We aimed to evaluate the humoral and cellular immune response to the COVID-19 vaccine in a cohort of patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myasthenia gravis (MG).MethodsPatients with MS (83), NMOSD (19), or MG (7) undergoing RTX (n=47) or OCR (n=62) treatment were vaccinated twice with the mRNA BNT162b2 vaccine. Antibodies were quantified using the SARS-CoV-2 IgG chemiluminescence immunoassay, targeting the spike protein. SARS-CoV-2-specific T cell responses were quantified by interferon γ release assays (IGRA). The responses were evaluated at two different time points (4-8 weeks and 16-20 weeks following the 2nd dose of the vaccine). Immunocompetent vaccinated individuals (n=41) were included as controls.ResultsAlmost all immunocompetent controls developed antibodies against the SARS-CoV-2 trimeric spike protein, but only 34.09% of the patients, without a COVID-19 history and undergoing anti-CD20 treatment (via RTX or OCR), seroconverted. This antibody response was higher in patients with intervals of longer than 3 weeks between vaccinations. The duration of therapy was significantly shorter in seroconverted patients (median 24 months), than in the non-seroconverted group. There was no correlation between circulating B cells and the levels of antibodies. Even patients with a low proportion of circulating CD19+ B cells (<1%, 71 patients) had detectable SARS-CoV-2 specific antibody responses. SARS-CoV-2 specific T cell response measured by released interferon γ was detected in 94.39% of the patients, independently of a humoral immune response.ConclusionThe majority of MS, MG, and NMOSD patients developed a SARS-CoV-2-specific T cell response. The data suggest that vaccination can induce SARS-CoV-2-specific antibodies in a portion of anti-CD20 treated patients. The seroconversion rate was higher in OCR-treated patients compared to those on RTX. The response represented by levels of antibodies was better in individuals, with intervals of longer than 3 weeks between vaccinations.