Detection of circulating lung cancer cells with strong thymidylate synthase reactivity in the peripheral blood of a patient with pulmonary adenocarcinoma treated with pemetrexed.

摘要: Circulating tumor cells (CTCs) can be collected from peripheral blood and may provide pharmacodynamic information to aid therapeutic decision making.1 Furthermore, CTCs as a “virtual real-time biopsy” have clear potential facilitate exploration of the same prognostic or predictive biomarkers those found in primary tumor.2,3 The multitarget antifolate agent pemetrexed (PMX) currently administered patients with nonsquamous non-small cell lung cancer (NSCLC). PMX primarily targets thymidylate synthase (TS), TS is being investigated biomarker for PMX-based chemotherapy.4,5 In November 2010, 50-year-old woman was diagnosed metastatic adenocarcinoma right lower lobe (cT4 cN3 cM1b, epidermal growth receptor factor wild type). First-line treatment cisplatin scheduled December 3, 2010. Before administration, we 20 ml venous isolate CTCs. Mononuclear including were enriched using modified buoyant density gradient centrifugation method Percoll PLUS solution (GE Healthcare GmbH, Munich, Germany). Hematopoietic negatively selected sample immunomagnetic beads anti-CD15 anti-CD456 monoclonal antibodies. Epithelial magnetic (Dynabead Enrich, Invitrogen Darmstadt, Germany) coated antibody BerEP41 against human epithelial antigen EpCAM.6 The resulting CTC-enriched population dissolved ThinPrep CytoLyt centrifuged at 150g 10 minutes. sediment dissociated fixating consisting 50% ethanol phosphate-buffered saline-buffered formalin. Cells fixed minimum minutes before mounted on slide. TS protein expression evaluated BenchMark XT autostainer (Ventana Medical Systems, Inc., Tucson, AZ). After pretreatment, CTC containing slides 4 μm sections formalin-fixed paraffin-embedded incubated 1 hour 25°C mouse anti-TS (clone 4H4B1, Invitrogen, Carlsbad, CA) counterstained hematoxylin Negative control obtained by nonimmunized ready-to-use antibody. Tissue section colorectal carcinoma served positive control. Microscopic examination revealed several varying ranging weak strong (Figures 1A–C). For estimation staining intensities, compared stained TS-stained tumors (Fig. 2). In addition, strongly TS-positive adjacent immune detected, whose shape similar dividing late prophase stage mitosis (Figure 1A). This presents chromosome maturation condensed chromosomes, which has rarely been observed To best our knowledge, this first report circulating NSCLC blood, most TS. FIGURE 1 Circulating isolated patient suffering an (TS). A, Strongly expressing resembles proliferating ... FIGURE 2 Adenocarcinoma hematoxylin/eosin (HE) (TS) 4-μm tumor. HE staining. B, ... As high associated inferior clinical outcome therapy, followed course patient. Until February, she received four cycles combined chemotherapy partial response per RECIST. Disease progression multiple sites May 9, 2011, 157 days after initiation 70 end first-line treatment. progression-free survival compatible median reported large phase III trial PMX.7 Despite receiving additional lines (erlotinib, docetaxel, gemcitabine/vinorelbine, mitomycin), never achieved second objective showed disease notably under each line within 6 weeks. She still alive August 8, 2011. In conclusion, established that immunocytochemical detection feasible, acting surrogate biopsies hold promise “real-time” monitoring personalized systemic treatments cancer.