Pragmatic, Prospective Comparative Effectiveness Trial of Carbon Ion Therapy, Surgery, and Proton Therapy for the Management of Pelvic Sarcomas (Soft Tissue/Bone) Involving the Bone: The PROSPER Study Rationale and Design.

Surgical treatment of pelvic sarcoma involving the bone is the standard of care but is associated with several sequelae and reduced functional quality of life (QOL). Treatment with photon and proton radiotherapy is associated with relapse. Carbon ion radiotherapy (CIRT) may reduce both relapse rates and treatment sequelae. The PROSPER study is a tricontinental, nonrandomized, prospective, three-arm, pragmatic trial evaluating treatments of pelvic sarcoma involving the bone. Patients aged at least 15 years are eligible for inclusion. Participants must have an Eastern Cooperative Oncology Group Performance Status score of two or less, newly diagnosed disease, and histopathologic confirmation of pelvic chordoma, chondrosarcoma, osteosarcoma, Ewing sarcoma with bone involvement, rhabdomyosarcoma (RMS) with bone involvement, or non-RMS soft tissue sarcoma with bone involvement. Treatment arms include (1) CIRT (n = 30) delivered in Europe and Asia, (2) surgical treatment with or without adjuvant radiotherapy (n = 30), and (3) proton therapy (n = 30). Arms two and three will be conducted at Mayo Clinic campuses in Arizona, Florida, and Minnesota. The primary end point is to compare the 1-year change in functional QOL between CIRT and surgical treatment. Additional comparisons among the three arms will be made between treatment sequelae, local control, and other QOL measures.

A retrospective study of adjuvant proton radiotherapy for breast cancer after lumpectomy: a comparison of conventional-dose and hypofractionated dose.

PURPOSE: This study aimed to compare the adverse reactions of conventional-dose and hypofractionated dose of proton therapy for breast cancer. MATERIALS AND METHODS: Breast cancer patients treated with proton radiotherapy in conventional-dose or hypofractionated dose were studied retrospectively. RESULT: From January 2017 to December 2019, our center treated 50 patients following lumpectomy with proton radiotherapy. According to the AJCC 8th Edition standard, there were stage I in 26 patients, stage II in 22 patients, and stage III in 2 patients. A total of 14 patients received intensity-modulated proton therapy at a dose of 50 Gy in 25 fractions, followed by a 10 Gy 4 fractionated boost to the lumpectomy cavity, while 36 received 40.05 Gy in 15 fractions, simultaneous integrated boost (SIB) 48 Gy to the lumpectomy cavity. Median follow-up time for 40.05 Gy group was 35.6 months (15-43 months). Median follow-up time for 50 Gy group was 46.8 months (36-68 months). For acute toxicity, the grade 1 and 2 radiodermatitis in conventional-dose group were 35.7% and 57.1%, respectively. In hypofractionated dose group, the grade 1 and 2 radiodermatitis were 91.7% and 8.3%, respectively. The radiodermatitis is hypofractionneted dose better than conventional-dose significantly. Grade 1 radiation-induced esophagitis in conventional-dose group and hypofractionated dose group were 85.71% and 60%, respectively. For late toxicity, no patients developed radiation-induced pneumonitis and rib fracture in conventional-dose group. Three patients presented grade 1 pneumonitis; one patient presented graded 2 pneumonitides and two patients presented rib fracture in hypofractionated dose group. One presented hypothyroidism in hypofractionated dose group. All patients were satisfied with breast shape. The one- and two-year OS and DFS for conventional-dose group were 100 and 100; 100 and 92.9%, respectively. The one- and two-year OS and DFS for hypofractionated dose group were 100 and 100; 100 and 100%, respectively. CONCLUSION: Proton radiation therapy can significantly reduce the normal tissue dose in breast cancer patients' hearts, lungs, and other organs. Hypofractionated proton therapy shortens the treatment course with mild radiation-related adverse effects, and has a better effect on addressing the acute adverse reactions than conventional proton radiotherapy.

Immunomodulatory effects of carbon ion radiotherapy in patients with localized prostate cancer.

PURPOSE: Radiotherapy is one of the main local treatment modalities for prostate cancer, while immunosuppressive effect induced by radiotherapy is an important factor of radiation resistance and treatment failure. Carbon ion radiotherapy (CIRT) is a novel radiotherapy technique and the immunomodulatory effect of CIRT provides the possibility of overcoming radioresistance and improving efficacy. The aim of this study was to assess the immune response evoked by CIRT in localized prostate cancer patients. METHODS: Thirty-two patients were treated by CIRT combined with or without hormone therapy and peripheral blood samples were collected before and after CIRT. Investigation of peripheral immune cell frequency, proliferation, and cytokine expression was conducted by flow cytometry, real-time quantitative PCR and ELISA. RESULTS: There were no significant differences in the frequencies of CD3 + , CD4 + , CD8 + T cells and NK cells after CIRT. CD4/CD8 ratio increased whereas B cells decreased. All lymphocyte subsets except regulatory T cells (Tregs) displayed increased proliferation and T cells exhibited increased functionality after CIRT, characterized by modestly increased cytokine secretion of TNF. Moreover, higher frequencies of Tregs were shown. Neither monocytic myeloid-derived suppressor cells (MDSCs) nor early MDSCs changed after CIRT. TGF-ß1 gene expression decreased while IL-6 showed a non-significant trend towards a decrease. Both IL-10 gene expression and plasma TGF-ß1 level were unchanged. CONCLUSION: CIRT demonstrates the potential to elicit immune activation in localized prostate cancer patients, based on sparing lymphocytes, increased lymphocyte proliferation, enhanced T-cell functionality, together with limited induction of immunosuppressive cells and reduced expression of immunosuppressive cytokines.

Carbon ion triggered immunogenic necroptosis of nasopharyngeal carcinoma cells involving necroptotic inhibitor BCL-x.

To explore the potential and mechanisms of necroptosis, a form of immunogenic cell death, induced by carbon ion as compared to photon beams in established photon resistant- (PR-) and sensitive nasopharyngeal carcinoma (NPC) cells. MLKL is considered a central executor of necroptosis and phosphorylation of MLKL (p-MLKL) was a critical event of necroptosis. The clonogenic survival and DNA microarray demonstrated that after repeated photon irradiation, radiosensitive NPC cells became apoptosis-resistant but could be effectively inhibited by carbon ion irradiation. The relative biologic effectiveness (RBE) at D10 and D37 were 2.15 and 2.78 for PR-NPC cells. Carbon ion induced delayed DNA damage repair, cell cycle arrest, cytogenetic damage, morphological change and cell necrosis, indicating the possibility of necroptosis in both PR- and sensitive NPC cell types. The lower expression of necroptotic inhibitors (caspase-8 and Bcl-x) and higher level of MLKL in PR-NPC cells showed it was relatively more predisposed to necroptosis compared to the sensitive cells. Subsequent experiments demonstrated the significant upregulation of p-MLKL in the PR-NPC cells treated by carbon ion (4 Gy) compared with photon irradiation at both physical (4 Gy) and RBE (10 Gy) doses (P≤0.0001). Moreover, carbon ion induced a robust (up to 28 folds) p-MLKL in the PR-NPC cells as well as sensitive cells (up to 6-fold) coupled with a lower level of BCL-x expression and increased GM-CSF implicated in resculputure of immune system. These results suggested that carbon ion could induce necroptosis of NPC cells, especially in PR-NPC cells, and its mechanisms involve BCL-x.

Intensity-Modulated Radiation Therapy for Esthesioneuroblastoma: 10-Year Experience of a Single Institute.

Objectives: To evaluate efficacy and safety of intensity-modulated radiotherapy (IMRT) in the management of esthesioneuroblastoma (ENB). Methods and Materials: A retrospectively analysis of 52 ENB patients treated with IMRT between 8/2008 and 8/2018 was performed. Thirteen of the 44 patients (29.5%) with newly diagnosed and 2 of the 8 patients with recurrent disease presented regional lymph node metastasis. The median dose of IMRT was 66 (range 52.5-75) Gy for all patients. Elective nodal irradiation (ENI) was provided to all excluding 6 patients in this cohort. Results: With a median follow-up time of 32.5 (6~121) months, the 3-year overall survival (OS), progression-free survival (PFS), local progression-free survival (LPFS), regional progression-free survival (RPFS), and distant metastasis-free survival (DMFS) rates for the entire cohort were 89.7, 69.5, 89.7, 95.1, and 85.4%, respectively. Multivariate analysis revealed that N-classification (N- vs. N+) at presentation was the only significant prognosticators for PFS. No significant prognosticator was identified for other survival outcome. No severe (i.e., grade 3 or 4) IMRT-induced acute toxicity was observed. Severe late toxicities were infrequent (11.5%), which included dysosmia (3.8%), hearing loss (3.8%), radiation brain injury (1.9%), and temporal lobe necrosis (1.9%). Moreover, late ocular toxicity secondary to IMRT was not observed. Conclusion: IMRT produced acceptable 3-year outcomes in terms of OS (89.7%), LPFS (89.7%), and RPFS (95.1%) rates without substantial late adverse effects. Further investigations for a more effective systemic strategy for distant disease control as well as a precision radiation technique for further improvement in local control are needed.

Salvage treatment using carbon ion radiation in patients with locoregionally recurrent nasopharyngeal carcinoma: Initial results.

BACKGROUND: Reirradiation for locoregionally recurrent nasopharyngeal carcinoma (NPC) after a definitive dose of radiotherapy (RT) is challenging and usually associated with severe toxicities. Intensity-modulated carbon ion RT (IMCT) offers physical/biologic advantages over photon-based intensity-modulated RT. Herein, the authors report their initial experience of IMCT in previously irradiated patients with locoregionally recurrent NPC. METHODS: Patients with locoregionally recurrent, poorly differentiated or undifferentiated NPC who underwent salvage therapy with IMCT at the Shanghai Proton and Heavy Ion Center between May 2015 and August 2017 were included in the current study. The IMCT doses were 50 to 66 Gray equivalent (GyE) (2.0-3.0 GyE/daily fraction), delivered via raster scanning technology. The 1-year overall survival, disease-specific survival, progression-free survival (PFS), local recurrence-free survival, regional recurrence-free survival, and distant metastasis-free survival were calculated. Univariate and multivariate analyses of PFS were performed to identify possible predictive factors. RESULTS: Among the 75 patients included, 4 patients, 14 patients, 29 patients, and 28 patients, respectively, had recurrent American Joint Committee on Cancer stage I, stage II, stage III, and stage IVA/B disease. With a median follow-up of 15.4 months (range, 2.6-29.7 months), the 1-year overall survival, disease-specific survival, PFS, local recurrence-free survival, regional recurrence-free survival, and distant metastasis-free survival rates were 98.1%, 98.1%, 82.2%, 86.6%, 97.9%, and 96.2%, respectively. A higher fraction size of 3 GyE (vs <3 GyE) or a higher biological equivalent dose significantly improved the PFS rate on univariate analysis, but not on multivariate analysis. No patient developed acute toxicity of grade ≥2 during IMCT. Late treatment-induced severe (grade 3 or 4) toxicities were infrequent, but included mucosal necrosis (9.3%), xerostomia (1.3%), and temporal lobe necrosis (1.3%). CONCLUSIONS: This initial experience in the first 75 patients with locoregionally recurrent NPC was encouraging. Carbon ion RT could provide promising survival rates with infrequent severe toxicities for patients with locoregionally recurrent NPC. Cancer 2018;124:2427-37. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Prognostic and diagnostic potential of miR-146a in oesophageal squamous cell carcinoma.

BACKGROUND: Accumulating evidence indicates that dysregulated microRNA-146a (miR-146a) is involved in tumour genesis and cancer progression. We aimed to evaluate its expression level and the potential for the diagnosis and prognosis in oesophageal squamous cell cancer (ESCC). METHODS: We examined miR-146a expression in 62 pairs of ESCC cancerous and matched paracancerous tissue, 115 formalin-fixed paraffin-embedded (FFPE) tissue samples and serum samples from 154 ESCC patients and 154 healthy volunteers using quantitative reverse transcription-PCR (qRT-PCR). Kaplan-Meier method, Cox regression and receiver-operating characteristic (ROC) curve analysis were applied to analyse its prognostic and diagnostic value. RESULTS: MicroRNA-146a expression level was significantly decreased in ESCC tissue compared with paracancerous tissue (P<0.001). Its regulation level was negatively associated with T factor and TNM stage. Kaplan-Meier curve revealed that its downregulation level predicted worse overall survival (OS) and progression-free survival (PFS). Both univariate and multivariate analyses identified miR-146a expression as independent prognostic factor for OS and PFS. Serum miR-146a was significantly reduced in ESCC patients than in healthy controls (P<0.001). Area under the curve ROC value, sensitivity and specificity for this marker were 0.863 ± 0.033, 85.7% and 68.6% in the Discovery Group, and 0.891 ± 0.027, 82.1% and 83.3% in the Validation Group. CONCLUSIONS: MicroRNA-146a is significantly reduced in cancerous tissue and serum samples of ESCC patients. It is an ideal biomarker for the prognosis and diagnosis of ESCC.

The effect of socioeconomic status on health-care delay and treatment of esophageal cancer.

BACKGROUND: Socioeconomic status (SES) has been focused on as a key determinant of the incidence of cancer, cancer stage at diagnosis as well as treatment choices in western countries. However, to the authors' knowledge, little work has been done concerning the relationship of SES and esophageal cancer in China. METHODS: Patients diagnosed with primary esophageal cancer from January to December 2007 in Qilu hospital were included. Socioeconomic status was determined by a questionnaire including religion, years of schooling and high education, place of residence, occupation, annual household income, and insurance. RESULTS: A total of 238 cases were collected in this study. Linear-by-linear association testing revealed that health-care delay was significantly associated with SES (P = 0.009). Multivariable logistic regression analysis revealed that increased health-care delay (>2 months) was more frequently observed in patients with lower SES (OR 2.271; 95% CI 1.069-4.853). Patients diagnosed at TNM I and II were more frequently in higher SES groups (P = 0.017). The association test was statistically significant for undergoing surgical resection only (P = 0.015) and chemotherapy (P = 0.015). Multivariable logistic regression analysis revealed that surgical resection only was less performed in higher SES group compared with lower SES group (OR 0.372; 95% CI 0.188-0.734). For chemotherapy, higher SES patients had a three-fold higher likelihood compared with lower SES group (OR 3.042; 95% CI 1.335-6.928). CONCLUSION: Socioeconomic status was found to be associated with health-care delay, tumor stage and treatment modalities in esophageal cancer.

Clinical potential of miR-3651 as a novel prognostic biomarker for esophageal squamous cell cancer.

Accumulating evidence indicates that dysregulated microRNA-3651(miR-3651) is involved in tumorigenesis and cancer progression. In this study, we investigated the expression of miR-3651 in esophageal squamous cell cancer(ESCC) and its relationship with tumor progression and clinical prognosis. The expression level of miR-3651 was examined by quantitative Real-time PCR (qRT-PCR) in fresh ESCC tissues and FFPE tissues. The correlation between miR-3651 expression and clinical features and prognosis were statistically analyzed. The results showed that the miR-3651 expression was significantly down-regulated in tumor tissues compared with the paracancerous tissues. Moreover, miR-3651 expression was negatively correlated with T stage of ESCC (P = 0.022) and tumor length (P = 0.015). Kaplan-Meier analysis demonstrated that low miR-3651 expression level was associated with poorer overall survival (OS) (P = 0.004) and disease-free survival (DFS) (P = 0.001). Multivariate analysis identified miR-3651 expression as independent prognostic factor for OS and DFS (P = 0.001 and P = 0.001, resp.). Further stratified analysis revealed the significant association between low miR-3651 expression and worse survival in early patients, but not in the advanced patients. Taken together, miR-3651 was down-regulated in cancerous tissues of ESCC. It may play an important role in cancer progression and could be used as an independent prognostic biomarker for ESCC patients.

Expression of CXCR4 and non-small cell lung cancer prognosis: a meta-analysis.

PURPOSE: The prognostic value of aberrant C-X-C chemokine receptor type 4 (CXCR4) levels in NSCLC has been described in empirical studies. This meta-analysis evaluates the value of CXCR4 as a prognostic marker for NSCLC and determines the relationship between CXCR4 and clinicopathological features of NSCLC. METHODS: A comprehensive search of the English-language literature in PubMed, Embase, Google Scholar and Web of Science was performed. Articles containing sufficient published data to determine an estimate of the hazard ratio (HR) and a 95% confidence interval (95% CI) for over survival (OS) or disease-free survival (DFS) were selected. Of 417 potentially relevant studies, 10 eligible studies (1,334 NSCLC patients) met the inclusion criteria. RESULTS: Overall, high CXCR4 expression was significantly associated with a poor OS rate (HR=1.59, 95% CI=1.36-1.87, P<0.001) while the association with DFS was not statistically significant (HR=1.00, 95% CI=0.37-2.69, P=0.993). Stratified analysis by subcellular localization found that CXCR4 overexpression in the non-nucleus predicts poor OS (HR=1.65, 95% CI=1.40-1.95, P<0.001) and DFS (HR=3.06, 95% CI=2.15-4.37, P<0.001), but elevated CXCR4 expression in the nucleus was positively associated with DFS (HR=0.44, 95% CI=0.26-0.75, P=0.002). NSCLC patients with CXCR4 expression were more likely to be diagnosed with adenocarcinoma cancer (OR=1.45, 95% CI=1.07-1.95, P=0.016), lymph node involvement (OR=0.69, 95% CI=0.50-0.96, P=0.027), and distant metastasis (OR=0.36, 95% CI=0.14-0.93, P=0.035). CONCLUSION: Aberrant overexpression of CXCR4 is associated with worse overall survival, adenocarcinoma histology, distant metastasis, lymph node involvement in NSCLC.

Prognostic role of hepatoma-derived growth factor in solid tumors of Eastern Asia: a systematic review and meta- analysis.

Hepatoma-derived growth factor (HDGF) is a novel jack-of-all-trades in cancer. Here we quantify the prognostic impact of this biomarker and assess how consistent is its expression in solid tumors. A comprehensive search strategy was used to search relevant literature updated on October 3, 2014 in PubMed, EMBASE and WEB of Science. Correlations between HDGF expression and clinicopathological features or cancer prognosis was analyzed. All pooled HRs or ORs were derived from random-effects models. Twenty-six studies, primarily in Eastern Asia, covering 2,803 patients were included in the analysis, all of them published during the past decade. We found that HDGF overexpression was significantly associated with overall survival (OS) (HROS=2.35, 95%CI=2.04-2.71, p<0.001) and disease free survival (DFS) (HRDFS=2.25, 95%CI =1.81-2.79, p<0.001) in solid tumors, especially in non-small cell lung cancer, hepatocellular carcinoma and cholangiocarcinoma (CCA). Moreover, multivariate survival analysis showed that HDGF overexpression was an independent predictor of poor prognosis (HROS=2.41, 95%CI: 2.02-2.81, p<0.001; HRDFS=2.39, 95%CI: 1.77-3.24, p<0.001). In addition, HDGF overexpression was significantly associated with tumor category (T3-4 versus T1-2, OR=2.12, 95%CI: 1.17-3.83, p=0.013) and lymph node status (N+ versus N-, OR=2.37, 95%CI: 1.31-4.29, p=0.03) in CCA. This study provides a comprehensive examination of the literature available on the association of HDGF overexpression with OS, DFS and some clinicopathological features in solid tumors. Meta-analysis results provide evidence that HDGF may be a new indicator of poor cancer prognosis. Considering the limitations of the eligible studies, other large-scale prospective trials must be conducted to clarify the prognostic value of HDGF in predicting cancer survival.

Irradiated fibroblasts promote epithelial-mesenchymal transition and HDGF expression of esophageal squamous cell carcinoma.

Recent evidence suggested that nonirradiated cancer-associated fibroblasts (CAFs) promoted aggressive phenotypes of cancer cells through epithelial-mesenchymal transition (EMT). Hepatoma-derived growth factor (HDGF) is a radiosensitive gene of esophageal squamous cell carcinoma (ESCC). This study aimed to investigate the effect of irradiated fibroblasts on EMT and HDGF expression of ESCC. Our study demonstrated that coculture with nonirradiated fibroblasts significantly increased the invasive ability of ESCC cells and the increased invasiveness was further accelerated when they were cocultured with irradiated fibroblasts. Scattering of ESCC cells was also accelerated by the supernatant from irradiated fibroblasts. Exposure of ESCC cells to supernatant from irradiated fibroblasts resulted in decreased E-cadherin, increased vimentin in vitro and ß-catenin was demonstrated to localize to the nucleus in tumor cells with irradiated fibroblasts in vivo models. The expression of HDGF and ß-catenin were increased in both fibroblasts and ESCC cells of irradiated group in vitro and in vivo models. Interestingly, the tumor cells adjoining the stromal fibroblasts displayed strong nuclear HDGF immunoreactivity, which suggested the occurrence of a paracrine effect of fibroblasts on HDGF expression. These data suggested that irradiated fibroblasts promoted invasion, growth, EMT and HDGF expression of ESCC.

Prognostic significance of lymph node ratio in esophageal cancer.

N staging predicting esophageal cancer patient prognosis has been studied. Lymph node ratio, which is considered to show metastatic lymph node status more accurately, is found to have prognostic significance in several tumors. We investigated whether lymph node ratio (LNR) was associated with the prognosis of esophageal cancer in this study. Esophageal cancer patients who underwent esophagectomy at Qilu Hospital of Shandong University from January 2007 to December 2008 were studied. A total of 209 cases were evaluated in this study. The median disease-free survival (DFS) of this cohort was 35.2 months, and 5-year DFS rate was 32.1%. The median overall survival (OS) was 46.4 months, and 5-year OS rate was 40.0%. Kaplan-Meier survival analysis revealed that patients with LNR higher than 0.2 had significantly poorer DFS (p < 0.001) and OS (p < 0.001) than those with LNR less than 0.2. In a multivariate analysis, LNR was found to be an independent prognostic factor for DFS (p = 0.008, HR 1.863, 95% CI 1.180-2.942) and OS (p = 0.025, HR 1.708, 95% CI 1.068-2.731). N stage (p = 0.028, HR 1.626, 95% CI 1.055-2.506) was also found to be an independent prognostic factors for OS. Subgroups analysis revealed significant difference in OS and DFS rates between different LNR categories within the same N stages (p < 0.05) but not between different N stages within the same LNR category (p > 0.05). LNR was recognized as an independent factor in both OS and DFS in esophageal cancer. Besides, LNR showed a better prognostic value than N stage for esophageal cancer.

BIIB021, a novel Hsp90 inhibitor, sensitizes esophageal squamous cell carcinoma to radiation.

BIIB021 is a novel, orally available inhibitor of heat shock protein 90 (Hsp90) that is currently in phase I/II clinical trials. BIIB021 induces the apoptosis of various types of tumor cells in vitro and in vivo. The aim of this study is to investigate the effect of BIIB021 on the radiosensitivity of esophageal squamous cell carcinoma (ESCC). The results indicated that BIIB021 exhibited strong antitumor activity in ESCC cell lines, either as a single agent or in combination with radiation. BIIB021 significantly downregulated radioresistant proteins including EGFR, Akt, Raf-1 of ESCC cell lines, increased apoptotic cells and enhanced G2 arrest that is more radiosensitive cell cycle phase. These results suggest that this synthetic Hsp90 inhibitor simultaneously affects multiple pathways involved in tumor development and progression in the ESCC setting and may represent a better strategy for the treatment of ESCC patients, either as a monotherapy or a radiosensitizer.

HDGF: a novel jack-of-all-trades in cancer.

HDGF is an important regulator of a broad range of cancer cell activities and plays important roles in cancer cell transformation, apoptosis, angiogenesis and metastasis. Such a divergent influence of HDGF on cancer cell activities derives from its multiple inter- and sub-cellular localizations where it interacts with a range of different binding partners. Interestingly, high levels of HDGF could be detected in patients' serum of some cancers. This review is focused on the role of HDGF in tumorigenesis and metastasis, and provides insight for application in clinical cancer therapy as well as its clinical implications as a prognostic marker in cancer progression.

Detection of esophageal squamous cell carcinoma by cathepsin B activity in nude mice.

BACKGROUND AND OBJECTIVE: Despite great progress in treatment, the prognosis for patients with esophageal squamous cell carcinoma (ESCC) remains poor, highlighting the importance of early detection. Although upper endoscopy can be used for the screening of esophagus, it has limited sensitivity for early stage disease. Thus, development of new diagnosis approach to improve diagnostic capabilities for early detection of ESCC is an important need. The aim of this study was to assess the feasibility of using cathepsin B (CB) as a novel imaging target for the detection of human ESCC by near-infrared optical imaging in nude mice. METHODS: Initially, we examined specimens from normal human esophageal tissue, intraepithelial neoplasia lesions, tumor in situ, ESCC and two cell lines including one human ESCC cell line (Eca-109) and one normal human esophageal epithelial cell line (HET-1A) for CB expression by immunohistochemistry and western blot, respectively. Next, the ability of a novel CB activatable near-infrared fluorescence (NIRF) probe detecting CB activity presented in Eca-109 cells was confirmed by immunocytochemistry. We also performed in vivo imaging of tumor bearing mice injected with the CB probe and ex vivo imaging of resected tumor xenografts and visceral organs using a living imaging system. Finally, the sources of fluorescence signals in tumor tissue and CB expression in visceral organs were identified by histology. RESULTS: CB was absent in normal human esophageal mucosa, but it was overexpressed in ESCC and its precursor lesions. The novel probe for CB activity specifically detected ESCC xenografts in vivo and in vitro. CONCLUSIONS: CB was highly upregulated in human ESCC and its precursor lesions. The elevated CB expression in ESCC allowed in vivo and in vitro detection of ESCC xenografts in nude mice. Our results support the usefulness of CB activity as a potential imaging target for the detection of human ESCC.