Purpose: Despite aggressive chemotherapy, radiotherapy, surgery, or combination approaches, the survival rate of patients with esophageal cancer remains poor. Recent studies have suggested that constitutive activation of the Hedgehog (Hh) pathway in cancers of the digestive tract may contribute to the growth and maintenance of cancer. However, the relationship between Hh signaling and therapeutic response is unknown. Experimental Design: The expression and temporal kinetics of Hh signaling and proliferation biomarkers after chemoradiotherapy were examined in esophageal tumor xenografts. Additionally, immunohistochemical analysis of Sonic Hh (Shh) and Gli-1 expression were done on residual tumors from patients who received neoadjuvant chemoradiotherapy followed by surgery. The ability of Shh signaling to induce proliferation in esophageal cell lines was determined. Expression of cell cycle checkpoint proteins was analyzed in cells in which Hh signaling was activated or inhibited. We further determined the effect of inhibiting Hh signaling in sensitizing esophageal tumors to radiation. Results: We showed that the Shh signaling pathway was extensively activated in esophageal cancer xenografts and residual tumors after chemoradiotherapy and the temporal kinetics of Hh signaling preceded increases in proliferation biomarker expression and tumor size during tumor regrowth. We further showed that Hh pathway activity influences proliferation rates of esophageal cancer cell lines through up-regulation of the G 1 -cyclin-Rb axis. Additionally, we found that blocking Hh signaling enhanced radiation cytotoxicity of esophageal cancer cells. Conclusions: These results suggest that activation of the Hh pathway may promote tumor repopulation after chemoradiotherapy and contribute to chemoradiation resistance in esophageal cancers.
The technological revolution in imaging during recent decades has transformed the way image-guided radiation therapy is performed. Anatomical imaging (plain radiography, computed tomography, magnetic resonance imaging) greatly improved the accuracy of delineating target structures and has formed the foundation of 3D-based radiation treatment. However, the treatment planning paradigm in radiation oncology is beginning to shift toward a more biological and molecular approach as advances in biochemistry, molecular biology, and technology have made functional imaging (positron emission tomography, nuclear magnetic resonance spectroscopy, optical imaging) of physiological processes in tumors more feasible and practical. This review provides an overview of the role of current imaging strategies in radiation oncology, with a focus on functional imaging modalities, as it relates to staging and molecular profiling (cellular proliferation, apoptosis, angiogenesis, hypoxia, receptor status) of tumors, defining radiation target volumes, and assessing therapeutic response. In addition, obstacles such as imaging-pathological validation, optimal timing of post-therapy scans, spatial and temporal evolution of tumors, and lack of clinical outcome studies are discussed that must be overcome before a new era of functional imaging-guided therapy becomes a clinical reality.
Proton therapy does not appear to reduce OAR volumes receiving high dose. Protons are able to reduce the treated volume receiving low-intermediate doses, however the clinical significance of this remains to be determined in future investigations.
Purpose: Early identification of esophageal cancer patients who are responding or resistant to combined chemoradiotherapy may lead to individualized therapeutic approaches and improved clinical outcomes. We assessed the ability of 3 ¶-deoxy-3 ¶- Conclusions: FLT-PET is suitable and more specific than FDG-PET for depicting early reductions in tumor proliferation that precede tumor size changes after chemoradiotherapy.
Around the world, recommendations for cancer treatment are being adapted in real time in response to the pandemic of COVID-19. We, as a multidisciplinary team, reviewed the standard management options, according to the Barcelona Clinic Liver Cancer classification system, for hepatocellular carcinoma. We propose treatment recommendations related to COVID-19 for the different stages of hepatocellular carcinoma (ie, 0, A, B, and C), specifically in relation to surgery, locoregional therapies, and systemic therapy. We suggest potential strategies to modify risk during the pandemic and aid multidisciplinary treatment decision making. We also review the multidisciplinary management of intrahepatic cholangiocarcinoma as a potentially curable and incurable diagnosis in the setting of COVID-19.
Hepatocellular carcinoma is the fourth leading cause of cancer-related death worldwide.
Depending on the extent of disease and competing comorbidities for mortality, multiple
liver-directed therapy options exist for the treatment of hepatocellular carcinoma.
Advancements in radiation oncology have led to the emergence of stereotactic body
radiation therapy as a promising liver-directed therapy, which delivers high doses of
radiation with a steep dose gradient to maximize local tumor control and minimize
radiation-induced treatment toxicity. In this study, we review the current clinical data
as well as the unresolved issues and controversies regarding stereotactic body radiation
therapy for hepatocellular carcinoma: (1) Is there a radiation dose–response relationship
with hepatocellular carcinoma? (2) What are the optimal dosimetric predictors of
radiation-induced liver disease, and do they differ for patients with varying liver
function? (3) How do we assess treatment response on imaging? (4) How does stereotactic
body radiation therapy compare to other liver-directed therapy modalities, including
proton beam therapy? Based on the current literature discussed, this review highlights
future possible research and clinical directions.
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