Patients with head and neck cancer who have never smoked have much better survival rates after radiation therapy than patients with a history of smoking, new research from UC Davis Cancer Center has found.
The study by Allen M. Chen and colleagues in the UC Davis radiation oncology and otolaryngology departments is among the first of its kind to examine prognosis differences based on smoking history in patients with head and neck cancer who are treated with radiation therapy.
The study, published online in American Journal of Clinical Oncology, found that patients with a history of smoking were more likely to die from their disease and more likely to experience a recurrence after radiation therapy than those without a smoking history.
“There is something unique about the biology of head and neck cancers among non-smokers that makes them more amenable to cure by radiation therapy,” said Chen. “These tumors just melt after a few doses of radiation. If we could understand why, there would be important implications for new drugs and treatments.”
Chen suspects one possible explanation for the difference in response to radiation is human papillomavirus (HPV), a sexually transmitted disease that has been highly associated with head and neck cancer in people who have never smoked.
“The most common theory is that these tumors express a characteristic viral antigen on the cell surface that makes the immune system recognize the cancers more readily, which may enhance the effects of radiation,” he said. “Another theory is that patients who have never smoked and who have HPV-related tumors have fewer mutations in key genes that are critical for radiation response.”
Chen compared 70 patients treated at the UC Davis Department of Radiation Oncology with newly diagnosed, non-metastatic squamous cell carcinoma of the mouth and throat who had a history of smoking with 70 patients with similar diagnoses who reported they had never smoked. Patients who continued to smoke during treatment were not included in the study. Subjects were evenly matched based on age, gender, ethnicity, primary tumor site, disease stage and treatment history.
The analysis found that 14 of the 70 never-smokers experienced a recurrence of their disease compared to 26 patients who had a history of smoking. In addition, 82 percent of never-smokers were disease-free after three years compared to 65 percent of patients who had smoked. Also, those who had never smoked had a lower incidence of complications related to treatment than those who had smoked.
Chen said the next step in the research is to identify biological or genetic differences among smokers and never-smokers diagnosed with head and neck cancers and treated with radiation therapy that might account for the differences in prognosis.
“We are in the process of conducting several laboratory experiments designed to better understand why cancers arising from never smokers are so exquisitely radiosensitive,” Chen said.
UC Davis Cancer Center is the only National Cancer Institute- designated center serving the Central Valley and inland Northern California, a region of more than 6 million people. Its top specialists provide compassionate, comprehensive care for more than 9,000 adults and children every year, and offer patients access to more than 150 clinical trials at any given time. Its innovative research program includes more than 280 scientists at UC Davis and Lawrence Livermore National Laboratory. The unique partnership, the first between a major cancer center and national laboratory, has resulted in the discovery of new tools to diagnose and treat cancer. Through the Cancer Care Network, UC Davis is collaborating with a number of hospitals and clinical centers throughout the Central Valley and Northern California regions to offer the latest cancer-care services.
Foods of the future
15.08.2018 | Georg-August-Universität Göttingen
New antibody analysis accelerates rational vaccine design
09.08.2018 | Scripps Research Institute
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
15.08.2018 | Physics and Astronomy
15.08.2018 | Earth Sciences
15.08.2018 | Physics and Astronomy