Fluorescence Visualization Detection of Field Alterations in Tumor Margins of Oral Cancer Patients

11/24/2006 Vancouver, British Columbia, Canada Catherine F. Poh et al. Clinical Cancer Research Vol. 12, 6716-6722, November 15, 2006 Purpose: Genetically altered cells could become widespread across the epithelium of patients with oral cancer, often in clinically and histologically normal tissue, and contribute to recurrent disease. Molecular approaches have begun to yield information on cancer/risk fields; tissue optics could further extend our understanding of alteration to phenotype as a result of molecular change. Experimental Design: We used a simple hand-held device in the operating room to directly visualize subclinical field changes around oral cancers, documenting alteration to fluorescence. A total of 122 oral mucosa biopsies were obtained from 20 surgical specimens with each biopsy being assessed for location, fluorescence visualization (FV) status, histology, and loss of heterozygosity (LOH; 10 markers on three regions: 3p14, 9p21, and 17p13). Results: All tumors showed FV loss (FVL). For 19 of the 20 tumors, the loss extended in at least one direction beyond the clinically visible tumor, with the extension varying from 4 to 25 mm. Thirty-two of 36 FVL biopsies showed histologic change (including 7 squamous cell carcinoma/carcinomas in situ, 10 severe dysplasias, and 15 mild/moderate dysplasias) compared with 1 of the 66 FV retained (FVR) biopsies. Molecular analysis on margins with low-grade or no dysplasia showed a significant association of LOH in FVL biopsies, with LOH at 3p and/or 9p (previously associated with local tumor recurrence) present in 12 of 19 FVL biopsies compared with 3 of 13 FVR biopsies (P = [...]

2009-04-13T09:16:32-07:00November, 2006|Archive|

Cyclooxygenase-2 Inhibition Suppresses {alpha}v{beta}6 Integrin-Dependent Oral Squamous Carcinoma Invasion

11/22/2006 United Kingdom Staff Cancer Res., November 15, 2006; 66(22): 10833-42 Worldwide oral squamous cell carcinoma (OSCC) represents about 5.5% of all malignancies, with approximately 30,000 new cases each year in the United States. The integrin alpha(v)beta(6) and the enzyme cyclooxygenase-2 (COX-2) are implicated in OSCC progression and have been suggested as possible therapeutic targets. Each protein also is reported to identify dysplasias at high risk of malignant transformation, and current clinical trials are testing the efficacy of nonsteroidal anti-inflammatory drugs (NSAID) at preventing OSCC development. Given the probable increased expression of alpha(v)beta(6) and COX-2 in OSCC and the inhibition of several integrins by NSAIDs, we investigated whether NSAIDs affected alpha(v)beta(6)-dependent cell functions. We found that expression of both alpha(v)beta(6) and COX-2 was significantly higher in OSCC compared with oral epithelial dysplasias. Neither protein preferentially identified those dysplastic lesions that became malignant. Using OSCC cell lines, modified to express varying levels of alpha(v)beta(6), we assessed the effect of COX-2 inhibition on cell invasion. We found that the COX-2 inhibitor NS398 inhibited specifically alpha(v)beta(6)-dependent, but not alpha(v)beta(6)-independent, OSCC invasion in vitro and in vivo, and this effect was modulated through prostaglandin E(2) (PGE(2))-dependent activation of Rac-1. Transient expression of constitutively active Rac-1, or addition of the COX-2 metabolite PGE(2), prevented the anti-invasive effect of NS398. Conversely, RNA interference down-regulation of Rac-1 inhibited alpha(v)beta(6)-dependent invasion. These findings suggest that COX-2 and alpha(v)beta(6) interact in promoting OSCC invasion. This is a novel mechanism that, given the ubiquity of alpha(v)beta(6) expression by head and [...]

2009-04-13T09:16:04-07:00November, 2006|Archive|

BC Cancer Agency study sheds new light on controlling oral cancer

11/22/2006 Vancouver, Canada BC Cancer Agency Vancouver, B.C. - A study recently published in Clinical Cancer Research takes BC Cancer Agency researchers into the operating room to shed new light on oral cancer. Using a hand-held blue light device that could chance clinical practices, pioneered at the BC Cancer Agency, researchers examined oral cancer patients for pre-cancerous and cancerous lesions that are not visible to the naked eye. The light device makes cancerous lesions that look like normal tissue under regular white light appear as dark patches. "This light device could revolutionize surgical practice, allowing us to see previously hidden changes at the edge of cancers during surgery," says Dr. Scott Durham, surgeon, Vancouver General Hospital. The light device detected dark patches that extended beyond the tumour and its surgical boundary in 19 of the 20 patients involved in the study. Biopsies taken from the tissue outside the surgical boundary confirmed the existence of both cancerous and abnormal cells. Recognizing the tissue surrounding oral cancers is at high-risk for developing cancer, surgeons generally remove an arbitrary width of 10 millimeter or more of normal-looking tissue surrounding the tumour, if anatomically possible. However, the study has shown that this approach still fails to completely remove the high-risk tissues in many patients. "By using the light device, we were able to see that cancerous and pre-cancerous lesions are not evenly distributed around the tumour," says Dr. Catherine Poh, Oral Pathology Specialist at the BC Cancer Agency and Principal Investigator of the study. [...]

2009-04-13T09:15:32-07:00November, 2006|Archive|

High HPV Concentrations, Cigarette Smoking Significantly Raise Risks of Later Cervical Cancer

11/21/2006 Philadelphia, PA staff PharmaLive (www.medadnews.com) Cigarette smoking and concurrent infection with high levels of the virus associated with cervical cancer can increase cancer risk by as much as 27 times, according to a study published in the November 2006 issue of Cancer Epidemiology, Biomarkers & Prevention. Anthony Gunnell, a medical biostatistician and epidemiologist and colleagues at the Karolinska Institutet in Stockholm reviewed the medical exams of women with non-invasive cervical cancer in situ (the most common type) and cancer-free women in one of the largest studies to date to examine the relationships between smoking and the human papilloma virus (HPV). The virus and smoking behavior have long been associated with the disease, but not enough evidence has come forth to determine how either may cause the disease. Gunnell’s study, in fact, suggests that both may create a biochemical synergy that propels the disease. The researchers looked at “Pap” smear examination data from 105,760 Swedish women and identified 499 women with cervical cancer in situ, along with 499 cancer-free women as controls. For these women, they compared their smoking behavior with concentrations (known as viral load) of HPV-16, the viral strain most associated with cervical cancer. The researchers found that a combination of high viral loads and smoking during the time they were initially examined resulted in very high risk of later cervical cancer. “We were surprised to see this dramatically increased risk among women with high viral loads who smoked,” Gunnell said. Among their findings: - Women who smoked [...]

2009-04-13T09:14:34-07:00November, 2006|Archive|

Shortage of NHS dentists is cancer case risk

11/20/2006 Lancashire, England Jane Lavender (www.thisislancashire.co.uk) A leading Bolton dentist is blaming a lack of access to NHS dental services for the soaring rates of mouth cancer. Chris Brooks, an NHS dentist and president of Bolton's Dental Society, believes people in the most high risk groups - those living in the most deprived communities and from ethnic minorities - are increasingly likely to develop the cancer because they cannot visit an NHS dentist. Smoking and drinking alcohol are two of the main contributing factors in developing mouth cancer. Ethnic minorities, especially those from the Asian community, who traditionally have difficulty seeing an NHS dentist, are also at very high risk because they chew Paan, a leaf snack used as a breath freshener, which can also cause oral cancer. Mr Brooks said: "Access to dental services is extremely important, but the groups that are most likely to be affected, such as those in deprived areas and those in ethnic minorities, are the ones who can't get an NHS dentist. "Mouth cancer is very treatable in the early stages, but not when it's advanced and could well have spread. If more people had access to an NHS dentist then the rates would reduce." Cases of mouth cancer have doubled in Bolton over the past 10 years. The number of people being diagnosed with the disease now matches that of those told they have skin cancer. In 1996, just eight people were told they had mouth cancer, but that figure reached 15 in [...]

2009-04-13T09:13:43-07:00November, 2006|Archive|

Monoclonal Antibody Shows Promising Results

11/20/2006 Las Tunas, Cuba Orfilio Pelaez Periodico (www.periodico26.cu) Results from recent clinical trials made with the humanized monoclonal antibody HR3, obtained by specialists from the Center for Molecular Immunology (CIM), show promise in the possibility of using this antibody in the treatment of head and neck tumors. Dr. Agustin Lage, director of the CIM, broke the good news at a press conference during the opening session of an Immunotherapy Workshop taking place simultaneously with the Biotechnology Havana 2006 convention. Dr. Lage said that test results received in trials held in Cuba and other countries such as India, China and Germany, showed a significant reduction in the malignant lesion of certain brain tumors (almost all of them non-treatable by surgery ) and of pharyngeal carcinomas. This humanized monoclonal antibody obtained the Gold Medal awarded by the World Organization of Intellectual Property, and is the first ever registered in Cuba for the treatment of advanced stages of cancer in the head and neck. The antibody inhibits cancer cells from multiplying by blocking the receptor of the EGF (Epidermal Growth Factor) a protein associated with the proliferation of cancer cells, metastasis and the invasion of healthy tissues. The antibody is administered together with other traditional therapeutic procedures.

2009-04-13T09:12:49-07:00November, 2006|Archive|

Cuba Leads Anti-Cancer Vaccines

11/16/2006 Havana, Cuba staff Prensa Latina (www.plenglish.com) In the coming years Cuba could present a new group of therapeutic vaccines against different types of cancer, foresaw the Director of the Cuban Center of Molecular Immunology (CIM) Agustin Lage. According to the scientist, the monoclonal antibody against cancer HR3 is presently among the products in advanced development by that entity. Participants in the 2006 International Immunotherapy Event taking place in the Cuban capital exchanged experiences with the results of the clinical tests of HR3 in China and India, where it has helped to treat head and neck tumors and pharynx carcinoma. Similarly the institution works on clinical tests of the antibody T1, a provisional name for the treatment of self-immune diseases, and of another against breast cancer. In addition, the CIM has another five similar products under pre-clinical tests. Therapeutic vaccines against cancer have been relatively unpopular in world clinical practice, but Lage highlighted that Cuba counts on a group of them in different test phases on humans.

2009-04-13T09:12:04-07:00November, 2006|Archive|

Hydrogen Peroxide Tooth Whiteners Do Not Cause Cancer, Study Finds

11/16/2006 Chevy Chase, MD press release ScienceDaily.com Common tooth whitening products, which have been used by millions of people, are found to be safe and do not increase the risk of oral cancer when used as directed. This exhaustive review of the literature, including numerous unpublished clinical studies involving over 4,000 human subjects, appeared in an article by Dr. Ian Monroe entitled, " Use of Hydrogen Peroxide-Based Tooth Whitening Products and it Relationship to Oral Cancer," published in Journal of Esthetic and Restorative Dentistry. Clinical and laboratory data on tooth whitening products show no evidence for the development of oral cancer or of other effects that could be associated with increased oral cancer risk. Exposures to hydrogen peroxide, generally the effective ingredient in tooth whiteners, are too low and of too short of a duration (30–60 minutes) to cause any oral tissue changes that could enhance risks for oral cancer development. Concentrations of hydrogen peroxide rapidly decline to near undetectable levels usually within 15 to 60 minutes. Given the likely use of tooth whitening products by smokers, the review also sought to examine any possibility of increased oral cancer development due to combined exposure (i.e., hydrogen peroxide and carcinogenic agents that are present in cigarette smoke). A possible combined-effect, as seen in the increased likelihood of lung cancer development in smokers also exposed to asbestos, was found to be groundless with regards to bleaching and smoking and further illustrates the relative safety of tooth whitening products.

2009-04-13T09:10:56-07:00November, 2006|Archive|

Binge drinking causes cancer

11/16/2006 London, UK staff The Sun (www.thesun.co.uk) Binge drinking is fuelling a rise in rates of mouth cancer, a leading expert warned today. Professor Saman Warnakulasuriya blamed excessive boozing for an increase in cases of the deadly disease. Mouth cancer kills one person every five hours in the UK, and the number of new cases is increasing each year. Prof Warnakulasuriya is Professor of Oral Medicine and Experimental Oral Pathology at Guy’s, King’s and St Thomas’ Dental Institute in London. He spoke out at at the launch of Mouth Cancer Awareness Week, a campaign to help victims catch the disease in its early stages. Early detection greatly increases chances of survival. Prof Warnakulasuriya said that rising cases of the illness were down to “recent increases in alcohol consumption, taken together with alarming levels of binge drinking by young people”. Dr Nigel Carter, chief executive of the British Dental Health Foundation, said: “Early detection of mouth cancer increases survival chances from just one in two to around nine out of 10, so increased awareness is vitally important. “Ulcers that won’t heal, lumps or red or white patches in the mouth can be common early symptoms of mouth cancer, so it is very important that people check their mouths on a regular basis, with a visit to a dentist or doctor following should they notice any changes.” Heavy drinking and smoking increase the risk of mouth cancer by up to 30 times. Chewing tobacco - or other substances like paan, areca nut [...]

2009-04-13T09:10:29-07:00November, 2006|Archive|

Severe Oral Mucositis Occurs Similarly in Patients Treated With Conventional or Intensity-Modulated Radiation Therapy

11/16/2006 Philadelphia, PA Ed Susman DocGuide.com Treatment of patients with head and neck cancer -- whether with conventional radiation or with intensity-modulated radiation therapy -- leave a majority of patients with severe oral mucositis, researchers reported here at the American Society for Therapeutic Radiology and Oncology (ASTRO) 48th annual meeting. There appears to be no significant difference in the proportion of patients who require hospitalization, opioid analgesics or gastronomy tubes among patients treated with intensity-modulated radiation therapy or conventional radiology, said Linda Elting, DrPH, professor of epidemiology, University of Texas School of Public health, Houston, Texas. Dr. Elting and colleagues undertook 2 studies; a retrospective record review of 160 consecutive, newly diagnosed patients with cancers of the oral cavity and oropharynx who were clinically scored for oral mucositis. Mucositis was scored on a scale of 0 to 4 --with 0 representing no oral mucositis and 4 representing "alimentation not possible." The second study was performed prospectively at 6 centers among 75 newly diagnosed patients with cancers of the oral cavity and oropharynx who were assessed for severity of oral mucositis 5 times over 6 weeks. In the retrospective study, 69% of 29 patients who received intensity-modulated radiation therapy and chemotherapy and 84% of 50 patients who received with intensity-modulated radiotherapy and chemotherapy experienced grade 3 or grade 4 mucositis. Mucositis occurred in 70% of 48 patients given intensity-modulated radiation therapy without chemotherapy and in 76% of 34 patients who received conventional radiation without chemotherapy. In her poster presentation on November [...]

2009-04-13T09:10:01-07:00November, 2006|Archive|
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