Oral Cancer News – Page 300

Discovery may result in new test to determine predisposition to cancer

Source: www.biocompare.com Author: staff Researchers at UCLA's Jonsson Comprehensive Cancer Center have developed an assay that may be used to help identify new genes that can predict a predisposition to cancer. The study, published in the April issue of Radiation Research, was done in yeast and mammalian cells. Cancer cells show persistent genetic instability and the researchers, led by Robert Schiestl, have discovered a mechanism that switches on that genetic instability. If they can uncover and understand the molecular pathways at work in promoting genetic instability, they may be able to develop ways to switch that mechanism off, restoring stability. "We all have several hundred cells in our body that go crazy every day, and they're taken out by our immune system," said Schiestl, a professor of pathology, radiation oncology and environmental health sciences and a Jonsson Cancer Center scientist. "What's important is that those cells don't grow and spread and invade other regions of our body. Cancer cells are able to grow, spread and invade because the continued genetic instability can disturb the cellular program and create a growth advantage. Unfortunately, the immune system is not very effective at taking cancer cells out." The assay determines the efficiency of the repair mechanism when DNA suffers a double-strand break, when both strands in the double helix are severed. These breaks cause genetic instability and are particularly dangerous because they can lead to genome rearrangements or deletions of certain genes that, when gone, result in cancer. "Every cell has double strand [...]

Oral Cancer Foundation News Team - A2009-04-02T13:52:45-07:00April, 2009|Oral Cancer News|

Mucositis versus tumor control: the therapeutic index of adding chemotherapy to irradiation of head and neck cancer

Source: Int J Radiat Oncol Biol Phys, March 20, 2009 Authors: Irwin H Lee and Avraham Eisbruch Purpose: To determine whether the addition of concurrent chemotherapy to radiation for head and neck cancer (HNSCC) improves the therapeutic ratio regarding tumor control vs. mucositis. Methods and Materials: Data were taken from 14 randomized trials of radiation with or without concurrent chemotherapy for HNSCC. Mucositis-bioequivalent dose (mBED) was computed for each study using mBED = D [1 + d/(alpha/beta)] - 0.693(T - Tk)/Tp. An "S-value," relating the increase in the rate of Grade 3 (confluent) mucositis to the increase in mBED with radiation alone, was determined using data from trials of radiation alone with altered fractionation. We then determined the difference in the rate of mucositis and used the S-value to estimate the apparent difference in mBED in the chemoradiation and radiation alone arms for each trial. After accounting for differences in the radiation schedules, we estimated the mBED attributable to adding chemotherapy and compared it with previously published estimates of increases in tumor BED. Results: Computed S-values ranged from 0.4 to 1.7. For S = 1, the mean increase in mBED attributable to chemotherapy was 8.3 Gy(10) (SD = 6.4). The average difference between tumor-BED and mBED was 2.8 Gy(10) (SD = 6.0). Increasing the S-value decreases the estimated increase in mBED due to chemotherapy. Conclusions: Concurrent chemotherapy improves the therapeutic index for radiation of HNSCC. Further refinements are needed in quantifying the therapeutic gain attributable to specific radiosensitizing agents in [...]

Oral Cancer Foundation News Team - A2009-04-02T13:38:55-07:00April, 2009|Oral Cancer News|

High dosage brachytherapy obtains excellent results in head and neck tumors

Source: www.health.am/cr Author: staff High-dosage perioperative brachytherapy (applied within the surgical process) obtains excellent results in the treatment of head and neck tumours, at the same time as reducing the period of radiation. These are the conclusions of research undertaken jointly by three Departments at the University of Navarra Hospital and which was published in the latest issue of Brachytherapy, official journal of the American Society of Brachytherapy. The work describes the application of this new radiotherapy technique to 40 patients between 2000 and 2006. Given the size of the sample, the article is a description of the greatest number of patients treated with high-dosage brachytherapy for head and neck tumours in world medical literature. According to results, after a seven-year follow-up, the illness was controlled in 86% of the cases and the percentage of survival was 52%. In concrete, the research focused on the treatment of tumours in the oral cavity, those affecting the tongue and the floor of the mouth, and those in the oropharyngeal region, such as tumours of the tonsils. Involved in the study was a multidisciplinary team of seven specialists from three departments at the University of Navarra Hospital: the Radiotherapy Department, the Department of Oral and Maxillofacial Surgery and the Ear, Nose and Throat Department. Intensifying radiation dosage As is known, brachytherapy is a radiotherapy treatment involving the placing of radioactive sources within the tumour or nearby. In the case in hand, the work analysed the application of brachytherapy as complementary post-surgery treatment, explained [...]

Oral Cancer Foundation News Team - A2009-03-30T19:22:09-07:00March, 2009|Oral Cancer News|

Genetic Changes Outside Nuclear DNA suspected to trigger more than half of all cancers

Source: www.newswise.com Author: staff A buildup of chemical bonds on certain cancer-promoting genes, a process known as hypermethylation, is widely known to render cells cancerous by disrupting biological brakes on runaway growth. Now, Johns Hopkins scientists say the reverse process — demethylation — which wipes off those chemical bonds may also trigger more than half of all cancers. One potential consequence of the new research is that demethylating drugs now used to treat some cancers may actually cause new cancers as a side effect. “It’s much too early to say for certain, but some patients could be at risk for additional primary tumors, and we may find that they need a molecular profile of their cancer before starting demethylating therapy,” says Joseph Califano, M.D., professor of otolaryngology–head and neck surgery and oncology at Johns Hopkins. The findings, based on studies of normal and cancer cells from human mouth, nose and throat tissue, provide more evidence that important regulators of gene activity occur outside as well as inside DNA in a cell’s nucleus. “While cancer-causing and other mutations alter vital protein-making pathways by rewriting the gene’s DNA code, epigenetic changes affect genes without changing the code itself. The new studies tell us that such changes occur not only when methyl groups bond to a gene’s on-off switch, but also when they come unglued,” says Califano. Califano says sporadic reports of demethylation as a tool in activating cancer-promoting genes led his team to develop a systematic way to discover these epigenetic changes [...]

Oral Cancer Foundation News Team - A2009-03-27T13:11:41-07:00March, 2009|Oral Cancer News|

HPV data may aid vaccine’s effectiveness

Source: health.usnews.com Author: staff The majority of invasive cervical cancers in New Mexico in the 1980s and 1990s contained DNA from human papillomavirus type 16 (HPV16) and HPV type 18 (HPV18), says a new study. It also found that women diagnosed with HPV16- or HPV18-positive cancers were an average of five years younger than those diagnosed with cancers associated with other HPV types. The HPV vaccine (Gardasil) protects against infections caused by HPV16 and HPV18, so the new findings may have implications for future cancer screening programs, the researchers said. The researchers analyzed U.S. data in the Surveillance, Epidemiology and End Results registry and identified 1,213 cases of in situ cervical cancer diagnosed between 1980 and 1999, as well as 808 cases of invasive cervical cancer diagnosed between 1980 and 1999 in New Mexico. HPV16 DNA was found in 53.2 percent of invasive cervical cancers, HPV18 DNA was found in 13.1 percent, and HPV45 DNA in 6.1 percent. HPV16 DNA was found in 56.3 percent of in situ cervical cancers, HPV31 DNA in 12.6 percent, and HPV33 DNA in 8 percent. Patients' median age at diagnosis of invasive cancer with HPV16 and HPV18 was 48.1 years, and 45.9 years, respectively. Median age at diagnosis of invasive cancer with other HPV genotypes was 52.3 years. The study is in the March 24 online issue of the Journal of the National Cancer Institute. "To our knowledge, this is the largest study of its kind conducted in a U.S. population," wrote a team [...]

Oral Cancer Foundation News Team - A2009-04-07T18:18:36-07:00March, 2009|Oral Cancer News|

A vaccine debate once focused on sex shifts as boys join the target market

Source: www.washingtonpost.com Author: Rob Stein When a vaccine designed to protect girls against a sexually transmitted virus arrived three years ago, the debate centered on one question: Would the shots make young girls more likely to have sex? Now the vaccine's maker is trying to get approval to sell the vaccine for boys, and the debate is focusing on something else entirely: Is it worth the money, and is it safe and effective enough? "We are still more worried about the promiscuity of girls than the promiscuity of boys," said Susan M. Reverby, a professor of women's studies and medical history at Wellesley College. "There's still that double standard." The shift in the discussion about Gardasil illustrates the complex interplay of political, economic, scientific, regulatory and social factors that increasingly influence decisions about new types of medical care. For the vaccine, the new dynamic reflects a strategic tack by Gardasil's critics, growing concern about health-care costs, fears about whether medical treatments are being vetted adequately and stubborn biases about gender, experts say. "There is the cost, the safety, the boys versus girls," said Susan F. Wood, a professor of public health at George Washington University. "These are some of the complexities that are going to have to be addressed one way or the other with this vaccine." Gardasil protects against the human papillomavirus, the most common sexually transmitted infection. HPV causes genital warts and, in women, can lead to cervical cancer -- a disease that strikes about 10,000 American women [...]

Oral Cancer Foundation News Team - A2009-03-27T08:30:59-07:00March, 2009|Oral Cancer News|

Oral health, mouthwashes and cancer – what is the story?

Source: www.nature.com Author: David Conway Question: What are the lifestyle, occupational and genetic risk factors for head and neck and oesophageal cancers? Abstract Design Two hospital-based case–control studies were conducted in central and eastern Europe and Latin America. Case/control selection Cases and controls were recruited in Moscow (Russia), Bucharest (Romania) and Lodz and Warsaw (Poland) from 1998 to 2002, and from 1998 to 2003 in Buenos Aires (Argentina), La Habana (Cuba) and the Brazilian towns Rio de Janeiro, São Paulo, Pelotas, Porto Alegre and Goiânia. Incident cases of squamous cell carcinoma of the head and neck (oral cavity, pharynx, larynx) and oesophagus, as well as age- (in quinquennia) and sex frequency-matched controls, were enrolled from 1998 to 2003. Control subjects included residents of the study areas for at least 1 year who were admitted to the same hospitals as the cases or in a comparable catchment area (controls in São Paulo were not recruited from oncology hospitals, and population-based controls were enrolled in Warsaw). Controls were hospitalised for prespecified conditions thought to be unrelated to tobacco use or alcohol consumption. Both studies were coordinated by the International Agency for Research on Cancer according to an identical protocol for both case and control recruitment. Data analysis Data from the central European and Latin American studies were analysed separately. Multivariable logistic regression models, including terms for oral health indicators, age, sex, education, country (central Europe) or centre (Latin America), tobacco pack–years and cumulative alcohol consumption, were used to obtain odds ratios (OR) [...]

Oral Cancer Foundation News Team - A2009-03-27T08:16:46-07:00March, 2009|Oral Cancer News|

Consistent evidence to support the use of xylitol- and sorbitol-containing chewing gum to prevent dental caries

Source: www.nature.com Author: Svante Twetman Question: Are polyol-containing chewing gums effective in reducing dental decay? Abstract Data Sources Studies were identified using searches with Medline, the Cochrane Library and Google Scholar. Study selection Studies were screened independently and were included if they evaluated the effect of one or more chewing gums containing at least one polyol (xylitol, sorbitol, mannitol or maltitol) on caries development, provided they supplied original data generated by means of a comparative design (experimental or observational) and were published in English. Studies were excluded if only an abstract was available or they described only the pharmacodynamic or pharmacokinetic properties of polyols or did not include a no-treatment arm in the study. Randomised trial quality was assessed using the Jadad scale, and the US Preventive Services Task Force criteria to grade the internal validity of individual nonrandomised studies. Data extraction and synthesis Data were extracted independently with only the final outcomes of a study being recorded. It was decided that surface rather than tooth level data would be recorded. Incremental caries was converted to prevented fraction (PF; the proportional reduction in dental caries in experimental groups relative to control groups) for meta-analysis. The studies were grouped according to type of polyol and a separate meta-analysis performed. Data were pooled using both a random and a fixed-effects model and heterogeneity assessed using I2. Results Of 231 articles identified 25 studies were initially selected with 19 being included in the review [six randomised controlled trials (RCT) of which four were [...]

Oral Cancer Foundation News Team - A2009-03-27T08:05:50-07:00March, 2009|Oral Cancer News|

Significant oral cancer risk associated with low socioeconomic status

Source: www.nature.com Author: Saman Warnakulasuriya Abstract Searches were made for studies in Medline, Medline In-Process and other Non-indexed Citations Embase, CINAHL, PsychINFO, CAB Abstracts 1973–date, EBM Reviews, ACP Journal Club, Cochrane Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Management Information Consortium database and Pubmed. Un-published data were also received from the International Head and Neck Cancer Epidemiology Consortium. Study selection Studies were identified independently by two reviewers and were included if their subject was oral and/ or oropharyngeal cancer; they used case–control methodology; gave data regarding socioeconomic status (SES; eg, educational attainment, occupational social classification or income) for both cases and controls; and the odds ratio (OR) for any SES measure was presented or could be calculated. Corresponding authors were contacted where there was an indication that data on oral and/ or oropharyngeal cancers could potentially be obtained from the wider cancer definition or grouping presented in the article, or if SES data were collected but had not been presented in the article. Methodological assessment of selected studies was undertaken. Data extraction and synthesis Countries where the study was undertaken were classified according to level of development and income as defined by the World Bank. Where available the adjusted OR (or crude OR) with corresponding 95% confidence intervals (CI) were extracted, or were calculated for low compared with high SES categories. Meta-analyses were performed on the following subgroups: SES measure, age, sex, global region, development level, time-period and lifestyle factor [...]

Oral Cancer Foundation News Team - A2009-03-27T07:52:33-07:00March, 2009|Oral Cancer News|

Treatment approach using radiofrequency waves heats up

Source: www.cancer.gov/ncicancerbulletin Author: Carmen Phillips It began with chemotherapy-induced sleeplessness and some pie pans. At one point hot dogs were involved. It inspired residents of two small communities 1,300 miles apart, and eventually landed in the labs of two major academic medical centers. And, sadly, just 5 weeks ago, the man who began it all died of treatment complications after a nearly 7-year battle with B-cell leukemia. The story of retired radio engineer and executive John Kanzius and the radiofrequency (RF) generator that he dreamed would one day be part of a highly effective cancer treatment captivated readers of Discover magazine and viewers of “60 Minutes.” Now his invention is maneuvering through the steps needed to demonstrate readiness for clinical testing in humans. “Realistically, we still have hoops to jump through and things to prove,” said Dr. Steven A. Curley from the University of Texas M.D. Anderson Cancer Center, who, along with Dr. David Geller from the University of Pittsburgh Medical Center, has been part of this project since its earliest days. “But I’ll continue to work on this and move it forward because I think it has great promise.” An image of pancreatic cancer cells treated with gold nanoparticles. The cells on the left received 2 minutes of external radiofrequency (RF) field treatment resulting in unstable nuclei and intracellular damage. The cells on the right received no RF treatment and their nuclei and organelles remain intact. (Image courtesy of Dr. Stephen Curley) A Trojan Horse…on Fire RF, Mr. Kanzius [...]

Oral Cancer Foundation News Team - A2009-03-25T08:41:09-07:00March, 2009|Oral Cancer News|