Yearly Archives: 2001

Zila Acquires ViziLite™ – Oral Examination Device

  • 12/5/2001
  • Phoenix
  • PR Newswire

Zila Professional Pharmaceuticals, a division of Zila, Inc. (Nasdaq: ZILA), announced the acquisition of world marketing rights (excluding the Pacific Rim) for the ViziLite(TM) chemiluminescent light technology, which is cleared by the U.S. Food & Drug Administration (FDA) for marketing in the United States. Using the ViziLite Test Kit in combination with a conventional visual oral mucosal examination, healthcare providers can improve the identification, evaluation and monitoring of oral mucosal abnormalities in those at increased risk for oral cancer. The American Cancer Society publication “Cancer Facts & Figures 2001” advises that the risk factors for oral cancer are cigarette, cigar or pipe smoking; use of smokeless tobacco; and excessive consumption of alcohol. Some 25 percent of oral cancer occurs in people with no known risk factors.

The transaction with Trylon Corporation of Torrance, California, involves up to 2,000,000 shares of restricted Zila common stock plus royalties (10 percent in the first five years, and 5 percent in the next five years) on ViziLite product sales.

Trylon continues to market a similar technology, the PapSure(R) screening test, for cervical health. That technology received FDA clearance based on a 13,000-patient clinical study involving 55 sites. Subsequently, in November 2001, the FDA granted clearance for oral application of the ViziLite Test Kit based on evidence of substantial equivalence as demonstrated by testing at the University of California/San Francisco and the University of the Pacific.

Dr. Ralph Green, Vice President and General Manager of Zila Professional Pharmaceuticals, noted, “Zila is pleased to bring this important device to market, even as the Company continues to support a Phase III clinical trial for its patented OraTest(R) oral cancer detection product. In those countries where both products are available, the two technologies are expected to be used in a complementary fashion. The acquisition and marketing of the ViziLite device furthers Zila’s objective of becoming the leader in oral soft tissue management.”

Dr. Green said the patented single-use ViziLite Test Kit will be distributed to U.S. and Canadian dentists exclusively by Patterson Dental Supply, Inc., with an expected U.S. marketing launch at the Chicago Midwinter Dental Meeting, February 22-24, 2002. The product will sell for approximately US$15. Zila intends to develop other international markets for the product, among both dentists and physicians.

Patterson Dental Supply, a subsidiary of Patterson Dental Company (Nasdaq: PDCO), provides a virtually complete range of consumable dental products, clinical and laboratory equipment, and value-added services to dentists, dental laboratories, institutions and other healthcare providers throughout North America. Patterson Dental Supply has the largest direct sales force in the industry, totaling over 1,100 sales representatives and equipment software specialists serving the United States and Canada.

The specific ViziLite wavelengths are absorbed by normal cells and reflected by abnormal cells (due to their higher nucleus-to-cytoplasm ratio). As a result, atypical or dysplastic mucosal abnormalities appear bright white, focusing the health professional’s attention on lesions which might not be seen otherwise and which may be revealed upon biopsy to include cancer and pre-cancer. Lesions identified with the ViziLite product can be monitored, biopsied, treated, or excised, according to the clinician’s judgment. ViziLite is used in conjunction with a traditional head and neck exam.

Prior to examination with the ViziLite device, the patient rinses with a 1% acetic acid solution; this disrupts the glycoprotein barrier of mucosal surfaces, improving visualization of abnormal tissue. The acetic rinse will be produced by Zila Technical Operations, and packaged with the device.

December, 2001|Archive|

Salivary Gland Studies Provide Breakthroughs in Gene Therapy and Tissues Engineering

  • 11/29/2001
  • New York
  • ADA News Releases

The use of gene-transfer technology to repair salivary-gland tissue, allowing a pathway for saliva to flow in patients undergoing radiation therapy for head and neck cancer is possible in principle, disclosed Bruce J. Baum, DMD, PhD.

Dr. Baum, who is chief of the Gene Therapy and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Md., spoke about the breakthrough study to attendees at the American Dental Association’s National Media Conference, held here today.

“We hypothesized that the major impediment to saliva flow from these irradiated, nonsecreting cells was the absence of a pathway for water in their membranes,” he explained. “Our strategy was to transfer a gene for a water channel protein into the radiation-surviving cells that would function as the pathway.”

Each year in the United States, the salivary glands of some 40,000 individuals are exposed to ionizing radiation (IR) during therapy for head and neck cancer. They experience irreversible salivary gland damage. In addition, patients with dry mouth or Sjogren’s syndrome (SS), (an autoimmune disorder characterized by progressive destruction of the lacrimal and salivary glands) also suffer the loss of salivary secretory tissue. Many patients receiving IR or those with SS experience complete gland destruction.

The primary function of salivary glands is to make saliva, the oral fluid that provides the major lubrication and protection for the mouth and upper gastrointestinal tract. In the absence of saliva, patients have difficulty swallowing food, develop mucosal infections like candidiasis, experience rampant dental decay, and suffer considerable pain and discomfort.

Salivary glands also may be useful target sites for gene-based protein replacement therapies (using transferred genes as drugs) with certain systemic deficiency disorders and for local oral diseases, Dr. Baum said.

“One obvious application for this concept is to augment saliva with gene products for upper-gastrointestinal (GI) tract disorders,” he explained. “Salivary secretions saturate the upper-GI tract lining continuously, and we envision both preventive and healing applications. An alternative strategy is to direct needed therapeutic proteins into the bloodstream for systemic use.”

Using rodent models in studies, we showed that salivary gland repairing and therapeutic applications are possible in principle, he said.

“In addition,” Dr. Baum said, “there is a realistic opportunity to develop a first-generation artificial salivary gland suitable for initial clinical testing relatively soon, within about 10 years.”

A pilot program to develop an artificial salivary gland for patients with little to no remaining secretory tissue was initiated several years ago.

November, 2001|Archive|

H. pylori may increase laryngeal cancer risk

  • 11/23/2001
  • Reuters Health

Infection with Helicobacter pylori may increase the risk of developing larynx cancer, researchers from Turkey report.

Dr. Erdinc Aygenc of Ankara Numune Hospital and colleagues screened 26 laryngeal cancer patients and 32 cancer-free subjects for H. pylori infection. About 73% of patients with laryngeal cancer had H. pylori infection, the investigators found, while 41% of those without cancer were infected with the bacterium.

“This study suggests that H. pylori may be an initiator or promoter organism of [larynx cancer], but we cannot say that H. pylori is absolutely the causative agent,” the authors write in the November issue of the journal Otolaryngology-Head and Neck Surgery. For example, they suggest, H. pylori may make laryngeal cells more susceptible to the effects tobacco and alcohol, which are associated with an increase risk of laryngeal cancer. According to the CDC, recent studies have shown an association between long-term H. pylori infection and the development of gastric cancer.

Cancer of the larynx is acommon type of cancer to occur in the head and neck. It is believed to have the same risk factors as oral cancer. Approximately 10,000 Americans will be diagnosed with the disease and roughly 4000 people will die from it in 2001.

Otolaryngol Head Neck Surg 2001;125:520-521.

November, 2001|Archive|

Age and marital status affect morbidity following cancer treatment

  • 11/13/2001
  • Reuters Health

Survivors of head and neck cancer generally report more morbidity, including more sexual dysfunction, than survivors of prostate cancer, but age and marital status appear to influence morbidity in both patient groups, according a study reported at the American Society for Therapeutic Radiation and Oncology annual meeting in San Francisco.

Dr. Charles Scott, lead author and statistician for the American College of Radiology, told Reuters Health the findings suggest “cancer survivors are often ill-prepared for the types of impairments that may accompany aggressive treatment.”

For example, Dr. Scott said that head and neck cancer survivors 65 years of age or older are more likely to have speech impairments, but that “younger survivors are more likely to complain about speech impairment. This is probably because younger survivors are more likely to be employed, which makes communication more important.”

Dr. Scott identified head and neck and prostate cancer survivors from the Radiation Therapy Oncology Group database. There were 460 survivors, 276 of whom agreed to participate in a survey that included questions on quality of life, mood, sexual function, alcohol and tobacco use, and mental status.

Twenty-one percent of the patients had head and neck cancers and 79% were prostate cancer patients. The average age of prostate cancer survivors was 75 years, while the average age for the head and neck cancer survivors was 65 years. Twelve percent of the head and neck cancer patients were African American, as were 16% of the prostate cancer patients.

Older head and neck cancer patients reported fewer chronic effects of disease and treatment, and said they had “greater spiritual well-being” than did younger survivors, Dr. Scott said. But regardless of age, head and neck cancer survivors reported “more illness and anger and more sexual dysfunction.” Among prostate cancer survivors, sexual dysfunction was much more common among married survivors, he said.

The findings suggest the need to “be more open when discussing the long-term effects of aggressive treatment,” Dr. Scott concluded. For example, radiation oncologists tend to “tell prostate cancer patients that there is less sexual dysfunction associated with radiation therapy. That’s true, but what if the patient is in that 20% that does experience sexual dysfunction? I don’t think this possibility is well-addressed.”

He also believes the findings suggest clinicians do not adequately assess the needs of older patients in terms of social interactions and sexual relationships. “These very aggressive treatments can have long-term effects and those need to be addressed before treatment begins,” he said.

November, 2001|Archive|

Pilocarpine improved salivary flow when used during radiation therapy for head and neck cancer patients

  • 11/6/2001
  • MGI PHARMA, INC, Press release

MGI PHARMA, INC., (Nasdaq:MOGN) today announced that the Radiation Therapy Oncology Group (RTOG) presented final results on data regarding the Company’s Salagen(R) Tablets product at this year’s American Society for Therapeutic Radiology and Oncology (ASTRO) meeting held in San Francisco on November 4-8, 2001. The resulting data were discussed by Dr. Charles W. Scarantino, lead investigator of the RTOG study on Salagen Tablets, in his presentation entitled: “A Phase 3 study on the concurrent use of pilocarpine to reduce hyposalivation and mucositis associated with radiation therapy in head an neck cancer patients – final results of RTOG 97-09.”

Study Data

The RTOG presented data showing that use of Salagen(R) Tablets (pilocarpine hydrochloride), MGI’s approved product to treat the symptoms of radiation-induced dry mouth, gave a statistically significant improvement of salivary flow versus placebo in head and neck cancer patients receiving curative radiation therapy. This Phase 3 trial, with 244 eligible patients, showed the pilocarpine group, who received active drug during radiation therapy and up to six months post therapy, had significantly better salivary flow than did the placebo group at end of radiation therapy, and at three-month and six-month follow-up visits. Based on these findings, RTOG concluded that these results provide new support for the use of Salagen Tablets during radiation treatment.

One of the main side effects of radiation therapy for head and neck cancer patients is dry mouth, a condition that can be permanent, according to Dr. Scarantino, a radiation oncologist with the Rex Healthcare Center, Raleigh, NC, and Southeastern Cancer Control Consortium. “We are quite pleased with the results of the study in that by taking pilocarpine three or four times a day in pill form, salivary flow was better than taking placebo,” said Dr. Scarantino. “These were just the results we were hoping for and we believe we can now build on this study in the future. These clinical results are of real importance to cancer patients.”

Dr. Scarantino said that although the drug had a real impact on dry mouth symptoms, it did not have an effect on mucositis, another side-effect of radiation treatment for head and neck cancer. Mucositis is a painful condition associated with inflammation of the mucous membrane.

About Salagen(R) Tablets

MGI developed and markets Salagen Tablets for the treatment of chronic dry mouth symptoms associated with head and neck cancer patients treated with radiation, and with Sjogren’s syndrome patients. MGI has marketed Salagen Tablets in the United States for the cancer-related indication since 1994 and the Sjogren’s syndrome indication since 1998. Salagen Tablets are the first and only prescription medication approved in the United States for treating dry mouth symptoms associated with both of these patient populations. Chronic dry mouth can be a potentially painful and debilitating condition. Salagen Tablets stimulate the exocrine glands, including the salivary glands, to increase their moisture-producing activity.

When head and neck cancer patients receive radiation treatment, this therapy often damages the salivary glands and their ability to produce moisture. Salagen Tablets can stimulate the glands to generate more moisture.

Salagen Tablets do not work for everyone and are contraindicated when uncontrolled asthma is present and when miosis is undesirable. When used for radiation-induced xerostomia, the most common side effect is sweating. Although less frequent, in some people, headache, flushing, and frequent urination can also occur. When used for Sjogren’s syndrome, the most common side effect is sweating, and in some people, chills, flushing, and frequent urination can occur.

**The Radiation Therapy Oncology Group (RTOG) is a federally funded cancer clinical trials cooperative group, which carries out multi-disciplinary research nationwide. It is a major clinical research component of the American College of Radiology.

November, 2001|Archive|

hotodynamic therapy shows efficiency in head and neck cancers

  • 10/31/2001
  • Lisbon, Portugal
  • Peter Hofland, PhD
  • Reuters Health

Temoporfin-mediated photodynamic therapy represents a major advance in the treatment of head and neck cancer, yielding complete response rates comparable with those published for surgery or radiotherapy, according to phase II data reported here last week during ECCO 11, the European Cancer Conference.

Temoporfin-mediated photodynamic therapy (Foscan PDT) is an “effective and well-tolerated treatment” and can be administered without surgery, said Dr. Colin Hopper, a consultant surgeon of the National Medical Laser Centre in London, UK. Dr. Hopper presented the results of a prospective non-randomised phase II study, conducted in 15 centers in 6 countries. The trial examined response rates to Foscan PDT in 114 patients with primary (Tis, T1 and T2) squamous cell carcinoma of the lip, oral cavity, oropharynx or hypopharynx.

Patients with Karnofsky status greater than or equal to 70 received Foscan (0.15 mg/kg IV), followed 4 days later by a single nonthermal illumination of the tumor with red light (20 J/cm?, irradiance 100 mW/cm? , wavelength 652 nm). The initial response was determined after 12 weeks. After 2 years of follow-up, 85% of patients had a complete response (elimination of the tumor) with Foscan PDT alone, and another 6% achieved a complete response with Foscan PDT followed by other adjunctive therapy, including surgery or radiotherapy, giving an overall response rate of 91%. Dr. Hopper reported that in 59% of all cases a complete response rate was biopsy-confirmed. The 1- and 2-year overall survival rates were 90% and 81% respectively, he said. There were 23 non-fatal serious adverse events of which only 5 were related to the treatment (two burns, one photosensitivity reaction, one excessive tissue necrosis, and one increase in pain and dysphagia). Twelve patients died during the first year, but their deaths were not associated with the treatment, the British researcher said. Dr. Hopper explained that “these response rates are comparable to those published for surgery or radiotherapy, but photodynamic therapy has the advantage of not being associated with the major toxicity of radiotherapy nor the tissue loss associated with surgery. It produces excellent cosmetic results, preserving form and function, and does not compromise future treatment options for recurrent, residual or second primary disease.” This is particularly important, because there is a significant risk in head and neck cancer that another cancer will develop at or near the original site, and will require such treatment, he noted.

The most common adverse event noted was local pain at the treatment site, but according to the physicians involved in the study, “this can be managed with standard analgesic treatment.”

October, 2001|Archive|

Animal-Based Nutrients Linked With Higher Risk Of Stomach And Esophageal Cancers

  • 10/31/2001
  • See end of article
  • Yale School of Medicine

Yale School of Medicine researchers have found that a diet high in cholesterol, animal protein and vitamin B12 is linked to risk of a specific type of cancer of the stomach and esophagus that has been increasing rapidly.

The researchers also found that plant-based nutrients such as dietary fiber, dietary beta-carotene, folic acid, vitamin C and vitamin B6 were associated with lower risk of these kinds of cancers. They further found that regular use of vitamin C supplements was associated with a 40 percent reduction in the risk of cancer in the middle and lower parts of the stomach.

The rate of a specific type of esophageal and stomach cancer, known as adenocarcinoma of the esophagus and gastric cardia, has increased by 300 percent since the mid-1970s, according to lead author Susan Mayne, associate professor in the Department of Epidemiology and Public Health at Yale School of Medicine, and associate director of the Yale Cancer Center. To identify reasons for this rapid increase, the United States National Cancer Institute launched a large study at three centers, including Yale, the University of Washington and Columbia University.

The researchers interviewed patients throughout Connecticut, New Jersey and western Washington State and compared the nutrient intake of 1,095 people with stomach or esophageal cancer to that of 687 healthy people in a control group. The team also looked at the participants’ use of nutrient supplements. Their results are published in the October issue of Cancer Epidemiology, Biomarkers & Prevention. “We found that many animal-based nutrients found in foods of animal origin are strongly associated with risk of developing these types of cancers and we were able to identify nutrients that presumably would be protective,” said Mayne. “We also found that regular users of vitamin C supplements were at significantly lower risk of stomach cancer.”

In a separate analysis of these data, the research team found that obesity is strongly linked with risk of these cancers. “The increase in the prevalence of obesity in the United States certainly contributes to the time trends,” said Mayne. “Our results suggest that prevention strategies for these cancers should emphasize increased consumption of plant foods, decreased consumption of foods of animal origin with the possible exception of dairy products, and control of obesity.”

Other researchers on the study include Principal Investigator of the Yale site Harvey A. Risch and Robert Dubrow at Yale; A. Brian West, previously at Yale and now at New York University Medical Center; Wong-Ho Chow and Joseph F. Fraumeni, Jr. of the U.S. National Cancer Institute; Marilie D. Gammon, previously at Columbia University and now at the University of North Carolina; Habibul Ahsan and Heidi Rotterdam of Columbia University; Janet B. Schoenberg, from the New Jersey Department of Health and Senior Services; Thomas L. Vaughan, Diana C. Farrow and Janet L. Stanford from the University of Washington; and William J. Blot from the International Epidemiology Institute.

Note: This story has been adapted from a news release issued by Yale University for journalists and other members of the public.

October, 2001|Archive|

Black Raspberries Show Multiple Defenses in Thwarting Cancer

  • 10/30/2001
  • Ohio
  • Ohio State University

A cup of black raspberries a day may help keep esophageal cancer at bay. Researchers found evidence in rats that black raspberries may both prevent the onset of esophageal cancer as well as inhibit precancerous growth already underway. “Black raspberries are loaded with nutrients and phytochemicals that may prevent the development of cancer,” said Gary Stoner, a study co-author and a professor of public health at Ohio State University.

Stoner, who has also found similar anti-carcinogenic effects with strawberries, said the study results suggest that a daily diet of about 1.4 to 2 cups of fresh berries may be ideal for staving off certain types of cancer. “Although this level is larger than a standard serving size of fruit, it is behaviorally possible,” he said. “The National Cancer Institute recommends that every American eat at least four to six helpings of fruit and vegetables each day. We suggest that one of these helpings be berries of some sort.” The research appears in the journal Cancer Research.

Esophageal cancer is the sixth-leading cause of cancer-related deaths worldwide. The outlook is bleak for those diagnosed with the disease,
five-year survival rates range from 8 to 12 percent.

In the current study, the researchers looked at black raspberries’ ability to halt the onset of cancer, as well as the fruit’s ability to inhibit the progression of precancerous cells to cancer. They conducted experiments on two groups of rats. Some of the rats from each group were injected with NMBA, a chemical carcinogen that induces esophageal cancer. NMBA is one of a group of chemicals called nitrosamines, compounds that have been linked to cancer. Nitrosamines are found in fried bacon, cured meats, tobacco products, beer and certain industrial products.

Rats in the study received NMBA and their diet in a variety of combinations. Some rats were fed a regular diet without raspberries, while others received diets consisting of 5 percent or 10 percent black raspberries. Some were fed raspberries only after receiving NMBA, while others were fed the raspberry diet before and after the injection with the carcinogen. Feeding the rats 5 and 10 percent black raspberries before and after NMBA treatment reduced the number of tumors per rat by 39 and 49 percent, respectively, when compared to animals not fed black raspberries. The fruit also hindered the development of esophageal cancer in individual rats fed black raspberries after NMBA treatment. By week 15 of the study, diets of 5 and 10 percent black raspberries appeared to decrease tumor occurrence and size. At week 25, diets of 5 and 10 percent black raspberries had reduced the number of tumors by an average of 62 percent and 43 percent, respectively. By week 35 of the study, a diet of 5 percent black raspberries had reduced the number of tumors per animal by 66.5 percent, compared with NMBA-treated control mice fed a regular diet.

“When berries were fed to the rats that had been pretreated with NMBA, the diet containing 5 percent black raspberries seemed to inhibit cancer to a greater degree than did a diet of 10 percent berries, a finding that has also emerged in other studies,” Stoner said. “There are certain compounds in berries – and other fruits and vegetables – that in very high doses may actually promote the cancer process. This certainly doesn’t mean to stop eating fruits and vegetables, but don’t overdo it.”

Scientists know that certain foods contain compounds that are likely to protect against specific types of cancer. Past studies suggest that tomatoes help protect against prostate cancer, and that tea consumption may reduce the risk for esophageal cancer. But the mechanism of prevention is still somewhat of a mystery.

Raspberries are chock full of compounds with potentially anti-carcinogenic effects, including vitamins, minerals and plant nutrients such as anthocyanins – strong antioxidants that give berries their color. “We’re currently looking at berry extracts and testing the ability of these extracts to inhibit the development and progression of cancer,” Stoner said. “As we identify these extracts, we will then try to pinpoint the specific compounds in them that help inhibit cancer.”

In the current study, Stoner and his colleagues tested the effects of ellagic acid – a plant nutrient shown to have protective effects against esophageal cancer. Berries are rich in ellagic acid. But the researchers found that ellagic acid alone could not account for the fruit’s ability to inhibit cancer. “One or more additional berry components are undoubtedly contributing to the fruit’s anti-cancer effects,” Stoner said. He chose black raspberries for this study because previous studies had shown that ellagic acid inhibited carcinogen-induced esophageal and colon cancer in animals. He and his colleagues then tested a series of fruits for their ellagic acid content, finding that berries contained the highest amount.

“We then decided to take a food-based approach to cancer prevention and began testing the berries’ ability to inhibit chemically-induced esophageal and colon cancer,” Stoner said. “Sure enough, we found that freeze-dried berries were highly protective in the esophagus and colon. But we also found that they were ineffective in protecting against lung cancer. “The protective compounds in berries may not be absorbed into the blood stream and delivered to the lungs in high enough amounts to be protective. We do believe that they protect the esophagus and colon because they are absorbed by these organs as the food moves through the digestive tract.”

The study was funded by a grant from the Ohio Department of Agriculture and the National Cancer Institute.

Stoner co-authored the study with Laura Kresty, Mark Morse, Peter Carlton, Ashok Gupta, Michelle Blackwood and Charlotte Morgan, all of Ohio State, and Jerry Lu of the M.D. Anderson Cancer Center at the University of Texas.

Note: This story has been adapted from a news release issued by Ohio State University for journalists and other members of the public. If you wish to quote from any part of this story, please credit Ohio State University as the original source.

October, 2001|Archive|

Applied Orally, Missle Defense Technology May Work. A New High-Tech Test Can Help Target Early Mouth Cancers

  • 10/25/2001
  • Jennifer Huget
  • The Washington Post

It’s not every day a dentist gets to play Star Wars. But that’s not why more than 30,000 dentists in the United States are deploying OralCDx, a new diagnostic tool that incorporates technology developed as part of the Strategic Defense Initiative. OralCDx, launched nationwide last year, offers dentists a better shot at catching oral cancer lesions while there’s time to treat them.

About 8,000 Americans die of oral cancer each year. Nearly 30,000 new cases are diagnosed annually, and only 53 percent of all oral cancer victims are still alive five years after diagnosis. But among those in whom the disease — which is most common among tobacco users and heavy drinkers and is more common among men, people over 40 and African Americans — is caught early, five-year survival rates soar to 88 percent.

The problem has been that early stage oral cancer lesions look like benign mouth lesions, even to vigilant dentists. By the time a lesion becomes obviously, visibly cancerous, successful treatment is difficult.

In the past, dentists have had to make tough choices: Should they perform traditional scalpel biopsies (or refer patients to oral surgeons for the procedure) on all of the estimated 5 percent to 15 percent of their patients who have oral lesions? At up to $300 per procedure, plus lab analysis fees of up to several hundred dollars, scalpel biopsy is costly. Plus, the procedure requires the uncomfortable surgical removal of chunks of tissue, and only a small number of the lesions caught in this net turn out to be cancerous.

OralCDx, produced by New York-based OralScan Laboratories Inc., helps dentists determine which lesions warrant a biopsy. When faced with a lesion that is even remotely suspicious, the dentist gathers three layers of tissue with a device that looks a bit like a tiny toilet brush. Having completed this painless procedure, he swabs a slide and mails it off to OralCDx.

The software at the heart of the OralCDx system is adapted from a program designed for the Strategic Defense Initiative, the ambitious missile defense system championed by President Reagan in the 1980s. With it, OralCDx can spot a cancerous cell even if it is partially obscured by other cells, much in the way that the SDI system is supposed to sort decoys from real missiles. Having identified, with the computer’s help, any suspicious cells, the OralCDx pathologist faxes a report to the dentist, who can either proceed with a scalpel biopsy or tell the patient to rest easy.

At $65 for the lab work plus the typical procedure fee of $100 to $150 charged by the dentist (who gets the test kits for free from OralScan), the new system might be pricey for the 108 million Americans without dental insurance. OralScan points out, though, that many medical insurance plans cover the cost.

While the SDI’s ability to distinguish real targets from decoys remains unproven, OralCDx, which received an American Dental Association Seal of Acceptance in October, is backed by a study published in the Journal of the American Dental Association in 1999. In that study, the system accurately detected 100 percent of the cancerous and precancerous lesions included in the trial and even picked up signs of cancer lesions that clinicians hadn’t considered suspicious.

No word so far, though, as to whether OralCDx can be fooled by Mylar balloons.

October, 2001|Archive|

Gene-Therapy Fights Oral Cancer

  • 5/16/2001
  • San Francisco, CA
  • Daniel Q. Haney
  • Associated Press

A gene-therapy mouthwash shows promise of warding off oral cancer by killing ominous growths before they turn malignant.

The idea is to attack these pre-malignant patches by unleashing viruses programmed to kill cells with cancer-causing genes.

The first study of this approach is still under way, but doctors said yesterday that it appears to work in at least some patients, making ominous patches in their mouths disappear completely. In the past 20 years, scientists have learned that all cancer arises from genetic defects that accumulate during a lifetime, causing cells to grow rampantly and spread in the body.

With this insight came the belief that it might be possible to target these bad genes to stop cancer. This was once one of the hottest ideas in cancer research. But enthusiasm cooled as scientists hit roadblocks. One was reaching and killing every cancer cell. Even reaching 80 percent of the cells is not good enough, because the rest keep growing.

So researchers decided that the mouth might be an excellent target for gene therapy, since the problem can be so easily reached. “The advantage is that it’s where we can see it,” said Dr. Ezra Cohen of the University of Chicago. “We can get to it, and the therapy does not get absorbed into the body.”

White or red patches in the mouth, so-called dysplastic lesions, frequently are a forerunner of malignancy and are common in smokers and heavy drinkers. These cells usually contain mutant genes, and one of the most common is a broken p53 gene. This tumor-suppressor gene ordinarily kills cells that contain dangerous mutations. Without a working copy of this gene, growths can become cancerous.

The treatment consists of adenovirus, a kind of cold virus, that lacks a working copy of one gene that ordinarily allows the virus to infect cells with good p53 genes. Without this gene, it should infect only cells with damaged p53 genes. In theory, the crippled virus will enter these precancerous cells and kill them.

May, 2001|Archive|