Monthly Archives: March 2003

More Evidence Curry Ingredient May Fight Cancer

  • 3/29/2003
  • Houston, Texas
  • Reuters News Service / SOURCE: Blood 2003;101:1053-1062.

An ingredient in the curry spice turmeric may help suppress and destroy a blood cancer, early lab research shows–suggesting yet another health benefit from this long-heralded substance. Turmeric is a common ingredient in Indian food and yellow mustard. Its active ingredient is curcumin, which gives turmeric its yellow color. Adding curcumin to human cells with the blood cancer multiple myeloma, Dr. Bharat B. Aggarwal of the University of Texas MD Anderson Cancer Center in Houston and his colleagues found, stopped the cells from replicating. And the cells that were left died.

Although the study did not test the benefits of curcumin in patients, previous research has shown the substance may fight other types of cancers, Aggarwal told Reuters Health. Studies have also shown that curcumin, even in large quantities, does not produce any known side effects in humans, the researcher noted. Based on this evidence, Aggarwal recommended that people with cancer should try to eat more curcumin, if possible. “Whichever way you can take it, as much as possible,” he said. Aggarwal added, however, that further research is needed to determine how much curcumin people need to get the most benefits.

Previous laboratory research has shown that curcumin may have antioxidant and anti-inflammatory properties, as well as treat and prevent cancer. Patients with multiple myeloma are in particular need of new treatments, Aggarwal and his colleagues point out in their report in the journal Blood. Once diagnosed with this blood cancer, patients typically live between two and three years.

During the current study, the researchers added curcumin to a sample of human cells with multiple myeloma, and observed how the substance influenced the progression of the cancer. In an interview, Aggarwal explained that curcumin appears to block the activity of a “light switch” called nuclear factor kappa-B (NF-kappaB). When turned on, he said, NF-kappaB appears to then turn on many genes linked to cancer. Examining the multiple myeloma cells before adding the curcumin, the authors found that virtually all contained activated forms of NF-kappaB.

After adding curcumin, however, NF-kappaB activity was inhibited, the multiple myeloma cells no longer replicated and the remaining cells died, Aggarwal said. Aggarwal explained that it is somewhat difficult to study the effects of curcumin in a large number of patients because these experiments cost a lot of money. Funding for similar research is often provided by a company that stands to benefit if the tested treatment works; however, in the case of curcumin, a natural compound, no company can reap the benefits if turmeric shows itself to be an effective anti-cancer drug, he said. However, Aggarwal said that he hopes the new findings and previous research suggesting curcumin’s benefits inspire other researchers to continue investigating its properties.

OCF NOTE:
The following is the actual science behind this new article for those interested. Taken from the publication Cancer Reasearch. (Cancer Res 2002 Oct 1;62(19):5451-6)

Curcumin activates the aryl hydrocarbon receptor yet significantly inhibits (-)-benzo(a)pyrene-7R-trans-7,8-dihydrodiol bioactivation in oral squamous cell carcinoma cells and oral mucosa.

Authors: Rinaldi AL, Morse MA, Fields HW, Rothas DA, Pei P, Rodrigo KA, Renner RJ, Mallery SR. College of Dentistry, Departments of Orthodontics and Oral Maxillofacial Surgery and Pathology, Ohio State University, Columbus, Ohio 43218, USA.

The development of oral squamous cell carcinoma (SCC) shows a positive correlation with the carcinogen exposure that occurs during tobacco and alcohol use. The purpose of this study was to investigate whether the naturally occurring chemopreventive agent, curcumin, modulates expression and function of carcinogen- metabolizing enzymes in human keratinocytes isolated from oral SCC tumors. Dose-response studies demonstrated that curcumin concentrations of >or=25 micro M were cytotoxic for oral SCC cells. Curcumin increased both expression (reverse transcription-PCR analyses) and function (high-performance liquid chromatography determination of ethoxyresorufin metabolism) of cytochrome P-450 (CYP) 1A1 and/or CYP1B1. The aryl hydrocarbon receptor (AhR), which up-regulates a battery of genes associated with carcinogen metabolism, is activated by polycyclic aromatic hydrocarbons such as the tobacco-associated carcinogen benzo(a)pyrene. Electromobility shift assays demonstrated that similar to the established AhR ligand 2,3,7,8,-tetrachlorodibenzo-p-dioxin, curcumin inclusion resulted in AhR nuclear translocation and formation of the transcriptionally active AhR-aryl hydrocarbon receptor nuclear translocator complex. Cellular capacity to bioactivate the tobacco-associated carcinogen (-)-benzo(a)pyrene-7R-trans-7,8-dihydrodiodiol was determined by evaluating conversion of the carcinogenic metabolite diol epoxide to stable tetrols via high-performance liquid chromatography. Results of our metabolism studies showed that curcumin significantly inhibited CYP1A1-mediated benzo(a)pyrene diol bioactivation in both oral SCC cells and intact oral mucosa. Because CYP1A1 is one of the primary carcinogen-activating enzymes in oral mucosa, the use of curcumin as an oral cavity chemopreventive agent could have significant clinical impact via its ability to inhibit carcinogen bioactivation.

March, 2003|Archive|

R&B Legend Hank Ballard Dies

  • 3/27/2003
  • Los Angeles
  • Rueters

Hank Ballard, the man responsible for starting the “twist” phenomenon that swept the nation in the late 1950s, passed away on March 2 after a battle with throat cancer. Ballard wrote and recorded legendary R&B hit “The Twist” in 1958 as a B-side to one of his singles; the following year, when Chubby Checker unveiled his cover of the song, it became a massive sensation, inciting other groups to record “twist” songs of their own, including “Twisting The Night Away” and “Twist And Shout” — the latter of which was written by the Isley Brothers and became one of the biggest early hits for the Beatles (as well as, many years later, providing one of the best moments in Ferris Bueller’s Day Off). Ballard was the lead vocalist in ’50s doo-wop group the Midnighters, originally known as the royals, and boasted nearly two dozen hits on the R&B charts, including 1954’s “Work With Me Annie,” which sold over one million copies. He became an inductee to the Rock And Roll Hall of Fame in 1990.

March, 2003|Archive|

Aspirin May Cut Risk of Throat Cancer

  • 3/26/2003
  • London
  • Patricia Reaney
  • Reuters

Taking low-dose aspirin regularly could cut the risk of developing cancers of the mouth, throat and esophagus, Italian researchers said on Tuesday. Millions of people already take the painkiller to relieve headaches and arthritis and to prevent heart attacks and stroke. Studies have also suggested the century-old drug could have a protective effect against bowel and lung cancer.

Researchers at the Institute of Pharmacological Research in Milan have now shown that aspirin can slash the risk of mouth and throat cancer by two-thirds. “We found aspirin had a protective effect against cancer of the upper aerodigestive tract,” Dr. Cristina Bosetti, an epidemiologist at the institute, said in an interview. Bosetti and her team analyzed three previous studies involving 965 cancer patients who had been taking aspirin for other problems, such as heart disease, for five years. The cancer patients and nearly 1,800 other people filled in questionnaires about their smoking and drinking habits, diet and how often they took aspirin.

The research, which is reported in the British Journal of Cancer, revealed fewer mouth and throat cancers in the patients who had been taking aspirin for five years or longer. “This is the first study which reports such protection. Few studies have been conducted on aspirin and the upper aerodigestive tract,” Bosetti added in a statement. The researchers believe aspirin may play a role in cutting cancer risk because of its impact on an enzyme called cyclooxegenase-2, which is involved in inflammation and is thought to be linked to the development of cancer. They also suspect aspirin may play an important role in preventing stomach, prostate and breast cancer.

“The effect of aspirin can also be seen in other cancers because cyclooxegenase is also implicated in cancer of the stomach and breast cancer. If this is the mechanism of action the effect of aspirin could be similar for these cancers,” Bosetti said. Dr. Richard Sullivan, of the charity Cancer Research UK, said the research is further proof that aspirin, which began as a simple painkiller, is one of the greatest finds in the history of drug discovery. “We’re not yet at the stage where we can recommend that everyone starts taking aspirin on a daily basis, as we’ll need to further investigate its effectiveness and possible side-effects of long-term use. However, it looks as though the drug could become an important part of cancer prevention,” he added.

March, 2003|Archive|

Single-dose cisplatin yields increased survival rates in head and neck cancer

  • 3/25/2003
  • Cleveland
  • Daniel Nester
  • Journal of Clinical Onocology

Standard radiation treatment combined with a single high dose of chemo increases survival rates.

Although it also increases toxicity rates, the addition of concurrent high-dose, single-agent cisplatin (Platinol, Bristol-Myers Squibb) to conventional radiation treatment significantly improves survival rates in patients with head and neck cancer. A new study has found that the three-year projected overall survival rate of patients who received the combination treatment was 37%, compared with 23% in those patients who received radiation alone.

Another arm of the seven-year study showed no improvement in efficacy from the use of multi-agent chemotherapy with a split-course of radiation despite the possibility of midcourse surgery. The three-year survival rate for that group was 27%.

The study proves that “concurrent chemotherapy and radiation can be safely administered with acceptable toxicity in a multi-institutional, cooperative oncology group trial,” said David J. Adelstein, MD, from the Cleveland Clinic Foundation, and lead researcher of the study. More investigation of this combination is needed, he said, but the results demonstrate the treatment “significantly improves survival.”

Materials and methods

Adelstein and colleagues at the Head and Neck Intergroup — comprising the Eastern Cooperative Oncology Group and the Southwest Oncology Group — were following-up their previous studies that have compared the standard care of radiation treatment and a combination of radiation and chemotherapy in patients with unresectable head and neck cancer. Those studies demonstrated increased response rates compared with radiation alone, but survival differences were statistically insignificant, Adelstein said. Overall survival rates of patients receiving radiation alone for unresectable disease, he pointed out, have in general been less than 25%.

Researchers conducted a randomized, phase-3 study that examined results of 295 patients (271 evaluable) with unresectable squamous cell head and neck cancer between 1992 and 1999. Patients were randomly assigned to a control group of patients who received a single, daily fractionated radiation (70 Gy at 2 Gy/d); a second group that received the identical radiation therapy along with concurrent bolus cisplatin (given on days 1, 22 and 43); or a third group that received a split course of a single daily fractionated radiation treatment and three concurrent cycles of fluorouracil and bolus cisplatin chemotherapy (30 Gy given with the first cycle and 30 to 40 Gy given with the third cycle).

Surgical resection was encouraged if possible, Adelstein said, after the second chemotherapy cycle in the multiagent split course group and, if necessary, as a salvage therapy in all three treatment groups.

Increased toxicity and survival

With a median follow-up of 41 months for patients who were still alive, researchers found that the three-year projected overall survival for the control arm was 23% with a median survival of 12.6 months. The survival of patients in the group given concurrent single-agent cisplatin was “significantly better” than controls, with a three-year projection of 37%, a median of 19.1 months (P=0.014).

Complete responses bore out similar results. Researchers reported a complete response in 27.4% of control patients receiving radiation alone, 40.2% in the single-agent cisplatin group, and 49.4% in the multiagent-split-course group. The difference between controls and the multiagent-split-course group was statistically significant (P=0.002), but was only “marginally significant” between controls and the single-agent cisplatin patients (P=0.07). The complete response rate for the split course group included patients who underwent midcourse surgical resection, Adelstein said.

Three-year disease-specific survival rates were 33% in controls, 51% in the single agent cisplatin group, and 41% in the multiagent split course group. Toxicity rates of grade 3 or worse occurred in 51% of controls, 85% in the combination group (P < 0.0001), and 72% in the split course group (P < 0.001).

“The toxicity was manageable,” he said, “and the benefit clear.”

Obstacles of definition

One of the major obstacles to the study, Adelstein said, as well as all studies of patients with unresectable head and neck cancer, is the definition of the term “unresectability.” The anatomic criteria for the term are “not standard and vary from surgeon to surgeon and institution to institution,” Adelstein said. Age and performance status of the patient, and the willingness to accept surgical morbidity also affects resectability, all of which “makes interpretation of the literature difficult,” he said.

Chemotherapy’s role in the definitive management of patients with squamous head and neck cancer “has undergone intensive investigation during the last 30 years,” Adelstein said. Despite “surprising chemosensitivity,” extensive phase-3 testing of induction chemotherapy “has failed to demonstrate any reproducible survival benefit,” he said. Concurrent chemotherapy and radiation, however, “has been a more consistently successful treatment.”

Another question raised in the present study is why the multiagent-split-course group’s three-year survival rates were not as successful as the single-agent cisplatin arm. Some reasons, Adelstein said, could include the use of the split-course radiation therapy schedule, a strategy employed with the hope that mid-course surgery would be possible. It is, however, “a suboptimal way to deliver radiation.”

For more information:

* Adelstein DJ. An intergroup phase III comparison of standard radiation therapy and two schedules of concurrent chemoradiotherapy in patients with unresectable squamous cell head and neck cancer. J Clin Oncol. 2003;21(1):92-98.

March, 2003|Archive|

Link between infection and oral cancer uncovered

  • 3/24/2003
  • Susan Aldridge, PhD
  • American Association of Dental Research

Researchers have found that people with periodontal disease are four times more likely to have oral cancer. Periodontal disease is a form of gum disease where the tissue surrounding and supporting the teeth becomes infected and inflamed. Data from the Third National Health and Nutrition Examination Survey now reveals a link between periodontal disease and oral cancer.

Participants were divided into two groups, depending on the measure of gum detachment from the teeth – a way of assessing the presence of periodontal disease. The researchers, from the University of Buffalo, then determined the presence of oral tumors, precancerous lesions and other problems in the oral cavity. They found that people with periodontal disease were four times more likely to have an oral cancer, and twice as likely to have a precancerous lesion.

This study doesn’t actually prove that periodontal infection causes oral cancer. But infection has been linked to other cancers – for instance, there is an association between Helicobacter pylori infection and stomach cancer. If periodontal disease does cause oral cancer, then there is enormous scope for prevention and earlier diagnosis.

OCF Note: This study was lacking significant control parameters which may have found other commonalities between subjects that would have refuted this generalized finding. This might have include factors such as smoking, alcohol consumption, drug use, genetic factors, and other possible co-factors that were not identified in this group of individuals in the study. People with periodontal disease invariably have poor hygiene habits, and likely take less interest in the other factors which lead to a healthy life. OCF would have preferred a study which considered all other commonalities, and posts this story here as an example of science, poorly structured, finding incomplete answers from a myriad of possiblities, and publishing something that is of little value to others.

March, 2003|Archive|

Separating Accurate Cancer Information on the Web From Quacks

  • 3/5/2003
  • San Diego, CA
  • Scott C. Matthews, MD
  • Psychosomatics

Following a simple checklist may help people separate fact from fiction in finding information about alternative cancer treatments on the Web. A new study shows that applying four basic criteria to Internet sources of information about herbal and other alternative cancer treatments might help steer people away from dubious web sites.

Researchers say the Internet has become an important source of medical information. But the quality of the information varies greatly, especially in regard to complementary or alternative medicine treatments that have not been widely studied.

By evaluating web sites according to four “red flag” criteria, researchers say they were able to quickly screen sites for likely scientific accuracy.

The study, published in the March-April issue of Psychosomatics, recommends that people avoid sites containing one or more of the following red flags in regard to alternative cancer treatments:

• Online purchasing of the product/therapy described is available.

• The description of the treatment includes patient testimonials.

• The treatment is described as a “cancer cure.”

• The treatment is described as “having no side effects.”

Researchers applied this checklist to searches for three common herbal treatments frequently used by cancer patients: floressence, amalaki, and selenium. They found over 90% of the sites for floressence and amalaki had at least one red flag. These sites provided a large amount of vague and inaccurate information.

In contrast, those sites without any red flags provided some scientifically accurate information and included links to scientific organizations such as the National Cancer Institute and the National Center for Complementary and Alternative Medicine.

“There is a staggering amount of medical misinformation on the Internet,” writes researcher Scott C. Matthews, MD, and colleagues at the University of California, San Diego. “When patients search the Internet for information on a topic for which there is little objective clinical research, use of these red flag questions may help identify questionable sites.”

March, 2003|Archive|

CuraGen Receives FDA Approval to Initiate Clinical Trials

  • 3/4/2003
  • New Haven
  • CuraGen Corporation

CuraGen Corporation , a genomics-based pharmaceutical company, today announced that the U.S. Food and Drug Administration (FDA) has approved its Investigational New Drug (IND) application to initiate clinical trials for CG53135, a potential protein therapeutic being investigated as a treatment for oral mucositis. Oral mucositis is a side effect of chemotherapy and radiotherapy that results in the degradation of mucosal tissue that can range from redness and irritation to severe ulcerations of the mouth and throat. CuraGen now plans to proceed with a multi-center Phase I clinical trial to evaluate safety and pharmacokinetics in patients with cancer who are at risk for mucositis following chemotherapy.

Mucositis is a debilitating complication of cancer chemotherapy or radiotherapy that affects the mucosal tissue, which acts as a protective lining within the digestive track, including the mouth and throat. Symptoms range from pain and discomfort to severe ulcerations that limit a patient’s ability to ingest nutrients. Mucositis can result in a suppressed immune system that can reduce a patient’s ability to tolerate further cancer therapy. Delayed treatment can lessen the effectiveness of the chemotherapy or radiotherapy, adversely impacting the value of the patient’s overall treatment regimen.

“CG53135 is a novel protein discovered through the application of CuraGen’s functional genomic technologies. In preclinical studies, this potential protein therapeutic reduced tissue inflammation and degeneration, and minimized the severity and extent of mucosal tissue damage. Mucositis is a significant unmet medical need, and we are pleased to have the opportunity to advance this promising molecule into human clinical trials,” stated Timothy M. Shannon, M.D., Senior Vice President of R&D and Chief Medical Officer of CuraGen Corporation.

“Through the filing of this IND, CuraGen has become one of the first genomics companies to successfully transition from a target discovery company into a genomics-based pharmaceutical company. This molecule represents the first of many promising candidates that we believe will emerge from our portfolio of discovery and preclinical stage projects. We are pleased with the progress of this potential therapeutic and look forward to additional future successes,” stated Jonathan M. Rothberg, Ph.D., Founder, Chairman, and CEO of CuraGen Corporation.

CuraGen Corporation is a genomics-based pharmaceutical company. CuraGen’s integrated, functional genomic technologies and Internet-based bioinformatic systems are designed to generate comprehensive information about genes, human genetic variations, gene expression, protein interactions, protein pathways, and potential drugs that affect these pathways. The Company is applying its industrialized genomic technologies, informatics, and validation technologies to develop protein, antibody, and small molecule therapeutics to treat obesity and diabetes, cancer, inflammatory diseases, and central nervous system (CNS) disorders. CuraGen is headquartered in New Haven, CT and additional information is available at http://www.curagen.com

March, 2003|Archive|

Is detection of oral and oropharyngeal squamous cancer by a dental health care provider associated with a lower stage at diagnosis?

  • 3/2/2003
  • The Journal of Oral and Maxillofacial surgery

Jon D. Holmes, DMD, MD
Eric J. Dierks, DMD, MD
Louis D. Homer, MD, PhD
Bryce E. Potter, DMD, MD

Purpose: Stage at diagnosis is the most important prognostic indictor for oral and oropharyngeal squamous cell cancers (SCCs). Unfortunately, approximately 50% of these cancers are identified late (stage III or IV). We set out to examinationine the detection patterns of oral and oropharyngeal SCCs and to determine whether detection of these cancers by various health care providers was associated with a lower stage.

Patients and Methods: Data were gathered on 51 patients with newly diagnosed oral or oropharyngeal SCC through patient interview and chart audit. In addition to demographic data, specific inquiry was made regarding the circumstances surrounding the identification of the lesion. The main outcome measure was tumor stage grouping based on detection source.

Results: Health care providers detecting oral and oropharyngeal SCCs during non–symptom-driven (screening) examinations were dentists, hygienists, oral and maxillofacial surgeons, and, in 1 case, a denturist. All lesions detected by physicians occurred during a symptom-driven examination. Lesions detected during a non–symptom-driven examination were of a statistically significant lower average clinical and pathologic stage (1.7 and 1.6, respectively) than lesions detected during a symptom-directed examination (2.6 and 2.5, respectively). Additionally, a dental office is the most likely source of detection of a lesion during a screening examination (Fisher exact test, P = .0006). Overall, patients referred from a dental office were of significantly lower stage than those referred from a medical office. Finally, patients who initially saw a regional specialist (dentist, oral and maxillofacial surgeon, or otolaryngologist) with symptoms related to their lesion were more likely to have appropriate treatment initiated than those who initially sought care from their primary care provider.

Conclusion: Overall, detection of oral and oropharyngeal SCCs during a non–symptom-driven examination is associated with a lower stage at diagnosis, and this is most likely to occur in a dental office. A regional specialist was more likely than a primary care provider to detect an oral or oropharyngeal SCC and initiate the appropriate treatment during the first visit for symptoms related to the lesion.

J Oral Maxillofac Surg 61:285-291, 2003

March, 2003|Archive|

Don’t Drink Alone Gets New Meaning

  • 3/1/2003
  • Aviano, Italy
  • Janet Raloff
  • Luigino Dal Maso of the Cancer Referral Center

In what may be bad news for bars and pubs, a European research consortium has found that people drinking alcohol outside of meals have a significantly higher risk of cancer in the mouth and neck than do those taking their libations with food. Luigino Dal Maso of the Cancer Referral Center in Aviano, Italy, and his colleagues studied the drinking patterns of 1,500 patients from four cancer studies and another 3,500 adults who had never had cancer. All lived in Italy or French-speaking Switzerland.

After the researchers accounted for the amount of alcohol consumed, they found that individuals who downed a significant share of their alcohol outside of meals faced at least a 50 to 80 percent higher risk of cancer in the oral cavity, pharynx, and esophagus, when compared with people who drank only at meals. Consuming alcohol without food also increased by at least 20 percent the likelihood of laryngeal cancer. The findings appear in the International Journal of Cancer. Roughly 95 percent of cancers at these four sites traced to smoking or drinking by the study volunteers, Dal Maso says. The discouraging news, his team reports, is that drinking with meals didn’t eliminate cancer risk at any of the sites.

For their new analysis, the European scientists divided people in the study into four groups, based on how many drinks they reported having in an average week. The lowest-intake group included people who averaged up to 20 drinks a week. The highest group reported downing at least 56 servings of alcohol weekly—or an average of eight or more per day. Cancer risks for the mouth and neck sites rose steadily with consumption—even for people who reported drinking only with meals. For instance, compared with people in the lowest-consumption group, participants who drank 21 to 34 alcohol servings a week at least doubled their cancer risk for all sites other than the larynx. If people in these consumption groups took some of those drinks outside meals, those in the higher consumption group at least quadrupled their risk for oral cavity and esophageal cancers.

People in the highest-consumption group who drank only with meals had 10 times the risk of oral cancer, 7 times the risk of pharyngeal cancer, and 16 times the risk of esophageal cancer compared with those who averaged 20 or fewer drinks a week with meals. In contrast, laryngeal cancer risk in the high-intake, with-meals-only group was only triple that in the low-intake consumers who drank only with meals. Alcohol can inflame tissues. Over time, that irritation can trigger cancer, Dal Maso says. He suspects that food reduced cancer risks either by partially coating digestive-tract tissues or by scrubbing alcohol off those tissues.

He speculates that the reason laryngeal risks were dramatically lower for all study participants traces to the tissue’s lower exposure to alcohol. Swallowed liquid doesn’t wash across the larynx, he points out. Any contact comes from vapors that escape a liquid being ingested.

The take-home message Dal Maso reads from his group’s data is “to consume alcohol in little amounts, and when you do—eat!”

OCF Note: While we find this article interesting, OCF disagrees with the concept that “irritation” of the tissues is the mechanism that causes the problem. Scientific evidence suggests that alcohol’s ability to thin the cell wall membranes is the important issue. It is known that combined alcohol and tobacco use is a greater risk than either alone. This is because the alcohol weakens the cell walls allowing the carcinogens in the tobacco to more easily affect the cells. We agree that high alcohol consumption can be a causative factor in oral cancers by itself, but this study’s parameters lacked tracking of a principal co-factor. This study tracked no use of tobacco in the drinkers in the new study.

March, 2003|Archive|

Laser Light Therapy Seen As “Magic Bullet” For Treating Some Throat And Oral Cancers

  • 3/1/2003
  • Maryland
  • University Of Maryland Medical Center

Photodynamic therapy, which uses a red laser and a light-sensitive drug to destroy cancer cells without harming normal tissue, represents a promising new treatment option for patients with throat or oral cancers, according to a voice and swallowing specialist at the University of Maryland Medical Center.

“It’s as close to a magic bullet as you can get to kill cancers that are close to the surface,” says Paul F. Castellanos, M.D., an otolaryngologist/head and neck surgeon who has treated a dozen patients with the minimally invasive laser light therapy in the past 18 months. Nine of those patients had throat cancer, and three had oral cancer.

“Photodynamic therapy is the only thing that kills the cancerous tissue and the precancerous tissue, but not the normal tissue,” says Dr. Castellanos, who is also an assistant professor of surgery at the University of Maryland School of Medicine. “We are very excited about this new frontier in the treatment of these kinds of cancers and premalignancies.”

Before patients receive the therapy, they are given an intravenous injection of a light-sensitive drug called porfimer sodium, which passes through normal cells but collects in cancerous and precancerous cells. Two or three days after the injection, doctors expose those areas to a red laser, causing a chemical reaction that destroys the diseased cells.

Other lasers kill cancer cells with heat—vaporizing or cutting out tumors, along with a portion of the surrounding healthy tissue. In photodynamic therapy, the red laser’s concentrated beam of light activates the Photofrin to produce a toxic form of oxygen that kills the cancer cells without harming the adjacent tissue. The procedure is performed in the operating room while patients are under anesthesia. In treating throat cancer, Dr. Castellanos uses a device called a laryngoscope to get a clear view of the patient’s throat and larynx. He then threads a thin fiber-optic conduit through the scope to deliver the laser beam directly to the cancer. The treatment lasts about nine minutes, and patients go home the same day.

Patients may experience some soreness or redness in the area that was exposed to the light, but the major side effect is sensitivity to direct sunlight. The photoactive drug lingers in the cells of the skin and eyes, and those who have been treated must stay out of the sun for about six weeks. “The photosensitivity is a big nuisance. But it’s nothing that time out of the sun won’t remedy,” Dr. Castellanos says, adding that sunscreen doesn’t protect patients because it only blocks ultraviolet rays, not red light from the sun. He advises patients to cover themselves completely and wear sunglasses or to venture outside only after dusk during the time they are light-sensitive. He says that standard treatments for throat and oral cancer, such as surgery and radiation, carry more risks and can have more serious and longer-lasting side effects. For example, six weeks of radiation therapy for throat cancer can cause a drying or stiffening of the vocal cords, reducing voice quality. The tumor can also be replaced by scar tissue, which would also affect the voice.

The laser therapy is most effective for cancers that are close to the surface or precancerous conditions because the red laser only penetrates a quarter of an inch, Dr. Castellanos says. But he notes that patients can be treated again within one or two weeks to remove deeper tumors. “Patients can also receive other forms of treatment, such as surgery or radiation, if their cancer does not respond to this therapy. It does not eliminate any options,” he says, adding that only two of the 12 patients treated so far have needed further therapy because their cancers were more advanced. Dr. Castellanos says that the procedure has been used successfully for late-stage or inoperable cancers and in combination with other treatments such as chemotherapy or radiation.

The U.S. Food and Drug Administration has approved photodynamic therapy to treat esophageal cancer, lung cancer and a precancerous skin condition known as actinic keratosis, but researchers have reported encouraging results in treating other cancers as well. In clinical studies of more than 350 people with early-stage cancers of the mouth, throat and larynx, 88 percent of the patients showed no evidence of the disease after the first treatment.

“We started using photodynamic therapy to treat throat and oral cancers a year and a half ago, and so far, we have had excellent results,” Dr. Castellanos says. “Based on the literature and our experience, it is as effective or in some cases even more effective than the other treatments.” And the treatment may become more useful for a broader range of cancers as researchers look for ways to increase the depth the laser can penetrate, test other photosensitive drugs and try to reduce the photosensitivity side effects, Dr. Castellanos says.

Photodynamic therapy is also used by Bruce D. Greenwald, M.D., a gastroenterologist at the University of Maryland Greenebaum Cancer Center and an associate professor of medicine at the University of Maryland School of Medicine, to treat esophageal cancer. Robert A. Ord, M.D., D.D.S., the head of the division of oral-maxillofacial surgery at the medical center and a professor at the University of Maryland Dental School, has also collaborated with Dr. Castellanos to treat patients with oral cancers.

The University of Maryland Medical Center recently opened the Center for Voice, Swallowing and Esophageal Disorders, combining the specialties of otolaryngology, gastroenterology and general and thoracic surgery to treat a broad range of diseases, including cancer. Dr. Castellanos and George Fantry, M.D., director of clinical gastroenterology at the Medical Center and an associate professor of medicine at the University of Maryland School of Medicine, are co-directors of the center.

March, 2003|Archive|