As new study results prove the efficacy of a test for cervical cancer, new therapies — a vaccine and two drugs — add to the arsenal of increasingly effective cancer weapons. An experimental vaccine for Alzheimer’s disease has also showed signs of success. The arsenal of diagnostic and therapeutic devices receives boosts from more precise brain scans and more precise shaping of radiation beams to fit their targets. Artificial blood will undergo trials at 20 hospitals around the nation, and a way has been found to strengthen tissue-engineered bone with aluminum.

Cervical Certainty: DNA with PAP

In a study of nearly 8,000 women in Germany, a laboratory test for cervical cancer combining PAP and a test for human papillomavirus (HPV) detected 100 percent of cervical cancer and precancerous changes in women over 30. PAP alone identified only 43.5 percent. A woman who tests negative with the new test (which was recently approved by the FDA) can be sure she does not have and is unlikely to soon develop cancer, according to the test’s developer.

A commentator notes that many of those who test positive with the combined test will not develop cervical cancer, since millions of women carry HPV but it only poses a danger to those whose infections persist.

Reference: Barbaro Michael (2003). “Digene’s Cancer Test Is Reliable, Study Finds.” Washington Post, May 22, p. E05.

Cancer Successes

After ten years of treatment with dendritic-cell vaccine, four Stanford cancer patients who were “very sick” in 1993 are still alive, along with 31 more who started receiving the treatment later. And of 18 patients with “incurable” melanoma injected with dendritic-cell vaccines in 1998, seven are still alive, and five of those are in remission. In 1998, they had been expected to live only four to six months.

At least ten academic and commercial teams are now testing dendritic-cell vaccines to treat everything from melanoma to prostate cancer, attendance at conferences on the treatment has mushroomed, and the approach has attracted growing funding.

Dendritic cells are key components of the immune system. To create individualized vaccines, dendritic cells from the patient’s own blood are fused with pieces of the patient’s tumor. The approach differs markedly from the standard chemotherapy approach where one size tries — and fails — to fit all.

Some cancer specialists are cautious, pointing out that the mechanisms remain poorly understood, that there have been many failures, and that there are other, newer, approaches that show equal or more promise.
Those approaches could include two experimental anti-cancer drugs that have had some success in clinical trials. They are not a cure, but they may extend lives or shrink tumors, without some of the serious side effects of conventional chemotherapy. Most important, they validate the angiogenic approach to treating cancer.

The two drugs are Avastin and Erbitux. Avastin gave 400 patients with advanced colorectal cancer nearly five months longer life, on average. Erbitux was tested in Europe among 329 patients with colorectal cancer that had metastasized. In combination with irinotecan, it shrank tumors in 22.9 percent of patients; alone, it shrank tumors in 10.8 percent of patients.
Erbitux could reach the market in 2004. It blocks activation of the epidermal growth factor receptor molecule, which causes tumor cells to grow. Another drug that works the same way, Iressa, has already received FDA approval for treating lung cancer. Similar colon cancer drugs are under development appear in early tests to be about as effective as Erbitux while avoiding some of the latter’s rare but serious allergic reactions.

While Erbitux has been shown to shrink tumors, Avastin has been shown to prolong survival, considered a more significant measure of effectiveness. It too could be approved in 2004. Avastin inhibits the growth of blood vessels that feed cancer cells, by blocking vascular endothelial growth factor. It had earlier failed to prolong life in breast cancer patients.

References: (1) Chase, Marilyn; and Rachel Zimmerman (2003). “Researchers Test New Weapon In the Ongoing Cancer Fight.” Wall Street Journal, May 23; (2) Pollack, Andrew (2003). “New Tacks in Cancer Treatment Show Promise.” New York Times, June 2.

Alzheimer’s Vaccine Promising

An experimental vaccine has slowed mental decline in 80 percent of 30 patients with Alzheimer’s disease. A year after receiving the inoculation, only 16 percent of those patients had deteriorated from mild or moderate dementia to severe dementia, compared with 67 percent of those who received a placebo or did not respond to the vaccine.

Elan, which developed the vaccine, hopes to begin testing two new vaccines on patients by year’s end, and Eli Lilly and Mindset Pharmaceuticals are known to be working on a vaccine, though many others may also be doing so in light of Elan’s results.

Elan’s preliminary findings stem from a larger experiment halted 18 months ago when some patients suffered potentially fatal brain inflammation. (See HFD April 2003 article It Ain’t Over for another mention of the vaccine.)

Reference: Dembner, Alice (2003). “Experiment finds hope in vaccine for Alzheimer’s.” Boston Globe, May 22, p. A1.

More Precise Brain Scans

Technology being developed jointly at two U.S. national labs compensates for patient movement during a brain scan. Reflective markers attached to the head are illuminated with an infrared strobe light, and two infrared cameras monitor the reflections to derive position data and enable the scanner to deliver a sharp and accurate image. The system could be ready in two to three years.

Reference: Unknown (2003). “Squirm Scan.” In “Prototype” section of Technology Review,” June.

Shaped Beam Surgery

“Shaped beam surgery” is already in use in several centers around the country and, as the technology improves, could benefit hundreds of thousands of people with brain abnormalities, liver cancer, prostate cancer, and other hard-to-treat illnesses in the United States alone. The radiation beam is shaped to the dimensions of the target tissue, avoiding damage to surrounding tissue — an especially important consideration in dealing with brain tumors.

Shaped beam surgery is currently viewed as a last resort for patients unable to tolerate or benefit from traditional surgery.

Reference: Hurst, Jack (2003). “New tumor center pinpoints radiation in brain surgery.” The Tennessean, June 2.

Artificial Blood Trial

Trauma doctors and ambulance crews at 20 hospitals around the country will test an experimental synthetic blood substitute called PolyHeme on seriously injured patients, who are at risk of serious complications and even death from hemorrhagic shock through massive blood loss. The synthetic blood is compatible with any blood type and can be administered by ambulance crews. Under an FDA waiver, patients whose lives are at stake and who cannot give consent may be given the experimental blood. PolyHeme‘s key ingredient is hemoglobin extracted from whole human blood whose 30-day shelf life has expired.

Reference: Auge, Karen (2003). “Synthetic-blood testing to begin at Denver Health.” Denver Post, May 20.
See also Longevity in the January 2003 issue of HFD for a nanotech approach to artificial blood.

Stronger Bones

Rice University researchers have developed a technique to strengthen tissue-engineered bone created from biodegradable polymer scaffolds seeded with cells. The cells tend to break down under the heavy skeletal stresses. The technique fuses nanoparticles of an aluminum-based compound to the polymer chains, making them three times stronger. Animal testing is expected to begin shortly.

Reference: Unknown (2003). “Aluminum Bone.” In “Prototype” section of Technology Review,” June.