The biggest medical stories of the year

There were some incredible breakthroughs in medicine this year:

Diabetes and Nerve function linked
Drop in the incidence of breast cancer
New treatments for Macular Degeneration
Progress toward an Alzheimer’s Vaccine and other treatments

Diabetes linked to nerve function in the pancreas
One of the biggest stories, if it is confirmed by other researchers, is the discovery of the relationship between the nervous system and diabetes.

Diabetes Breakthrough | National Post

From the article by Tom Blackwell:

Dr. Dosch had concluded in a 1999 paper that there were surprising similarities between diabetes and multiple sclerosis, a central nervous system disease. His interest was also piqued by the presence around the insulin-producing islets of an “enormous” number of nerves, pain neurons primarily used to signal the brain that tissue has been damaged.

Suspecting a link between the nerves and diabetes, he and Dr. Salter used an old experimental trick — injecting capsaicin, the active ingredient in hot chili peppers, to kill the pancreatic sensory nerves in mice that had an equivalent of Type 1 diabetes.

“Then we had the biggest shock of our lives,” Dr. Dosch said. Almost immediately, the islets began producing insulin normally “It was a shock ? really out of left field, because nothing in the literature was saying anything about this.”
It turns out the nerves secrete neuropeptides that are instrumental in the proper functioning of the islets. Further study by the team, which also involved the University of Calgary and the Jackson Laboratory in Maine, found that the nerves in diabetic mice were releasing too little of the neuropeptides, resulting in a “vicious cycle” of stress on the islets.

So next they injected the neuropeptide “substance P” in the pancreases of diabetic mice, a demanding task given the tiny size of the rodent organs. The results were dramatic.

The islet inflammation cleared up and the diabetes was gone. Some have remained in that state for as long as four months, with just one injection.

They also discovered that their treatments curbed the insulin resistance that is the hallmark of Type 2 diabetes, and that insulin resistance is a major factor in Type 1 diabetes, suggesting the two illnesses are quite similar.

Hormone Replacement Therapy strongly linked to breast cancer:
Another big story involved the results of the unintended experiment on millions of women beginning in 2003, when Hormone Replacement Therapy was linked to increased heart disease. The use of HRT dropped substantially, and 3 years later, so did breast cancer, by 7.2 percent.
A sharp decrease in breast cancer incidence in the United States in 2003

From the abstract:
Breast cancer incidence in the United States gradually increased at 1.7% per year from 1990 to 1998. Between 1998 and 2003 incidence began to decrease at 1% per year. In 2003 there was a 7% decrease in incidence within a single year. This marked decrease was seen both for in situ cancers (5.5%) and malignant cancers (7.3%). In order to gain additional insight as the possible reasons for the decline in incidence of breast cancer we conducted further subset analyses. The steep decline seemed to begin in early 2003 with relative rates (compared to a 2000/2001) showing a 1% decline in the first and second halves of 2002, 6% in the first half of 2003, and 9% in the second half of the year. The decline in incidence in 2003 relative to 2000/2001 was most evident in patients older than 50 (a 1%, 11%, 11%, and 7% decline in incidence for women in their 40s, 50s, 60s, and 70s respectively). The decline in incidence in ER positive invasive tumors was greater than ER negative tumors (8% versus 4%). When the analysis was restricted to patients 50-69 years of age this difference in decline in the incidence by ER was more striking (12% versus 4%).

As a side note: it would be interesting to know the cause of the 1% per year decrease in incidence of breast cancer between 1998 and 2003.

New Treatments for Macular Degeneration

Several drugs are now being used that can slow the progression of Wet Macular Degeneration.

Macular degeneration: Treatment – MayoClinic.com

From the article:
The newest treatment being used for macular degeneration involves use of drugs called anti-vascular endothelial growth factor (anti-VEGF) medications. These drugs help stop new CNV from growing by blocking the effects of a growth factor these blood vessels need to thrive. Anti-VEGF medications are injected directly into your eye. Some anti-VEGF agents that have been approved for use or are currently being investigated for treating macular degeneration include:

Macugen. Pegaptanib (Macugen) is approved for the treatment of wet macular degeneration. This drug is given as a series of injections into the vitreous fluid in the eye. It helps to prevent further vision loss by stopping the formation of new blood vessels and decreasing leakage from existing blood vessels.

Lucentis. Like Macugen, ranibizumab (Lucentis) is an anti-VEGF drug used to treat wet macular degeneration. It also impedes new growth of abnormal blood vessels and helps dry up leaking vessels. However, ranibizumab may be able to reverse some of the effects of macular degeneration, not just prevent further vision loss.

Bevacizumab (Avastin). Some doctors are prescribing this drug, which is closely related to ranibizumab, hoping that it will have effects. Bevacizumab hasn’t been approved by the Food and Drug Administration (FDA) as a treatment for macular degeneration, but it has been approved as a treatment for colon and rectal cancer. That means that the use of this medication to treat macular degeneration is currently considered an off-label use of the drug. Still, some physicians are using bevacizumab injections to treat wet macular degeneration.

Progress toward an Alzheimer’s vaccine:
Progress on Alzheimer’s vaccine – Campus Vienna Biocenter

There was a lot of publicity a few years ago about a possible vaccine for Alzheimer’s disease which targeted the amyloid protein plaques which build up in the brains of Alzheimer’s patients.

A clinical trial was halted in 2002 when 15 patients developed brain inflammation. However after the study ended, researchers determined that those that received the vaccine showed substantial improvement.

According to a press release from the University of Michigan, one new trial is based on

… injections of humanized antibodies against part of the beta amyloid molecule. The antibodies should help trigger the immune system to attack beta amyloid, but will be cleared by the body soon after injection…

Another promising avenue, published in Science Daily this year is to block the interaction between amyloid protein and another protein called Apo E.:

From the article in Science Daily:

In a new animal study, the NYU School of Medicine researchers report that they have reduced by around 50 percent the aggregation of toxic amyloid protein in the brains of mice by blocking the interaction between a protein called apolipoprotein E (apo E) and amyloid. Apo E acts as a sort of biological chaperone, ferrying cholesterol and fats around the brain.

Post script: Jan 29, 2007:

Patching up Alzheimer’s safely by Susan Gotensparre

“US-based researchers have developed a transdermal vaccine for Alzheimers disease which has been shown to clear brain-damaging amyloid plaques in preclinical studies, offering hope to millions of sufferers worldwide.

The researchers at the University of South Florida (USF) suggest that the patch-based delivery approach will not be associated with toxicities that have caused problems with other injectable vaccines for Alzheimers.”