Animal Testing for Cancer Research is . . .

The results of animal model systems for drugs or other modalities have done nothing but confuse and mislead the cancer researchers who have tried to extrapolate from mice to man.

Cancer research scientist Irwin D.J. Bross, Ph.D., director of biostatistics at Roswell Park Memorial Institute in New York, attributes the public's lack of knowledge about cancer to misleading animal studies: "Not a single new drug for the treatment of human cancer was first picked up by an animal model system...the results of animal model systems for drugs or other modalities have done nothing but confuse and mislead the cancer researchers who have tried to extrapolate from mice to man.

Moreover, when they have been used to guide clinical research they have sent investigators on one long and costly wild goose chase after another. Thus, scientifically speaking, the animal studies are a fraud. Privately, they [vivisectors] will concede that animal models don't work, but they shrug this off because nothing works."
Every year, $30 billion is spent on cancer research, detection, and treatment in the United States, yet cancer remains our nation's No. 2 killer. In fact, the incidence of cancer has risen 18% and the mortality rate has increased by 7% since 1971.

Why hasn't progress against cancer been commensurate with the effort (and money) invested? One explanation is the unwarranted preoccupation with animal research. Crucial genetic, molecular, immunologic and cellular differences between humans and other animals have prevented animal models from serving as effective means by which to seek a cancer cure. Mice are most commonly used, even though the industry’s own Lab Animal magazine admits: "Mice are actually poor models of the majority of human cancers." Leading cancer researcher Robert Weinberg has commented: "The preclinical [animal] models of human cancer, in large part, stink… Hundreds of millions of dollars are being wasted every year by drug companies using these models."

{Animal experimentation is lucrative.
Its traditionally respected place in modern medicine results in secure financial support, which is often an integral component of a university's budget. Many medical centers receive several hundred million dollars annually in direct grants for animal research, and an average of over 40% more for overhead costs that are supposedly related to that research. Since many medical centers faced with declining clinical revenues depend on this financial windfall for much of their administrative costs, 
construction and building maintenance, they perpetuate animal experimentation by praising it in the media and to legislators.}

According to Clifton Leaf, a cancer survivor himself: "If you want to understand where the War on Cancer has gone wrong, the mouse is a pretty good place to start."

Critical Differences
Those who profit from animal experimentation continually insist that animals are physiologically similar to humans--similar enough to persuade us to believe that what happens in a rat, mouse, dog, cat, or other-than-human primate will occur in humans. However, research chemist Dr. Edward Sharpe points out that cancer tumors found in animals are of a completely different nature from those found in humans.

Most animal cancers arise in the bone, connective tissue, or muscle (sarcomas), whereas most human cancers arise in living membranes (carcinomas). Furthermore, animals confined to small laboratory cages, repeatedly manipulated, and otherwise subjected to pain and stress make very poor "models" of human cancer patients.

Such animals are often heavily irradiated in attempts to give them cancer tumors, or are given highly concentrated doses of substances that a human being would never be exposed to.

Former American Cancer Society president Dr. Marvin Pollard has acknowledged the problems with animal studies. "My own belief is that we have relied too heavily on animal testing, and we believed it too strongly. Now, I think we are commencing to realize that what goes on in an animal may not necessarily be applicable to humans.

Why using animals persists:

• In the "publish or perish" world of academic science, it requires little originality or insight to take an already well-defined animal model, change a variable or the species being used, and obtain "new" and "interesting" findings within a short period of time.
• Scientists' salaries and professional status are often tied to grants, and a critical element of success in grant applications is proof of prior experience and expertise.
• For the chemical and pharmaceutical industries, animal experiments provide an important legal sanctuary. In cases of death or disability caused by chemical products or adverse drug reactions, the responsible companies claim due diligence by pointing out that they performed the legally prescribed "safety tests" on animals and are therefore not accountable. As a result, the victims or their families most often come away empty-handed after suing for damages.14

Morality:

Animal experimenters’ language betrays their efforts to avoid morality. For example, they "sacrifice" animals rather than kill them, and they may note animal "distress", but they rarely acknowledge pain or other suffering. Young scientists quickly learn to adopt such a mind-set from their superiors, as sociologist Arnold Arluke explains: "One message – almost a warning – that newcomers got was that it was controversial or risky to admit to having ethical concerns, because to do so was tantamount to admitting that there really was something morally wrong with animal experimentation, thereby giving ‘ammunition to the enemy’." Physician E. J. Moore also observes: "Sadly, young doctors must say nothing, at least in public, about the abuse of laboratory animals, for fear of jeopardizing their career prospects."

Sources:
http://scienceblog.cancerresearchuk.org/2011/06/21/animal-research-is-helping-us-beat-cancer/
http://www.mrmcmed.org/crit3.html