The Sloan-Kettering Institute for Cancer Research tested one of the herbs in Essiac, sheep sorrel, between 1973 and 1976. Caisse sent a quantity of the herb to Sloan-Kettering, along with detailed instructions on how to prepare it as an injectable solution. On June 10,1975, Dr. Chester Stock, a Sloan-Kettering vice president, wrote to Rene: "Enclosed are test data in two experiments indicating some regressions in sarcoma 180 of mice treated with Essiac" (emphasis added).8 Despite these promising results, the tests ground to a halt when Rene was horrified to learn that instead of boiling the herb, as she had instructed, the scientists were freezing it.

In 1977, Rene sold the formula for Essiac to the Resperin Corporation, a Canadian company. Resperin's tests on Essiac, though initially encouraging, dragged on for years. Patients in Canada seeking Essiac through the government must first find a physician who will sponsor them and submit the appropriate official form. The physician should contact the Health Protection Branch of the Canadian Health and Welfare department to arrange to purchase the product from Resperin Corporation. The physician's request should roughly read: "I have a patient who has (type of cancer) affecting (body parts or organs). I request permission to treat the patient with Essiac on an emergency basis." The physician should mail the request to the Health Protection Branch, Bureau of Human Prescription Drugs, Director's Office, c/o Emergency Drug Division, Tower B- Second Floor, 355 River Road, Place Vanier, Vanier, Ontario K1A 1B8. Many doctors are reluctant to do this, however, fearing establishment pressure or ridicule. Even if the necessary forms are submitted, permission to use Essiac is not always granted.

A report issued in 1982 by the Health Protection Branch of the Canadian Health and Welfare department finds that "no clinical evidence exists to support claims that Essiac is an effective treatment for cancer." This blanket condemnation ignores sixty years of clinical documentation and observational evidence as well as laboratory studies. The report says:

In 1982, 112 physicians who had received Essiac under these circumstances, were asked to submit case reports. Seventy-four responded on 87 cancer patients. Of these, 78 showed no benefit.

Investigation of the nine remaining cases revealed that the cancer was progressing (four cases), the patient had died (two cases) or that the disease had stabilized (three cases).

Of this last group, all the patients had previously undergone some form of cancer treatment which could have stabilized the disease.

The report does not explain why only 74 of the 112 physicians responded. Were the other 38 doctors perhaps afraid to submit responses favorable towards Essiac, fearing orthodox ridicule and peer pressure?

It is also not clear whether the 78 patients that "showed no benefit" experienced a reduction in pain or an improvement in appetite. These important components of cancer care are generally not counted as a benefit in such studies.

Were any of the 87 patients, all severely ill, given intramuscular injections of Essiac, as Rene Caisse so often administered in advanced cases? Critics of the report say that no patients were given intramuscular injections.

Was the herbal mixture prepared correctly, or were the herbs possibly frozen and damaged, as was done at Sloan-Kettering? Were the oral doses given frequently enough? Neither answer is known.