The term "laetrile " is an acronym (laevorotatory and mandelonitrile) used to describe a purified form of the chemical amygdalin, a cyanogenic glucoside (a plant compound that contains sugar and produces cyanide) found in the pits of many fruits and raw nuts and in other plants such as lima beans, clover, and sorghum. Reviewed in [1,2,3,4,5,6] In the 1970s, laetrile gained popularity as an anticancer agent. By 1978, more than 70,000 individuals in the United States were reported to have been treated with it. Reviewed in [2,7,8] Laetrile has been used for cancer treatment both as a single agent and in combination with a metabolic therapy program that consists of a specialized diet, high-dose vitamin supplements, and pancreatic enzymes. Reviewed in 
In the United States, researchers must file an Investigational New Drug (IND) application with the US Food and Drug Administration (FDA) to conduct drug research in human subjects. In 1970, an application for an IND to study laetrile was filed by the McNaughton Foundation (San Ysidro, California). This request was initially approved but later rejected because preclinical evidence in animals showed that laetrile was not likely to be effective as an anticancer agent, Reviewed in [3,11,12] and because there were questions about how the proposed study was to be conducted. Reviewed in  Laetrile supporters viewed this reversal as an attempt by the U.S. government to block access to new and promising cancer therapies, and pressure mounted to make laetrile available to the public. Court cases in Oklahoma, Massachusetts, New Jersey, and California challenged the FDA's role in determining which drugs should be available to cancer patients. Consequently, laetrile was legalized in more than 20 states during the 1970s. In 1980, the U.S. Supreme Court overturned decisions by the lower courts, thereby reaffirming the FDA's position that drugs must be proven to be both safe and effective before widespread public use. Reviewed in [2,14] As a result, the use of laetrile as a cancer therapy or as a treatment for any other medical condition is not approved in the United States, but the compound continues to be manufactured and administered as an anticancer therapy, primarily in Mexico.
Many of the improvements in survival in childhood cancer have been made as a result of clinical trials that have attempted to improve on the best available, accepted therapy. Clinical trials in pediatrics are designed to compare new therapy with therapy that is currently accepted as standard. This comparison may be done in a randomized study of two treatment arms or by evaluating a single new treatment and comparing the results with those that were previously obtained with existing therapy.