John Beard and the Laetrile Connection

(Part Two of the Beard Paper Centenary)

(NOTE: Last week I explained the origins of Dr. John Beard’s Trophoblastic Theory of Cancer. In this week’s newsletter I discuss its fate in the second half of the 20th century.)

In the early 1940s, Ernst T. Krebs, Jr. (1912-1996), a graduate student in the anatomy department of the University of California Medical School, San Francisco, began to reinterpret Beard's writings. Together with his father, a San Francisco physician, he created the John Beard Memorial Foundation. In 1946, he published a letter in the Journal of the American Medical Association on the "pathology of the trophoblast." In this, he discussed 20 areas of identity between trophoblasts and cancer, concluding, "These data suggest that the trophoblast cell per se is malignant."

He argued, in good Beardian fashion, that cancer was a single disease whose individual characteristics were caused by hormonal factors in the microenvironment of the various anatomical sites in which it occurs (7, 8). In July 1950, he published his key work, "The Unitarian or Trophoblastic Thesis of Cancer." Over the next four decades Krebs refined his theory that "cancer is trophoblast" growing at the wrong time and in the wrong place (9). Towards the end of his life, Krebs dogmatically characterized his theory as the "trophoblastic fact of cancer."

It was Beard's misfortune, however, that his champion subsequently co-invented Laetrile, a trade name for amygdalin, the cyanide-containing glycoside naturally present in bitter almonds, apricot kernels and other foods. Krebs and his supporters vigorously promoted Laetrile's use as an anti-cancer vitamin. This notion was entirely foreign to Beard's thinking, but the reputation of the trophoblastic theory became intertwined with the trials and tribulations of Krebs's alleged "vitamin B17." Krebs himself died in 1996, having done much to promote, but also to discredit, the work of his master.

Role of hCG

If all human cancers were trophoblastic in origin, one might expect them to express human chorionic gonadotropin (hCG). hCG is the standard hormonal marker of pregnancy and the standard marker for germ cell tumors. In 1994, scientists at Columbia University showed that cancer cells express hCG in all its forms (10).

In mid-1995, Prof. Hernan Acevedo and colleagues showed that the "synthesis and statement of hCG...is a common biochemical denominator of cancer" (11). Acevedo demonstrated the presence of hCG, its subunits, and/or fragments, in 85 different cancer cell lines (12-13). He also consistently found hCG in human malignant tumor tissues. Acevedo concluded that "hCG, the hormone of pregnancy and development that also has chemical and physiological properties of growth factors, is a common phenotypic characteristic of cancer." In his 1995 article in the journal Cancer, Acevedo concluded that, after nearly a century, "Beard has been proven to be conceptually correct..."

In an editorial in the same issue of the journal Cancer, Prof. William Regelson concurred, writing that hCG "defines the metastatic aggressiveness of the tumors in which it is found." Neither non-embryonic cells nor benign tumor cells express hCG. But hCG-beta is "a defining phenotypic statement of malignant transformation" (14).

Oncologist M. Rigdon Lentz, MD, PhD, similarly wrote that "pregnancy and cancer are the only two biologic conditions in which antigenic tissue is tolerated by a seemingly intact immune system" and that "trophoblastic tissue has all the characteristics of a true cancer; it is deeply invasive, it is highly anaplastic in morphology, it has a high mitotic index, and it produces oncofetal antigens...[I]n every respect, [it] behaves as a true cancer" (15).

In 1902, Beard had called attention to the role of "totipotent germ cells" in the development of cancer. In embryology, the word "totipotent" means that a cell is capable of giving rise to all types of differentiated cells found in that organism. This anticipated the contemporary attention to totipotent stem cells, although human embryonic stem cells (ESC) were not isolated until 1998 (16). Human ESCs are described as totipotent and in fact they release hCG (17,18). The relationship between Beard's totipotent germ cells and contemporary totipotent stem cells deserves further study.

Contemporary Use of Enzymes

The unconventional use of proteolytic enzymes to treat cancer remains widespread. The CAM practitioner Nicholas J. Gonzalez, MD, of New York City, uses pancreatic enzymes in his practice, along with a regimen of diet, nutritional supplements, and "detoxification." In 1993, Gonzalez presented selected cases to the National Cancer Institute (NCI). At their urging, he conducted and published a pilot study of the treatment of 11 patients with pancreatic cancer (19). That study was supported by the Nestle Corporation. According to the National Institutes of Health, "patients on the Gonzalez regimen lived an average of 17 and a half months, which is nearly three times the usual survival period for patients with advanced pancreatic cancer." As a result, NIH has funded a clinical trial at Columbia-Presbyterian Hospital, New York, with a grant of $1.4 million (20).

A century after Beard proposed it, the trophoblastic theory of cancer, and the pancreatic enzyme treatment that follows from it, are getting a scientific test. A successful outcome could lead to renewed interest in Beard’s therapeutic approach, an integration of his idea of the "totipotent germ cell" into stem cell research, and a reevaluation of his overall contribution to cancer science.

--Ralph W. Moss, Ph.D.

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