We searched PubMed and found a twenty-year-old abstract on a concept for cancer therapy:
Medical Hypotheses

1980 Jan;6(1):85-92
A minimal toxicity approach to cancer therapy: possible role of beta-glucuronidase
Rubin DM, Rubin EJ

Most cancer cells differ from normal cells in that they show higher beta-glucuronidase activity and lower pH of their cytoplasm. Anti-cancer drugs can be designed which take advantage of these gradients to deliver maximal toxicity to tumors and minimal toxicity to normal tissue. Many design criteria are suggested here, the most basic of which is the use of the glucuronide structure, in which glucuronic acid acts as a protective carrier of a toxic fragment which becomes active when split off by the beta-glucuronidase at the tumor site. The high beta-glucuronidase activity in cancer cells is also discussed here as a possible explanation for some of the pathognomonic features of a malignant growth: the automatic proliferation of tumor tissue, the invasion of tumors into adjacent tissue, the metastases to remote sites, and the weak response of the immune system.
PMID: 7382890, UI: 80209382

One other submission appeared three years later:

Med Hypotheses
1983 Apr;10(4):469-471
The possible role of tyrosinase in malignant growth
Rubin DM, Rubin EJ

This paper, which supports some of David Rubin's later work on his drug, is consistent with a paper in Cancer Res 1979 Sep;39(9): 3485-3490 Serum tyrosinase in malignant disease . . . " Chen YM, Lim BT, Chavin W. Chen's paper reported higher serum tyrosinase "in many persons with metastatic diseases," i.e. in cancer generally, although "The highest activity was observed in melanoma and breast carcinoma."

But a new assay had already found lack of higher tyrosinase activity except in melanoma. Int J Cancer 1977 Nov 5; 20 (5):689-693 Tyrosinase activity in the sera of patients with malignant melanoma: method and specificity. Nishioka K, Romsdahl MM, Fritsche HA Jr, McMurtrey MJ.

Research on tryosinase in melanoma continues to be very active but tyrosinase seems to be unimportant for most other cancers including prostate cancer. Dr. Rubin, it seems fair to say, has never modified his basic theory to bring it in line with new technology and research (unless to use those for window-dressing).

PubMed atNIH (National Institutes of Health). Search medical abstracts

We E-mailed
Quackwatch
and made contact with Wallace Sampson, M.D. We sent him material including the abstract (left). He replied:

Sat, 21 Mar 1998
To: [email protected]
From: wallace i sampson
Re: Glucuronide
The theory is similar to that of laetrile, which is a benzoic acid with a CN- at position 1, and side chains of glucosides (not glucuronides which are close cousins.)

The theory was that the enzyme, b-glucosidase was low in normal cells and higher in cancer cells, etc. This was a misinterpretation of the work of Anlyan et al in 1948 who reported higher b-glucuronidase in cancer cells. But both were subsequently proved incorrect, when all cells were found to have similar amounts of b-glucuronidase (and all mammalian cells have no b-glucosidase - cancer and normal).

Differences in respiration (oxidative and non-oxidative) thought to be present (Warburg) between cancer and normal cells were also found later to be insignificant despite the Nobel Prize having been won for that "discovery." Cancer cells can respire in absence of oxygen (fermentation) but do not have to. Fermentation produces lactic acid which lowers the pH, but nothing has ever come of that quality.

Medical Hypotheses is a journal that publishes anyone's ideas regardless of degree of connection to reality. It published Charles Gurchot's original laetrile ideas. But none of the above would give a rationale for why "glucuronides" would have anticancer effects. It is not surprising that followers and takers of glucuronides swear by them, as they did and do with laetrile, antineoplastons, etc. It is cult behavior, no matter which method is chosen, and none of them works.

W. Sampson, MD
Clinical Professor of Medicine
Stanford University School of Medicine.

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NEXT: People told us David Rubin has a lot of patents. We took a look and found they began from a laetrile reading list. And ended up 15 years later being used to make drugs tested (one notch up from laetrile) in clinical trials in Mexico.

PSA Rising Magazine April 15, 1998 http://www.psa-rising.org © 1997-1998.