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Gonzalez Regimen (PDQ®)

  • Last Modified: 02/04/2014

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Laboratory/Animal/Preclinical Studies

Directly relevant laboratory or animal data concerning the anticancer potential of the Gonzalez regimen are limited. Published animal studies focus on the role of pancreatic enzymes in cancer treatment rather than the regimen as a whole.

An animal study published in 1999 measured the ability of orally administered porcine pancreas preparation (PPP) to slow or halt the growth of cancer and to inhibit metastasis. Sixty Fischer F344 female rats were divided into five groups of 12 each. All groups were fed the same basic diet. After 5 days, R13762 transplantable rat mammary tumor was implanted into a mammary fat pad on each rat. The animals were maintained on their assigned diets for another 40 days. After the tumors had taken hold, two groups were given a high dose of PPP (20% by weight) and two groups were given a lower dose (2% by weight). The fifth group was used as a control and received no enzymes. In addition, one group from each of the PPP-dosed rat groups was also given a magnesium citrate supplement because magnesium is often given with PPP in clinical practice.[1]

Results showed that PPP had no effect on tumor growth, and PPP alone did not show any significant effect on the amount of metastases. However, when the rate of metastases in the rats dosed at the 20% rate was compared with those dosed at 2%, it was noted that there was an increase in metastases in the rats given a higher dose of PPP. The lowest rate of metastases was seen in the rats given the 2% dose plus magnesium citrate.[1]

In another study, the effects of porcine pancreatic enzyme (PPE) extracts on survival and tumor growth were examined in 5- to 6-week-old male beige X-linked immunodeficient mice. In the survival study, two groups of mice received pancreatic cancer cells AsPc1 injected into their pancreas. The treatment group (14 mice) received PPE in water at a dose of 400 mg/kg of body weight, which corresponds to the dose used in patients receiving the Gonzalez regimen. The control group (13 mice) was given only water. After death, the pancreas was removed and measured for volume and weight. The median survival rates for the treatment group and the control group were 43.5 days and 35 days, respectively. At day 35, the survival rates were 79% in the treatment group and 38% in the control group. In addition, the control mice showed reduced activity as compared with the treatment group, which showed normal activity and no signs of disease. In general, the size of tumors and the rate of invasion in the liver and peritoneum correlated with length of survival time.[2]

In the tumor growth segment of this study, a second group of 30 mice was taken through the same procedures. Tumor size and weight were measured in two mice from each group on day 52, and again in two mice from the control group and five mice from the treatment group on day 60. Ascites were much more apparent in the control group than in the treatment group. Physical activity among the treated mice was much greater than in the control group. Results showed that the treatment group had significantly smaller tumors than the control group in both weight and volume. The mean tumor weight was 1.2 g in the control group and 0.75 g in the treatment group. The tumor volume was 0.42 cm3 in the treatment group and 0.91 cm3 in the control group. All mice in the control group showed steatorrhea, hyperglycosuria, hyperbilirubinuria, and ketonuria in the early stages of tumor growth, whereas in the treated group only a few mice showed these abnormalities in the final stages. There were no differences in the tumors of the treatment and control groups in the expression of growth factors, epidermal growth factor receptor, or apoptotic rate.[2]

References
  1. Cohen LA, Aliaga C, Pittman B, et al.: Oral enzyme therapy and experimental rat mammary tumor metastasis. Life Sci 65 (24): 2603-14, 1999.  [PUBMED Abstract]

  2. Saruc M, Standop S, Standop J, et al.: Pancreatic enzyme extract improves survival in murine pancreatic cancer. Pancreas 28 (4): 401-12, 2004.  [PUBMED Abstract]