The anticancer efficacy of the Gonzalez regimen has been investigated in two human studies (CPMC-IRB-8544 ), both involving patients with pancreatic cancer.
The first study, a prospective nonconsecutive case series conducted by the developer and an associate, included 11 patients diagnosed with adenocarcinoma of the pancreas (stage II through stage IV). None of the patients had received chemotherapy or radiation therapy, and none had undergone surgical resection with curative intent. All the patients had pancreatic tumors that were either unresected or partially resected. Survival from the time of diagnosis was the only study endpoint, and all 11 patients (including one who left the study) were included in this survival analysis.
This complementary and alternative medicine (CAM) information summary provides an overview of the use of milk thistle as a treatment and adjunct agent for people with cancer.
The summary includes a brief history of milk thistle, a review of the laboratory studies and clinical trials, and a description of adverse effects associated with milk thistle use.
This summary contains the following key information:
Milk thistle is a plant whose fruit and seeds have been used for more than 2,000 years...
The investigators reported a median survival time of 17 months and a mean survival time of 25.2 months for these patients. Nine patients (82%) survived 1 year, five patients (45%) survived 2 years, and four patients (36%) survived 3 years. At the time the study was reported, two patients were alive: one who had survived 3 years, and one had survived 4 years. The researchers concluded that the 1-year and 2-year survival percentages for this group of patients were superior to those observed for other U.S. patients diagnosed with adenocarcinoma of the pancreas (1-year survival, all stages = 25%; 2-year survival, all stages = 10%).
The small number of patients in this study and the absence of a control group are limitations that raise doubts about the reliability of its findings. It is possible that important, unidentified differences between these patients and other patients diagnosed with stage II to stage IV pancreatic cancer contributed to the relatively long survival. The investigators report that 25 additional patients with pancreatic cancer were seen during the study period but were excluded from study participation. Eleven of these patients were excluded on the basis of comorbidities, previous treatment, or delay between diagnosis and beginning the program; 14 otherwise eligible patients were excluded on the grounds that they chose not to start the program, complied only briefly, or predicted noncompliance.
The second study is a nonrandomized prospective case-control observational study sponsored by the National Center for Complementary and Alternative Medicine and the National Cancer Institute in which median survival and quality of life were found to be better in patients treated with gemcitabine -based (i.e., other drugs may be included) chemotherapy than for patients treated with the Gonzalez regimen. This study was originally planned for randomization but changed after few patients elected to participate in the randomized trial. The same eligibility criteria were used to select patients for both treatment arms. The results of this study were reported in the peer-reviewed Journal of Clinical Oncology. According to the report, 70 patients were evaluated for the study and 55 were enrolled: 23 in the gemcitabine arm and 32 in the enzyme treatment arm. The enzyme treatment included orally ingested proteolytic enzymes, nutritional supplements, detoxification, and an organic diet (as used in the pilot study by Gonzalez and Isaacs). Patients received three pancreatic enzyme capsules and two magnesium citrate capsules with each meal. The patients also took specified numbers of capsules with magnesium citrate and Papaya Plus every 4 hours on an empty stomach. The dose for patients with stage II disease was 69 enzyme capsules per day, and the dose for patients with stages III or stage IV was 81 capsules per day. After day 16, patients had a 5-day rest period and then resumed treatment on day 22. Patients in the experimental arm received proteolytic treatment under the care of a practitioner familiar with the regimen; those in the chemotherapy arm received treatment by the oncologist they selected. Treatment could be adjusted by the physician, and it could be increased for cancer progression. The gemcitabine treatment patients received various gemcitabine-containing regimens, with 19 of the 23 patients receiving a combination of gemcitabine, capecitabine, and docetaxel. The two groups had similar clinical characteristics. The median survival for the patients in the gemcitabine arm was 14 months and, on the enzyme arm, 4.3 months. The quality of life as measured by the FACT-PA was also better in the chemotherapy arm. The paper does not list Dr. Gonzalez as an author, and does not identify him as participating in the study; however, Dr. Gonzalez published comments on his Web site indicating his participation in the study and detailing his concerns about how the study was conducted, including patient compliance with the prescribed treatment in the enzyme arm.