Results from a randomized phase 2 clinical trial show that adding high-dose, intravenous (IV) vitamin C to chemotherapy doubles the overall survival of patients with late-stage metastatic pancreatic cancer from eight months to 16 months. The findings, mark another success for high-dose, intravenous vitamin C, which has overcome many hurdles in the almost 20 years University of Iowa researchers have persevered to demonstrate its benefit for cancer patients. In the study, 34 patients with stage 4 metastatic pancreatic cancer were randomized to receive either standard chemotherapy (gemcitabine and nab-paclitaxel), or the chemotherapy plus infusions of high-dose vitamin C. The results showed that average overall survival was 16 months for the patients receiving the chemotherapy plus vitamin C, compared to eight months for the patients getting just chemotherapy. In addition, progression-free survival was extended from four months to six months.
The new study is not the only evidence of the benefit of including IV vitamin C as part of cancer treatment. Earlier this year, the results of another phase 2 clinical trial in patients with glioblastoma, a deadly form of brain cancer, were published. That study also showed a significant increase in survival when high-dose, IV vitamin C was added to standard of care chemotherapy and radiation. A third phase 2 trial in non-small cell lung cancer is still underway, with results expected within the year. All three trials were funded by a grant from the National Cancer Institute (NCI). This funding was incredibly important for us to conduct these phase 2 trials and obtain these really encouraging results. Our aim is to show that adding high-dose, IV vitamin C, which is very inexpensive and very well tolerated, can improve treatment for these cancers that are among the deadliest affecting the U.S. population.
Drs. Cullen, Allen and their colleagues at UI Health Care have been researching the anti-cancer effect of high-dose, IV vitamin C for decades. Their work revealed a critical difference between vitamin C given intravenously and vitamin C taken orally. Giving vitamin C through an IV produces very high levels in the blood, which cannot be achieved with oral delivery. These high concentrations result in unique chemical reactions within cancer cells that render the cells more vulnerable to chemo- and radiation therapies. Cullen notes that despite skepticism towards vitamin C as a cancer therapy, the results he and his colleagues have obtained, from basic science findings to understand the biological mechanisms at work, through the various clinical trials, have been highly encouraging and robust. The reslults apper the november issue of Redox Biology, a specilialized journal dedicated mostly to basic science about redox.dependent processes in cell biology.
However, Dr. Cullen and his lab is dedicating efforts to understand the applicability of high-dose vitamina C administration in another deadly cancer: glioblastoma, the most aggressive form of brain cancer. Some time earlier, a single-arm phase 2 clinical trial demonstrated a significant increase in overall survival when ascorbate was combined with temozolomide and radiotherapy. Last year he performed a clinical trial of Phase 2 administrating pharmacological ascorbate (i.v. delivery reaching plasma concentrations of about 20mM. Fifty-five articipants with newly diagnosed glioblastoma were enrolled in thistrial conducted at the University of Iowa. Tumor samples obtained during surgical resection were processed and stained for transferrin receptor and ferritin heavy chain expression. Through univariate analysis, a significant inverse association was observed between tumor transferrin receptor expression and overall and progression-free survival.
Results of the previous trial enlenghtened the overall survival from 17.6 to 26.5 months, representing a big step ahead for the treatment of this cancer. Beside, since ascorbate biology and toxicological effects on tumors rely of iron and its metabolism, the researchers deem that transferrin receptor and ferritin heavy chain expression may represent potential molecular markers to predict pharmacological ascorbate treatment response.
- Edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
Scientific references
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