Lifestyle choices are pieces of the cancer prevention puzzle, but exactly which steps to take remain unclear, even to scientists. Still, more and more individuals are incorporating small changes into their daily routine such as drinking green tea in hopes of keeping cancer risk at bay.

Is it working? A large new Cochrane review of studies that examined the affect of green tea on cancer prevention has yielded conflicting results.

Researchers looked at 51 medium- to high-quality studies that included more than 1.6 million participants. The studies focused on the relationship between green tea consumption and a variety of cancers, including breast, lung, digestive tract, urological prostate, gynecological and oral cancers.

The comprehensive review analyzed studies conducted from 1985 through 2008. Many of the reviewed studies took place in Asia, where tea drinking is widespread and part of the daily routine for many.

The review appears in the latest issue of The Cochrane Library, which is a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

“Despite the large number of included studies the jury still seems to be out on the question of whether green tea can in fact prevent the development of various cancer types,” said lead review author Katja Boehm, Ph.D. Since people drink varying amounts of green tea, and different types of cancers vary in how they grow, it is impossible to state definitively that green tea is “good” for cancer prevention.

“One thing is certain…green tea consumption can never account for cancer prevention alone,” said Boehm, a member of the Unconventional and Complementary Methods in Oncology Study Group in Nuremburg, Germany.

Three types of tea black, green and oolong come from the plant Camellia sinensis, and all contain polyphenols. Catechins, a subgroup of the polyphenols, are powerful antioxidants. Some say the polyphenols in green tea are unique, preventing cell growth and thus having the potential to prevent cancer.

The review found that green tea had limited benefits for liver cancer, but found conflicting evidence for other gastrointestinal cancers, such as cancer of the esophagus, colon or pancreas. One study found a decreased risk of prostate cancer for men who consumed higher quantities of green tea or its extracts.

The review did not find any benefit for preventing death from gastric cancer, and found that green tea might even increase the risk of urinary bladder cancer. Despite conflicting findings, there was “limited moderate to strong evidence” of a benefit for lung, pancreatic and colorectal cancer. None of the studies that simply observed a group of people over time found a benefit for breast cancer prevention. However, both of the case control studies which compare people without a condition to people with it found a positive association between green tea consumption and a decreased risk of breast cancer.

Nagi Kumar, Ph.D., director of Nutrition Research at Moffitt Cancer Center in Tampa, Fla., is optimistic about the potential for green tea in cancer prevention. “The substances found in green tea are certainly promising,” Kumar said. “The field now has progressed to where we [can]…test the effectiveness and safety of green tea polyphenols using a drug form similar to the constituents in tea to see if we can prevent cancer progression. Time will tell.”

Kumar said the Cochrane review was “more an inventory of studies completed rather than a systematic scientific review,” adding that “the discussion lacks a scientific approach in the interpretation of the discordant findings.”

Kumar also noted that several groups are conducting randomized clinical trials, including one comprising six institutions: the Moffitt Cancer Center and the James A Haley VA Medical Center, University of Chicago, Jefferson in Philadelphia, University of Florida and Louisiana State University.

Both scientists agreed that more research is a good idea. Boehm said she highly recommends the conduction of a large, well-designed, study with adequate green tea consumption levels.

“The review provides where we have been in this field of research and where we are going and how much more we have on hand,” Kumar said. “Although not as thorough as I would like it, it is a good quality review.”

Therefore, while the questions about green tea consumption and cancer prevention remain unanswered, one thing remains clear: It is fine to consume green tea if you enjoy it and it might prove beneficial in the over time.

“If not exceeding the daily recommended allowance those who enjoy a cup of green tea should continue its consumption,” Boehm said. “Drinking green tea appears to be safe at regular, habitual and moderate use at its recommended dosage of up to 1200 ml/day.” That comes to a little over five cups a day.

The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions.

Boehm K, et al. Green tea (Camellia sinensis) for the prevention of cancer. Cochrane Database of Systematic Reviews Issue 3, 2009.

Source: Health Behavior News Service

Keryx Biopharmaceuticals, Inc. (Nasdaq: KERX) announced today the initiation of a Phase 1 clinical study to evaluate KRX-0401 (perifosine) as a single agent treatment for recurrent solid tumors in pediatric patients. This Phase 1 study is now open for enrollment at Memorial Sloan-Kettering Cancer Center in New York City. Oren Becher, MD, Instructor, Department of Pediatrics, in coordination with Eric Holland, MD, PhD, Director of the Brain Tumor group at Memorial Sloan-Kettering Cancer Center, will act as the study’s Principal Investigator. The study announced is being fully funded by an external grant provided by a private organization.

KRX-0401 is a novel, oral, anticancer agent that modulates Akt and several other important signal transduction pathways. Keryx is currently in the process of finalizing late-stage protocols for Perifosine in the treatment of Multiple Myeloma and Metastatic Colon Cancer.

STUDY RATIONALE:

Activation of the PI3K/AKT pathway has been associated with poor prognosis, or proliferation, in several pediatric tumors such as neuroblastoma, glioblastoma, rhabdomyosarcoma, and medulloblastoma. Perifosine’s inhibition of this and other pathways, as well as its ability to cross the blood-brain barrier has generated much interest in exploring its potential activity in the treatment of patients with advanced brain tumors. In vitro and in vivo data presented at AACR 2009 by investigators from the National Cancer Institute demonstrated that single agent perifosine not only induced tumor regression and delayed tumor growth, but that perifosine also improved the survival of mice bearing neuroblastoma tumors. Moreover, in a Phase 2 study conducted at Memorial Sloan-Kettering Cancer Center, perifosine induced responses and delayed disease progression in adult patients with advanced brain tumors.

Additionally, combination studies of perifosine with novel agents in patients with advanced brain tumors are expected to commence later this year. Such studies also to be funded by external grants.

Ron Bentsur, Chief Executive Officer of Keryx Biopharmaceuticals, commented, “We’re very excited that Memorial-Sloan Kettering has taken on a leadership role in the first pediatric study of perifosine.” Mr. Bentsur continued, “We are extremely grateful for the external financial support which we have received, and we look forward to working with Drs. Becher and Holland, and their team of renowned oncologists on this study.”

STUDY DESIGN:

The single-center, open-label, Phase 1 study is entitled “Study of Single Agent Perifosine for Recurrent Pediatric Solid Tumors.” In this study, perifosine is being evaluated as a single-agent in pediatric patients with any solid tumor that has failed standard therapy. Patients up to 18 years of age with a performance status of greater than 40% are eligible for this study. The study has been designed as a dose escalation study to determine the maximum tolerated dose (MTD) of perifosine alone in recurrent/progressive pediatric tumors. A standard 3+3 dose escalation design will be employed with 3 to 6 patients at each dose level. All patients will receive perifosine at a loading dose on the first day, followed by a maintenance dose to start on day two until progression of disease. A minimum of 4 and a maximum of 24 patients will be required to complete the study.

KRX-0401 (perifosine) is in-licensed by Keryx from Aeterna Zentaris, Inc. in the United States, Canada and Mexico.

About Recurrent Pediatric Tumors

Approximately 12,400 children and adolescents younger than 20 years of age are diagnosed with some type of cancer each year. Among these, approximately 2,300 children and adolescents die of cancer each year making cancer the most common cause of disease-related mortality for children 1 to 19 years of age. (NCI SEER Data) There are 12 major types of childhood cancers, and of these leukemias, brain and other central nervous system tumors (ie, gliomas and medulloblastomas) account for over 50% of the new cases. The remainder of new cases include extracranial tumors such as neuroblastomas, Wilms tumors, and rhabdomyosarcomas. Although improvements in imaging equipment and treatments have resulted in an overall decline in mortality and increased survival, approximately half of all children with malignant solid tumors will experience relapse and, of these children, less than 10% will achieve long-term survival after standard multimodal therapy.

About Keryx Biopharmaceuticals, Inc.

Keryx Biopharmaceuticals is focused on the acquisition, development and commercialization of medically important, novel pharmaceutical products for the treatment of life-threatening diseases, including renal disease and cancer. Keryx is developing Zerenex(TM)(ferric citrate), an oral, iron-based compound that has the capacity to bind to phosphate and form non-absorbable complexes. Zerenex has recently completed a Phase 2 clinical program as a treatment for hyperphosphatemia (elevated phosphate levels) in patients with end-stage renal disease. The Company is also developing KRX-0401 (perifosine), a novel, potentially first-in-class, oral anti-cancer agent that modulates Akt, a protein in the body associated with tumor survival and growth. KRX-0401 also modulates a number of other key signal transduction pathways, including the JNK and MAPK pathways, which are pathways associated with programmed cell death, cell growth, cell differentiation and cell survival. KRX-0401 is currently in Phase 2 clinical development for multiple tumor types. The Company also actively engages in business development activities that include seeking strategic relationships for its product candidates, as well as evaluating compounds and companies for in-licensing or acquisition. Keryx is headquartered in New York City.

Cautionary Statement

Some of the statements included in this press release, particularly those anticipating future clinical and business prospects for KRX-0401 (perifosine), may be forward-looking statements that involve a number of risks and uncertainties. For those statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. Among the factors that could cause our actual results to differ materially are the following: our ability to successfully complete clinical trials for KRX-0401; our ability to successfully finalize late stage protocols for KRX-0401 with the FDA; our ability to meet anticipated development timelines for KRX-0401 due to recruitment, clinical trial results, manufacturing capabilities or other factors; and other risk factors identified from time to time in our reports filed with the Securities and Exchange Commission. Any forward-looking statements set forth in this press release speak only as of the date of this press release. We do not intend to update any of these forward-looking statements to reflect events or circumstances that occur after the date hereof.

Source: Keryx Biopharmaceuticals, Inc

SCIENTISTS have developed a new drug which can reduce the growth of tumours* in mice by up to 98 per cent, according to a study published in Molecular Cancer Therapeutics ** this week.

The work was carried out by researchers from Roche ***.

In this study, the team of scientists found that the drug reduced the growth of glioblastoma - the most common form of brain tumour - in mice by 98 per cent and decreased the growth of ovarian tumours in mice by 80 per cent. In separate investigations, scientists also found the drug worked against a number of cell lines derived from other human cancers.

The team used markers to show how the drug works by targeting the PI3 kinase pathway ****, which is known to be linked to the growth and spread of many cancers.

The drug works by blocking this pathway which is often ‘hijacked’ in human cancers - enabling them to grow and spread. It corrects faulty genetic signals that cause unrestricted cancer progression, as well as preventing the function of cells in the body that support the tumour by increasing its essential blood supply - a process called angiogenesis.

The researchers who conducted these laboratory studies believe that GDC-0941, licensed to Genentech by Piramed, may have potential in a wide range of human cancers. At Genentech, GDC-0941 has progressed into Phase I clinical trials in the UK and the USA. Scientists and oncologists from Genentech have designed several trials to determine how GDC-0941 works in humans.

Lead author of the article describing the pre-clinical lab studies, Professor Paul Workman, director of the Cancer Research UK Centre for Cancer Therapeutics at the ICR said: “We know the PI3 kinase super-highway is hijacked in many cancers. We show here that GDC-0941 works in the way it was designed to, inhibiting the PI3 kinase pathway and blocking tumour growth.”

“Our hope is that that we have created a potent anti-cancer weapon that directly targets the processes which feed the cancer cells while sparing most of the healthy cells. But it’s early days and we still have a lot to learn about the potential of this drug. The next step is to see if the drug targets human cancers as effectively.”

The Institute of Cancer Research’s chief executive Professor Peter Rigby said:”We are very excited about the promise this drug is showing in targeting a range of cancers in the laboratory, and look forward to the results of the ongoing clinical trials.”

Cancer Research UK’s chief executive, Harpal Kumar, said: “We’re delighted to see our investment over many years in understanding this aspect of cancer bear fruit in the form of a drug that is showing promise in early studies. We hope further investigation into this drug will continue to yield positive results which could lead to a powerful new weapon to treat a wide range of cancers.”

Notes

*This percentage growth was measured by comparing the size of the tumours growing in the mice that were given the drug in comparison to the mice that were not given it.

**Biological properties of potent inhibitors of class I phosphatidylinositide 3-kinases: from P1-103 through P1-540, P1-620 to the oral agent GCD-0941. Molecular Cancer Therapeutics. F. Raynard. July 2009.

***This work was carried out by the Cancer Research UK Centre for Cancer Therapeutics and the start-up company Piramed, which was established by Cancer Research Technology (CRT), The Institute of Cancer Research (ICR) and the Ludwig Institute of Cancer Research. Cancer Research UK has supported much of this work. The development of this drug is being carried out by Genentech, which licensed the drug from Piramed, and is now owned by Roche.

****PI3 kinase is the short name for the phosphatidylinositide 3-kinase.

Source
Cancer Research UK