Tag Archives: Vascular endothelial growth factor

Green tea may inhibit breast cancer

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Mechanisms of action for an oral green tea extract in breast cancer prevention have been identified.

The extract, Polyphenon E, appears to inhibit vascular endothelial growth factor and hepatocyte growth factor, both of which promote tumour cell growth, migration and invasion, researchers said.

They made this discovery during a secondary analysis of a phase Ib randomized, placebo-controlled study of Polyphenon E in a group of 40 women with hormone receptor-negative breast cancer.

“Many preclinical studies have looked at epigallocatechin-3-gallate, or EGCG, which is one of the main components of green tea, and the various possible mechanisms of its action against cancer, but it is very difficult to do those same kinds of studies in humans,” said Katherine D. Crew, M.D., assistant professor of medicine and epidemiology at Columbia University Medical Center in New York, N.Y.

“This study was too small to say for sure if green tea will prevent breast cancer, but it may move us forward in terms of understanding antitumor mechanisms,” she stated.

In the primary analysis, presented at last year’s Frontiers in Cancer Prevention Research meeting, 40 women were randomly assigned to 400 mg, 600 mg or 800 mg of Polyphenon E or to placebo twice daily for six months. During that time, researchers collected blood and urine samples from participants at baseline and at two, four and six months.

Green tea

Green tea

In this secondary analysis, Crew and colleagues used the blood and urine samples to examine biologic endpoints, such as inflammatory proteins, growth factors and lipid biomarkers, which might point to the mechanism of action behind green tea extract. Biomarker data were available for 34 of the 40 patients.


Women assigned to the extract had an average 10-fold increase in green tea metabolites compared with placebo. In addition, they had a significant reduction in hepatocyte growth factor levels at two months compared with women assigned to placebo. However, at the four-month and six-month follow-ups, the difference was no longer statistically significant.

The researchers also identified a trend toward decreased total serum cholesterol and decreased vascular endothelial growth factor in women assigned to the extract.

According to Crew, it is still too early to recommend green tea extract to prevent breast cancer. Currently, researchers are conducting several ongoing studies to explore the use of oral green tea extract in high-risk women for the primary prevention of breast cancer.

New thyroid cancer drug approved

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The European Commission has approved AstraZeneca’s thyroid cancer pill Caprelsa.

Caprelsa (vandetanib) is now available in Europe for the treatment of aggressive and symptomatic medullary thyroid cancer in patients with unresectable locally advanced or metastatic disease.

Advanced medullary thyroid cancer (MTC) is a rare type of the disease with a poor prognosis, and currently there are no approved therapies in Europe.

But whilst the drug was approved, there was one snag: Caprelsa may not be as beneficial in patients without, or are not known to have, a particular mutation – the Rearranged during Transfection (RET) mutation.

For patients in whom RET mutation is not known or is negative, a possible lower benefit should be taken into account before treatment, AZ said.

The firm added that its clinical data shows patients benefit from treatment with the drug regardless of their RET status.

But in line with Europe’s requirements, AZ said it would conduct a further study to confirm the benefits in patients who are RET-negative.

A pharmacovigilance plan for Caprelsa will also be implemented as part of the marketing authorisation, given its high number of common adverse events.

Thyroid gland

Thyroid gland

Caprelsa works as a once-daily oral treatment that uses two distinctive mechanisms of action.

The first is by blocking the blood supply to the tumour, by slowing the vascular endothelial growth factor receptor pathway and reducing the growth and survival of the tumour through epidermal growth factor receptor and RET pathways.

Caprelsa was first approved by the FDA and launched in April last year, and is expected to bring in $112 million a year by 2016, according to analysts.


This is a much lower prediction than the blockbuster figures touted last year, when the drug was also being investigated for non-small cell lung cancer.

The drug however failed to succeed in clinical trials involving this patient population.

But for MTC it has performed well in late-stage trials, and showed statistically significant improvements versus placebo, including six months additional progression-free survival.

Caprelsa may soon have some competition from Exelixis’ MTC candidate cabozantinib, which was granted orphan drug status by the FDA in January last year.

It also impressed in a Phase III study last October when its drug improved median progression-free survival in by 11.2 months, versus just four months in the placebo arm.