Research projects

Ginkgo biloba preserves cognitive function in women treated with adjuvant chemotherapy for early breast cancer: A double-blind, placebo-controlled, randomised phase III trial

Principal researchers

Associate Professor Janette Vardy 1, 2
Dr Haryana Dhillon1
Dr Melanie Bell1
Prof Martin Tattersall 1, 3
Dr Lucette Cysique4
Associate Professor Frances Boyle 5,1
Prof Stephen Clarke 6,1 
Prof Andrew McLachlan1
Dr Victoria Bray1
Associate Professor Philip Beale2
Dr Stephen Della-Fiorentina7
Associate Professor Jane Beith3
Dr Anne Sullivan2
Dr Catriona McNeil3
Dr Belinda Kiely3
Dr Lorraine Chantrill8
Dr Ray Asghari9
Dr Davendra Segara9


1 University of Sydney
2 Sydney Cancer Centre, Concord Repatriation General Hospital
3 Sydney Cancer Centre, Royal Prince Alfred Hospital
4 University of NSW
5 The Mater Hospital Northern Clinical School
6 Royal North Shore Hospital
7 Bowral Hospital
8 Macarthur Cancer Therapy Centre, Campbelltown Hospital
9 Bankstown Hospital


$200,000 (Total funding $600,000)

Co-funded with

Cancer Australia

Award type

Priority-driven Collaborative Cancer Research Scheme (PdCCRS)

Project completion year


Project brief

Up to 70 per cent of breast cancer survivors report cognitive symptoms after chemotherapy and around 30 per cent have cognitive impairment on formal neuropsychological (NP) testing. There is no proven treatment. The herb Ginkgo biloba (GB) has been shown in randomised placebo controlled trials to improve cognitive function in the cognitive domains most often impaired in cancer survivors (i.e. working memory, executive function, processing speed and memory retrieval) with no difference in side-effects in the GB arms and the placebo arms. The researchers’ pharmacokinetic pilot study confirms that GB does not interact with chemotherapy or endocrine therapy. They aim to evaluate in a prospective, longitudinal, randomised placebo-controlled trial whether GB improves cognitive function in women with localised breast cancer who receive adjuvant chemotherapy.


  1. Women receiving GB will report less cognitive impairment
  2. Women receiving GB will have less measurable (objective) impairment
  3. GB improves fatigue4) GB improves quality of life (QoL)
  4. Increased levels of pro-inflammatory cytokines are predictive of cognitive impairment and fatigue
  5. GB decreases cytokine levels.

Research plan

The study is a longitudinal, phase III, multicentre double-blind, randomised placebo-controlled trial with stratification by chemotherapy regimen. The study population consists of women with breast cancer who will be receiving adjuvant chemotherapy with an anthracycline and/or a taxane regimen and trastuzumab. Consenting patients will be randomised to receive either a standardised extract of GB (EGb 761 120mg bd) or placebo for 12 months, and will have NP testing, questionnaires evaluating self-reported cognitive function, fatigue and QoL. They will also have blood tests prior to commencing chemotherapy,  and at three, six, 12 and 24 months.

Outcomes in those who receive GB and those who do not will be compared. Women will also donate blood for cytokine levels.


The primary outcome will be self-reported cognitive function (FACT-COG Perceived Cognitive Impairment scale -PCI). Secondary outcomes will include objective NP performance, fatigue, QoL, anxiety, depression, stress and menopausal symptoms. Potential mechanisms of cognitive impairment will be investigated (cytokines, sex hormones, blood clotting factors, apolipoprotein E4 genotyping).

Statistical analysis

A sample size of 240 provides 94 per cent power to detect a difference of 6.7 on the FACT-Cog PCI subscale, allowing for 30 per cent attrition. Linear mixed models will be used to model all continuous outcomes while accounting for covariance between repeated measures on patients and adjusting for baseline measures.

Potential outcomes and significance

Cognitive impairment is recognised by breast cancer survivors as an important side-effect of treatment that impairs function and QoL. There is no known prevention or treatment. A number of cancer patients take GB without proof of efficacy. Here it will be determined if GB is able to prevent cognitive impairment in women with breast cancer receiving potentially curative chemotherapy. This study has the potential to improve breast cancer survivors’ QoL and their ability to function in their day-to-day activity, as well as exploring the underlying mechanisms of cognitive impairment in cancer survivors.

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