Naturally occurring symptoms may be mistaken for tamoxifen side-effects

December 09, 2016

Women taking tamoxifen to prevent breast cancer were less likely to continue taking the drug if they suffered nausea and vomiting, according to new data presented at the San Antonio Breast Cancer Symposium* today (Friday).

The researchers found that women who experienced these symptoms after starting tamoxifen as part of the Cancer Research UK funded International Breast Cancer Intervention Study (IBIS-1),** were more likely to stop taking the medication.

But this new analysis also reveals that women given a placebo who experienced the same symptoms were equally as likely to stop. This suggests that some symptoms due to other causes, were being mistaken for side effects of tamoxifen.

Previous results from the IBIS-1 trial showed that tamoxifen reduces the incidence of breast cancer among women at a high risk of the disease by over 30 per cent. These preventive effects last for more than 20 years.

However, a third of women on the trial did not continue with treatment for the recommended five years.

In this examination of the trial data, the researchers based at the University of Leeds and Queen Mary University of London, looked at symptoms that may have led to women not taking the full course of therapy.

While some women who stopped the medication experienced menopausal side effects*** including hot flushes and gynaecological changes, others may have stopped after mistakenly linking vomiting and nausea to the drug. This suggests that the understanding of what may be causing certain symptoms could be an important barrier to some women continuing with tamoxifen.

The highest drop-out rates occurred within the first 12 months of the IBIS-1 trial, highlighting a period during which interventions to support women should be targeted.

Dr Samuel Smith, a Cancer Research UK fellow and university academic fellow at the University of Leeds, said: "Our findings have implications for how doctors talk to patients about the benefits and side effects of preventive therapies such as tamoxifen.

"It's important to manage expectations and provide accurate information on the likelihood of experiencing specific side effects and how these differ from symptoms that women may experience anyway.

"The high drop-out rate observed in the early stages of the trial suggest that more support is needed to help women understand and manage side-effects that may be linked to their treatment."

Sarah Williams, Cancer Research UK's health information manager, said: "Breast cancer is the most common cancer in the UK but research is helping us find new ways of preventing the disease in women at high risk.

"While drugs such as tamoxifen and anastrozole can cut the risk of the disease, they do cause side effects. Research like this to understand more about the side effects women experience and the decisions this leads them to make, is vital to offering them appropriate support so they can make the best choice for them.

"It's important for anyone experiencing symptoms that are unusual for them, that don't clear up, or that keep coming back to tell their doctor."
-end-
For media enquiries contact Kathryn Ingham in the Cancer Research UK press office on 020 3469 5475 or, out of hours, on 07050 264 059.

Notes to editor:

* http://www.abstracts2view.com/sabcs/

** IBIS-I was carried out at the Wolfson Institute of Preventive Medicine, Queen Mary University of London, with Professor Jack Cuzick as its principal investigator.

This trial looked at whether the hormone therapy drug tamoxifen could reduce the risk of breast cancer developing in women who are at a high risk of getting it. This trial was supported by Cancer Research UK.

http://www.cancerresearchuk.org/about-cancer/find-a-clinical-trial/ibis-international-breast-cancer-intervention-study#undefined

*** Side effects of Tamoxifen include typical menopausal symptoms such as hot flushes and gynaecological changes as well as headaches, nausea and vomiting.

http://www.cancerresearchuk.org/about-cancer/cancers-in-general/treatment/cancer-drugs/tamoxifen

About Cancer Research UK

For further information about Cancer Research UK's work or to find out how to support the charity, please call 0300 123 1022 or visit http://www.cancerresearchuk.org. Follow us on Twitter and Facebook

Cancer Research UK

Related Breast Cancer Articles from Brightsurf:

Oncotarget: IGF2 expression in breast cancer tumors and in breast cancer cells
The Oncotarget authors propose that methylation of DVDMR represents a novel epigenetic biomarker that determines the levels of IGF2 protein expression in breast cancer.

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.

Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.

Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.

More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.

Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.

Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.

Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.

Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.

Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.

Read More: Breast Cancer News and Breast Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.