LATTE 

Full Title: Long-term Anastrozole versus Tamoxifen Treatment Effects

Study acronym: LATTE

Sponsor: Queen Mary University of London

Funder(s): Cancer Research UK, AstraZeneca

Chief Investigator: Prof Jack Cuzick, Professor of Epidemiology, Queen Mary University of London

Contact(s):

• Prof Jack Cuzick – j.cuzick@qmul.ac.uk

• Miss Joanna Zahedi (Project Manager/Data Manager) – j.zahedi@qmul.ac.uk

Registration: https://www.clinicaltrials.gov/study/NCT01745289

Background:

LATTE follows participants from the ATAC trial (Arimidex, Tamoxifen, Alone or in Combination), a large international randomised, double-blind study that ran from 1996–2003. ATAC compared three adjuvant hormone treatments in post-menopausal women with early breast cancer: anastrozole (Arimidex) alone, tamoxifen (Nolvadex) alone, or a combination of both.

ATAC included 9,366 women across 20 countries, who were randomised to receive one of the three treatments for five years, followed by five years of additional follow-up. The trial showed that anastrozole was more effective than tamoxifen at preventing recurrence in hormone receptor-positive breast cancer, with fewer serious side effects. Combination therapy offered no additional benefit over tamoxifen alone, so participants on combination therapy were subsequently switched to a single drug. The results of ATAC influenced clinical guidelines, including NICE recommendations for anastrozole as first-line therapy in post-menopausal women with early breast cancer.

LATTE focuses specifically on the long-term outcomes of ATAC participants who received monotherapy (anastrozole or tamoxifen).

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Purpose of the Study:

LATTE is designed to determine whether long-term results differ between women treated with anastrozole and those treated with tamoxifen in the ATAC trial. The study focuses on cancer recurrence after the initial ATAC follow-up and overall survival. Long-term safety (including fractures), major ischaemic cardiac and cerebrovascular events along with any new primary cancers (contralateral or other sites) that have been caused by the long-term effects of tamoxifen and anastrozole will also be evaluated.

This study provides essential evidence on the relative efficacy and safety of these two adjuvant treatments over a prolonged period, helping clinicians and patients make informed decisions. 

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Who Can Take Part?:

Participants include women who:

• Took part in the ATAC trial between 1996–2003

• Were post-menopausal and aged 45 or older at randomisation

• Were randomised to monotherapy (anastrozole or tamoxifen)

• Were alive at the 10-year ATAC follow-up

Participants who withdrew consent or whose follow-up is not possible are excluded. Women who received the combination therapy in ATAC were also not included. 

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What Participation Involves:

LATTE is a non-interventional follow-up study, meaning participants do not attend study visits or provide new samples. Information is collected either from the original ATAC trial sites (2010–2019) or from routine NHS Digital registries (2019 onward). These registries supply updates on cancer diagnoses, further treatments, and deaths.

There is no direct patient contact, and participation involves no additional procedures or appointments.

Recruitment Status:

-Status: No longer recruiting

-Date of final enrolment: 21/01/2019

Study Design and Status:

The LATTE study follows participants from the ATAC trial to collect extended outcome data. Between 2010 and 2019, follow-up information was obtained through the original ATAC sites. From 2019 onwards, long-term outcomes for UK participants have been gathered via NHS Digital, including updated cancer diagnoses and mortality information.  Post-menopausal women previously enrolled in the ATAC trial are included and over 1,000 UK participants continue to be followed through routine registry data.

Expected Outcomes:

The information collected during LATTE will be used to assess long-term differences between anastrozole and tamoxifen, including cancer recurrence rates, overall survival, efficacy and adverse effects and long-term safety. Findings will help clinicians and patients understand how these endocrine therapies compare many years after treatment has ended with the aim to guide treatment decisions for post-menopausal women with early breast cancer.

This includes evaluation of:

• Late recurrence risk

• Long-term survival outcomes

• Differences in late-emerging side effects

 

Participant Information:

If you took part in the ATAC/LATTE trial and wish to either withdraw your consent for the use of additional follow-up data or would like to know which treatment you were originally assigned, please email bartsctu-fup@qmul.ac.uk.

Study Completion Date:

• 28/02/2026