The Scottish Breast Studies Group (SBSG) continues the work of the Scottish Cancer Trials Breast Group (SCTBG). For over forty years, this network has connected surgeons, oncologists, pathologists, and scientists from Edinburgh, Glasgow, Dundee, Aberdeen, and Inverness.

Using Scotland’s integrated healthcare system, the Group has produced evidence that has influenced clinical practice globally. The history of the group is defined by a series of trials led by Scottish investigators which have contributed to international standards of care.

Screening and Early Detection (1970s)

The origins of the Group are linked to Professor Sir Patrick Forrest (University of Edinburgh). In the late 1970s, during a period of debate regarding the efficacy of mammography, Sir Patrick and his colleagues launched the Edinburgh Randomised Trial of Breast Cancer Screening.

Recruiting over 44,000 women, this study provided data regarding mortality reduction that was used to evaluate population-based screening. The findings supported the 1987 Forrest Report, chaired by Sir Patrick, which led to the establishment of the NHS Breast Screening Programme.

Surgical Conservation and Innovation (1980s–1990s)

Following the shift from mastectomy to breast-conserving surgery, the Group investigated the necessity of additional treatments. The Scottish Breast Conservation Trial (launched 1985) examined whether postoperative radiotherapy could be omitted in selected patients.

This study is noted for its long-term follow-up. A 30-year update published in the 2020s, provided data through novel techniques applied to historical bio-samples confirming that for specific low-risk biological subgroups, the omission of radiotherapy increased local recurrence but did not affect overall survival.

In Glasgow, Professor Tim Cooke (St Mungo Professor of Surgery) was a pivotal figure during this period. He was instrumental in modernizing surgical oncology in the West of Scotland, championing the multidisciplinary team approach that is now standard practice, and driving research into the biological behaviour of breast cancer cells, with UK leadership in HER2 testing.

Systemic and Endocrine Therapy (1990s–2000s)

In the 1990s, the Group focused on adjuvant systemic therapy. The SCTBG BR9601 trial was a Phase III study investigating the efficacy of anthracyclines. Scottish investigators collaborated with the National Epirubicin Adjuvant Trial (NEAT) to pool data, demonstrating that adding Epirubicin to standard CMF regimens improved survival outcomes.

Rob Leonard and John Crown established the Anglo-Celtic Cooperative Oncology Group to unite UK and Irish patient populations, enabling them to conduct large-scale, powered studies like the Anglo-Celtic I (comparing doxorubicin/docetaxel vs. AC) and Anglo-Celtic IV (optimizing paclitaxel scheduling) trials that refined the use of taxanes in adjuvant breast cancer treatment.

Laying the foundation for the subsequent SOFT and TEXT trials, a major collaboration between SCTBG and Guy’s demonstrated that ovarian ablation offered survival rates equivalent to CMF chemotherapy for premenopausal women with ER-positive breast cancer. This pivotal finding established that endocrine control could match the efficacy of cytotoxic drugs in hormone-sensitive disease, fundamentally reshaping adjuvant treatment strategies.

In Aberdeen, Professors Andrew Hutcheon and Steven Heys led the Aberdeen Neoadjuvant Trial. This study focused on patients with large or locally advanced breast cancers and demonstrated that introducing the drug docetaxel sequentially after anthracycline-based chemotherapy significantly increased response rates. This was a key study in establishing the utility of taxanes in the neoadjuvant setting.

Concurrently, Professor Mike Dixon in Edinburgh established himself as a global leader in endocrine therapy. His pioneering work on neoadjuvant letrozole and aromatase inhibitors fundamentally altered the management of large operable breast cancers. Professor Dixon’s research was instrumental in defining the biological drivers of response to hormonal treatments and refining surgical techniques for breast conservation.

Translational Excellence and Biomarkers

As research moved toward genomic profiling and precision medicine, the Group expanded its translational capabilities.

Professor John Bartlett played a crucial role in this evolution, driving significant biomarker research that underpinned major trials such as TEAM and TACT. His work in translational pathology ensured that Scottish clinical trials did not just answer “what works,” but “why it works,” linking clinical outcomes to molecular drivers.

In Dundee, Professor Alastair Thompson became a critical leader in this space. Serving as Chair of the NCRI Breast Clinical Studies Group, he played a central role in the landmark MINDACT trial. This international study evaluated genomic signatures (MammaPrint) to identify women who could safely avoid chemotherapy, marking a major step toward de-escalation based on biology.

Radiotherapy Optimization (2000s)

Under the leadership of Professor Ian Kunkler, the Group conducted radiotherapy trials designed to assess treatment necessity. PRIME II was a randomized trial that recruited over 1,300 women aged 65 and over. It demonstrated that for low-risk, hormone receptor-positive patients, omitting radiotherapy after breast-conserving surgery was a safe option that did not impact overall survival. SUPREMO (BIG 2-04) was a trial that investigated the role of chest-wall radiotherapy following mastectomy in intermediate-risk disease, refining the selection criteria for post-mastectomy radiation.

International Leadership

As clinical research expanded globally, Scottish investigators took on prominent leadership roles. Professor David Cameron, a long-standing member of the Group was Chief Investigator of the TACT2 trial, served as the Chair of the Breast International Group (BIG).

Based in Brussels, BIG is the world’s largest network of academic breast cancer research groups. Under Professor Cameron’s leadership, Scottish researchers participated in massive international collaborations. Notably, Professor Cameron served as Chief Investigator for the global BEATRICE trial. While the trial found that adding bevacizumab did not improve outcomes in triple-negative breast cancer, the study set a global benchmark for the rapid recruitment and execution of large-scale international trials in aggressive disease subtypes.

Operational Support and Restructuring (2000s–2026)

For much of the 21st century, the Group’s trials were supported by CACTUS (Cancer Clinical Trials Unit Scotland). Formed as a partnership between the CRUK Clinical Trials Unit in Glasgow (at the Beatson) and the Scottish Clinical Trials Research Unit in Edinburgh, CACTUS provided the infrastructure for regulatory management.

In 2020, CACTUS was adopted within Public Health Scotland (PHS), where it continued to support the cancer research portfolio until its conclusion in 2025.

Following the dissolution of the CACTUS infrastructure, the clinical community formed the Scottish Breast Studies Group (SBSG). Launched in 2026, the SBSG continues the mission of coordinating collaborative research across Scotland to improve outcomes for patients with breast cancer.