Early Diagnosis and Better Treatments Improve Breast Cancer Outcomes

Since 2000, women diagnosed with breast cancer are about 20 percent less likely to have their tumour come back or spread, compared to those diagnosed in the 1990s.

A study published in the Lancet in 2024 analysed data from a massive database of 151 clinical breast cancer trials involving more than 155,000 people with early-stage breast cancer. The aim was to determine how the risk of breast cancer spreading, or metastasizing, had changed over time.

Women with breast cancer that is sensitive to oestrogen are known to have an increased risk of their disease returning for at least 20 to 30 years after treatment, even with use of therapies that block hormones. But less is known about the long-term recurrence rate in women with breast cancer that isn’t sensitive to hormones.

Given the many recent advances in treatment of both oestrogen receptor-positive and oestrogen receptor-negative, researchers in the Early Breast Cancer Trialists’ Collaborative Group were interested in how that recurrence rate in both cancer types might have changed over time.

They did what’s called a ‘pooled analysis’ of all the relevant clinical trial data from their database, which enabled them to analyse all the participants in those studies as one enormous group, to see how the risk of recurrence had changed between 1990 and 2009, and what factors might have played a role in those changes.

Overall, they found that the recurrence rates for both types of breast cancer had gone down over time. This was due not only of improved treatments, but also to improved diagnostic technology and screening programs, which meant cancer was being detected and treated earlier which increased the likelihood of survival and a cure.

There have also been advancements in tailoring treatments to an individual cancer.

One of the trials included in the analysis was the TailorX study, which tried to work out whether hormone-sensitive breast cancers that had an intermediate risk of recurrence – based on genetic analysis – would benefit from more intensive treatment with chemotherapy on top of hormone-blocking therapy.

Associate Professor Nicholas Wilcken was a member of the Breast Cancer Trials Scientific Advisory Committee when the TailorX trial was running.

“TailorX essentially showed that, at least for post-menopausal women, the chemotherapy did not make any difference, so you were just as well off having only hormone-blockers alone,” Prof Wilcken says. That finding was significant because it meant many women could avoid chemotherapy and its side-effects, which not only improved outcomes but also quality of life, without increasing their risk of the cancer coming back.

Publication

Early Breast Cancer Trialists’ Collaborative Group (2024). Reductions in recurrence in women with early breast cancer entering clinical trials between 1990 and 2009: a pooled analysis of 155 746 women in 151 trials, Lancet 404: 1407-18. doi: 10.1016/S0140-6736(24)01745-8