2024 San Antonio Breast Cancer Symposium

2024 San Antonio Breast Cancer Symposium

The San Antonio Breast Cancer Symposium (SABCS) is one of the largest and most influential events in the field of breast cancer research, where the latest clinical trials, research and treatment innovations are presented.

The event attracts thousands of delegates from around the world each year, including several researchers and consumers from Breast Cancer Trials (BCT).

The following is a selection of highlights from SABCS 2024.

Results from the PATINA Clinical Trial

Researchers say that the results of the PATINA clinical trial may represent a new standard of care for patients diagnosed with metastatic breast cancer that is hormone receptor positive and HER2-positive.

PATINA investigated if the addition of the drug Palbociclib, when given in combination with anti-HER2 treatment (trastuzumab and pertuzumab) and endocrine therapy, could improve cancer control rates for women with hormone receptor (HR) positive, HER2-positive metastatic breast cancer. These patients received initial treatment with chemotherapy, trastuzumab and pertuzumab. If eligible for the trial, all patients received standard treatment with ongoing Trastuzumab, Pertuzumab and hormone blocking therapy, and half received Palbociclib in addition.

Researchers have found that adding Palbociclib to standard treatment significantly improved progression free survival by 15.2 months, compared to standard treatment alone (trastuzumab, pertuzumab and hormone blocking treatment). The study also found that patients experienced manageable side effects from this additional treatment.

PATINA is an international clinical trial, which enrolled 496 patients worldwide, including 49 patients from Australia and New Zealand.

For more information on these results, click here.

The Lancet Breast Cancer Commission Report: Progress and Afterlife

In 2024, the Lancet Breast Cancer Commission Report provided a critical update on breast cancer, highlighting urgent challenges and inequalities throughout the world. It emphasised six key themes: prevention, personalisation, inclusion, collaboration, identification, and communication.

The Executive Summary of the report states:

“Despite tremendous advances in breast cancer research and treatment over the past three decades—leading to a reduction in breast cancer mortality of over 40% in some high-income countries—gross inequities remain, with many groups being systematically left behind, ignored, and even forgotten. The work of the Lancet Breast Cancer Commission highlights crucial groups, such as those living with metastatic breast cancer, and identifies how the hidden costs of breast cancer and associated suffering are considerable, varied, and have far-reaching effects. The Commission offers a forward-looking and optimistic road map for how the health community can course correct to address these urgent challenges in breast cancer.”

During the 2024 SABCS, a panel of experts discussed the report findings and recommendations. BCT researchers Professor Kelly-Anne Phillips, Professor Prue Francis and Ms Rebecca Angus (Member of the BCT Consumer Advisory Panel) were guest speakers.

COMET Shows Promising Early Results

Ductal carcinoma in situ (DCIS) is a non-invasive condition where abnormal cells are found in the milk ducts of the breast but have not spread outside these ducts. While DCIS itself is not breast cancer, it is considered a precursor or potential risk for invasive breast cancer if left untreated.

In Australia, studies suggest that about 30-50% of untreated DCIS cases may progress to invasive breast cancer over time. This risk depends on various factors, including the grade of the DCIS (low, intermediate, or high), its size, and the presence of certain molecular characteristics.

What is not known is how best to treat DCIS. ‘Active monitoring’ is a strategy in which patients are monitored closely, with surgery reserved for those patients whose DCIS worsens, including those who develop cancer. With close monitoring, those cancers are typically found at a very early, and curable, stage.

In the primary analysis of the COMET trial, researchers found that active monitoring patients with low-risk DCIS was comparable to treating patients upfront with surgery.

Researchers also found that patients with low-risk DCIS who underwent active monitoring reported similar physical, emotional, and psychological outcomes to patients who received upfront treatment.

The data suggest that, in the short term, active monitoring is a reasonable approach in terms of the patient experience. Researchers will now examine longer-term follow up data, which could lead to a new management option for women with low-risk DCIS.

EBCTCG Obesity Overview

An analysis of data from 206,904 women with early breast cancer has found that elevated BMI (Body Mass Index) increases the risk of breast cancer mortality and recurrence.

BMI is a measure used to assess whether a person has a healthy body weight for a given height. It is calculated by dividing a person’s weight in kilograms by the square of their height in meters (kg/m²). BMI is often used as an indicator to categorize individuals into weight ranges such as underweight, normal weight, overweight, or obese. It helps identify potential health risks associated with underweight or excess weight, including complications related to obesity and chronic conditions like breast cancer.

The research was undertaken by the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG), who found that there is an increased risk of breast cancer recurrence and risk of mortality regardless of age, tumour, type, year of diagnosis and hormone receptor status.

Researchers say that this confirmation of data suggests that future studies are needed to explore whether weight loss interventions can reduce the risk of recurrence or mortality among women with early breast cancer and elevated BMI.

The OlympiA Clinical Trial

The latest results from the OlympiA clinical trial – released 10 years after the trial began recruitment – show that olaparib successfully keeps cancer at bay in the long-term and reinforces the importance of BRCA testing at cancer diagnosis, so that patients who may benefit from olaparib treatment can be identified as early as possible.

New findings presented at the SABCS, show that adding olaparib to standard treatment cuts the risk of cancer coming back by 35 per cent, and the risk of women dying by 28 per cent.

After six years, 87.5 per cent of patients who were treated with the drug were still alive compared with 83.2 per cent of those who were given the placebo pills alongside standard treatment.

Inherited mutations in the BRCA1 or BRCA2 genes account for five per cent of all breast cancers. Women with early-stage breast cancer who have inherited BRCA1 or BRCA2 mutations are typically diagnosed at a younger age and often require more intensive treatment. Olaparib targets the specific biology of the BRCA genes, killing cancer cells while leaving healthy cells alone.

1,836 patients worldwide participated in the OlympiA clinical trial, including 60 women from 12 participating institutions in Australia.

DECRESCENDO

HER-2 positive breast cancer represents around 15% of all breast cancer diagnoses. Treatment of early stage disease typically includes intensive chemotherapy along with targeted agents such as trastuzumab and pertuzumab.

The DECRESCENDO researchers aimed to find out if a shorter duration of chemotherapy with trastuzumab and pertuzumab before surgery would lead to outcomes that were just as good as if a more intense treatment were used, but without as many side effects. Patients with lymph node negative, hormone receptor negative, HER2-positive early breast cancer were given treatment prior to surgery. The findings reported a very high 86% complete clearance of cancer cells by the time of surgery.

139 patients were recruited worldwide to this trial, including 22 from Australia.

SUPREMO

Patients with lymph node positive or high risk lymph node negative early stage breast cancer may be offered chest wall radiotherapy after mastectomy to remove the cancer. This has been shown to improve outcomes in selected patients. This treatment comes with long and short term side effects and a cost to the health care system.

The SUPREMO trial aimed to find out if some patients might be able to be spared radiotherapy without any detriment to their long term outcomes. Eligible patients were randomly assigned after their mastectomy to receive either chest wall radiotherapy, or no radiotherapy, and were followed up for an average of 10 years. The trial found equivalent overall survival in both groups, without any differences according to lymph node involvement or oestrogen receptor status. There was a very small 1.4% increase in chest wall cancer recurrence in the patients who did not receive radiotherapy, but this did not translate into any difference in regional or metastatic recurrence.

These findings suggest that selected patients with a low axillary nodal burden can safely avoid radiotherapy after mastectomy.