E. Dewulf

Highlights in HR-positive breast cancer

With respect to hormone receptor (HR)-positive, human epidermal growth factor 2 (HER2)-negative breast cancer, a post hoc analysis of the TAILORx trial was presented during SABCS 2024, in which the potential benefit of adding adjuvant anthracyclines to a taxane-containing regimen was evaluated according to genomic risk using Oncotype DX. In addition, in early breast cancer (EBC), nab-paclitaxel was compared to solvent-based (sb)-paclitaxel in the chemotherapy cohort of the WSG-ADAPT HR+/HER2- trial. Also, additional analyses related to the NATALEE trial were presented, including the effect of adjuvant ribociclib dose reduction on efficacy, and assessment of the benefit of ribociclib plus non-steroidal aromatase inhibitors (NSAIs) on distant disease-free survival (dDFS) across several subgroups. In the metastatic setting, SABCS 2024 featured the results of the phase III EMBER trial, which evaluated the efficacy and safety of imlunestrant as monotherapy or combined with abemaciclib in patients with endocrine-resistant oestrogen receptor (ER)-positive, HER2-negative metastatic breast cancer (MBC); they either progressed during adjuvant or first-line endocrine therapy (ET) and prior cyclin dependent kinase 4 or 6 inhibitor (CDK4/6i) was allowed. Moreover, the PADMA trial evaluated the use of palbociclib plus ET vs mono-chemotherapy in women with high-risk, previously untreated, HR-positive, HER2-negative MBC. Finally, an exploratory post hoc analysis of the DESTINY-Breast06 trial assessed the efficacy of trastuzumab deruxtecan (T-DXd) according to pace of progression on prior endocrine-based therapy.

Highlights in HER2-positive breast Cancer

In this article, some highlights on human epidermal growth factor 2 (HER2)-positive breast cancer presented during SABCS 2024 are discussed. In the early setting, several studies investigated neoadjuvant chemotherapy de-escalation strategies. Furthermore, the role of margetuximab in early breast cancer (EBC) was investigated in the phase II MARGOT trial. In the metastatic setting, the addition of palbociclib to endocrine and anti-HER2 therapy was evaluated in the PATINA trial including patients with hormone receptor (HR)-positive HER2-positive metastatic breast cancer (MBC). Finally, the final results of the PHILA trial were presented.

Highlights in triple-negative breast cancer (TNBC)

Data for the treatment of triple-negative breast cancer (TNBC) were rather limited during SABCS 2024. The general sessions did feature two studies evaluating the addition of immune checkpoint inhibition to neoadjuvant chemotherapy in patients with newly diagnosed stage II or III TNBC. Both studies showed improved rates of pathological complete response (pCR) with the addition of immune checkpoint inhibition. In addition, two exploratory analyses of the KEYNOTE-522 trial were presented. In the advanced setting, the prophylactic use of granulocyte-colony stimulating factor (G-CSF) and loperamide was assessed in patients who received treatment with sacituzumab govitecan.

Advances in local therapy for patients with early-stage breast cancer

At SABCS 2024, several abstracts were dedicated to advances in local therapy for patients with early-stage breast cancer (EBC). An EBCTCG database analysis and the EUROPA trail addressed local therapy in the elderly population. Next, the INSEMA trial assessed whether surgical axillary staging as part of breast-conserving therapy (BCT) can be avoided. Furthermore, the SUPREMO trial evaluated the impact of post-mastectomy radiotherapy (PMRT) on survival in intermediate-risk patients. In addition, the Alliance A221803 trial investigated how to reduce radiation dermatitis, a common source of morbidity seen in patients undergoing radiotherapy (RT). Finally, ultrahypofractionated RT regimens either as whole-breast irradiation or as boost to the lumpectomy cavity were evaluated in two studies.

Advances in ductal carcinoma

During SABCS 2024, a number of abstracts were dedicated to the treatment of ductal carcinoma in situ (DCIS). A combined analysis of two trials investigated the impact of tamoxifen use on ipsilateral breast recurrence in patients with “good-risk” DCIS. In addition, the COMET trial provided data on the omission of surgical treatment for low-risk DCIS, by evaluating the impact on the short-term on both ipsilateral invasive breast recurrence and patient-reported outcomes (PROs).

Miscellaneous news from SABCS

This final article summarises some of the presentations of SABCS 2024 that did not fit in the categories discussed earlier. Firstly, a retrospective study assessed the impact of risk-reducing surgeries on survival in BRCA carriers with a prior history of breast cancer at a young age. Furthermore, the PRO B trial evaluated the effect of alert-based patient-reported outcome (PRO) monitoring on symptom control and physical functioning. Subsequently, an EBCTCG analysis assessed the association of overweight and obesity with cancer outcomes in patients with early-stage breast cancer (EBC). Finally, the BWEL trial studied the impact of weight loss intervention on inflammatory and metabolic biomarkers in obese patients with EBC.

Prostate RT in patients with de novo mHPSC: results from the PEACE-1 study