RECENT findings reveal high stromal tumour-infiltrating lymphocytes (sTILs) levels are associated with excellent long-term survival in stage I triple-negative breast cancer (TNBC) patients without chemotherapy. Data on the absolute benefit of chemotherapy for survival outcomes in stage I TNBC patients are lacking, and no biomarkers are available to identify patients for whom neoadjuvant or adjuvant chemotherapy may provide negligible benefit. This study investigated sTILs as biomarkers to identify patients who might benefit from tailored treatment approaches, reducing unnecessary chemotherapy.
Researchers used the Netherlands Cancer Registry to identify patients diagnosed with stage I TNBC between January 2005 and December 2015. The study included 4,511 patients who had not received chemotherapy. Clinical data were matched with pathology data from the Dutch Pathology Registry. A central review of histologic subtype, grade, and lymphovascular invasion was conducted using hematoxylin and eosin–stained slides. The primary endpoint was breast cancer-specific survival (BCSS) at 5, 10, and 15 years, analysed based on sTIL levels at predefined cutoffs of 30%, 50%, and 75%. sTIL levels were assessed for 1041 individuals, with a median follow-up of 11.4 years.
The study found that higher sTIL levels were significantly associated with better outcomes. Patients with sTIL levels of 50% or greater in pT1c tumours exhibited a 10-year BCSS of 95%, increasing to 98% for those with sTIL levels of 75% or greater. Patients with pT1ab tumours also demonstrated a positive, albeit less pronounced, association between sTIL levels and survival outcomes. Overall, patients with sTIL levels of at least 30% had better BCSS than those with lower levels, showing survival rates of 96% versus 87%. For patients with pT1c tumours, high sTIL levels (50% or greater) were strongly linked to improved survival outcomes (hazard ratio [HR], 0.27), underscoring the potential of sTILs as predictive biomarkers.
In conclusion, this study highlights the potential of sTILs to determine the prognosis for patients with stage I TNBC who do not undergo chemotherapy. High sTIL levels were associated with excellent 10-year survival rates, suggesting that sTILs could guide treatment decisions. Future clinical trials should investigate the optimisation of chemotherapy based on sTIL levels, potentially sparing certain patients from the adverse effects of chemotherapy while maintaining excellent survival outcomes.
Reference:
Geurts VC et al. Tumor-infiltrating lymphocytes in patients with stage i triple-negative breast cancer untreated with chemotherapy. JAMA oncology. 2024;DOI:10.1001/jamaoncol.2024.1917.
