TIL-Based Computational Pathology Biomarker for Ductal Carcinoma In Situ

By: Joshua D. Madera, MD
Posted: Tuesday, July 30, 2024

The novel tumor-infiltrating lymphocyte (TIL)-based computational pathology signature may play a critical role in evaluating the prognosis and predicting clinical outcomes for patients with ductal carcinoma in situ, according to the results of the UK/ANZ DCIS study, published in The Lancet Digital Health. An increased density of TILs may be associated with an increased risk of invasive recurrence in this patient population, suggested Mangesh A. Thorat, PhD, of Queen Mary University of London, and colleagues.

“We have a robust biomarker that not only predicts which patients are at a substantially higher risk of progressing to invasive breast cancer, but also tells us which subgroup of patients can avoid radiotherapy and thus helps us prevent overtreatment,” commented Dr. Thorat in an institutional press release.

A total of 755 patients with ductal carcinoma in situ were retrospectively evaluated in the study. The TIL-based biomarker was used to stratify patients, based on the number of TILs identified in the tumor microenvironment. Patients were classified as either TIL-high or TIL-low. They were assessed for evidence of ipsilateral breast events, defined as ductal carcinoma in situ recurrence or invasive disease progression.

The study authors reported an increased risk of an ipsilateral breast event in TIL-high patients compared with TIL-low patients (hazard ratio [HR] = 2.10). Specifically, the risk of invasive disease progression was increased in TIL-high patients compared with TIL-low patients (HR = 3.09). However, no significant differences were identified between TIL-high and TIL-low patients for the risk of ductal carcinoma in situ recurrence (HR = 1.61).

Furthermore, a significant interaction between treatment with radiotherapy and the TIL group was revealed. The benefit of radiotherapy seemed to be more pronounced in preventing ductal carcinoma in situ in TIL-high patients than in TIL-low patients (HR = 0.40).

Disclosure: For full disclosures of the study authors, visit thelancet.com.

The Lancet Digital Health

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