Tumour-infiltrating lymphocytes in non-invasive breast cancer: A systematic review and meta-analysis

Multimodal histopathologic models stratify hormone receptor-positive early breast cancer

The Oncotype DX® Recurrence Score (RS) is an assay for hormone receptor-positive early breast cancer with extensively validated predictive and prognostic value. However, its cost and lag time have limited global adoption, and previous attempts to estimate it using clinicopathologic variables have had limited success. To address this, we assembled 6172 cases across three institutions and developed Orpheus, a multimodal deep learning tool to infer the RS from H&E whole-slide images. Our model identifies TAILORx high-risk cases (RS > 25) with an area under the curve (AUC) of 0.89, compared to a leading clinicopathologic nomogram with 0.73. Furthermore, in patients with RS ≤ 25, Orpheus ascertains risk of metastatic recurrence more accurately than the RS itself (0.75 vs 0.49 mean time-dependent AUC). These findings have the potential to guide adjuvant therapy for high-risk cases and tailor surveillance for patients at elevated metastatic recurrence risk.

Integrating traditional biomarkers and emerging predictors to assess neoadjuvant chemotherapy efficacy in breast cancer: a multifactorial analysis of Ki-67, CDK4, EGFR, TILs and ctDNA

OBJECTIVE

This study aimed to analyse the correlation between the expression of cell proliferation-associated antigen (Ki-67), cell cycle protein-dependent kinase 4 (CDK4), epidermal growth factor receptor (EGFR), tumour-infiltrating lymphocytes (TILs) and circulating tumour DNA (ctDNA) with the outcome and prognosis of patients with breast cancer (BC) undergoing neoadjuvant chemotherapy (NACT).

METHODS

We retrospectively analysed the clinicopathological data of 231 patients with BC who underwent preoperative NACT at XX Hospital between 1 January 2018 and 31 December 2021. Logistic regression models were used to analyse factors influencing NACT efficacy. The Cox risk regression model was used to analyse prognostic factors. The TILs were assessed on pre-treatment biopsies, and ctDNA levels were monitored during NACT. Propensity score matching and subgroup analyses were performed.

RESULTS

After 4-6 cycles of chemotherapy, the response rate was 77.92% (180/231), with 58.87% (136/231) achieving pathological complete response (pCR). Multifactorial analysis showed that tumour, node and metastasis (TNM) stage II, EGFR positivity, low Ki-67 expression, CDK4 negativity, non-triple-negative subtypes and effective NACT results were associated with higher pCR rates. Higher TIL levels correlated with increased pCR rates (72.4% for high TILs vs 39.1% for low TILs, p < 0.001). The ctDNA levels decreased significantly in patients with pCR compared with patients without pCR during NACT (p < 0.001). After propensity score matching, the 3-year disease-free survival rate was significantly higher in the pCR group (88.9% vs 71.1%, p = 0.003). Subgroup analysis revealed varying pCR rates and predictive biomarkers across BC subtypes.

CONCLUSION

The TNM classification, EGFR, Ki-67, CDK4 expression, BC subtype and NACT results have predictive value for pCR in patients with BC. Lower TNM classification, lower Ki-67 expression and EGFR positivity are associated with better outcomes. High TIL levels and significant decreases in ctDNA during NACT correlate with improved response and prognosis. These findings highlight the potential for integrating traditional clinicopathological factors with novel biomarkers for personalised treatment strategies in BC.

Evaluation of tumor infiltrating lymphocytes as a prognostic biomarker in patients with ductal carcinoma in situ of the breast

PURPOSE

To assess the association between tumor-infiltrating lymphocytes (TILs) in ductal carcinoma in situ (DCIS) samples and disease recurrence.

METHODS

This retrospective cohort study included women aged 18 years and older who underwent treatment between January 2007 and December 2020. Male patients, individuals diagnosed with invasive or microinvasive disease based on anatomopathological examination of surgical specimens, and those with a personal history of any other cancers were excluded. Additionally, the presence of "touching TILs" (lymphocytes in direct contact with tumor cells) and periductal desmoplasia were evaluated as complementary methods to represent the immunological microenvironment. The primary outcome was relapse-free survival based on TIL quantification adjusted for potential confounders. Pathologists assessed TILs in the sample with the highest tumor representation and quantified them as a percentage. Survival was evaluated using Kaplan‒Meier curves, log-rank tests, and Cox regression models.

RESULTS

A total of 191 patients met the eligibility criteria. The mean follow-up duration was 77.2 months, with a recurrence rate of 9.2%. Patients with TILs ≥ 17% had a greater risk of recurrence (HR 2.97, 95% CI 1.17-7.51; p = 0.02). Additionally, focal necrosis (HR 6.4, 95% CI 1.39-34.71; p = 0.018) or comedonecrosis (HR 4.53, 95% CI 1.34-15.28; p = 0.015) were associated with increased recurrence risk. According to the multivariate model, comedonecrosis and TILs ≥ 17% were significantly associated with recurrence (p = 0.034 and p = 0.035, respectively). Regarding the evaluations of "touching TILs" and periductal desmoplasia, no statistical significance was found when assessing their association with disease recurrence.

CONCLUSION

In our cohort, a high percentage of TILs (≥ 17%) and the presence of comedonecrosis were independently associated with DCIS recurrence.

Thematic trends and knowledge-map of tumor-infiltrating lymphocytes in breast cancer: a scientometric analysis

Background

Tumor-infiltrating lymphocytes (TILs), essential for the anti-tumor response, are now recognized as promising and cost-effective biomarkers with both prognostic and predictive value. They are crucial in the precision treatment of breast cancer, particularly for predicting clinical outcomes and identifying candidates for immunotherapy. This study aims to encapsulate the current knowledge of TILs in breast cancer research while evaluating research trends both qualitatively and quantitatively.

Methods

Publications on TILs in breast cancer studies from January 1, 2004, to December 31, 2023, were extracted from the Web of Science Core Collection. Co-occurrence and collaboration analyses among countries/regions, institutions, authors, and keywords were performed with Bibliometrix R packages and VOSviewer software. CiteSpace was used for reference and keyword burst detection, while high-frequency keyword layouts were generated using BICOMB. gCLUTO was employed for biclustering analysis of the binary co-keyword matrix.

Results

A total of 2,066 articles on TILs in breast cancer were identified. Between 2004 and 2023, the USA and Milan University led productivity in terms of country/region and institution, respectively. The journals "CANCERS," "Breast Cancer Research and Treatment," and "Frontiers in Oncology" published the most articles on this topic. Loi S was the leading author, with the highest number of publications and co-citations. Co-keyword analysis revealed six research hotspots related to TILs in breast cancer. The pathological assessment of TILs using artificial intelligence (AI) remains in its early stages but is a key focus. Burst detection of keywords indicated significant activity in "immune cell infiltration", "immune checkpoint inhibitors", and "hormone receptor" over the past three years.

Conclusion

This study reviews recent advancements and trends in TILs research in breast cancer using scientometric analysis. The findings offer valuable insights for funding decisions and developing innovative strategies in TILs research, highlighting current research frontiers and trends.

Tumor-Infiltrating Lymphocytes (TILs) in Breast Cancer: Prognostic and Predictive Significance across Molecular Subtypes

Tumor-infiltrating lymphocytes (TILs) are pivotal in the immune response against breast cancer (BC), with their prognostic and predictive significance varying across BC subtypes. In triple-negative BC (TNBC), higher TIL levels correlate with improved prognosis and treatment response, guiding therapeutic strategies and potentially offering avenues for treatment de-escalation. In metastatic TNBC, TILs identify patients with enhanced immunotherapy response. HER2+ BC, similar to TNBC, exhibits positive correlations between TILs and treatment response, especially in neoadjuvant settings. Luminal BC generally has low TILs, with limited prognostic impact. Single hormone receptor-positive BCs show distinct TIL associations, emphasizing subtype-specific considerations. TILs in ductal carcinoma in situ (DCIS) display ambiguous prognostic significance, necessitating further investigation. Standardizing TIL assessment methods is crucial for unlocking their full potential as biomarkers, guiding treatment decisions, and enhancing patient care in BC.

Evaluation of tumour infiltrating lymphocytes in luminal breast cancer using artificial intelligence

BACKGROUND

Tumour infiltrating lymphocytes (TILs) are a prognostic parameter in triple-negative and human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). However, their role in luminal (oestrogen receptor positive and HER2 negative (ER + /HER2-)) BC remains unclear. In this study, we used artificial intelligence (AI) to assess the prognostic significance of TILs in a large well-characterised cohort of luminal BC.

METHODS

Supervised deep learning model analysis of Haematoxylin and Eosin (H&E)-stained whole slide images (WSI) was applied to a cohort of 2231 luminal early-stage BC patients with long-term follow-up. Stromal TILs (sTILs) and intratumoural TILs (tTILs) were quantified and their spatial distribution within tumour tissue, as well as the proportion of stroma involved by sTILs were assessed. The association of TILs with clinicopathological parameters and patient outcome was determined.

RESULTS

A strong positive linear correlation was observed between sTILs and tTILs. High sTILs and tTILs counts, as well as their proximity to stromal and tumour cells (co-occurrence) were associated with poor clinical outcomes and unfavourable clinicopathological parameters including high tumour grade, lymph node metastasis, large tumour size, and young age. AI-based assessment of the proportion of stroma composed of sTILs (as assessed visually in routine practice) was not predictive of patient outcome. tTILs was an independent predictor of worse patient outcome in multivariate Cox Regression analysis.

CONCLUSION

AI-based detection of TILs counts, and their spatial distribution provides prognostic value in luminal early-stage BC patients. The utilisation of AI algorithms could provide a comprehensive assessment of TILs as a morphological variable in WSIs beyond eyeballing assessment.

Tumor-Infiltrating Lymphocytes in HER2-Low Breast Cancer

INTRODUCTION

Tumor-infiltrating lymphocytes (TIL) is a predictive and prognostic biomarker for breast cancer (BC) HER2-positive and triple negative, but its presence in HER2-low tumors is unknown. We aimed to determine TIL levels in HER2-low tumors and its correlation with other clinicopathologic features.

MATERIALS AND METHODS

We retrospectively analyzed all the pathology reports of breast surgeries of a tertiary hospital in Sao Paulo, Brazil, from January 2021 to March 2022. Inclusion criteria were stage I to III invasive BC, and exclusion criteria were nonmalignancies and neoadjuvant therapy. We assumed HER2 categories according to ASCO/CAP guidelines. TILs were defined as absent (0), low (1%-10%), intermediate (11%40%) and high (≥ 41%). Ki-67 levels were categorized as low (up to 19%) and high (≥ 20%).

RESULTS

From 272 patients, 198 met the inclusion criteria. Histological grade 3 was found in 10, 19 and 47% of HER2-0, low, and positive tumors (P < .001). HER2-positive tumors had 82.6% of high Ki-67 levels, while HER2-negative and HER2-low showed 25.8% and 31.4% (P = .005). TILs in HER2-0, low, and positive tumors were, respectively, absent in 16.1%, 17.6%, and 8.7%; low in 70.2%, 52.9% and 34.8%; intermediate in 11.3%, 25.5% and 47.8%; and high in 2.4%, 3.9% and 8.7%. There was a statistically significant difference in TILs between HER2-negative versus HER2-positive groups (P < .001), but not between HER2-negative versus HER2-low, or HER2-low versus HER2-positive.

CONCLUSION

TILs in HER2-low are marginally higher than HER2-negative, but significantly lower than HER2-positive levels. HER2-low tumors do not seem to significantly differ biologically from HER2-negative tumors.

Clinicopathologic Features and Immune Cell Subtypes Analysis of Tumor-infiltrating Lymphocytes Rich Invasive Breast Carcinoma of No Special Type

Tumor-infiltrating lymphocytes (TILs) rich invasive breast carcinoma no special type (IBC-NST) is an updated name introduced in the fifth edition WHO classification of breast tumors. Typical medullary breast carcinoma (MBC) represents one end of the spectrum of TILs-rich IBC-NST rather than a distinct morphologic subtype in the new category. A total of 42 cases of MBC and 180 cases of high-grade triple-negative breast cancer (TNBC) without medullary features were included. All samples were stained for CD20, CD4, CD8, and FoxP3 by immunohistochemistry staining. TILs infiltration was more prominent in the MBC tumor nests and in the stroma of high-grade TNBC without medullary features. The average stromal TILs percentage was 78.10% and 61.33%. MBC showed significantly lower numbers of lymphocytes expressing FoxP3 ( P < 0.001), no significant difference in the number of CD4 ( P = 0.154), CD8 ( P = 0.199), and a significantly higher CD8/FoxP3 ratio ( P < 0.001) than the other high-grade TNBC. MBC cases demonstrated less aggressive features such as lower TNM stage ( P = 0.031), smaller tumor size ( P = 0.010), and negative lymph node status ( P = 0.021) than the other high-grade TNBC. The 5-year disease-free survival and overall survival were significantly higher for MBC 82.50% and 85.00% compared with the other high-grade TNBC(54.49% and 58.68%). MBC is mostly triple-negative with higher nuclear atypia. Despite advanced staging based on cell morphology, it has low malignancy and a good prognosis. Differences in biological features and prognosis between MBC and high-grade TNBC without medullary features may be associated with the composition and function of TILs. Immune cell subtypes are complex in TILs-rich IBC-NST and deserve further investigation.

A Comprehensive Review on Electrochemical Nano Biosensors for Precise Detection of Blood-Based Oncomarkers in Breast Cancer

Breast cancer (BC), one of the most common and life-threatening cancers, has the highest incidence rate among women. Early diagnosis of BC oncomarkers is considered the most effective strategy for detecting and treating BC. Finding the type and stage of BC in women as soon as possible is one of the greatest ways to stop its incidence and negative effects on medical treatment. The development of biosensors for early, sensitive, and selective detection of oncomarkers has recently attracted much attention. An electrochemical nano biosensor (EN) is a very suitable option for a powerful tool for cancer diagnosis. This comprehensive review provides information about the prevalence and pathobiology of BC, recent advances in clinically available BC oncomarkers, and the most common electrochemical nano biosensors for point-of-care (POC) detection of various BC oncomarkers using nanomaterial-based signal amplification techniques.

Identifying recurrences and metastasis after ductal carcinoma in situ (DCIS) of the breast

Ductal carcinoma in situ (DCIS) of the breast is a non-invasive tumour that has the potential to progress to invasive ductal carcinoma (IDC). Thus, it represents a treatment dilemma: alone it does not present a risk to life, however, left untreated it may progress to a life-threatening condition. Current clinico-pathological features cannot accurately predict which patients with DCIS have invasive potential, and therefore clinicians are unable to quantify the risk of progression for an individual patient. This leads to many women being over-treated, while others may not receive sufficient treatment to prevent invasive recurrence. A better understanding of the molecular features of DCIS, both tumour-intrinsic and the microenvironment, could offer the ability to better predict which women need aggressive treatment, and which can avoid therapies carrying significant side-effects and such as radiotherapy. In this review, we summarise the current knowledge of DCIS, and consider future research directions.

Epigenetic oncogenesis, biomarkers and emerging chemotherapeutics for breast cancer

Breast cancer remains one of the leading causes of cancer-related deaths globally and the most prominent among females, yet with limited effective therapeutic options. Most of the current medications are challenged by various factors including low efficacy, incessant resistance, immune evasion and frequent recurrence of the disease. Further understanding of the prognosis and identification of plausible therapeutic channels thus requires multimodal approaches. In this review, epigenetics studies of several pathways to BC oncogenesis via the inducement of oncogenic changes on relevant markers have been overviewed. Similarly, the counter-epigenetic mechanisms to reverse such changes as effective therapeutic strategies were surveyed. The epigenetic oncogenesis occurs through several pathways, notably, DNMT-mediated hypermethylation of DNA, dysregulated expression for ERα, HER2/ERBB and PR, histone modification, overexpression of transcription factors including the CDK9-cyclin T1 complex and suppression of tumour suppressor genes. Scientifically, the regulatory reversal of the mechanisms constitutes effective epigenetic approaches for mitigating BC initiation, progression and metastasis. These were exhibited at various experimental levels by classical chemotherapeutic agents including some repurposable drugs, endocrine inhibitors, monoclonal antibodies and miRNAs, natural products, metal complexes and nanoparticles. Dozens of the potential candidates are currently in clinical trials while others are still at preclinical experimental stages showing promising anti-BC efficacy. The review presents a model for a wider understanding of epigenetic oncogenic pathways to BC and reveals plausible channels for reversing the unpleasant changes through epigenetic modifications. It advances the science of therapeutic designs for ameliorating the global burden of BC upon further translational studies.