Relationship between FDG-PET and the immune microenvironment in breast cancer

Objective: To investigate the relationship between fluorodeoxyglucose (FDG) uptake (maximum standardised uptake value [SUVmax]) and immune markers (tumour-infiltrating lymphocytes [TILs] and neutrophil-to-lymphocyte ratio [NLR]) and evaluate the potential prognostic value of any correlations.Methods: Data from 502 patients with breast cancer, including 346 oestrogen receptor (ER)-positive / human epidermal growth factor receptor 2 (HER2)-negative, 88 HER2-positive, and 68 triple-negative cases, who had undergone surgery were reviewed. Relationships between the clinicopathological factors, SUVmax, TILs, NLR, recurrence-free survival (RFS), and overall survival of all patients and each subtype were evaluated using a Cox proportional hazards model and log-rank test. A sub-analysis of patients divided into low and high TIL groups was also undertaken.Results: High SUVmax was significantly related to high TILs (p < 0.0001). In low TIL (TILs1) group, patients with high SUVmax (>= 3.585) had a significantly shorter RFS than those with low SUVmax (<3.585; p < 0.0001). In high TIL (TILs2,3) group, patients with high SUVmax had a shorter RFS than those with low SUVmax without a significant difference (p = 0.35). Multivariate analysis of 502 patients showed high SUVmax, high T status, and nodal metastasis were independent negative predictors of RFS. In 317 TILs-low patients, high SUVmax, high T status, nodal metastasis, and ER-positivity were independent predictors of RFS. In 185 TILs-high patients, nodal metastasis was an independent predictor of RFS. In ER-positive/HER2-negative and HER2-positive subtypes, SUVmax was a significant predictive parameter in the TILs-low but not TILs-high groups.Conclusion: FDG uptake may be predictive of immunological features and aggressive features in breast cancer patients.

Automated summary

This study investigates the relationship between FDG uptake (SUVmax) and immune markers (TILs and NLR) in breast cancer patients, and evaluates the prognostic value of any correlations. Data from 502 patients who underwent surgery were reviewed, and the relationships between clinicopathological factors, SUVmax, TILs, NLR, recurrence-free survival (RFS), and overall survival were evaluated. The results indicate that FDG uptake may be predictive of immunological features and aggressive features in breast cancer patients.