The influence of receptor expression and clinical subtypes on baseline [18F]FDG uptake in breast cancer: systematic review and meta-analysis

BACKGROUND: To quantify the relationship between [18F]FDG uptake of the primary tumour measured by PET-imaging with immunohistochemical (IHC) expression of ER, PR, HER2, Ki-67, and clinical subtypes based on these markers in breast cancer patients. METHODS: PubMed and Embase were searched for studies that compared SUV(max) between breast cancer patients negative and positive for IHC expression of ER, PR, HER2, Ki-67, and clinical subtypes based on these markers. Two reviewers independently screened the studies and extracted the data. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were estimated by using DerSimonian-Laird random-effects models. P values less than or equal to 5% indicated statistically significant results. RESULTS: Fifty studies were included in the final analysis. SUV(max) is significantly higher in ER-negative (31 studies, SMD 0.66, 0.56–0.77, P < 0.0001), PR-negative (30 studies, SMD 0.56; 0.40–0.71, P < 0.0001), HER2-positive (32 studies, SMD − 0.29, − 0.49 to − 0.10, P = 0.0043) or Ki-67-positive (19 studies, SMD − 0.77; − 0.93 to − 0.61, P < 0.0001) primary tumours compared to their counterparts. The majority of clinical subtypes were either luminal A (LA), luminal B (LB), HER2-positive or triple negative breast cancer (TNBC). LA is associated with significantly lower SUV(max) compared to LB (11 studies, SMD − 0.49, − 0.68 to − 0.31, P = 0.0001), HER2-positive (15 studies, SMD − 0.91, − 1.21 to − 0.61, P < 0.0001) and TNBC (17 studies, SMD − 1.21, − 1.57 to − 0.85, P < 0.0001); and LB showed significantly lower uptake compared to TNBC (10 studies, SMD − 0.77, − 1.05 to − 0.49, P = 0.0002). Differences in SUV(max) between LB and HER2-positive (9 studies, SMD − 0.32, − 0.88 to 0.24, P = 0.2244), and HER2-positive and TNBC (17 studies, SMD − 0.29, − 0.61 to 0.02, P = 0.0667) are not significant. CONCLUSION: Primary tumour SUV(max) is significantly higher in ER-negative, PR-negative, HER2-positive and Ki-67-positive breast cancer patients. Luminal tumours have the lowest and TNBC tumours the highest SUV(max). HER2 overexpression has an intermediate effect. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13550-023-00953-y.