False-positive MRI Findings in Breast Cancer After Neoadjuvant Chemotherapy and Correlation Between Tumor Response Patterns and HER2 Status

Avdan Aslan A., Erdemli S., Erdoğdu I. H., Gültekin S., Uras C., Tokat F., ...Daha Fazla

ACTA ONCOLOGICA TURCICA, cilt.56, sa.2, ss.97-105, 2023 (Hakemli Dergi)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 56 Sayı: 2
  • Basım Tarihi: 2023
  • Doi Numarası: 10.5505/aot.2023.60973
  • Dergi Adı: ACTA ONCOLOGICA TURCICA
  • Derginin Tarandığı İndeksler: TR DİZİN (ULAKBİM)
  • Sayfa Sayıları: ss.97-105
  • Gazi Üniversitesi Adresli: Evet

Özet

Objective: To demonstrate false-positive MRI findings after neoadjuvant chemotherapy (NAC) in patients with pathologic complete response (pCR) and investigate the correlation between post-NAC MRI findings and tumor response patterns based on human epidermal growth factor receptor 2 (HER2) status. Methods: This retrospective multicenter study enrolled 118 patients with breast cancer who received NAC and achieved pCR. Tumors were evaluated with MRI pre- and post-NAC. MRI evaluation included lesion characteristics, kinetic curve analysis, background parenchymal enhancement (BPE), and post-NAC changes of MRI features. Tumor response patterns were also assessed and categorized based on MRI findings. Tumor response patterns and post-NAC MRI findings were correlated with HER2 status. Results: The residual MRI findings following NAC differed significantly between HER2+ and HER2− groups (p=0.02). The most frequent false-positive MRI finding was focus and foci in HER2+ tumors, whereas non-mass enhancement (NME) in HER2− group. The presence of ductal carcinoma in situ (DCIS) and fibrosis in surgical pathology is significantly associated with NME on post-NAC MRI (p<0.001). Axillary pCR was achieved significantly higher in the HER2+ group (p=0.04). Conclusion: Although MRI is considered the most reliable method for evaluating tumor response after NAC, over and underestimation is still possible. This study revealed that tumor response patterns and post-NAC MRI findings differ according to HER2 status. The diagnostic accuracy of post-NAC MRI is evolving by understanding the underlying mechanisms and tumor biology.