Apparent diffusion coefficient cannot predict molecular subtype and lymph node metastases in invasive breast cancer:...

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Breast cancer (BC) diagnosis relies heavily on radiological imaging.
• Diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) values are explored for prognostic value in BC.
• Existing literature presents conflicting data on ADC's association with BC prognostic factors.

Purpose of the Study:

• To investigate the relationship between quantitative ADC values from DWI and pathological prognostic factors in breast cancer.
• To provide clear data on the utility of ADC in characterizing BC subtypes and predicting outcomes.

Main Methods:

• Multi-center study involving 661 female patients with invasive ductal or lobular carcinoma.
• Analysis of ADC values across different molecular subtypes (Luminal A, Luminal B, HER2+, triple negative) and TNM staging.
• Statistical comparison using Mann-Whitney U and Kruskal-Wallis H tests; correlation with Ki 67 using Spearman's rank correlation.

Main Results:

• Significant overlap in ADC values among different BC molecular subtypes.
• Luminal B carcinomas showed significantly lower ADC values than Luminal A and HER2+ subtypes.
• No significant differences in ADC values were found between Luminal A, HER2+, and triple-negative tumors, nor across different T or N stages.
• A weak, statistically significant negative correlation between ADC and Ki 67 was observed only in Luminal B carcinoma.

Conclusions:

• Apparent diffusion coefficient (ADC) values are not sufficiently discriminative for breast cancer molecular subtypes.
• ADC cannot reliably serve as a surrogate marker for disease stage or proliferation activity (Ki 67) in breast cancer.
• Further research may be needed to explore other imaging biomarkers for BC characterization.