Biological behavior of DCIS with or without microinvasion. Same and different

Area of Science:

• Oncology
• Pathology
• Breast Cancer Research

Background:

• Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer often detected by calcifications.
• While typically treated with surgery, a subset of DCIS patients experience recurrence.
• Microinvasion (≤1 mm invasive focus) presents diagnostic and therapeutic challenges, with its biological behavior debated.

Purpose of the Study:

• To determine if DCIS with microinvasive foci represents a distinct biological entity compared to pure DCIS.
• To analyze the impact of microinvasion on recurrence rates and survival.
• To identify pathological and clinical factors associated with outcomes in DCIS with microinvasion.

Main Methods:

• Retrospective analysis of 148 surgically treated DCIS patients with complete data.
• Categorization into pure DCIS (126 patients) and DCIS with microinvasion (22 patients).
• Correlation of microinvasion and pathological parameters with time-to-event (TTE) using Kaplan-Meier curves.

Main Results:

• Overall, 18.9% of patients experienced events (recurrent DCIS, invasive cancer, or breast cancer death).
• DCIS with and without microinvasion showed no significant difference in TTE.
• Microinvasive DCIS was associated with higher recurrence rates in extensive disease, high nuclear grade, necrosis, narrow margins, younger age, and lack of adjuvant therapy.

Conclusions:

• The biological behavior of DCIS with microinvasive foci does not significantly differ from pure DCIS in terms of overall time-to-event.
• However, specific high-risk features in microinvasive DCIS correlate with increased recurrence.
• Further research is needed to understand the biology of microinvasive DCIS and explore distinct therapeutic options.