Overview
Ductal carcinoma in situ (DCIS) with microinvasion represents a subset of non-invasive breast cancer where tumor cells have breached the basement membrane but remain within the breast ducts with minimal invasion. Progression to invasive cancer is rare, occurring in only a minority of cases over a decade 3.Diagnosis
Key Criteria: Presence of abnormal cell proliferation confined to the ductal system without stromal invasion.
Microinvasion: Minimal invasion of surrounding stroma, typically defined by less than 1 mm in depth.
Grading: Pathologists vary significantly in defining comedo necrosis, with thresholds ranging from 10% to 70% of duct diameter 1.
Assessment Tools: Web-based pathology assessment tools can enhance reproducibility in grading DCIS, though usage varies 2.
Exclusion Criteria: Close or positive margins and high-grade (grade 3) DCIS are typically excluded from certain trials 2.Management
Primary Treatment: Surgical excision (lumpectomy) often with clear margins is standard 2.
Adjuvant Therapy: Radiation therapy is commonly recommended, especially for higher-risk features like microinvasion 2.
Active Surveillance: Considered for low-risk DCIS without comedo necrosis, though criteria for low-risk vary 12.
Monitoring: Regular follow-up imaging and clinical exams are essential post-treatment 2.Special Populations
Pregnancy: Specific management guidelines for DCIS during pregnancy are not addressed in provided abstracts.
Elderly: No specific considerations mentioned in the abstracts regarding elderly patients.
Comorbidities: Management considerations for patients with comorbidities are not detailed in the abstracts.Key Recommendations
Central Pathology Review: Utilize central pathology review to ensure accurate grading and eligibility for clinical trials (Evidence: Moderate) 2.
Consistent Grading Criteria: Standardize diagnostic thresholds for comedo necrosis to improve consistency among pathologists (Evidence: Weak) 1.
Tailored Treatment Based on Risk: Implement active surveillance for low-risk DCIS without high-risk features like microinvasion, while high-risk cases should receive definitive local therapy (Evidence: Expert opinion) 12.References
1 Harrison BT, Hwang ES, Partridge AH, Thompson AM, Schnitt SJ. Variability in diagnostic threshold for comedo necrosis among breast pathologists: implications for patient eligibility for active surveillance trials of ductal carcinoma in situ. Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2019. link
2 Woodward WA, Sneige N, Winter K, Kuerer HM, Hudis C, Rakovitch E et al.. Web based pathology assessment in RTOG 98-04. Journal of clinical pathology 2014. link
3 . Ductal carcinoma in situ: progression to invasive cancer is slow and only occurs in a minority of case. Prescrire international 2013. link