What Do We Know About DCIS
  • 22% of all Breast Ca diagnosis is NON-INVASIVE
    • 85% DCIS
    • 15% LCIS
    • 0.5-5% Paget Disease
  • Mostly non-palpable
    • Palpable lesions with biopsy=DCIS → higher chance of have invasive component

Risk factors for DCIS

  • Age
  • Benign breast dis.
  • Family Hx
  • Nulliparity
  • Older age at first pregnancy

Chemoprevention with Tamoxifen

o Decrease the chance by 50%
o NSABP trial
• How do we know that DCIS transforms to Invasive?
o 10 fold higher risk of Invasive Ca
o Shared identical genetics between DCIS and synchronous Invasive
• ⇒ Clonal relationship of biologic progression
• Pathology:
o Proliferation of cancerous cells within the mammary ductal-lobular system
o سلول های پوششی (اپیتلیال) — > بدخیم شده اند ولی در محل خود باقی مانده ولی از غشا پایه تجاوز نکرده اند.
o در غشا پوششی (لایه اپی تلیال ) هیچگونه عروق خونی و لنفی وجود ندارد.
o ⇒متاستاز نمیدهد.
o Atypical ductal hyperplasia →DCIS→invasive
o ریسک سرطان مهاجم به دنبال این تشخیص 8-10 برابر است.
o If comedo DCIS ⇒ MORE RISK
o No germ line mutation
• اسید رتینوییک رگولاتور ساخت غشا پایه
o نقش در chemo prevention
o Mammogram→ microcalcification( 80-90% )
• High-grade →continuous-linear branching
• Intermediate grade →heterogeneous granular calc.
• Low-grade→ + gap; multifocal→fine granular calc.
o 80% only microcacification
o 10% microcal+ other findings
o 10% Noncalcified lesion
• Poorly defined mass
• Circumscribed nodule
• Asymmetry
• Architectural distortion
• What to look for in pathology report?
o Type
• Comedo
• Non-Comedo
• Cribriform
• Micropapillary
• Papillary
• Solid
o Size and Extent
o Margin
o Grade
• Nuclear Grade
• Any Necrosis?
o Any microcalcification

Architectural Pattern Differentiation Necrosis ER Nuclear Grade Mitosis
COMEDO Poor Present Negative High Numerous
NON-COMEDO Well Absent Positive Low Infrequent

• Van Nuys Classification for DCIS:
o Group 1
• Non-high grade
• No Necrosis
o Group 2
• Non-high grade
• + Necrosis
o Group 3
• High grade
• What do we know about margins of DCIS?
o DCIS may have different pattern of growth
• Continuous
• Which is usually seen in poorly diff lesions
• Discontinuous(multifocal)
• Which is mostly seen in well diff lesions
• Growth of two or more foci of DCIS separated by less than 4cm
• In this pattern in one study:
• 63% of lesions were <5mm apart
• 85% of lesions were <1cm apart
• ONLY 8% of lesions were >1cm apart
o From this data we conclude that margin of 1cm in lumpectomy for DCIS is safe for about 90% of cases