In-situ disease Background and Recommendations

Question 1

Histologic subtypes of DCIS?

Answer 1

Cribriform
Comedo (worse prognosis)
Papillary 
Medullary 
Solid (2nd worse prognosis)

Question 2

What is the most common presentation of DCIS?

Answer 2

1. Asymptomatic

2. Microcalcifications on mammogram

Question 3

LCIS most common presentation?

Answer 3

Incidental finding on biopsy

LCIS is not associated with any radiographic findings

Question 4

What is the risk of developing invasive breast cancer for a patient with LCIS?

Answer 4

7%

Only 25-50% are invasive lobular and the risk is equal in both breasts

Question 5

What is the effect of tamoxifen on the risk of contralateral breast cancers?

Answer 5

It reduces the risk from 4.9% to 2.3% as seen in B24

Question 6

What imaging must be done post-lumpectomy?

Answer 6

1. Post-excision mammography to ensure all of the microcalcifications have been removed
2. Specimen radiograph

Question 7

What is the treatment paradigm for DCIS

Answer 7

1. Mastectomy
   or.
2. Lumpectomy with +PORT +/- tamoxifen if ER+

Question 8

What is the minimal margins for DCIS after lumpectomy?

Answer 8

2 mm

Question 9

Which subtype of LCI has the worst prognosis?

Answer 9

pleomorphic

Question 10

What percentage of DCIS is ER+?

Answer 10

75-85%

Question 11

What are the grades of DCIS?

Answer 11

Low, intermediate, high

Question 12

How does tamoxifen modify the risk for invasive breast cancer in patients with LCIS?

Answer 12

Tamoxifen reduces the risk by 50%

Fischer B, Lancet 1999