Source of information:Abeloff’s oncology text, 2nd edition, 2000
10 minute presentation for Friday, 08/16/2002, General Surgery.
Definition of CIS. Carcinomatous cells with intact BM bylight microscopy. DCIS is one of 2 types of breast CIS.
Incidence of CIS. 1.5-5.1% in 1978;9% in 1985;15% in 1995.Do these figures just reflect better screening? Probably yes.
Table 1. Comparing LCIS and DCISLCIS DCIS Presentation Nonpalpable, incidental finding at biopsy Presents as palpable mass or occult mammogram abnormality Mammography Not identified by mammography More than 90% detected by mammography:
72% microcalcification
12% tissue density + microcalcification
10% tissue density Significance Marker for high risks of developing cancer, with peak incidence 10-15 years later:
Relative risk: 8-11 X general population
Absolute risk: 20-25% in 15 years Small cancer. Percursor of a bigger invasive ductal carcinoma. Treatment 65% of oncologists recommend observation; 30% recommend ipsilateral mastectomy; 5% recommend bilateral mastectomy.
Tamoxifen is being tested for prevention of cancer in LCIS (NSABP trial). Mastectomy – almost 100% effective;
Excision + beamo;
Excision alone. Epidemiology More common in premenopausal women. Peak incidence between 51-59 y.o. Distribution is similar to that of invasive ductal carcinoma.
The question is: Is CIS a cancer that was caught early or is it simply amarker of unstable epithelium (i.e. a risk factor for cancer development)?Apparently, the answer depends on whether it is LCIS or DCIS. Ductal carcinoma in-situ
Histology. DCIS can be of these histological types:cribriform, comedo, solid, micropapillary, and clinging.
Biology. Most comedo express the HER-2/neu protein. Incontrast, invasive ductal carcinomas express HER-2/neu in 14-28% of cases.bFGF — normally found the myoepithelial cells — appears to be absentfrom invasive tumors. TGF-beta1 is found in both DCIS and invasive ductalcancers. Although basement membranes are intact by light microscopy,defects can be found with electron microscopy and even with PASstain.
Treatment. Clean margins are essential and reexcision isindicated if margins are not clean. In addition, all microcalcificationfoci must be excised and verified by mammogram. See table 2 formore details.
Table 2. Guidelines for evaluation and treatment of nonpalpable DCIS
Evaluation
Treatment
