Rosen's Breast Pathology, 4e

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Ductal Carcinoma In Situ

contralateral biopsies was provided. A population-based study of cases identified in the Connecticut Tumor Registry found that 22% of 217 patients with DCIS in one breast had intraductal or invasive carcinoma in the opposite breast. 22 Overall, 17% of the patients with DCIS also had a nonmam- mary malignant neoplasm. A systematic evaluation of the contralateral breast was reported by Urban, 89 who biopsied the opposite breast in 70% of his cases. Among 16 women with DCIS treated be- tween 1966 and 1968, he found that three (19%) had had a prior contralateral mastectomy. There were no patients with simultaneous bilaterality. Ringberg et al. 90 carried out bilat- eral mastectomy in patients with unilateral carcinoma. The contralateral breast specimens were subjected to a detailed pathologic analysis. Among 23 women with DCIS in one breast, the distribution of contralateral disease was as follows: LCIS, two cases (9%); DCIS, three cases (13%); and invasive carcinoma, two cases (9%). In another study, simultaneous contralateral mastectomy in 25 of 78 patients who had non- comedo DCIS in one breast revealed contralateral DCIS in 3 (12%). 91 The type of DCIS and indications for performing the operation in these cases were not indicated. Schuh et al. 92 re- ported that 7 of 52 (13%) patients with DCIS had previously undergone a contralateral mastectomy for carcinoma. Simul- taneous bilateral carcinoma was found in 3 of the remaining 45 women (7%), including two contralateral invasive lesions and one with LCIS. Schwartz et al. 93 reported that 3 of 47 pa- tients (6%) with nonpalpable DCIS treated by mastectomy had clinically detected DCIS in the opposite breast. Silver- stein et al. 87 found bilateral simultaneous or metachronous carcinoma in 22 of 208 patients (11%) with pure or micro- invasive DCIS, including 5 (2.4%) with bilateral intraductal lesions. Ciatto et al. 32 reported contralateral carcinoma in 44 of 350 women (13%) with DCIS, including 9 (3%) with synchronous bilateral intraductal, 9 (3%) with synchronous invasive, 2 (6%) with metachronous invasive, and 5 (1.4%) with metachronous DCIS. After excluding synchronous con- tralateral carcinoma, Ciatto et al. 32 calculated the frequency of metachronous contralateral carcinoma based on breast years at risk to be 8.5%, 5.6 times the expected risk of 1.5% for unilateral breast carcinoma in a normal population. The occurrence of contralateral carcinoma in women with DCIS was studied in a population-based cancer regis- try from the state of Washington by Habel et al. 94 The au- thors identified 1,929 women with DCIS diagnosed in one breast between 1974 and 1993. Contralateral invasive carci- noma developed at a rate twice that of the control popula- tion. When contralateral in situ carcinoma was found, it was intraductal in 78% of these patients. The detection rate for contralateral DCIS was highest in the first year after diag- nosis of the ipsilateral lesion, with a relative risk (RR) com- pared with controls of 21.4 (95% confidence interval [CI], 11.8 to 38.7). Five years or more after ipsilateral diagnosis, the RR was 3.1 (95% CI, 1.0 to 9.8). The frequency of subsequent invasive carcinoma in the contralateral breast of women with DCIS was 4.3% in one series, considerably less than that for patients with LCIS. 95 A similar observation was recorded by Habel et al. 94 who found that the RR of contralateral invasive carcinoma was

1.8 (95% CI, 1.4 to 2.4) for women with ipsilateral DCIS and 3.0 (95% CI, 1.7 to 5.1) for women with LCIS compared with a control population. The majority of deaths due to breast carcinoma recorded in patients with DCIS in one breast have been due to invasive carcinoma of the contralateral breast. 32,41,72 Deaths due to contralateral invasive carcinoma were reported in 3.6%, 52 1.9%, 43 and 1.0% 32 of cases, whereas in two of these studies deaths caused by invasive recurrence in the ipsilateral breast occurred in 2 of 140, or 1.4%, 32 and 2 of 61, or 3.2%, 56 of patients treated with breast conservation. It is clear from the foregoing review that data regarding bilaterality in women with DCIS in one breast are heavily influenced by methodologic issues relating to how the in- formation was assembled. Clinically apparent synchronous contralateral carcinoma occurs in less than 10% of patients, with at least half also being intraductal. Metachronous subse- quent carcinoma occurs more frequently than initial primary DCIS in the general population, with a RR of about 2. Subse- quent contralateral invasive carcinoma is responsible for the majority of breast carcinoma deaths in women with ipsilat- eral DCIS, ranging from 1% to nearly 4%. A small number of deaths are also attributable to ipsilateral invasive recurrences after breast conservation therapy. Contrast-enhanced MRI is an efficient method for detecting occult concurrent contra- lateral carcinoma in women with ipsilateral DCIS. 65 Gross Pathology Noncomedo DCIS and nonpapillary DCIS are usually not evident grossly. Comedocarcinoma involving multiple ducts occasionally produces a firm mass (Fig. 11.3). A pal- pable, high-grade solid type of DCIS with necrosis (i.e., of the

FIG. 11.3.  DCIS, “comedo.” Gross biopsy specimen show- ing numerous round and pale yellow foci of “comedo” type necrosis. Inset : cross section of a duct with high-grade in situ carcinoma with central necrosis from another case. The latter corresponds to the “comedo” appearance on the cut section of the gross specimen.