同侧导管＋小叶原位癌对侧乳腺癌风险

乳腺导管原位癌＋同侧乳腺小叶原位癌

女性患者对侧乳腺癌发生风险显著增加

　　虽然乳腺小叶原位癌是发生乳腺浸润癌的风险因素之一，但是并非乳腺浸润癌前病变。不过，乳腺小叶原位癌对于合并同侧乳腺导管原位癌的影响尚不明确。

　　2019年9月24日，美国乳腺外科医师学会和美国肿瘤外科学会《肿瘤外科学报》在线发表纽约纪念医院斯隆凯特林癌症中心、凯斯西储大学、普金斯大学黎巴嫩贝鲁特克列孟梭医疗中心的研究报告，比较了乳房保留手术（保乳手术）治疗乳腺导管原位癌患者±同侧乳腺小叶原位癌的对侧乳腺癌发生率和同侧乳腺癌复发率。

　　该研究对2000～2011年纽约纪念医院斯隆凯特林癌症中心有对侧乳腺风险的1888例乳腺导管原位癌保乳手术患者进行分析，根据是否同时存在同侧乳腺小叶原位癌进行分层，对乳腺导管原位癌±乳腺小叶原位癌进行比较。对侧、双侧或原有同侧乳腺小叶原位癌的患者已被剔除。对患者因素、肿瘤因素、治疗因素与对侧乳腺癌和同侧乳腺癌复发的相关性进行评价。

　　结果，其中乳腺导管原位癌1475例（78%）、乳腺导管原位癌＋乳腺小叶原位癌413例（22%）。中位随访7.2年（范围0～17），307例患者随后发生首次乳腺事件，其中207例同侧乳腺癌复发、100例对侧乳腺癌。

　　乳腺导管原位癌＋乳腺小叶原位癌与乳腺导管原位癌相比：

• 10年累积同侧乳腺癌复发率相似：15.0%比14.2%（对数秩，P=0.8）

• 10年累积对侧乳腺癌发生率较高：10.9%比 6.1%（对数秩，P<0.001）

　　对其他影响因素进行校正后，乳腺导管原位癌＋乳腺小叶原位癌与乳腺导管原位癌相比：

• 对侧乳腺癌发生风险仍高2.06倍（95%置信区间：1.36～3.11，P=0.001）

• 同侧乳腺癌复发风险相似

　　因此，该研究结果表明，乳腺导管原位癌＋乳腺小叶原位癌与单纯乳腺导管原位癌相比，虽然同侧乳腺癌复发风险相似，但是对侧乳腺癌发生风险加倍。该结果应该为治疗决策提供依据，尤其对于减少风险的内分泌治疗决策。

Ann Surg Oncol. 2019 Sep 24. [Epub ahead of print]

Risk of Contralateral Breast Cancer in Women with Ductal Carcinoma In Situ Associated with Synchronous Ipsilateral Lobular Carcinoma In Situ.

Megan E. Miller, Shirin Muhsen, Emily C. Zabor, Jessica Flynn, Cristina Olcese, Dilip Giri, Kimberly J. Van Zee, Melissa Pilewskie.

Memorial Sloan Kettering Cancer Center, New York, USA; University Hospitals, Case Western Reserve University School of Medicine, Cleveland, USA; Clemenceau Medical Center, Johns Hopkins International, Beirut, Lebanon.

BACKGROUND: Lobular carcinoma in situ (LCIS) is a risk factor for breast cancer, but the effect of LCIS found in association with ductal carcinoma in situ (DCIS) is unknown. In this study, we compared contralateral breast cancer (CBC) and ipsilateral breast tumor recurrence (IBTR) rates among women with DCIS with or without synchronous ipsilateral LCIS treated with breast-conserving surgery (BCS).

METHODS: DCIS patients undergoing BCS from 2000 to 2011 with a contralateral breast at risk were stratified by the presence or absence of synchronous ipsilateral LCIS with the index DCIS (DCIS + LCIS vs. DCIS). Those with contralateral, bilateral, or prior ipsilateral LCIS were excluded. Associations of patient, tumor, and treatment factors with CBC and IBTR were evaluated.

RESULTS: Of 1888 patients identified, 1475 (78%) had DCIS and 413 (22%) had DCIS + LCIS. At median follow-up of 7.2 (range 0-17) years, 307 patients had a subsequent first breast event; 207 IBTR and 100 CBC. The 10-year cumulative incidence of IBTR was similar in both groups: 15.0% vs. 14.2% (log-rank, p = 0.8) for DCIS + LCIS vs. DCIS, respectively. The 10-year cumulative incidence of CBC was greater in the DCIS + LCIS group: 10.9% vs. 6.1% for DCIS (log-rank, p < 0.001). After adjustment for other factors, CBC risk remained higher in DCIS + LCIS compared with DCIS (hazard ratio 2.06, 95% confidence interval 1.36-3.11, p = 0.001); there was no significant difference in IBTR risk.

CONCLUSIONS: Compared with DCIS alone, DCIS + LCIS is associated with similar IBTR risk but double the risk of CBC. This finding should inform treatment decisions, in particular regarding endocrine therapy for risk reduction.

DOI: 10.1245/s10434-019-07796-9