Srivastava Pooja, Wang Tiannan, Clark Beth Z, Yu Jing, Fine Jeffrey L, Villatoro Tatiana M, Carter Gloria J, Brufsky Adam M, Gorantla Vikram C, Huggins-Puhalla Shannon L, Emens Leisha A, Basili Thais, da Silva Edaise M, Reis-Filho Jorge S, Bhargava Rohit
Departments of Pathology, UPMC Magee-Womens Hospital, Pittsburgh, PA, USA.
Keck School of Medicine of USC, Los Angeles, CA, USA.
NPJ Breast Cancer. 2022 Apr 20;8(1):51. doi: 10.1038/s41523-022-00415-z.
Triple-negative breast cancers (TNBCs) often have a high Ki-67 proliferation index and respond favorably to neoadjuvant chemotherapy (NACT) with pathologic complete response (pCR) resulting in ~40% of cases. Nevertheless, morbidity/mortality remain high, mostly due to recurrence in patients with residual disease. In contrast, the incidence and clinical features of TNBC with low proliferation (TNLP), defined as TNBC with a Ki-67 index of ≤30% remains unknown. We report 70 cases of TNLP identified at our center from 2008 to 2018, including 18 treated with NACT. TNLP tumors represent <1% of all breast cancers, and ~5-10% of TNBCs. Ninety percent of carcinomas were grade I/II and 70% were either pure apocrine or showed apocrine differentiation. Fifty cases had available immunohistochemistry results; 80%, 84%, 22%, and 20% were positive for AR, INPP4B, nestin, and SOX10, respectively. With a median follow-up of 72 months, 14% experienced recurrence, and 11% died of breast cancer. The tumor stage was prognostic. Among 39 stage-I patients, 18 (46%) received chemotherapy, but this did not impact survival. There was a trend for improved recurrence-free survival with chemotherapy in stage-II patients. Of the 18 patients treated with NACT, 2 (11%) showed pCR; these were notable for either high stromal TILs or a high mitotic count despite a low Ki-67 index. TNLPs are enriched in low to intermediate-grade carcinomas with apocrine features. Due to overall good prognosis of stage-I TNLP and the lack of clear benefit of chemotherapy, de-escalation of chemotherapy may be considered in select patients with stage-I TNLP.
三阴性乳腺癌(TNBC)通常具有较高的Ki-67增殖指数,对新辅助化疗(NACT)反应良好,约40%的病例可获得病理完全缓解(pCR)。然而,发病率/死亡率仍然很高,主要是由于残留疾病患者的复发。相比之下,增殖率低的TNBC(TNLP)的发病率和临床特征尚不清楚,TNLP定义为Ki-67指数≤30%的TNBC。我们报告了2008年至2018年在我们中心确诊的70例TNLP病例,其中18例接受了NACT治疗。TNLP肿瘤占所有乳腺癌的比例不到1%,占TNBC的5%-10%。90%的癌为I/II级,70%为纯大汗腺癌或显示大汗腺分化。50例有免疫组化结果;AR、INPP4B、巢蛋白和SOX10的阳性率分别为80%、84%、22%和20%。中位随访72个月,14%的患者出现复发,11%死于乳腺癌。肿瘤分期具有预后意义。在39例I期患者中,18例(46%)接受了化疗,但这并未影响生存率。II期患者化疗有改善无复发生存率的趋势。在18例接受NACT治疗的患者中,2例(11%)显示pCR;尽管Ki-67指数较低,但这些患者的基质肿瘤浸润淋巴细胞(TIL)较高或有丝分裂计数较高。TNLP富含具有大汗腺特征的低至中级癌。由于I期TNLP的总体预后良好且化疗缺乏明确益处,对于部分I期TNLP患者可考虑降低化疗强度。