Clinicopathologic characteristics of HER2-positive metaplastic squamous cell carcinoma of the breast

Abstract

AimsThe aim of this study was to analyse the clinicopathological features and prognosis of human epidermal growth factor receptor-2 (HER2)-positive metaplastic squamous cell carcinoma (MSCC).MethodsFifty-eight patients with MSCC of the breast who were classified into 45 triple-negative and 13 HER2-positive subgroups diagnosed at the West China Hospital, Sichuan University, from 2004 to 2018, were enrolled. Clinicopathological features were collected and compared between HER2-positive MSCC, triple-negative MSCC, HER2-positive invasive breast carcinoma of no special type (NST) and triple-negative NST groups. In the prognostic survival analysis, HER2-positive MSCCs was compared with triple-negative MSCCs, HER2-positive NSTs and triple-negative NSTs.ResultsCompared with triple-negative MSCCs, more patients with Ki-67 low expression were in HER2-positive MSCCs (p<0.05). More patients with HER2-positive MSCC than patients with HER2-positive NST were postmenopausal (p<0.05). Compared among HER2-positive MSCCs, triple-negative MSCCs and triple-negative NSTs, patients of HER2-positive MSCCs with high Ki-67 expression were the least, and HER2-positive MSCCs had more strongly associated with postmenopausal disease status (p<0.05). In survival analyses, HER2-positive MSCCs had a high risk of recurrence and poor prognosis (p<0.05). Lymph node status was significantly associated with the disease-free survival of patients with HER2-positive MSCC.ConclusionIn conclusion, our study indicates that HER2-positive MSCC is an aggressive disease with unique clinicopathological characteristics. Both HER2-positive status and an SCC component are critical factors for poor prognosis. HER2-positive MSCC and triple-negative MSCC are distinct subgroups. Corresponding targeted therapy recommendations should be made for this HER2-positive MSCC group.

Pathological Complete Response to Neoadjuvant Chemotherapy in a Patient with HER2-Positive Squamous Cell Carcinoma of the Breast

“…Shui et al [ 15 ] reported that 3 of 30 cases of SCC (10%) were HER2 positive. Lei et al [ 16 ] reported that 13 of 58 cases of metaplastic SCC (22%) were HER2 positive. Additionally, because few clinicopathologic and therapeutic studies have examined HER2-positive SCC because of the rarity of the disease, the effect of neoadjuvant chemotherapy is unclear.…”

“…HER2-positive breast cancer is rather unusual in SCC, and all available data regarding HER2-positive SCC of the breast were generated by case reports and small retrospective studies [1,[12][13][14][15][16], and the clinicopathologic features of this rare subtype of SCC have not been described in detail. In this study, we reported a case of HER2-positive SCC of the breast, an extremely rare breast cancer, which exhibited a pathological complete response to neoadjuvant chemotherapy.…”

An Update on the Molecular Pathology of Metaplastic Breast Cancer

“… 3 Conversely, HER2-positive metaplastic squamous cell carcinomas were recently demonstrated to have a poorer prognosis than the TN metaplastic squamous variants. 4 MpBC fit into the claudin-low and/or basal breast cancer intrinsic subtypes, 5 , 6 although whether or not claudin low represents an intrinsic subtype or phenotype has recently come into question. 7 A recent large meta-analysis reported that approximately three quarters of all MpBC stain positively for pan-cytokeratin biomarkers (AE1/3, MNF116) and basal cytokeratin biomarkers (34βE12, CK5/6, CK14 and CK17).…”

Significant efficacy of paclitaxel plus carboplatin (TP) as a neoadjuvant regimen for metaplastic squamous cell carcinoma of the breast: a rare case report and literature review

“…Metaplastic squamous cell carcinoma of the breast (MSCCB) is a rare tumor that exists as one of the subgroups of metaplastic breast carcinoma, which accounts for less than 0.1% of all breast carcinomas (1). Since MSCCB is a very invasive tumor, its prognosis is poor (2). Besides, the cause and underlying mechanism of MSCCB remain unclear as a result of few clinical case reports and a lack of standard treatment guidelines.…”