Efficacy of neoadjuvant therapy on HER2-positive breast cancer: a clinicopathological analysis / 中华病理学杂志

Objective: To investigate the efficacy of neoadjuvant therapy (NAT) on HER2-positive breast cancer and to analyze their clinicopathological features. Methods: A total of 480 cases of HER2-positive breast cancer who received neoadjuvant therapy (NAT), diagnosed at the Department of Pathology of Fudan University Shanghai Cancer Center from 2015 to 2020, were retrospectively identified. Clinicopathological parameters such as age, tumor size, molecular subtype, type of targeted therapy, Ki-67 proliferation index, ER and HER2 immunohistochemical expression, and HER2 amplification status were analyzed to correlate with the efficacy of NAT. Results: Among 480 patients with HER2-positive breast cancer, 209 achieved pathology complete response (pCR) after NAT, with a pCR rate of 43.5%. Of all the cases,457 patients received chemotherapy plus trastuzumab and 23 patients received chemotherapy with trastuzumab and pertuzumab. A total of 198 cases (43.3%) achieved pCR in patients with chemotherapy plus trastuzumab, and 11 cases (47.8%) achieved pCR in patients with chemotherapy plus trastuzumab and pertuzumab. The pCR rate in the latter group was higher, but there was no statistical significance. The results showed that the pCR rate of IHC-HER2 3+patients (49%) was significantly higher than that of IHC-HER2 2+patients (26.1%, P<0.001). The higher the mean HER2 copy number in the FISH assay, the higher the pCR rate was achieved. The expression level of ER was inversely correlated with the efficacy of NAT, and the pCR rate in the ER-positive group (28.2%) was significantly lower than that in the ER-negative group (55.8%, P<0.001). The pCR rate (29.1%) of patients with luminal B type was lower than that of HER2 overexpression type (55.8%, P<0.001). In addition, higher Ki-67 proliferation index was associated with higher pCR rate (P<0.001). The pCR rate was the highest in the tumor ≤2 cm group (57.7%), while the pCR rate in the tumor >5 cm group was the lowest (31.1%). The difference between the groups was significant (P=0.005). Conclusions: HER2 copy numbers, HER2 immunohistochemical expression level, molecular subtype, ER expression level and Ki-67 proliferation index are significantly associated with pCR after NAT. In addition, fluorescence in situ hybridization results, HER2/CEP17 ratio and tumor size could also significantly affect the efficacy of NAT.

Clinicopathological features of adult Wilms tumor with BRAF V600E mutation / 中华病理学杂志

Objective: To identify BRAF V600E mutations in adult Wilms tumor (WT) with overlapping histologic features of metanephric adenoma (MA) and to investigate the clinicopathological features of adult WT. Methods: The clinical features of adult WT diagnosed at the Fudan University Shanghai Cancer Center, Shanghai, China from 2012 to 2021 were reviewed. HE-stained slides of all cases were reviewed by 2 expert pathologists. Representative tissues were selected for BRAF V600E immunohistochemical (IHC) staining and gene sequencing. Results: In adult WT with MA-like areas (cohort Ⅰ, n=6), 5 of the 6 cases were composed of epithelial-predominant and were positive for WT-1 and CD56, respectively, and all were positive for CD57. All 6 cases revealed highly variable Ki-67 indices, ranging from 1% in some areas to 60% in others. 5 of the 6 cases harbored a BRAF V600E mutation. All cases in cohort I were followed up for 23 to 71 months, and all survived. In classical adult WT without MA-like areas cohort (cohort Ⅱ, n=13), all 7 cases with available material were negative for BRAF by IHC and none of them had any BRAF mutation. Conclusions: BRAF V600E mutations are frequently present in adult WT with overlapping morphologically features of MA, but not in those without. More importantly, adult WTs with overlapping histologic features of MA may be an intermediate entity between typical MA and WT that may have a favorable prognosis and possible therapeutic targets.