[Effects of adjuvant trastuzumab on long-term survival of T1N0M0 stage human epidermal growth factor receptor 2 positive breast cancer: a real-world study]

Objective: To investigate the prognosis impact of adjuvant trastuzumab treatment on human epidermal growth factor receptor 2 (HER-2) positive early breast cancer patients. Methods: A retrospective study was conducted, HER-2-positive T1N0M0 stage breast cancer patients who underwent surgery in the Affiliated Tumor Hospital of Xinjiang Medical University from January 2010 to December 2019 were divided into treatment group and control group according to whether they were treated with trastuzumab or not. Propensity score matching (PSM) was used to balance the confounding bias caused by differences in baseline characteristics between the two groups. Cox proportional hazards model was used to analyze the risk factors affecting disease-free survival (DFS). The Kaplan-Meier method was used to estimate the 3- and 5-year DFS and overall survival (OS) rates of the two groups before and after PSM. Results: There were 291 patients with HER-2 positive T1N0M0 stage breast cancer, including 21 cases in T1a (7.2%), 61 cases in T1b (21.0%), and 209 cases in T1c (71.8%). Before PSM, there were 132 cases in the treatment group and 159 cases in the control group, the 5-year DFS rate was 88.5%, and the 5-year OS rate was 91.5%. After PSM, there were 103 cases in the treatment group and 103 cases in the control group, the 5-year DFS rate was 86.0%, and the 5-year OS rate was 88.5%. Before PSM, there were significant differences in tumor size, histological grade, vascular invasion, Ki-67 index, postoperative chemotherapy or not and radiotherapy between the treatment group and the control group (P<0.05). After PSM, there were no significant difference in clinicopathological features between the treatment group and the control group (P>0.05). Multivariate analysis showed that histological grade (HR=2.927, 95 CI: 1.476, 5.805; P=0.002), vascular invasion (HR=3.410, 95 CI: 1.170, 9.940; P=0.025), menstrual status (HR=3.692, 95 CI: 1.021, 13.344, P=0.046), and chemotherapy (HR=0.238, 95 CI: 0.079, 0.720; P=0.011) were independent factors affecting DFS. After PSM, the 5-year DFS rate of the treatment group was 89.2%, while that of the control group was 83.5%(P=0.237). The 5-year OS rate of the treatment group was 96.1%, while that of the control group was 84.7%(P=0.036). Conclusion: Postoperative targeted therapy with trastuzumab can reduce the risk of recurrence and metastasis in patients with HER-2-positive T1N0M0 stage breast cancer.

Human epidermal growth factor receptor 2 positive rates in invasive lobular breast carcinoma: The Singapore experience

BACKGROUND

Invasive lobular carcinomas (ILC) form 5%-10% of breast cancer and rarely show overexpression of human epidermal growth factor receptor 2 (HER2).

AIM

To describe the prevalence and prognostic factors of HER2 positive (HER2+) ILC in an Asian population.

METHODS

A retrospective review of patients with ILC seen between January 1985 and March 2018 at various SingHealth medical institutions was conducted. Demographic and clinical data were collected from medical records. We examined clinicopathological characteristics and survival in relation to HER2 status.

RESULTS

A total of 864 patients were included. Prevalence of HER2 positivity was 10.1% (87 patients). Compared with HER2 negative (HER2-) ILC, HER2+ ILC was associated with a higher proportion of estrogen receptor negative (24.4% vs 5.9%, P < 0.001), progesterone receptor negative (PR-) (40.2% vs 24%, P = 0.002) and grade 3 tumours (Grade 3, 29.0% vs 10.2%, P < 0.001). Overall survival rate was poorer in patients with HER2+ compared to HER2- ILC (56.7% vs 72.9% alive at 10 years; hazard ratio 1.87, 95% confidence interval: 1.21-2.90, P = 0.004). Based on multivariate analysis, negative prognostic factors for overall survival included HER2 positivity, PR negativity, older age, Indian ethnicity and higher tumour stage.

CONCLUSION

Prevalence of HER2+ ILC was 10.1%. HER2+ ILC was more likely to have poorer prognostic features such as estrogen receptor negative, PR- and higher tumour grade, and have a poorer survival.

A retrospective, multicenter study of the efficacy of lapatinib plus trastuzumab in HER2-positive metastatic breast cancer patients previously treated with trastuzumab, lapatinib, or both: the Trastyvere study

PURPOSE

To evaluate the efficacy and safety of lapatinib (L) and trastuzumab (T) combination in HER2-positive metastatic breast cancer (MBC) patients previously treated with T and/or L.

MATERIALS AND METHODS

We conducted a retrospective, post-authorized, multicenter study including patients with HER2-positive MBC or locally advanced breast cancer (ABC) treated with the combination of L-T. Concomitant endocrine therapy, as well as brain metastasis and/or prior exposure to L, were allowed.

RESULTS

One hundred and fifteen patients from 14 institutions were included. The median age was 59.8 years. The median number of prior T regimens in the advanced setting was 3 and 73 patients had received a prior L regimen. The clinical benefit rate (CBR) was 34.8% (95% CI 26.1-43.5). Among other efficacy endpoints, the overall response rate was 21.7%, and median progression-free survival (PFS) and overall survival were 3.9 and 21.6 months, respectively. Heavily pretreated and ≥ 3 metastatic organ patients showed lower CBR and PFS than patients with a low number of previous regimens and < 3 metastatic organs. Moreover, CBR did not significantly change in L-pretreated compared with L-naïve patients (31.5% versus 40.5% for L-pretreated versus L-naïve). Grade 3/4 adverse events were reported in 19 patients (16.5%).

CONCLUSION

The combination of L-T is an effective and well-tolerated regimen in heavily pretreated patients and remains active among patients progressing on prior L-based therapy. Our study suggests that the L-T regimen is a safe and active chemotherapy-free option for MBC patients previously treated with T and/or L.