Frequency and clinical characteristics of HER2 over-expressed breast cancer in Saudi Arabia: a retrospective study

Jamal Zekri,Ahmed Saadeddin,Hulayel Alharbi

doi:10.1186/s12905-020-01159-3

Abstract

IntroductionThis study aimed to determine the frequency of human epidermal growth factor receptor 2 (HER2) over-expression in newly diagnosed breast cancer (BC) patients in Saudi Arabia and to assess the clinical characteristics and outcomes in patients with HER2-positive disease.MethodsIn the first part of the study, we retrospectively reviewed the pathology records of all patients diagnosed with BC between 2007 and 2013 at 3 hospitals in the largest 3 cities in Saudi Arabia to determine the frequency of HER2 over-expression. In the second part, a representative sample from the patients identified with HER2 over-expressed BC was selected for further investigation. Data collected included demographic and clinical characteristics such as hormone-receptor status, treatment regimens, survival data, response to treatment, and selected adverse events.Results1867 BC records were included in the study. HER2 was overexpressed in 559 patients (29.9%); of those, 348 HER2-positive BC patients were included in subsequent analyses. In the sample of HER2-positive BC patients, median age at diagnosis was 46 years, 0.9% were male, 92.5% were Saudi, 42.4% were Hormone Receptor-negative, and 13.1% had stage IV tumors. Most patients (84.2%) underwent curative intent surgery and 71.8% received radiotherapy. Average tumor size was 3.5 ± 2.5 cm and infiltrating ductal carcinoma was the most common pathology (92.9%). As for pharmacological therapy, the most commonly used regimens were Chemotherapy + Trastuzumab combination (79.1%) in neoadjuvant setting, Hormonotherapy alone (56.2%) in adjuvant setting, and Chemotherapy + Targeted therapy combination (64.8%) as palliative treatment. At the last patient evaluation, 36.9% had complete response, while 33.2% had progressive disease. Median overall survival (OS) and progression-free survival (PFS) were not reached in patients on neoadjuvant/adjuvant pharmacotherapy. As for patients on palliative intent pharmacotherapy, median OS and PFS were 64.7 and 29.3 months respectively.ConclusionThis study provided updated figures regarding HER2 overexpression in BC in Saudi Arabia: HER2 overexpression rate (29.9%) was within the range reported in previous studies. Patients’ demographic and clinical characteristics were also similar to those reported earlier, with a median age at diagnosis of 46 years and one third of patients having locally advanced/metastatic disease at diagnosis.

Highlights

This study aimed to determine the frequency of human epidermal growth factor receptor 2 (HER2) over-expression in newly diagnosed breast cancer (BC) patients in Saudi Arabia and to assess the clinical characteristics and outcomes in patients with HER2-positive disease
In part 2 of the study, we aim to present an in-depth description of the clinic-pathological features, management and the clinical outcome of HER2-positive BC in Saudi Arabia
Of the 559 HER2-positive BC cases identified in part 1, 348 patients were included in part 2 of the study (Fig. 1)

Summary

Introduction

This study aimed to determine the frequency of human epidermal growth factor receptor 2 (HER2) over-expression in newly diagnosed breast cancer (BC) patients in Saudi Arabia and to assess the clinical characteristics and outcomes in patients with HER2-positive disease. Zekri et al BMC Women’s Health (2021) 21:10 are diagnosed annually, accounting for almost 1 in 4 cancer cases among women and 15% of cancer mortality in both developed and developing countries [1]. Age at diagnosis varies substantially between industrialized and Arab countries; in USA and Europe, the median age at presentation is around 63 years [2]. In the Arab countries, almost 50% of the cases are diagnosed at age below 50 (median age at diagnosis is 49.8 years). The situation in Saudi Arabia is no exception from other parts of the Arab world, where BC accounts for 30.1% of female cancers [4]. The Saudi National Cancer Registry reported an incidence of 127.8 BC cases per 100,000 women and a mortality rate of 25.5 per 100,000 between 2000 and 2004 [5]. Most patients are diagnosed under 50 years [6] and one fourth under 40 [7] and 15% present with distant or metastatic disease [4]

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