Immunohistochemical subtypes of the breast cancer in the ultrasound and clinical aspect – literature review

Abstract

Breast cancer is a heterogeneous disease both in its clinical and radiological manifestations and response to treatment. This is largely due to the polymorphism of the histological types as well as diversified molecular profiles of individual breast cancer types. Progress in the understanding of the biology of breast cancer was made with the introduction of immunohistochemical research into the common practice. On this basis, four main breast cancer subtypes were distinguished: luminal A, luminal B, HER2 positive (human epidermal growth factor receptor-2 positive), and triple negative cancer. The classification of a tumour to an appropriate subtype allows for the optimisation of treatment (surgery or pre-operative chemotherapy). In this study, the authors present different patterns of breast cancer subtypes in ultrasound examination and differences in their treatment, with particular emphasis on aggressive breast cancer subtypes, such as triple negative or HER2 positive. They can, unlike the luminal subtypes, create diagnostic problems. Based on multifactorial analysis of the ultrasound image, with the assessment of lesion margins, orientation, shape, echogenicity, vascularity, the presence of calcifications or assessment by sonoelastography, it is possible to initially differentiate individual subtypes.

Editorial

“…In Poland in 2018, according to the National Cancer Registry, there were 18,869 cases of BC in women and 154 in men. At the same time, a total of 6,895 and 75 deaths were recorded for women and men, respectively [1,2]. The neoplasm is characterised…”

“…Currently, breast cancer treatment consists of a comprehensive approach to the diagnostic and therapeutic processes. Three main imaging methods are used in the diagnosis of breast cancer: ultrasonography, mammography, and magnetic resonance imaging [1,3,4]. Each of these methods plays a special role in diagnostics.…”

“…Contemporary breast ultrasonography means not only mapping the morphology of focal lesions and their surroundings but also involves a combination of additional techniques such as sonoelastography and colour Doppler. These techniques allow an increase in the accuracy of imaging and qualification of patients for biopsy or observation [1,5]. Early diagnosis of breast cancer and knowledge of its oncological characteristics based on biopsy findings facilitate the choice of optimal therapy, including surgical treatment which, in selected cases, is preceded by neoadjuvant chemotherapy.…”

“…Early diagnosis of breast cancer and knowledge of its oncological characteristics based on biopsy findings facilitate the choice of optimal therapy, including surgical treatment which, in selected cases, is preceded by neoadjuvant chemotherapy. Treatment of early breast cancer is complex and includes a combination of surgical methods (breast conserving therapy, BCT), radiotherapy, systemic therapies (chemotherapy, hormone therapy, molecularly targeted therapies), and adjunctive therapy in various sequences [1,3]. The use of predictive bio-markers such as the histological type of BC (invasive or preinvasive forms), the expression of ER/PgR (estrogen receptor (ER) and progesterone receptor), Ki67 (proliferation index) and HER2 (human epidermal growth factor receptor 2), genomic signatures, if available, stage of the primary tumor, condition of the axillary lymph nodes, and patient's preferences, affect the choice and sequence of therapies.…”

“…Additionally, short-term and long-term toxicity, the biological age of the patients, and their general health and comorbidities should be considered. In the current recommendations of all scientific oncological societies, neoadjuvant chemotherapy is recommended not only in locoregional advanced breast cancer but also in the early stages of the following subtypes: triple-negative breast cancer (TNBC) and in combination with molecularly targeted treatment in the subtypes with the presence of HER2 receptors (luminal B HER2 positive and HER2 positive non-luminal subtypes [1,5]. Neoadjuvant chemotherapy can also be used in cases of HER2 negative luminal B cancer with low expression of hormone receptors, high grade (G3), and in young individuals (≤ 35 years of age), stage II or III [1,3] (Fig.…”