Male Breast Carcinoma

Abstract

With minimal estimated annual cases, male breast carcinoma is a relatively rare disease. With low instances of clinical and pathological understanding of male breast cancer, this disease is not prevalent in any one institution. Although similar in its tendencies, male and female breast cancer carcinomas differ in risk, prognosis and survival. This review of literature focuses its investigation on the clinicopatholical features of 73 cases of male breast carcinoma in Chinese population and classified the molecular subtype based on surrogate immunohistochemical definitions. Expressions evaluated are; GCDFP15, MGB, AR, and FOXP1. No special type is the most abundant histological type in this study group of invasive carcinoma among Chinese population. This study also revealed that the luminal A and B subtypes were the major types of male breast carcinoma.

Introduction

Research for male breast carcinoma is often extrapolated from its female counterpart and while studies showed specific shared characteristics, differences are also present; such as histological type and hormone receptor status. Prior studies and analysis of female breast cancers are classified into multiple groups with separate outcomes. Due to a lack of feasibility and high costs associated with, immunohistochemical markers have been used as surrogates for classifying breast cancers. These studies have created conflicting results due to different subtyping algorithms and have yet to be applied to male breast carcinoma in Chinese population, with molecular subtypes remaining understudied as well (Zhou 2014).

Review of Methods

Male patients with complete clinicopatholical data was collected in a search for breast carcinoma through the data bases of the Department of Pathology at Fudan University Shanghai Cancer Center between January 2004 and April 2012. This included 46 residing patients and 27 consultation patients as well as HE-stain slides for all 73 patients. Paraffin-embedded tissue blocks and tissue sections were available for molecular subtyping, as well as numerous cases for further immunohistochemical studies (Zhou 2014). All patients were evaluated histologically and clinical information was recorded, including but not limited too; patient age, clinical symptoms, tumor site, tumor size, lymph node status and treatment history.

When looking to determine the stage of the tumor the seventh edition of the American Joint Committee on Cancer (AJCC) staging system. Two pathologists independently reviewed slides of all cases confirming diagnosis. Additionally, classifications of histological type were characterized by using WHO Classification of Tumours of the Breast. Histological grade was defined with the Bloom and Richardson score scheme for invasive carcinoma. Ductal carcinoma in situ, necrosis, sclerotic stroma, calcification of the tumors and dermis or nipple infiltration were also recorded if present. When micropapillary components accounted for less than 90% of all present carcinoma, a diagnoses of invasive ductal carcinoma with invasive micropapillary carcinoma was given. Mixed invasive ductal and mucinous carcinoma was rendered when less than 90% of mucinous components existed. Invasive papillary carcinoma, intraductal papillary carcinoma, encapsulated papillary carcinoma and solid papillary carcinoma where all noted as papillary carcinoma for this study (Zhou 2014).

Immunohistochemical staining of subtypes ER, PR, Her2, Ki-67, CK5/6 and EGFR were accomplished using Ventana BenchMark ULTRA automated stainer (Ventana Medical Systems Inc., Roche, Tuscon, AZ, USA) and Ventana Ultra View Universal DAB Detection kit. Guidelines followed by The American Society of Clinical Oncology (ASCO) and the College of American Pathologists where used when scoring slides for ER, PR and HER2. This task was completed and evaluated by two experienced pathologists who remained unaware of the results and tumor characteristics of other stains (Zhou 2014).

Applied Discussion of Current Information

Background

To fully cognize male breast carcinoma we must continue to gain a better understanding on the disease as a whole. Male breast cancer occurs when certain breast cells divide faster than healthy cells. The accumulation of cells forms a tumor that is then capable of metastasizing to nearby tissue (Mayo Clinic). Male breast cancer usually presents its self as a painless mass located in the central subareolar region. Other clinical symptoms include nipple discharge and skin changes. In addition, male breast cancer is predominantly unilateral (Zhou et al).

Add Genetic Factors

There are known mutated genes that cause certain men to be more susceptible. These genes are inherited from their parents and specific mutations, such as BRCA2, can put you at a greater risk of developing breast and prostate cancers. The normal function of these genes is to make protein that prevents abnormal growth, but these mutated genes are not as effective at cancer protection (Mayo Clinic).

Add Other Risk Factors

Factors that increase male breast cancer include: age, exposure to estrogen, Klinefelter's syndrome, liver disease, obesity, radiation exposure and testicle disease and surgery (Mayo Clinic).

Discussion

The majority of male breast carcinoma research data are drawn from retrospective studies. The median age at diagnosis among male breast cancer patients is 67 years (Zhou et al). Additionally, the age adjusted incidence rate of male breast carcinoma is increasing, while female breast carcinoma has been well established and stable at 61 years. Further studies have also "shown that the incidence of breast carcinoma in men has increased from 1973 to 1998 although, overall, it remains a rare condition" (Giordano et al 2004). The median age of male breast carcinoma in the Chinese population is lower at 57-59 years, which is similar to this study cohort of 59 years (Zhou et al). Furthermore, in general, "men are frequently diagnosed with more advanced stage cancer than women" (Korde 2010). Reasons surrounding this may be linked to multiple different factors and future studies should be conducted to better understand. For example, women are more susceptible to screenings such as mammography causing earlier detection rates with increased survival time. However, "mortality of male