Comparison of Estrogen Receptor and Progesterone Receptor in Ductal Carcinoma and Lobular Carcinoma With Regard to Age Prevalence

Copyright © 2017 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (http:// creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1. Background Breast cancer is a common disease among women, and its incidence is increasing worldwide. This disease still has complex and vaguely-understood aspects. Hormonal disorders are one of the strong factors in the development of this disease. Accordingly, many studies have investigated estrogen and progesterone receptors (PRs) on breast cancer cell tissues, and researchers have achieved good progress in the control and treatment of this disease. Adjunctive therapies that are effective on hormonal receptors such as tamoxifen can be used for a better prognosis of breast cancer if the breast cancer tissue tests positive for progesterone and estrogen. This drug can significantly reduce the recurrence of breast cancer; its preventive effects for breast cancer in high-risk groups have also been proven.1,2 Based on histological origin, invasive breast cancers are classified into different types such as invasive lobular carcinoma (ILC). This type is the second most prevalent breast cancer and forms about 10% of breast cancers. ILC metastasizes through the blood stream. The most common type of breast cancer is invasive, or infiltrative ductal carcinoma (IDC), and forms about 80% of all breast cancers. IDC usually metastasizes through the local lymph nodes (especially axillary nodes). Other types of intraluminal cancer that are less common are mucinous ductal carcinoma, medullary ductal carcinoma, papillary ductal carcinoma, and tubular ductal carcinoma.1 Age is one of the most significant predisposing factors for malignancies such as breast cancer; moreover, age at diagnosis is a known prognostic factor of breast cancer.2 ER-positive/PR-negative breast cancers are most prevalent after age 40 in all groups of breast cancer patients.3 It has been shown that growth-factor-activated pathways downregulate PR expression, and this explains the ER-positive/PR-negative phenotype.4-6 In breast cancer studies, tumor markers are of notable importance because of their role in prognosis. The status of ER in invasive breast cancers is important, and its Abstract


Background
Breast cancer is a common disease among women, and its incidence is increasing worldwide.This disease still has complex and vaguely-understood aspects.Hormonal disorders are one of the strong factors in the development of this disease.Accordingly, many studies have investigated estrogen and progesterone receptors (PRs) on breast cancer cell tissues, and researchers have achieved good progress in the control and treatment of this disease.Adjunctive therapies that are effective on hormonal receptors such as tamoxifen can be used for a better prognosis of breast cancer if the breast cancer tissue tests positive for progesterone and estrogen.This drug can significantly reduce the recurrence of breast cancer; its preventive effects for breast cancer in high-risk groups have also been proven. 1,2ased on histological origin, invasive breast cancers are classified into different types such as invasive lobular carcinoma (ILC).This type is the second most prevalent breast cancer and forms about 10% of breast cancers.
ILC metastasizes through the blood stream.The most common type of breast cancer is invasive, or infiltrative ductal carcinoma (IDC), and forms about 80% of all breast cancers.IDC usually metastasizes through the local lymph nodes (especially axillary nodes).Other types of intraluminal cancer that are less common are mucinous ductal carcinoma, medullary ductal carcinoma, papillary ductal carcinoma, and tubular ductal carcinoma. 1ge is one of the most significant predisposing factors for malignancies such as breast cancer; moreover, age at diagnosis is a known prognostic factor of breast cancer. 2R-positive/PR-negative breast cancers are most prevalent after age 40 in all groups of breast cancer patients. 3][6] In breast cancer studies, tumor markers are of notable importance because of their role in prognosis.The status of ER in invasive breast cancers is important, and its determination is a common practice in the management and prognosis evaluation of the disease. 7he ER-positive and/or PR-positive breast cancer patients have a lower disease-related mortality rate in comparison with ER-and/or PR-negative patients.10][11]

Objective
The current study compared ILC and invasive ductal carcinoma considering the prevalence of estrogen, PRs, and age prevalence.

Methods
In this cross-sectional study, 225 women with a diagnosis of ILC or invasive ductal carcinoma were included.All patients were admitted to the Department of Surgery of Baqiyatallah hospital between March 2014 and March 2015.
Non-probability convenience sampling was used to select the subjects.
The data collection tool was a self-made checklist.This standard checklist was confirmed by five experts in the field of study.
The enrollment of patients in the current study was approved by the ethics committee of Baqiyatallah University of Medical Sciences, and written informed consent was obtained from each patient.ER and PR levels from the pathologists' interpretation of the assay are reported.Both ER and PR were estimated to be positive when immunoperoxidase staining of the tumor cell nucleus was more than 10%.
Descriptive statistics were calculated for the data presented herein.Categorical data was compared with either chi-square or Fisher exact test depending on the sample size.The nonparametric Mann-Whitney test was used to compare the groups.The Kolmogorov-Smirnov test was used for normality of data.The data was analyzed by SPSS 20 software (SPSS Inc., Chicago, IL, USA).The significance level for all the tests was considered 0.05.

Results
Overall, 225 eligible patients were evaluated for study participation.The most common malignancy was invasive ductal carcinoma found in 213 (94.7%) participants who had a mean age of 49.30 ± 12.25 years.The minimum and maximum ages of patients were 24 and 86 years, respectively.There were no significant differences in the ages of patients with various types of tumors (0.706).
The most common subtype of invasive ductal carcinoma was NOS; patients of this type had a mean age of 49.68 ± 12.27 years (Table 1).
Figure 1 depicts the distribution of age levels of the study samples.The most frequent was 74 patients (32.9%) ranging in age from 40 to 49 (Table 1).with ILC, however, only 11 cases (91.7%) were ER positive.
There was a significant relationship between the outcomes of ER and pathology (P < 0.03).Table 2 depicts a cross table of the study samples regarding outcomes of PR and pathology.Among patients with IDC, 107 (50.2%) of them were PR-positive.In patients with ILC, 6 cases (50.0%) were ER positive.There was no significant relationship between the outcomes of PR and pathology (P = 0.98).
The average age of ER-positive patients was higher than that of ER-negative patients (P = 0.036).Also, the mean age of patients who were PR positive was significantly higher than that of patients with negative PR (P = 0.020; Table 3).

Discussion
Estrogen and PR tests are performed on the resected breast cancer tissues by Immunohistochemical (IHC) assay.If both tests are positive for receptors, the patient may benefit from adjuvant hormonal therapy, which leads to a better prognosis and better treatment outcome. 12Obviously, if one or both receptors are negative, the treatment strategy will change, and the prognosis and treatment outcome will be worse.In studies performed in Iran, the most common age at which women are diagnosed with breast cancer is between 30-40 years; that is a decade earlier than international statistics. 13he prevalence rates of different types of breast cancer in the current study are like those of other studies. 14The average age of ER-positive patients was higher than that of ER-negative patients.
This correlation was seen in both ductal and lobular carcinomas; it explains why aging breast cancer patients have a better response to hormonal therapy.
In the current study, only one patient had a positive PR, while her ER was negative.In almost all ER-negative patients, the PR was negative simultaneously.This particular topic was not found in any other studies, although in most studies the rate of (ER +, PR-) was low. 15t seems that the findings of the current study are unique, perhaps because of the ethnic characteristics of the Iranian population or an accidental finding.A systematic review of this issue in more studies is necessary.

Conclusion
Results of the current study indicate that the age prevalence of breast cancer in Iran is a decade earlier than the rest of the world.Moreover, the prevalence of positive estrogen and PRs was lower in this study than in the majority of other studies, and these two features make a worse prognosis in the treatment of Iranian patients.

What This Study Adds?
Breast cancer in patients in Iran occurs a decade sooner than the international norm.Furthermore, the prevalence rates of positive estrogen and PRs, factors that worsen prognoses, were lower in this study than in the majority of other studies.

Figure 1 .
Figure 1.Distribution of Patients According to Age.

Table 2
depicts a cross table of the study samples regarding outcomes of ER and pathology tests.Among the IDC patients, 129 (60.6%) were ER-positive.In patients

Table 1 .
Distribution of Patients Regarding Types of Cancer

Table 2 .
Distribution of the Study Samples Regarding Outcomes of Estrogen Receptor, Progesterone Receptor, and Pathology Tests

Table 3 .
Mean Ages of Patients Based on Estrogen Receptor and Progesterone Receptor Results Patients with ER-positive and/or PR-positive tumors in breast cancer have lower risks of mortality after diagnosis compared to patients with ER-and/or PR-negative tumors.Age is one of the most significant risk factors for human malignancies, including breast cancer; moreover, age at diagnosis has been determined to be explanatory of breast cancer prognosis.