Having hormone receptor positive breast cancer is an uncommon form of cancer that only affects a few thousand women each year, and yet it’s one of the most aggressive types of breast cancer. Although a patient’s prognosis will depend on her particular cancer type, there are treatments available that can offer patients a good chance of survival.
ER + PR+ tumors showed lower stage
ER + PR+ tumors are rare. According to the National Comprehensive Cancer Network (NCCN), less than one percent of breast cancers are PR-positive and ER-negative. However, ER/PR status does not reflect the overall prognosis. In fact, the ER+/PR+/HER2- subtype has nearly identical prognosis with the ER+/PR+/HER2+ subtype.
According to the SEER database, the proportion of ER-negative/PR-positive tumors decreased from 1990 to 2015, with the overall number of cases decreasing by more than 80%. Although the SEER data is incomplete, it provides a general picture of the distribution of ER/PR/HER2 subtypes.
In the study, 272 patients with ER-positive, and HER2-negative tumors were analyzed. The patients were divided into three groups based on ER expression: ER+/PR+/HER2-, ER+/PR-/HER2-, and ER+/PR-/HER2+. The ER+/PR+/HER2- the group had a slightly higher survival rate than all other subtypes.
ER + PR+ tumors exhibited a higher EGFR expression and a lower Ki-67 level, which is associated with a higher nuclear grade. However, a lower p53 expression was observed in ER + PR+ tumors. The ER + PR- tumors were less invasive than the ER + PR+ tumors. A higher percentage of patients with ER + PR- tumors received chemotherapy. Moreover, more patients with ER + PR- tumors were treated with endocrine therapy. Compared with ER+ PR+ tumors, ER + PR- tumors showed a poorer OS and DFS.
The ER + PR+ tumors showed a lower stage than ER + PR- tumors. However, this difference was not statistically significant. The distribution of demographic and tumor characteristics was assessed using contingency tables. ER + PR+ tumors showed similar characteristics to ER + PR- tumors, but the differences between the two subtypes were moderate.
ER + PR+ tumors showed ER and PR expression in nearly the same proportion. However, a small percentage of patients were discordant. In addition, the percentage of patients who did not express either receptor was also low. Moreover, patients with low expression were more likely to have TP53 mutations.
ER-negative breast cancer vs ER-positive breast cancer
ER-negative breast cancer is a subtype of breast cancer in which the estrogen receptor (ER) is absent in tumor tissue. The progesterone receptor (PR) is present. ER-positive breast cancer is a subtype in which both the ER and the PR are present in tumor tissue.
The ER is a hormone receptor that is naturally present in our bodies. Estrogen fuels the growth of breast cancer cells. It is important to test for the presence of ER and PR in breast tumors, as this can affect treatment decisions.
The ER is present in breast tumors in varying intensities. It may be weak or strong. ER-positive tumors have a better chance of surviving than ER-negative tumors.
The percentage of ER-negative breast cancer decreased over the past few decades. A study by Li and colleagues found that the percentage of ER-negative tumors increased during the 1990s but then decreased in the following decade.
The study also found that the difference in survival between ER-positive and ER-negative tumors was relatively small. The 10-year survival rate was about 75% for ER-negative/PR-positive breast cancer and about 86% for ER-positive/PR-negative breast cancer. However, the ER-negative/PR-positive subtype had the third-highest 20-year survival rate, while the ER-positive/PR-negative subtype had the second-highest survival rate.
However, the difference in survival between the ER+/PR+/HER2- and the ER+/PR+/HER2+ subtypes was not statistically significant. In fact, the differences between the ER+/PR+/HER2- subtype and the other three subtypes were less than 1% for stage 1.
The percentage of ER-negative/PR-positive breast tumors was intermediate between the ER-positive/PR-positive and ER-negative/PR-negative subtypes. This may be a result of a decline in ER-negative tumors over the past few decades, as well as increased detection of ER-positive tumors.
HER2-positive breast cancer
HER2-positive breast cancer (BC) is an aggressive subtype of breast cancer that historically has a poor prognosis. However, new targeted treatments have improved outcomes in this group of patients. The most important goal of therapy is to avoid recurrence. However, new treatments are still needed for BCs that recur.
A number of standard chemotherapy drugs have been proven to be effective in treating HER2-positive BC. These drugs include cisplatin and fluoropyrimidine. However, HER2+ BCs often develop resistance to these drugs. The NCI continues to support research on HER2-targeted therapies.
Several monoclonal antibodies have been developed targeting the HER2 gene. These antibodies have shown a significant antitumor effect. They disrupt the activity of the HER2 protein. These therapies have been approved by the FDA. However, they are not without adverse events. Some of these adverse events may be exacerbated by chemotherapy. Therefore, further evaluation of HER2 ADCs in high-risk patient populations is necessary.
In addition to targeted therapies, immunotherapy is another approach to combating proliferating cancer cells. This approach harnesses the innate immune system to target and attack cancer cells. In addition to HER2, antibodies targeting alternative HER2 domains have also been tested.
However, the HER2 gene is not always expressed at high levels in cancer cells. The protein is mainly overexpressed in tumors that have developed resistance to HER2 targeted therapies. This is likely due to the overexpression of mucin 4, which is a masked binding site for trastuzumab. In addition, tumors that are highly HER2 positive may have a higher risk of recurrence and death.
Although HER2-positive BCs are an aggressive subtype, targeted therapy and chemotherapy have improved patient outcomes. Some of these new strategies include a combination of targeted therapy, chemotherapy, and immunotherapy. These approaches are being tested in clinical trials.
Endocrine-based treatments are the backbone of initial therapy for advanced hormone receptor-positive breast cancer
Currently, endocrine-based treatments are the backbone of initial therapy for advanced hormone receptor-positive breast cancer. These treatments may include estrogen receptor (ER) blockers or aromatase inhibitors. Endocrine therapy has been proven effective in pre-and postmenopausal patients. These therapies have been associated with reduced mortality and improved breast cancer survivorship.
The treatment options for advanced breast cancer are based on the stage of the disease and the specific patient’s situation. If the patient has an early-stage disease, then the treatment option may be chemotherapy or targeted therapy. However, in cases where cancer has progressed, most clinicians recommend chemotherapy or endocrine-based therapy.
Endocrine therapies are effective in preventing breast cancer recurrence. A variety of clinical trials have been conducted to evaluate the effectiveness of these treatments. The present publication summarizes the results of these trials. It is a comprehensive systematic review of the literature and can be used as a standalone reference to the extensive data.
Currently, the most common endocrine therapies are tamoxifen and letrozole. Tamoxifen is a pill that is taken by mouth. Letrozole can be used for five years after menopause. Other options include fulvestrant, an endocrine therapy used for premenopausal women.
Tamoxifen and other endocrine therapies have been shown to increase breast cancer survival. However, they also increase the risk of cardiovascular disease. Increasing research is focused on determining whether or not extended endocrine therapy is effective.
Treatment directed at the tumor site includes surgery, radiation frequency ablation, chemoembolization, and targeted radiation. While some doctors favor treatment directed at the tumor site, the evidence is mixed.
In women with HR-positive breast cancer, the ovaries are the main site for hormone production. However, some women develop metastatic disease in only one organ. Whether endocrine therapy is appropriate for these patients is based on the type of cancer, the patient’s menopausal status, and the treatment goals.
Tamoxifen is the standard hormonal therapy for premenopausal women
Compared to women with hormone receptor-positive breast cancer who were treated with chemotherapy, women treated with hormone therapy had a lower risk of breast cancer death. Despite a relatively small increase in the risk of uterine cancer and deep vein thrombosis, the benefits outweighed the harms. In addition to reducing the risk of invasive breast cancer, tamoxifen may also be useful in treating advanced breast cancer.
The most commonly used hormone therapies are anti-estrogen drugs and aromatase inhibitors. Anti-estrogen drugs stop estrogen production in the body, whereas aromatase inhibitors prevent the action of estrogen at the receptor site. Whether or not a woman’s cancer responds to hormone therapy depends on the drug and her particular cancer. Generally, women who have early-stage ER-positive breast cancer may benefit from treatment with both tamoxifen and an aromatase inhibitor.
Ovarian suppression, a strategy used in adjuvant therapy, has been shown to reduce estrogen levels in premenopausal women with hormone-dependent breast cancer. Ovarian ablation is often performed surgically or with radiation. A patient may also be switched to another drug to reduce the risk of recurrence.
Combined tamoxifen-ovarian suppression was found to be better than tamoxifen alone in women with hormone receptor-positive, HER2-negative disease. Compared to women in the tamoxifen group, those in the combined group had a higher rate of disease-free survival and overall survival. However, they reported a higher rate of targeted adverse events in grades 3 or 4 (27.8%, 11.4%, and 5.7%, respectively).
The risk of recurrence was higher in women in the chemotherapy group. The risk was higher in younger women. However, the benefits were similar, both in terms of absolute benefits and relative benefits.
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