278 ‒ Breast cancer: how to catch, treat, and survive breast cancer | Harold Burstein, M.D., Ph.D.

Added: Nov 6, 2023

Breast cancer is the most common diagnosis of cancer in women worldwide, with a lifetime risk of about 1 in 8. However, the majority of breast cancer cases are not fatal, with a cure rate of 80-85%. Breast cancer can be classified into different subtypes, including estrogen receptor positive, HER2 positive, and triple negative. The risk factors for breast cancer include early puberty, longer exposure to estrogen, shorter duration of breastfeeding, and fewer pregnancies. However, the individual risk for breast cancer is still relatively small.

The breast undergoes various stages of development throughout a woman's life. During puberty, the breast enlarges and matures to prepare for potential lactation. The breast is composed of glandular tissue and fat, with the size of the breast determined by the amount of non-glandular tissue. Breast cancer typically arises from the glandular tissue. The incidence of breast cancer has been increasing, possibly due to factors such as early puberty, longer exposure to estrogen, and fewer pregnancies.

There are different types of breast cancer, including estrogen receptor positive, HER2 positive, and triple negative. Estrogen receptor positive breast cancers are the most common and have the most favorable prognosis. Triple negative breast cancers are more aggressive and tend to occur in younger women. HER2 positive breast cancers have an amplification of the HER2 gene and account for about 10-15% of all breast cancers.

Obesity and smoking are known risk factors for cancer, but they have a relatively weak impact on breast cancer risk. Breast density, which can be seen on mammograms, is associated with a slightly increased risk of breast cancer. However, the overall risk for an individual is still relatively small.

Benign lumps in the breast are common and often do not indicate breast cancer. Most women have variations in breast texture, and it is important for women to be aware of their bodies and seek medical evaluation if they notice any changes or lumps. If a lump is suspicious, further imaging or a tissue biopsy may be necessary to determine if it is benign or cancerous.

Ductal carcinoma in situ (DCIS) is a precancerous lesion that occurs within the ducts of the breast. It is considered stage zero breast cancer and is not invasive. DCIS is often detected through screening mammograms and is typically treated with surgical excision to remove the affected portion of the breast. Radiation therapy may also be recommended to lower the risk of recurrence. Anti-estrogen therapy, such as tamoxifen, may be considered to further reduce the risk of recurrence.

The risk of developing invasive breast cancer after DCIS is relatively low, but it is important for women to undergo regular surveillance and follow-up. The treatment approach for DCIS depends on various factors, including the extent of the lesion and the individual's preferences. Mastectomy may be recommended for some cases, while others may opt for lumpectomy with or without radiation therapy.

The majority of women with DCIS who undergo lumpectomy and have no invasive cancer have a low risk of developing invasive breast cancer. The risk varies depending on the grade of the DCIS lesion, with higher grade lesions having a slightly greater risk of recurrence.

Burstein explains that mammography is the primary screening tool for breast cancer and is supplemented by other imaging techniques such as ultrasound and MRI in certain cases. Mammography can detect abnormalities in the breast, such as calcifications or architectural changes, which may indicate the presence of cancer. However, it is important to note that not all abnormalities detected on mammography turn out to be cancerous, and further evaluation through biopsy is necessary to confirm the diagnosis.

Once a suspicious lesion is identified, a core biopsy is performed to obtain a tissue sample for pathological examination. The biopsy results provide information about the type of breast cancer, such as ductal carcinoma in situ or invasive cancer, as well as the grade of the tumor. The grade indicates the aggressiveness of the cancer cells, with higher grades being associated with a poorer prognosis.

Burstein also discusses the importance of biomarker testing, which includes evaluating the expression of estrogen receptor , progesterone receptor, and human epidermal growth factor receptor 2 . These biomarkers help determine the appropriate treatment approach and predict the response to certain therapies. Additionally, other factors such as the proliferation rate of the tumor cells and the presence of tumor-infiltrating lymphocytes may also be considered in the evaluation.

The treatment options for breast cancer depend on various factors, including the stage of the cancer, the size of the tumor, and the presence of lymph node involvement. For early-stage breast cancer, lumpectomy (removal of the tumor) followed by radiation therapy is often the preferred approach. In some cases, a mastectomy (removal of the entire breast) may be recommended, especially if there are concerns about the extent of the disease or the patient's personal preference.

The speaker explains that the prognosis for breast cancer varies depending on the stage and the biological characteristics of the tumor. Generally, the earlier the cancer is detected and treated, the better the prognosis. The 10-year cancer-free survival rates for stage 1 breast cancer are around 90%, while for stage 2 and 3, the rates range from 65% to 80%. However, it is important to note that these are general statistics, and individual outcomes may vary.

The discussion also touches on the role of chemotherapy in breast cancer treatment. Chemotherapy is often used in the adjuvant setting, meaning it is given after surgery to reduce the risk of recurrence. The choice of chemotherapy regimen depends on various factors, including the tumor characteristics and the patient's overall health. The speaker emphasizes that chemotherapy has significantly improved outcomes for breast cancer patients, especially when given in the early stages of the disease.

Radiation therapy is recommended for the majority of women who are 70 and younger and have early stage breast cancer. It helps to sterilize the breast and chest area and prevent recurrence. Drug therapy is also commonly used and can include anti-estrogen medicines like tamoxifen or aromatase inhibitors for estrogen receptor positive tumors. For tumors that are HER2 positive, drugs like trastuzumab are used. Chemotherapy may also be used, especially for triple negative breast cancers.

The use of chemotherapy has changed over the years, and now there are genomic tests available that can help determine whether chemotherapy is necessary. These tests look at the patterns of gene expression in the tumor and can identify which patients are likely to benefit from chemotherapy. This has led to a shift in how chemotherapy is used in ER positive breast cancers, with many patients now able to avoid chemotherapy.

There are different types of breast cancer, and each type has its own treatment paradigm. For triple negative breast cancers, immunotherapy has been a transformative treatment. For HER2 positive breast cancers, the development of trastuzumab has greatly improved outcomes. For estrogen receptor positive breast cancers, there has been a shift towards using less chemotherapy and more hormonal therapy. There are also new drugs called CDK46 inhibitors that are being used for high-risk cancers.

Breast cancer can be caused by inherited gene mutations, such as BRCA1 and BRCA2. These mutations increase the risk of developing breast and ovarian cancer. Genetic testing is recommended for women with a strong family history of breast cancer, and if a mutation is found, preventive measures can be taken, such as mastectomy or removal of the ovaries. There are also other genes, such as PALB2, CHEK2, and ATM, that can increase the risk of breast cancer.

Multidisciplinary care is important in the treatment of breast cancer. This involves a team of specialists working together to develop a treatment plan. It is important for the providers to communicate and collaborate with each other to ensure the best outcomes for the patient. While it is ideal to receive treatment at a top cancer center, there are many places around the country that offer excellent breast cancer care. The key is to find a team that specializes in cancer care and works together effectively.

Men can also develop breast cancer, although it is much less common than in women. The treatment for male breast cancer is similar to that for women, including surgery, radiation therapy, and drug therapy. Genetic testing is also important for men with breast cancer, as they may have inherited gene mutations that increase their risk.