Understanding the different types of breast cancer, treatments, and outcomes

There isn’t one single description or treatment plan for breast cancer. It is a complex disease that comes in many shapes and sizes. Some types of breast cancer tend to grow slowly and respond well to treatment. Others spread aggressively and require urgent and immediate intervention.

This guide answers some of the most asked questions about breast cancer:

• What is invasive vs. non-invasive breast cancer?
• What are the most common types of breast cancer and their outcomes?
• What are the less common types of breast cancer and their outcomes?
• What are my options if I have breast cancer?

The most important thing to understand is that early detection is key. Understanding how to make the right decisions for any specific type of breast cancer requires a proper diagnosis. And early detection means faster decisions and a faster path to care.

📖  Read more about the value of early detection.

Whether invasive or non-invasive, knowing what you’re up against can make all the difference in treating breast cancer.

What is invasive vs. non-invasive breast cancer?

Breast cancer is categorized based on whether it has spread beyond the original site.

• Invasive breast cancer: Cancer that has spread into surrounding breast tissue and gone beyond the ducts or lobules.
• Non-invasive (in situ) breast cancer: Cancer that has not yet spread beyond the milk ducts or lobules and remains localized.

What are the most common types of breast cancer and their outcomes?

• Invasive ductal carcinoma (IDC): The most common type of breast cancer is IDC. IDC accounts for about 80% of all invasive cases, according to John Hopkins Medicine. It begins in the milk ducts and invades nearby breast tissue. The Office on Women’s Health published that the five-year survival rate for localized IDC is approximately 99%, but if it spreads to nearby lymph nodes, the survival rate drops to 86%. If metastasized, survival is around 32%.
• Invasive lobular carcinoma (ILC): ILC start sin the breast lobules and spreads to surrounding tissues. According to the Cleveland Clinic, ILC accounts for about 10-15% of invasive breast cancers and is often harder to detect than IDC due to its tendency to grow in a dispersed pattern. When localized, the five-year survival rate is similar to that of IDC, at 90-99%. Most ILC are hormone receptor-positive (ER+ and/or PR+),making them responsive to hormone therapy and often associated with better outcomes.
• Ductal carcinoma in situ (DCIS): DCIS is anon-invasive cancer that starts in the milk ducts but has not spread into surrounding tissues. According to the National Institutes of Health (NIH), it is highly treatable when detected early, with a nearly 98% ten-year survival rate.

What are the less common types of breast cancer types and outcomes?

• Triple-negative breast cancer (TNBC): TNBC lacks estrogen, progesterone, and HER2 receptors. It accounts for about 10-15%of breast cancers and tends to be more aggressive. The five-year survival rate is approximately 77% for localized breast cancer, but it is significantly lower at 11% for metastatic cases. Black women are nearly twice as likely to be diagnosed with TNBC as white women, according to the National Breast Cancer Foundation.
• HER2-Positive breast cancer: This type of cancer overexpresses the HER2 protein, leading to rapid cell growth. Targeted therapies like trastuzumab (Herceptin) have significantly improved treatment outcomes. The Breast Cancer Research Foundation estimates that with modern treatment, the five-year survival rate for localizedHER2-positive breast cancer is over 90%.
• Inflammatory breast cancer (IBC): IBC is a rare but aggressive form of breast cancer that blocks lymphatic vessels in the skin, causing redness, swelling, and warmth in the breast. The American Cancer Society says that IBC accounts for only 1-5% of breast cancers but has a five-year survival rate of around 40%due to its rapid progression.
• Lobular carcinoma in situ (LCIS): LCIS is not considered a true cancer but rather a marker of risk. Women with LCIS have an increased risk of developing invasive breast cancer, according to Dr. Jane Brock of Brigham and Women’s Hospital in her recently published research.
•  Paget’s disease of the breast: This rare cancer affects the skin of the nipple and is usually associated with DCIS or invasive breast cancer. Paget's disease of the breast usually affects patient solder than 60 years, per the National Institutes of Health (NIH), and the most common treatment is surgery to remove the affected breast. The 5-yearsurvival rate of patients with Paget's disease of the breast is greater than80%.
• Metaplastic breast cancer: Metaplastic breast cancer is a rare and aggressive form of breast cancer. It contains a mix of cell types and behaves differently from typical IDC. Metaplastic breast cancer is often more complicated to treat, and MD Anderson Cancer Center places the five-year survival rate around 55%.

📖Read more about breast cancer risk factors.

What are my options if I have breast cancer?

Advancements in breast cancer treatment have significantly improved survival rates, according to Dr. Eric Winer’s Journal of the American Medical Association (JAMA)article. Yet, Dr. Winer emphasized that continued efforts in personalized medicine are needed to address the diverse nature of the disease and optimize therapy for individual patients.

Treatment depends on the type, stage, and molecular characteristics of breast cancer:

• Surgery: A lumpectomy or mastectomy removes the tumor. Surgery is highly effective for localized cancers, contributing to high survival rates.
• Radiation therapy: Post-surgery radiation is an additional treatment that is sometimes recommended after surgery to kill cancer cells that may remain behind. The Mayo Clinic explains that adding radiation after a lumpectomy reduces the risk of cancer returning to the affected breast.
• Chemotherapy: Chemotherapy, or the shorthand “chemo,” is commonly used for aggressive or advanced-stage cancers, improving survival in high-risk cases.
•  Hormonal therapy: Approximately 70% of breast cancers are estrogen receptor (ER)-positive. People with this type of breast cancer are usually treated with endocrine therapy - a daily pill that blocks estrogen - for at least 5 years. In ER-positive disease, 5 years of treatment with tamoxifen or an aromatase inhibitor cut the risk of recurrence in half.
• Targeted therapy: Target therapies like HER2 inhibitors for HER2-positive breast cancer have improved survival rates dramatically.

Breast cancer may be complex, but one thing is clear: early detection and personalized treatment are game-changers. The good news is that advancements in medical research are continually improving  survival rates.

Whether facing a common type like IDC or a rare form like IBC, understanding your specific diagnosis empowers you to take control of your health. The fight against breast cancer isn’t just about survival—it’s about thriving, staying informed, and advocating for the best possible care.

If you or a loved one is concerned about breast cancer, Defiant Health is here to help. Seeking early detection and expert guidance gives you the power to make the best decisions for you.