What is Invasive Lobular Carcinoma? Symptoms, Causes, & Treatment

Invasive lobular carcinoma (ILC) is the second most common type of breast cancer, making up about 10-15% of all breast cancers. Unlike other breast cancers that form distinct lumps, ILC grows in a single-file pattern through breast tissue, which can make it harder to detect on physical exams and imaging tests.

This type of cancer starts in the milk-producing glands (lobules) of your breast and then spreads into nearby breast tissue. While the word "invasive" might sound scary, it simply means the cancer cells have moved beyond where they started. Many people with ILC respond very well to treatment, especially when caught early.

What are the symptoms of invasive lobular carcinoma?

ILC often doesn't create the typical hard lump that most people associate with breast cancer. Instead, it tends to grow in a way that can make it feel like a thickening or fullness in your breast tissue.

Here are the signs you might notice, keeping in mind that early ILC may not cause any symptoms at all:

• A subtle thickening or firmness in part of your breast rather than a distinct lump
• Changes in the texture or feel of your breast tissue
• Breast swelling or enlargement on one side
• Skin dimpling or puckering that looks like an orange peel
• Nipple discharge that isn't breast milk
• Nipple turning inward when it didn't before
• Changes in breast shape or size
• Persistent breast pain or tenderness in one area

Because ILC can be subtle, many cases are found during routine mammograms before any symptoms appear. This is actually good news because it means the cancer is often caught at an earlier, more treatable stage.

What are the types of invasive lobular carcinoma?

Most invasive lobular carcinomas fall into the classic type, but there are a few less common variations that your doctor might identify. Understanding these types helps guide your treatment plan.

The classic type makes up about 80% of all ILC cases. These cancer cells grow in the characteristic single-file pattern and tend to be hormone receptor-positive, meaning they respond well to hormone therapy treatments.

Less common types include pleomorphic lobular carcinoma, which tends to be more aggressive and may not respond to hormone therapy. There's also solid lobular carcinoma and alveolar lobular carcinoma, but these are quite rare. Your pathologist will determine exactly which type you have by examining tissue samples under a microscope.

What causes invasive lobular carcinoma?

Like most breast cancers, ILC develops when normal breast cells undergo changes in their DNA that cause them to grow and divide uncontrollably. However, we don't fully understand why these specific changes happen to lobular cells.

Several factors may contribute to the development of ILC, though having these factors doesn't mean you'll definitely develop cancer:

• Age - most cases occur in women over 50
• Family history of breast or ovarian cancer
• Inherited gene mutations like BRCA1 or BRCA2
• Personal history of breast cancer or certain benign breast conditions
• Long-term hormone replacement therapy use
• Dense breast tissue
• Radiation exposure to the chest area
• Lifestyle factors like alcohol consumption and lack of physical activity

It's important to remember that many people with these risk factors never develop breast cancer, while others with no known risk factors do. Cancer development is complex and often involves multiple factors working together over time.

When to see a doctor for invasive lobular carcinoma?

You should contact your doctor if you notice any persistent changes in your breast, even if they seem minor. Since ILC can be subtle, it's better to have any concerns checked out rather than waiting to see if they go away.

Schedule an appointment promptly if you experience any breast changes that last longer than one menstrual cycle. This includes new areas of thickening, changes in breast size or shape, skin changes, or nipple discharge. Even if you've recently had a normal mammogram, new symptoms should still be evaluated.

If you have a family history of breast or ovarian cancer, consider discussing genetic counseling with your doctor. They can help you understand your risk and determine if genetic testing might be appropriate for you.

What are the risk factors for invasive lobular carcinoma?

Understanding your risk factors can help you and your doctor make informed decisions about screening and prevention strategies. Some risk factors you can control, while others you cannot.

Factors you cannot change include your age, family history, and genetic makeup. ILC is more common in women over 50, and having close relatives with breast or ovarian cancer increases your risk. Certain inherited gene mutations, particularly BRCA2, may slightly increase ILC risk compared to other breast cancer types.

Factors that may be within your control include maintaining a healthy weight, limiting alcohol consumption, staying physically active, and discussing the risks and benefits of hormone replacement therapy with your doctor. While these lifestyle changes can help reduce risk, they don't guarantee prevention.

What are the possible complications of invasive lobular carcinoma?

When detected early and treated appropriately, most people with ILC have excellent outcomes. However, like any cancer, there are potential complications to be aware of so you can work with your healthcare team to monitor and address them.

The main concern with any invasive breast cancer is the possibility of spread to nearby lymph nodes or other parts of the body. ILC has a slightly higher tendency than some other breast cancers to occur in both breasts, either at the same time or years later. This is why your doctor may recommend more frequent monitoring of both breasts.

Treatment-related complications can include surgical side effects, such as changes in breast sensation or arm mobility after lymph node removal. Chemotherapy and radiation therapy, if needed, may cause temporary side effects like fatigue, nausea, or skin changes. Long-term hormone therapy, while very effective, may increase the risk of blood clots or bone loss in some people.

Rare complications might include the development of a second, different type of cancer later in life, though this risk is generally low. Your healthcare team will discuss your specific situation and help you understand which complications are most relevant to your case.

How can invasive lobular carcinoma be prevented?

While there's no guaranteed way to prevent ILC, you can take steps to reduce your overall breast cancer risk and catch any problems early when they're most treatable.

Lifestyle modifications that may help include maintaining a healthy weight, exercising regularly, limiting alcohol consumption, and avoiding unnecessary hormone therapy. If you're considering hormone replacement therapy for menopause symptoms, discuss the risks and benefits thoroughly with your doctor.

Regular screening is your best defense against ILC. Follow mammography guidelines for your age group, and don't skip appointments. If you have dense breast tissue or other risk factors, your doctor might recommend additional imaging tests like breast MRI or ultrasound.

For those at high risk due to family history or genetic factors, preventive measures might include more frequent screening, genetic counseling, or in rare cases, preventive surgery. These decisions are highly personal and should be made with input from specialists who understand your unique situation.

How is invasive lobular carcinoma diagnosed?

Diagnosing ILC often requires multiple steps because this type of cancer can be harder to see on standard imaging tests. Your doctor will likely start with a physical exam and review your symptoms and medical history.

Imaging tests typically include a mammogram, though ILC may not show up clearly on this test. Your doctor may also order a breast ultrasound or MRI, which can be more effective at detecting lobular cancers. MRI is particularly useful for ILC because it can show the true extent of the cancer and check for cancer in the opposite breast.

A definitive diagnosis requires a tissue biopsy, where a small sample of suspicious tissue is removed and examined under a microscope. This can be done with a core needle biopsy, which is usually performed in the doctor's office with local anesthesia. The pathologist will determine not only if cancer is present but also important characteristics like hormone receptor status and growth rate.

Additional tests might include blood work to check your overall health and imaging studies to see if the cancer has spread to other parts of your body. Your healthcare team will explain each test and what the results mean for your treatment plan.

What is the treatment for invasive lobular carcinoma?

Treatment for ILC is highly individualized based on the size and location of your cancer, whether it has spread, and its biological characteristics. The good news is that ILC often responds very well to treatment, especially when caught early.

Surgery is usually the first step and may involve either a lumpectomy (removing just the cancer and some surrounding tissue) or mastectomy (removing the breast). Because ILC can be more extensive than it appears, your surgeon might recommend MRI-guided surgery to ensure complete removal. Some people may also need lymph node removal to check for cancer spread.

Many people with ILC will receive hormone therapy because this type of cancer is often hormone receptor-positive. This might include medications like tamoxifen or aromatase inhibitors, which block hormones that fuel cancer growth. These treatments are typically taken for 5-10 years and are very effective at preventing recurrence.

Depending on your specific situation, your oncologist might also recommend chemotherapy, radiation therapy, or targeted therapy drugs. The decision depends on factors like tumor size, lymph node involvement, and your overall health. Your treatment team will work with you to create a plan that gives you the best chance of a successful outcome while maintaining your quality of life.

How to manage invasive lobular carcinoma at home?

Managing ILC at home involves taking care of your physical and emotional well-being while following your treatment plan. Small, consistent steps can make a big difference in how you feel during treatment and recovery.

Focus on eating nutritious foods that give you energy and help your body heal. This doesn't mean following a strict diet, but rather choosing plenty of fruits, vegetables, lean proteins, and whole grains when possible. Stay hydrated and don't worry if your appetite changes during treatment - this is normal.

Gentle exercise, as approved by your doctor, can help reduce fatigue and improve your mood. This might be as simple as taking short walks or doing light stretching. Rest when you need to, and don't feel guilty about taking time to recover.

Managing side effects is important for your comfort and treatment success. Keep track of any symptoms and communicate regularly with your healthcare team. They can provide medications or strategies to help with issues like nausea, fatigue, or pain. Don't hesitate to reach out between appointments if you have concerns.

How should you prepare for your doctor appointment?

Preparing for your appointment can help you make the most of your time with your healthcare team and ensure you get all the information you need. Start by writing down your questions before you arrive.

Bring a list of all medications you're taking, including over-the-counter drugs and supplements. Also, gather any relevant medical records, especially previous mammograms or breast imaging studies. If possible, bring a trusted friend or family member to help you remember important information discussed during the visit.

Think about your symptoms and when they started. Be prepared to describe any changes you've noticed in your breasts, even if they seem minor. Your doctor will also want to know about your family history of cancer and any previous breast problems you've had.

Write down your most important questions first, in case time runs short. Don't be afraid to ask for clarification if you don't understand something - your healthcare team wants to make sure you're fully informed about your condition and treatment options.

What's the key takeaway about invasive lobular carcinoma?

The most important thing to understand about ILC is that it's a very treatable form of breast cancer, especially when caught early. While it may be harder to detect than other breast cancers, advances in imaging and treatment have greatly improved outcomes for people with this condition.

Early detection through regular screening and attention to breast changes remains your best tool for a positive outcome. Don't let the subtle nature of ILC symptoms cause you to delay seeking medical attention if you notice any changes in your breasts.

Remember that having ILC doesn't define you, and with proper treatment and support, most people go on to live full, healthy lives. Your healthcare team is there to guide you through every step of the process, and there are many resources available to help you and your loved ones navigate this journey.