Invasive lobular breast cancer: symptoms, diagnosis and treatment

Invasive lobular breast cancer, also known as invasive lobular carcinoma (ILC), is a cancer of the lobules, the milk-producing glands of the breast. "Invasive" means the cancer cells have spread outside the lobules into the surrounding breast tissue. Breast Cancer Now says women of any age can develop it, but it is more common as they get older.

Cancer Research UK says it is the second most common type of breast cancer, making up around 15% of cases. Breast cancer is very rare in men, and it is very unusual for a man to have the lobular type; Breast Cancer Now agrees it is very rare. Breast Cancer Now adds that lobular breast cancer is sometimes found mixed with other types, such as ductal carcinoma in situ (DCIS) or invasive ductal breast cancer.

Cancer Research UK stresses that if your doctor has told you that you have lobular carcinoma in situ (LCIS), you do not have invasive lobular breast cancer. These are two different things and LCIS is not cancer.

Cancer Research UK says invasive lobular breast cancer does not always form a firm lump, and you are more likely to have a thickened area of breast tissue. Breast Cancer Now adds that it may not cause any obvious changes to the breast at all, and that a breast lump is less common with this type.

Possible symptoms listed by the two charities include the following.

• An area of thickening or swelling in the breast tissue.

• A change in the shape or size of the breast.

• A change in the skin, such as dimpling, puckering or thickening.

• A change in the nipple, such as turning inwards (becoming inverted), or discharge from the nipple.

• A lump or swelling under the arm.

• Less commonly, a breast lump.

The NHS says to see a GP if you have a lump or swelling in your breast, chest or armpit, any changes in your breasts or nipples that are not normal for you, or pain in your breast or armpit when other people in your family have had breast cancer or ovarian cancer. It adds that breast pain by itself is not usually a symptom of breast cancer. Many of these symptoms are common and can be caused by other conditions, but it is important to get checked, and finding cancer early may make it easier to treat.

At the appointment the GP will ask about your symptoms and may examine your breasts; you can have a friend, family member or another member of staff in the room. If the GP thinks symptoms could be cancer you may be referred to a breast clinic. The NHS stresses this does not definitely mean you have cancer. Breast Cancer Now says to see your GP if you notice a change to your breast that is new or unusual for you.

Cancer Research UK says your GP may refer you to a breast clinic if you have symptoms that could be due to ILC, or you may be referred if a screening mammogram shows an abnormal area. At the clinic the doctor or specialist nurse takes your medical history, examines your breasts and feels for enlarged lymph nodes under your arms and at the base of your neck.

Breast Cancer Now says sometimes more than one area of invasive lobular cancer is found in the same breast, and it can also sometimes be found in both breasts (bilateral). Cancer Research UK says that because ILC is sometimes found in more than one area within the breast, it might not be possible to remove just one area, in which case the surgeon may recommend removal of the whole breast.

Cancer Research UK says treatment for ILC is the same as for invasive breast cancer of no special type. Your doctor considers the size of the cancer and whether it has spread (stage), how abnormal the cells look (grade), whether the cells have receptors for particular cancer drugs, your general health and fitness and whether you have had the menopause. You may have one or more treatments, and the NHS says the specialist team will explain the benefits and side effects and work with you on a plan.

Breast Cancer Now says a breast MRI does not always give an accurate estimate of the size of invasive lobular cancer, so some people who have breast-conserving surgery need a second operation to make sure all the cancer, and a margin of normal tissue around it, has been removed. In some cases the second operation is a mastectomy.

Cancer Research UK says after treatment you may have regular check-ups, which might go on for at least 5 years and might include yearly mammograms. UK guidelines say everyone treated for early breast cancer should have a written care plan with the tests you will have, signs and symptoms to look out for and contact details for specialist staff such as your breast care nurse. In some hospitals follow-up is by patient-initiated follow-up (PIFU), where you contact the team if you have new symptoms.

Breast Cancer Now says that after breast-conserving surgery follow-up includes regular mammograms of both breasts, and after a mastectomy a mammogram of the untreated breast. If the cancer was not originally seen on a mammogram, mammograms are still useful for picking up early changes. A follow-up breast MRI is not currently standard practice but may be considered case by case. Having breast cancer in one breast means the risk of a new cancer in the other breast is slightly higher, so report any new changes promptly.

Breast Cancer Now says secondary invasive lobular breast cancer can affect the digestive organs (stomach and intestine), reproductive organs (uterus and ovaries), lungs, liver, bones, brain and skin. The NHS says secondary breast cancer most commonly affects the bones, liver, lungs or brain, with general symptoms such as feeling tired or having no energy, loss of appetite, weight loss without trying, feeling unwell with no clear cause, feeling or being sick and difficulty sleeping. If you have had breast cancer and develop these symptoms, tell your breast care nurse or GP without waiting for the next appointment.

Breast Cancer Now says there is no right or wrong way to feel after a diagnosis, and your breast care nurse, specialist or GP can arrange counselling or psychological support. It names Lobular Breast Cancer UK as a charity sharing personal stories of people diagnosed with lobular breast cancer and campaigning for better information and research.

On the NHS the route is usually a GP appointment, an urgent referral to a breast clinic if cancer is possible, imaging and biopsy at the clinic, and a multidisciplinary team that includes a breast care nurse. Breast screening is also offered on the NHS and can pick up lobular cancer before symptoms.

Some people choose a private breast clinic for quicker imaging or an opinion. The tests and treatments are the same, and your results and plan should be shared with your GP and NHS team. Ask your clinic whether treatment would continue with them or be transferred to the NHS.