Invasive ductal carcinoma: what it is, symptoms, tests and treatment

Breast tissue contains ducts that carry milk towards the nipple and lobules that make it. Invasive ductal carcinoma begins in the cells lining the ducts and, as Cancer Research UK explains, has grown through the duct lining into the surrounding breast tissue. Cancer Research UK now uses the term invasive breast cancer, noting that it was previously also known as invasive ductal carcinoma.

Under the microscope, most invasive cancers have no special features and are classed as no special type (NST) or not otherwise specified (NOS). Cancer Research UK says between 70 and 80 out of 100 breast cancers fall in this group. The remainder are special types, which have particular microscopic features and include some rare cancers. Your pathology report may use any of these terms, which refer to the same common diagnosis.

It is also different from DCIS. In DCIS some cells have started to turn into cancer but all remain inside the ducts. If you have been told you have DCIS, Cancer Research UK says you do not have invasive breast cancer.

Pathology reports use several overlapping terms. This table sets out how Cancer Research UK describes them, so you can recognise your own diagnosis when you read your letter.

Cancer Research UK lists symptoms of invasive breast cancer as a new lump or thickening in the breast or armpit, a change in the size, shape or feel of the breast, skin changes such as puckering, dimpling, a rash or redness, fluid leaking from the nipple in a woman who is not pregnant or breastfeeding, and a change in the position of the nipple. It adds that these are more often caused by other medical conditions but it is important to see your GP if you have any of them.

The NHS lists a lump or swelling in the breast, chest or armpit, a change in skin such as dimpling that may look or feel like orange peel, colour change (darker on black or brown skin, red on white skin), a change in size or shape, nipple discharge that may contain blood, an inverted nipple, or a rash that may look like eczema. You can have these symptoms without pain, and the NHS says breast pain by itself is not usually a symptom of breast cancer. Seeing a GP is advised for any change that is not normal for you, or for pain with a family history of breast or ovarian cancer.

Both sources stress that many of these symptoms, including breast lumps, are common and can be caused by other conditions. Finding cancer early may make it easier to treat, which is why prompt assessment matters.

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 and other people in your family have had breast or ovarian cancer. It stresses that some of these symptoms, including breast lumps, are very common and can be caused by other conditions, but that if the cause is cancer, finding it early may mean it is easier to treat.

At the appointment the GP will ask about your symptoms, any breast screening you have had and your family history, and may examine your breasts; you can have a friend, family member or another member of staff in the room. If the GP thinks your symptoms could be cancer you may be referred to a breast clinic, which the NHS says does not definitely mean you have cancer.

The NHS also says that breast pain by itself is not usually a symptom of breast cancer, and that checking your breasts regularly helps you know what is normal for you.

• See a GP: a new lump or swelling in the breast, chest or armpit.

• See a GP: skin dimpling, a colour or size or shape change, an inverted nipple, a nipple rash, or nipple discharge when not pregnant or breastfeeding.

• See a GP: breast or armpit pain with a family history of breast or ovarian cancer.

• Tell your breast care team promptly about new symptoms after treatment; do not wait for the next appointment (Cancer Research UK).

The NHS says anyone can get breast cancer and it is not always clear what causes it. It lists being over 50, having dense breast tissue, a family history of breast or ovarian cancer including an inherited faulty gene such as a BRCA gene, and certain breast conditions such as benign breast disease, DCIS or LCIS as factors that might make it more likely.

Hormones also matter. According to the NHS, higher levels of oestrogen, progesterone or testosterone may play a part, which may be more likely if periods started before 12 or the menopause came after 55, if someone has not given birth or first gave birth after 30, did not breastfeed, or has used the contraceptive pill in the last 10 years or takes HRT. The NHS stresses that the pill and HRT only slightly increase risk, and that for many people the benefits outweigh the risks. Smoking is also linked to many breast cancers.

You cannot always prevent breast cancer, but the NHS recommends going to breast screening when invited, cutting down alcohol and avoiding drinking more than 14 units a week, losing weight if overweight and stopping smoking. If close relatives have had breast or ovarian cancer, a GP can discuss referral for NHS genetic testing.

Your GP may refer you to a breast clinic if you have symptoms that could be due to invasive breast cancer, or you may be called back after an abnormal screening mammogram. Cancer Research UK says you usually have one or more of the following: a breast examination, a mammogram, a breast ultrasound scan and a biopsy, in which a sample of tissue is taken. The NHS says that a referral does not definitely mean you have cancer.

The biopsy is what confirms the diagnosis and gives the details that guide treatment. Cancer Research UK says treatment is influenced by the type of cells the cancer started in, its size and whether it has spread (the stage), how abnormal the cells look (the grade), and whether the cells have receptors for particular cancer drugs. Receptor testing tells the team whether hormone therapy or targeted drugs might work.

The NHS says the main treatment for breast cancer is usually surgery, with chemotherapy, radiotherapy, hormone therapy, and targeted medicines and immunotherapy as other common treatments. Which you have depends on the size and type of cancer, where it is, whether it has spread and your general health. Cancer Research UK adds that whether you have been through the menopause also feeds into the decision.

Drug treatment can come before surgery. Cancer Research UK says chemotherapy or hormone therapy given before surgery is called neoadjuvant therapy, and its main aim is to shrink the cancer. Surgery may be breast-conserving surgery, which removes the cancer and a surrounding area of healthy tissue (also called wide local excision or lumpectomy), or a mastectomy, which removes the whole breast, with the option of reconstruction at the same time or later. Armpit lymph nodes may also be removed.

Afterwards, you may have radiotherapy, chemotherapy, hormone therapy, targeted cancer drugs, or bone-strengthening drugs called bisphosphonates. The NHS says radiotherapy after surgery is used to lower the chance of the cancer coming back, and that hormone therapy lowers or blocks certain hormones because some breast cancers grow faster in response to them.

Cancer Research UK says you usually have a mammogram every year for at least 5 years after treatment, and may have regular check-ups depending on your situation. Some hospitals use supported self-management or patient-initiated follow-up (PIFU), where you have regular phone calls with a breast specialist nurse and can arrange an appointment if you have new symptoms or concerns. UK guidelines say everyone treated for early breast cancer should have a written care plan setting out tests, symptoms to look out for, and contact details such as the breast care nurse.

The NHS tells people to talk to their specialists about any symptoms or side effects without waiting for the next check-up. Cancer Research UK acknowledges that coping with the diagnosis can be difficult and that help is available for you and your family. If breast cancer spreads to other parts of the body, the NHS calls it secondary breast cancer, and treatment may focus on managing symptoms and helping you feel better.

Most diagnoses begin with a GP or screening appointment and an NHS breast clinic, where examination, imaging and biopsy are often combined, and treatment is planned by a multidisciplinary team. Some people choose to have initial assessment or treatment privately, for instance through health insurance. The treatments described above are the same; what differs is access, timing and who coordinates your care. If you are weighing options, ask who will be in the team, how results are reviewed and what support, such as a breast care nurse, is available throughout.