What are the main types of breast cancer?
Breast cancer is not a single disease: it is described by where it starts (usually the milk ducts or the lobules), whether it has spread into surrounding tissue (in situ or invasive) and its biology (hormone receptors and HER2). Together with the stage, these features decide which treatments are most likely to help.
When your team describes your breast cancer, they are usually combining three layers of information:
- Histological type — what the cells look like under the microscope, for example invasive ductal (no special type) or invasive lobular.
- Molecular or receptor subtype — whether the cancer is hormone receptor-positive, HER2-positive or triple-negative.
- Stage — how large the cancer is and whether it has reached the lymph nodes or other organs.
These details come from the biopsy and later from the surgical specimen. Our guide to breast cancer diagnosis explains how the pathology report is put together.
What is DCIS (ductal carcinoma in situ)?
DCIS is a non-invasive, or “stage 0”, breast condition in which abnormal cells are found inside the milk ducts but have not grown through the duct wall into the surrounding breast tissue. Because the cells are contained, DCIS itself cannot spread to the lymph nodes or other organs.
DCIS is most often found on a screening mammogram, typically as a cluster of tiny calcifications, and it rarely causes a lump. It is treated because some cases, if left alone, may develop into invasive cancer over time — although it is not yet possible to predict reliably which ones will.
Treatment usually involves surgery to remove the area, either breast-conserving surgery (often followed by radiotherapy) or, if the DCIS is widespread, mastectomy. Hormone therapy may be considered for hormone receptor-positive DCIS. Lower-risk DCIS is being studied in trials of active monitoring, but this is not yet standard care everywhere.
What is invasive ductal carcinoma (no special type)?
Invasive ductal carcinoma, now officially called invasive breast cancer of no special type (NST), is the most common form of breast cancer, accounting for roughly 70 to 80 percent of invasive cases. It starts in the cells lining the ducts and grows into the surrounding breast tissue.
“No special type” simply means the cells do not have the particular features that define rarer types. It does not describe how serious a cancer is: NST cancers range from slow-growing, hormone-sensitive tumours to faster-growing HER2-positive or triple-negative ones. Grade, receptors and stage give much more useful information about behaviour and treatment.
Less common “special types” include tubular, mucinous (colloid), cribriform and medullary-pattern cancers; some of these tend to have a more favourable outlook.
How is invasive lobular breast cancer different?
Invasive lobular cancer is the second most common type, making up roughly 10 to 15 percent of invasive breast cancers; it starts in the milk-producing lobules and its cells tend to grow in single-file lines rather than forming a firm lump. This makes it harder to feel and to see on a mammogram.
Key features of lobular cancer include:
- it may cause a vague thickening or area of fullness rather than a distinct lump;
- a breast MRI is often used to measure its true extent before surgery;
- it is more often found in both breasts or in more than one area of the same breast;
- most lobular cancers are hormone receptor-positive and HER2-negative.
Because its size can be underestimated, a re-excision after breast-conserving surgery is somewhat more common with lobular cancer, and some women choose mastectomy. Lobular carcinoma in situ (LCIS) is different again: it is generally considered a marker of increased risk rather than a cancer that needs surgery.
What are the molecular subtypes of breast cancer?
The molecular subtypes group breast cancers by their biology — mainly hormone receptors (ER and PR), HER2 and how fast the cells are dividing (Ki-67 or grade) — and they are among the most important factors in choosing treatment. In everyday practice, these subtypes are usually estimated from the standard pathology tests.
| Subtype | Typical receptor profile | How it often behaves | Main treatments usually considered |
|---|---|---|---|
| Luminal A | ER-positive, often PR-positive, HER2-negative, low Ki-67 / low grade | The most common subtype; tends to grow slowly | Surgery, radiotherapy where indicated, hormone therapy; chemotherapy less often needed |
| Luminal B | ER-positive, HER2-negative or positive, higher Ki-67 / grade | Grows faster than luminal A | Hormone therapy, often with chemotherapy and, if HER2-positive, anti-HER2 drugs |
| HER2-positive | HER2 overexpressed (3+ or gene-amplified), ER-positive or negative | Can grow quickly, but responds well to targeted therapy | Chemotherapy with anti-HER2 drugs such as trastuzumab and pertuzumab, often before surgery |
| Triple-negative | ER-negative, PR-negative, HER2-negative | Often higher grade; more common in younger women and BRCA1 carriers | Chemotherapy, often before surgery; immunotherapy in selected cases |
HER2-positive cancers make up roughly 15 to 20 percent of breast cancers, and triple-negative cancers around 10 to 15 percent. A newer label, HER2-low, describes cancers with small amounts of HER2; it matters mainly for treatment choices if the cancer spreads. Your oncologist will explain what your subtype means; see also breast cancer treatment.
What are the rarer types of breast cancer?
A small proportion of breast cancers are rarer types that can look or behave differently, and recognising them early matters because the treatment pathway may change.
Inflammatory breast cancer
Inflammatory breast cancer is an uncommon, fast-growing type in which cancer cells block lymph channels in the skin. The breast may become red, swollen, warm and heavy, with skin that looks like orange peel, often over a few weeks and without a clear lump. It can be mistaken for an infection, so redness that does not settle quickly with antibiotics should be checked urgently. It is usually treated with chemotherapy first, followed by mastectomy and radiotherapy.
Paget’s disease of the nipple
Paget’s disease causes a scaly, red, itchy or crusted rash on the nipple that may spread to the areola, sometimes with bleeding or discharge. It is usually linked to DCIS or invasive cancer in the breast behind it. Any persistent nipple rash, especially one affecting only one side, should be assessed by a doctor.
Phyllodes tumours
Phyllodes tumours are rare tumours that grow from the connective tissue of the breast rather than the ducts. Most are benign, some are borderline and a few are malignant. They are usually treated by removing them with a margin of healthy tissue.
Male breast cancer
Men also have a small amount of breast tissue and can develop breast cancer, although it accounts for less than 1 percent of cases. It usually appears as a painless lump behind the nipple. Men with breast cancer are more likely to carry an inherited BRCA2 change, so genetic testing is often offered (see hereditary breast cancer and BRCA).
How is breast cancer staged (TNM)?
Breast cancer is staged using the TNM system, which describes the size of the Tumour, whether cancer has reached the lymph Nodes and whether it has spread (Metastasised) to other parts of the body. These three scores are then combined into an overall stage from 0 to IV.
- T (tumour) — Tis is in situ disease such as DCIS. T1 is 2 cm or smaller, T2 is more than 2 cm up to 5 cm, T3 is more than 5 cm, and T4 means the cancer has grown into the chest wall or skin, including inflammatory breast cancer.
- N (nodes) — N0 means no cancer in the nearby lymph nodes. N1 to N3 describe cancer in increasing numbers of nodes or in nodes further away, such as those above the collarbone or behind the breastbone.
- M (metastasis) — M0 means no distant spread has been found; M1 means the cancer has spread to other organs, such as bones, lungs, liver or brain.
The current staging system also takes grade, ER, PR and HER2 into account to give a “prognostic stage”, so two people with the same TNM size may be placed in slightly different stages. Your team may refer to a clinical stage (from examination and scans) and a pathological stage (after surgery). Lymph node status is often confirmed with a sentinel node biopsy, explained in breast cancer surgery.
What are the stages of breast cancer (0 to IV)?
The stages of breast cancer run from stage 0, where abnormal cells are contained within the ducts, to stage IV, where cancer has spread to distant parts of the body. The table below is a simplified guide; the exact stage depends on the full TNM details and the cancer’s biology.
| Stage | In plain words | Treatment aim |
|---|---|---|
| Stage 0 | Non-invasive (in situ), such as DCIS; cells have not spread beyond the ducts | Cure; usually surgery, sometimes with radiotherapy |
| Stage I | A small invasive cancer (up to about 2 cm) with no or only microscopic spread to lymph nodes | Cure; surgery plus treatments matched to the biology |
| Stage II | A larger tumour (about 2–5 cm) and/or cancer in a few armpit lymph nodes | Cure; surgery with systemic therapy and often radiotherapy |
| Stage III | Locally advanced: a large tumour, many involved lymph nodes, or spread into the skin or chest wall | Cure is still the aim; usually treatment before surgery, then surgery and radiotherapy |
| Stage IV | Metastatic: cancer has spread to distant organs such as bones, lungs, liver or brain | Control the cancer, relieve symptoms and protect quality of life, often for many years |
Stages II and III are subdivided into A, B and sometimes C. A stage is assigned at diagnosis and normally stays the same, even if the cancer responds well to treatment.
What does the stage mean for treatment?
The stage helps your team decide the order and intensity of treatment, but it is always considered together with the cancer’s subtype, your general health and your own preferences. Two people with the same stage may be offered quite different treatment plans.
In broad terms:
- Early breast cancer (stages 0–II) is usually treated with surgery first — breast-conserving surgery or mastectomy — followed by radiotherapy, hormone therapy, chemotherapy or targeted therapy depending on the biology.
- HER2-positive and triple-negative cancers of stage II or above are often treated with chemotherapy before surgery (neoadjuvant treatment). This can shrink the cancer, sometimes allows breast-conserving surgery, and shows how well the cancer responds.
- Locally advanced cancer (stage III) usually starts with systemic treatment, followed by surgery and radiotherapy.
- Metastatic cancer (stage IV) is mainly treated with medicines that work throughout the body; surgery and radiotherapy are used in selected situations.
Whether radiotherapy is needed after mastectomy is particularly relevant to reconstruction planning; our page on reconstruction after radiotherapy explains why.
- Tumour and margin removed
- Rest of breast kept
- All breast tissue removed
What is metastatic (stage IV) breast cancer?
Metastatic, or stage IV, breast cancer means that cancer cells have spread from the breast to other parts of the body, most often the bones, lungs, liver or brain. It is sometimes also called secondary or advanced breast cancer, and it may be found at the first diagnosis or years after earlier treatment.
Hearing that cancer has spread is very hard, and it is natural to feel frightened. It may help to know that, although metastatic breast cancer is generally not considered curable, it is increasingly treated as a long-term condition. Many people live well for years, moving through different treatments as needed.
Treatment depends heavily on the subtype. Hormone receptor-positive cancers are often treated with hormone therapy combined with targeted drugs; HER2-positive cancers with several anti-HER2 options; and triple-negative or HER2-low cancers may be treated with chemotherapy, immunotherapy or newer antibody-drug conjugates. A biopsy of a metastasis is often recommended, because receptors can change over time.
Palliative and supportive care teams can be involved from the start — not only at the end of life — to help with pain, fatigue, emotional wellbeing and practical matters. Specialist nurses and patient organisations for secondary breast cancer can also be a valuable source of support.
What affects breast cancer prognosis?
Prognosis — the likely course of the disease — depends on several factors, and the most important are the stage at diagnosis, the subtype and how well the cancer responds to treatment. Overall, breast cancer found early, while it is still in the breast, generally has a high chance of successful treatment, with around 9 in 10 people or more alive five years after diagnosis in many countries.
Factors your team may take into account include:
- tumour size and the number of involved lymph nodes;
- grade and Ki-67;
- ER, PR and HER2 status;
- response to treatment given before surgery;
- genomic test results, where used;
- age, general health and inherited factors such as BRCA.
Survival statistics describe large groups of people diagnosed years ago and cannot predict what will happen to any one person. Treatments continue to improve. Your own oncologist is the best person to discuss what the figures mean for you.
Where breast reconstruction fits in
The type and stage of breast cancer can influence which reconstruction options are suitable and when they are best performed, so it helps to discuss reconstruction early, alongside your oncology team’s plan. Cancer treatment always comes first; reconstruction is planned around it.
For example, early-stage cancers suitable for breast conservation may benefit from oncoplastic surgery to preserve shape. When mastectomy is needed, immediate reconstruction with an implant or your own tissue, such as a DIEP flap, may be possible. When radiotherapy after mastectomy is likely — as in many stage II–III cancers — some teams recommend delaying or staging the reconstruction. People living with metastatic breast cancer can also discuss reconstruction or revision where it would improve comfort and quality of life.
Not everyone wants reconstruction. Going flat or using an external breast prosthesis are equally valid choices. Dr. Fatih Kılıç, a plastic and reconstructive surgeon, can explain the reconstructive options so that you can decide what feels right — see the breast reconstruction overview to start.
- Tumour with clear margin
- Tissue rearranged (reduction pattern)
- Symmetry on the other side
Sharing your diagnosis for a reconstruction opinion from abroad
If you live outside Türkiye, you can send your pathology report, staging summary and your oncology team’s treatment plan to Dr. Fatih Kılıç for an opinion on reconstruction options and their timing. Your diagnosis and cancer treatment remain with your own oncology team at home, and any reconstruction plan is coordinated around their recommendations. You can begin through the international patients page or the contact form.
Frequently asked questions
What is the most common type of breast cancer?
The most common type is invasive breast cancer of no special type, previously called invasive ductal carcinoma. It makes up roughly 70 to 80 percent of invasive breast cancers.
Is DCIS cancer?
DCIS is described as a non-invasive or stage 0 breast cancer. The abnormal cells are confined to the milk ducts and cannot spread elsewhere in this form, but it is usually treated because some cases may become invasive over time.
Is lobular breast cancer worse than ductal?
Not necessarily. Lobular cancer is harder to see on scans and more often affects more than one area, but it is usually hormone receptor-positive. Outlook depends mainly on stage and biology rather than on the lobular or ductal label alone.
What does triple-negative breast cancer mean?
Triple-negative means the cancer cells do not have oestrogen receptors, progesterone receptors or extra HER2 protein. Hormone therapy and anti-HER2 drugs do not work for it, so chemotherapy, sometimes with immunotherapy, is the main treatment.
What does HER2-positive breast cancer mean?
HER2-positive means the cancer makes too much of a growth protein called HER2. These cancers can grow quickly, but they usually respond well to targeted anti-HER2 treatments given together with chemotherapy.
What is the difference between grade and stage?
Grade describes how abnormal the cancer cells look and how quickly they are likely to grow. Stage describes the size of the cancer and how far it has spread, to lymph nodes or other organs.
Is stage 2 breast cancer curable?
Stage 2 breast cancer is treated with the aim of cure, and many people are successfully treated. Treatment usually combines surgery with other therapies chosen according to the cancer’s subtype.
Is stage 3 breast cancer curable?
Stage 3, or locally advanced, breast cancer is still treated with the aim of cure. Treatment is usually more intensive, often starting with chemotherapy or other systemic therapy, followed by surgery and radiotherapy.
How long can you live with stage 4 breast cancer?
This varies widely and depends on the subtype, where the cancer has spread and how it responds to treatment. Stage 4 breast cancer is generally not curable, but many people live for years with treatment, and your oncologist can give the most relevant guidance.
Can men get breast cancer?
Yes. Men have a small amount of breast tissue and can develop breast cancer, although it accounts for less than 1 percent of cases. Any lump or change behind the nipple in a man should be checked by a doctor.
What does inflammatory breast cancer look like?
It often causes redness, swelling and warmth over a large part of the breast, sometimes with skin that looks like orange peel, usually without a distinct lump. It can develop over weeks and may be mistaken for infection, so it needs urgent assessment.
Does the stage of breast cancer affect reconstruction?
It can. The stage influences whether radiotherapy is likely after mastectomy, which affects the choice and timing of reconstruction. Discussing reconstruction early with both your oncology team and a plastic surgeon helps keep options open.
Medically reviewed by Dr. Fatih Kılıç, Plastic, Reconstructive and Aesthetic Surgeon. This page is for general information and does not replace an individual consultation.