Other established risk factors include having no children, having the first child later, not breastfeeding, early menarche (the first menstrual period), late menopause and taking hormone replacement therapy.
The probability of breast cancer rises with age but breast cancer tends to be more aggressive when it occurs in younger women.
Two genes, BRCA1 and BRCA2, have been linked to the familial form of breast cancer. Women in families expressing these genes have a much higher risk of developing breast cancer than women who do not.
At this stage mammography is still the modality of choice for screening of early breast cancer. It is the gold-standard for other imaging methods such as ultrasound, NMR-tomography and CT which are less useful due to their lower spatial resolution. CT by itself is nearly useless for breast cancer screening as NMR-tomography provides better resolution and quality (and costs much more).
A pathology report will usually contain a description of cell type and grade. The most common invasive breast cancer cell type is infiltrating ductal carcinoma. Other types include adenocarcinoma, and infiltrating lobular carcinoma.
After diagnosis, the next phase is tumour staging - this aims to measure the extent of the tumour and whether or not it has metastasized (spread to distant sites).
Oncologists then assign a TNM code as a shorthand categorisation which in turn determines treatment recommendations.One way of categorising tumour is by staging it using the TNM system which is short for Tumour, Nodes and Metastasis. Some biological features of the cancer such as estrogen receptor and HER2-neu oncogene are also determined as they also affect treatment recommendations.
Depending on the staging and type of the tumour, just a lumpectomy (removal of the lump only) may be all that is necessary or removal of larger amounts of breast tissue may be necessary. Surgical removal of the entire breast is called mastectomy.
Standard practice requires that the surgeon must establish that the tissue removed in the operation has margins clear of cancer, indicating that the cancer has been completely excised. If the tissue removed does not have clear margins, then further operations to remove more tissue may be necessary. This may sometimes require removal of part of the pectoralis major muscle which is the main muscle of the anterior chest wall.
During the operation, the lymph nodes in the axilla are also considered for removal. In the past, large axillary operations took out 10-40 nodes to establish whether cancer had spread - this had the unfortunate side effect of frequently causing lymphedema of the arm on the same side as the removal of this many lymph nodes affected lymphatic drainage. More recently the technique of sentinel lymph node dissection has become popular as it requires the removal of far fewer lymph nodes, resulting in fewer side effects.
At present, the treatment recommendations follow a pattern. This pattern may be adapted as every two years a worldwide conference takes place in St. Gallen, Switzerland to discuss the actual results of worldwide multi-center studies. Depending an clinical criteria (age, type of cancer, size, metastasis) patients are roughly divided to high risk and low risk cases which follow different rules for therapy. The following list is a compilation af possibilities:
after a breast preserving therapy (lumpectomy, quadrant-resection), the high local recurrence risk (~40%) is reduced by radiation therapy to the breast
if the lymph nodes are positive, the high mortality risk (30-80%) is reduced by systemic treatment (either anti-hormones or chemotherapy).
in young patients, the most useful systemic therapy is chemotherapy (usually regimens such as CMF,FAC,AC and/or taxol)
in older patients, the most useful systemic therapy is anti-hormone therapy (tamoxifen, GnRH-analogues)
chemotherapy has increasing side effects as the patient's age passes 65
in patients with estrogen receptor negative tumours, the most useful systemic therapy is chemotherapy
in patients with estrogen receptor positive tumours, the most useful systemic therapy is hormone therapy
For some early tumours, systemic treatments may not be recommended. Following mastectomy, radiation therapy may not be recommended if the number of lymph nodes involved are less. For advanced tumours, there is an established role for all three modalities of treatment (surgery, radiation, systemic therapy) as the combination produces the best results.
The emotional impact of cancer diagnosis, symtoms, treatment, and related issues can be severe. Most larger hospitals are associated with cancer support groups which can help patients cope with the many issues that come up in a supportive environment with other people with experience with similar issues.
