Breast cancer is cancer of breast tissue. Worldwide, it is the most common form of cancer in females, affecting approximately 10% of all women at some stage of their life in the Western world. Although significant efforts are made to achieve early detection and effective treatment, about 20% of all women with breast cancer will die from the disease, and it is the second most common cause of cancer deaths in women.
increasing signs and symptoms of breast cancer
The risk of getting breast cancer increases with age. For a woman who lives to the age of 90 the odds of getting breast cancer her entire lifetime is about 12.5% or 1 in 8. Men can also develop breast cancer, although their risk is less than 1 in 1000. This risk is modified by many different factors. In some families, there is a strong inherited familial risk of breast cancer. Some racial groups have a higher risk of developing breast cancer - notably, women of European and African descent have been noted to have a higher rate of breast cancer than women of Asian origin.
Other established risk factors include having no children, delaying first childbirth, 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. One type of breast cancer that is especially aggressive and disproportionately occurs in younger women is Inflammatory Breast Cancer. It is initially staged as Stage IIIb or Stage IV. It also is unique because it often does not present with a lump so that it often is not detected by mammography or ultrasound. It presents with the signs and symptoms of a breast infection like mastitis.
Two genes, BRCA1 and BRCA2, have been linked to the familial form of breast cancer. Women in families expressing mutations in these genes have a much higher risk of developing breast cancer than women who do not. Together with Li-Fraumeni syndrome (p53 mutations), these genetic abberations determine around 5% of all breast cancer cases, suggesting that the remainer is sporadic. Genetic counseling and genetic testing should be considered for families who may carry a heritidary form of cancer.
identifying breast cancer symptoms
Symptoms of breast cancer are often subtle, and self discovery can be alusive. Due to the high incidence of breast cancer among older women, screening is now recommended in many countries. Screening methods suggested include breast self-examination and mammography. Only mammography has been proven to reduce mortality from breast cancer. In some countries routine (annual) mammography of older women is encouraged as a screening method to diagnose early breast cancer.
At this stage mammography is still the modality of choice for screening of early breast cancer symptoms. It is the gold-standard for other imaging methods such as ultrasound, MRI and CT which are less useful due to their lower spatial resolution. CT by itself is nearly useless for breast cancer screening as MRI provides better resolution and quality (and costs much more).
Breast cancers detected by mammography are usually smaller than those detected clinically, and women who undergo mammography are more likely to be eligible for breast-conserving therapy.
diagnosing breast cancer symptoms
Many breast cancers are diagnosed now by mammography before they are large enough to be palpated, but despite screening efforts, many women are diagnosed with breast cancer after they notice a lump or when experiencing symptoms due to metastatic disease.
Breast cancer can be suspected after a cautious clinical history, physical examination and imaging (either mammography or ultrasound). The diagnosis can only be established when a suspicious lump is biopsied for histological confirmation of whether it is malignant or not. The biopsy is usually performed either with a fine needle guided by ultrasound or with a larger "core" needle. Some cases require an open biopsy after wire localization under x-ray.
A pathology report will usually contain a description of cell type and grade. Other useful information derived from the pathology laboratory include estrogen receptor and progesterone receptors status and HER2Neu status; these can help to guide treatment. The most common invasive breast cancer cell type is infiltrating ductal carcinoma. Other types include ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS), infiltrating lobular carcinoma, medullary carcinoma.
After diagnosis, the next phase is tumour staging - this aims to assess the extent of the tumour and whether or not it has metastasized (spread to distant sites).
For suspicious, high risk cases, other investigations which include CT scans, nuclear medicine imaging, chest X-rays and blood tests will be done to look for any metastasis or secondary cancer that has spread a long way from the site of the primary tumour.
The standard way of categorising tumour is by staging it using the TNM (Tumour, Nodes and Metastasis) system, which in turn determines treatment recommendations. The TNM system is specific for each type of cancer. Some biological features of the cancer such as estrogen receptor and HER2-neu oncogene expression are also determined as they also affect treatment recommendations.
The TNM classification of breast cancer:
- Tumor size:
- T0 no primary tumor found
- Tis in situ
- T1 =< 2 cm
- T1mic ≤ 0.1 cm (microinvasive)
- T1a > 0.1 to 0.5 cm
- T1b > 0.5 to 1 cm
- T1c > 1 to 2 cm
- T2 > 2 to 5 cm
- T3 > 5 cm
- T4 Chest wall /skin
- T4a Chest wall
- T4b Skin oedema (peau d'orange), ulceration, or satellite skin modules
- T4c Both 4a and 4b
- T4d Inflammatory carcinoma
- Lymph nodes:
- N0 No lymph nodes
- N1 Movable axillary
- N2a Fixed axillary
- N2b Internal mammary clinically apparent
- N3a Infraclavicular
- N3b Internal mammary clinically apparent with axillary lymph node involvement
- N3c Supraclavicular lymph nodes
- Distant metastasis:
- M0 No
- M1 Yes
- Stage 0: Tis
- Stage I: T1,N0,M0
- Stage IIA: T0-1,N1,M0 or T2,N0,M0
- Stage IIB: T2,N1,M0 or T3,N0,M0
- Stage IIIA: T3,N1,M0 or T0-3,N2,M0
- Stage IIIB: T4,any N,M0
- Stage IIIC: any T,N3,M0
- Stage IV: any T,any N,M1
The cancer is staged depending on factors which include the size of the tumour, whether there is lymph node involvement or not and whether there is distant spread of cancer cells. Stages are a composite of the TNM. Stage I is small tumor (T1) without any spread, while stage IV is metastatic disease. Stages correllate with long-term prognosis, and treatment decisions are often made on the basis of the stage.
Posted by Staff at June 3, 2005 8:17 AMblog comments powered by Disqus