Breast cancer is the most common cancer diagnosed in women and second most common cause of cancer related death in women worldwide. Approximately 1 in every 10 new cancer cases account for breast cancer. Most of the times breast cancer is diagnosed during routine check up as the disease is silent. Breast cancer spreads lymphatically as well as haematologically and leads to distant metastasis.
Types of breast cancer:
A. Non invasive neoplasms
B. Invasive neoplasms
A. Non invasive neoplasms:
Non invasive breast cancer never invades basement membrane of breast however if not treated, non invasive cancer can transform into invasive cancer. Non invasive breast cancer is further divided into following two types;
1. Lobular carcinoma in situ (LCIS)
2. Ductal carcinoma in situ (DCIS).
1. Lobular carcinoma in situ:
Lobular carcinoma in situ is the risk factor for the development of breast neoplasm. It is confined to the lobular outline of breast and has characteristic acini.
2. Ductal carcinoma in situ;
Ductal carcinoma in situ is a malignant lesion and has discrete spaces which are filled with neoplastic cells. Immediate diagnosis and treatment is required as it has high chance to transform into invasive breast neoplasms.
B. Invasive neoplasms
Invasive breast cancer do not have overall architecture and cells infiltrate haphazardly into a variable amount of stroma. Invasive breast cancer always invades breast basement membrane. Depending upon the histology, invasive breast cancer is broadly divided into two major types;
1. Invasive ductal carcinoma
2. Invasive lobular carcinoma
A. Invasive ductal carcinoma:
Invasive ductal carcinoma grows as a cohesive mass and is palpable as characteristic small lump in the breast. Usually it is diagnosed on mammography because of its discrete appearance. Invasive ductal carcinoma accounts for 50% to 70% of invasive cancers.
B. Invasive lobular carcinoma:
Invasive lobular carcinoma is the second most common type of invasive breast cancer. It consists of individually dispersed, non cohesive cells. It may present as organized single file linear pattern in a fibrous stroma. It accounts for 10% to 15% of invasive breast cancers.
Causes of breast cancer:
1. Family history of breast cancer
2. Advance age
3. Female gender
4. Hormone replacement therapy specially oestrogen
5. Nulliparity
Diagnosis:
Diagnosis of breast cancer requires clinical evaluation, imaging and breast tissue biopsy. However ultrasound and MRI scan are also useful in certain clinical cases. Breast cancer is silent most of the times and is diagnosed on screening mammography. In young women, mammography along with breast ultrasound is good technique to diagnose breast cancer. Tissue biopsy is another excellent diagnostic modality for the diagnosis of breast cancer.
Conclusion:
Breast cancer is the most common cancer in women worldwide. It is divided into invasive and non invasive types. Patients with advance age, having family history of breast cancer and getting hormone replacement therapy ( oestrogen ) are at higher risk of developing breast cancer. It is more common in women however it may develop in man. Breast clinical evaluation, mammography, tissue biopsy, ultrasonography and magnetic resonance imaging ( MRI ) are the main diagnostic techniques for early detection of breast neoplasms.
