90% of all breast cancers in men and 80% in women are invasive ductal carcinoma. As the name suggests this cancer like DCIS initiates in the milk ducts of the breast. DCIS is non – invasive while IDC is invasive in nature implying that it has infiltrated or invaded surrounding breast tissue. This tumor spreads to the nearby cells, sometimes even lymph nodes and can metastasize to other parts of the body. Thus it is also referred to as infiltrating ductal carcinoma. The IDC can affect both male and female population, in female population the incidence rates is higher in older women.
IDC usually is presented with a lump or a mass which is firm and hard. This immovable mass with irregular edges can be felt in a breast examination. Also there may be swelling in the breast (whole or part), breasts may feel painful with reddening or scaling of skin of the breast. In some cases the nipple may turn inward with a nipple discharge. There also might be irritation or dimpling of the breast skin. These are the associated abnormal changes in the breast with IDC.
The first step in detecting an invasive ductal carcinoma is the physical examination in which a lump can be felt in the breast. The physical examination will also cover the lymph nodes near the arm pit and the collar bone.
This shall be followed by mammography which is the x-ray of the breast. The mammography print will show the calcified dead cells due to necrosis of cancerous tissue. This test also is used for assess the spread of cancerous growth into other tissues. This imaging tests can be accompanied with other imaging tests like ultrasound (uses sound waves) and MRI (uses magnetic waves) to assess the tumour growth in the breast.
In case the results of the imaging tests are affirmative to presence of tumour, biopsy would be done by extracting cancerous cells from breast tissue for pathological examination. This will further grade the cancer advancement and prognosis. This biopsy can be of invasive or non invasive nature depending on the requirement.
Sometimes the lump my show in imaging tests but it cannot be felt in such cases a stereotactic needle biopsy is done which is guided by mammography or ultrasound. It is also referred to as ultrasound guided biopsy. A guided biopsy is also done in cancer cases when the lump cannot be felt. In these a small wire is inserted and ultrasound or mammography is used to guide the wire inside. This is called needle wire localization. IDC spreads to connecting tissue and affects surrounding tissue as such to assess the invasion or infiltration, tests which may be undertaken are: CT scan, MRI, bone scan, chest X- Ray, PET scan. Also an axillary lymph node sampling is done mandatorily in IDC in patients to detect the spread of cancer in the armpits lymph nodes.