As the name indicates this type of cancer invades the lobular part of the breast. the lobules are that part of the breast which secrete milk which is carried to the nipples through the ducts. It is invasive in nature meaning that the cancer initiates in the lobes and spreads to surrounding tissue, even lymph nodes at times and other body part or organs. The other name for Invasive lobular carcinoma (ILC) is infiltrating lobular carcinoma. IDC is the most common type of breast cancer after invasive ductal carcinoma; ILC is the second most common carcinoma. Of all invasive breast cancer, IDC forms 90% and ILC forms 10% of cancer cases. ILC is known to have higher incidence percentages in older women of the age group beyond 60s. A documented 2/3rds of affected female population is over 55 when diagnosed with this cancer.
Similar to any other cancer initially, invasive lobular carcinoma would not present any identifiable symptoms. This cancer is least to lead to lump formation in the breast and the cancerous cells are arranged in a linear structure surrounding the connective tissue. The symptoms of an ILC include: a firm or thickened tissue in portion of breast, skin texture of breast may change; it may appear reddish, with swelling and pain. The nipple may pain, become inverted and secrete discharge.
Diagnosis and detection of invasive lobular carcinoma requires a multi-modal approach. ILC is usually involves a combination of procedures, including a physical examination and imaging tests. ILC tends to be multifocal, meaning that there is more than one area of cancer within the breast. Also at times it affects both the breasts and then it is called bilateral cancer.
The first step is the usual physical check up to confirm any lump formations, though in ILC there is no distinct lump like formation but a thickening of tissue can be felt. Also the physician would check the collar bone and the armpit areas for any other cancerous firm tissue growth.
This is as a routine followed by mammography which is like an X-ray of the breast. this imaging test not a very conclusive test for ILC for 2 reasons. Firstly the cancer may appear to be much smaller than its actual size and secondly it would be difficult to detect it with ILc cells growth in a linear fashion. This test would be possibly done for both the breasts to detect presence in either or both the breasts.
Ultrasound and MRI (magnetic resonance imaging) can be done to assess the extent of the tumor growth and detect the spread of the cancer with the help of magnetic field.
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. Tissue removed during biopsy is examined by a pathologist under a microscope. A pathologist confirms the presence of ILC when he detects cell structure and formation typical to ILC in the sample. E- cadherin protein or CDH1 is a controlling gene which keeps in check the invasion or spread of tumor cells to healthy cells. A pathologist would also want to do study on this protein to assess the protein formation by this gene; which might be a causative factor on the ILC. This can happen due to gene mutation. This testing is useful to the pathologist in differentiating the ILC growth from LCIS. LCIS is growth of abnormal cells which are not cancerous in nature in the breast lobules. Predominantly lobular cancers do have LCIS. The presence of LCIS is indicative that the individual is at an increased risk of breast cancer.
Invasive lobular carcinoma is an aggressive cancer and has a tendency to spread and invade lymph nodes and other parts of the body. Staging is a process which is adopted in ILC to determine the same. LIC 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 ILC in patients to detect the spread of cancer in the armpits lymph nodes.
With the outcome of these results the cancer may be categorized in to any phase from 0 to IV. The doctor may test the levels of alkaline phosphates in the body, blood tests and liver function tests will be used as they’ll provide concrete data. This alkaline phosphate level is higher in the liver or the bones of the affected individual. The other tests to determine the stage and the prognosis to be done on the patient will include a bone scan – taken by administering a radioactive substance injection, imaging tests (CT, ultrasound, MRI) of abdomen and pelvis and other areas of the body as per the requirement. PET which is positron emission tomography and CT scan tests are done, these provide with images of body cells in working mode. In PET a radioactive dye is injected in the body which is absorbed by cancer cells, these are then reflected in the scan. Thus highlighting the areas which are affected by cancer or have tumor growth.
Invasive lobular carcinoma does have the tendency to spread but it spreads to the abdomen area affecting organs like stomach and intestines, brain and spinal cord and also sometimes to reproductive organs like ovaries.
Once the extent to which they have spread is established, the doctors would also initiate a pathological examination to assess the prognosis by grading the cancer. This will define how aggressive the cancer may be and what treatment course is to be followed. In grading the first grade of ILC cells is a healthy looking cell cluster and also referred to as well differentiated. Then the high grade or grade III is poorly differentiated where the cells are abnormal looking. The pathologist would also look for the lining around the cancerous growth for clean surgical removal of the tumor cells.these surgical margins are categorized as: negative – when there are no visible cancer cells at the outer edge, positive – when the cancerous growth can be seen right at the edge and close when the cancer cells and healthy tissue are in close proximity.
Hormone receptor test is also done on the cancer tissue. Some cancers respond positively to hormone and show growth in presence of the hormones while some are hormone receptor negative which means that the hormones are not promoting cancer growth. If the test comes out hormone receptor positive then the patient is put on hormone therapy to block the hormone (estrogen and progesterone) effect.
HER2-receptor status is also done to assess the protein receptor status of the cancer. Some cancers are fuelled by a protein called HER2 and as such if they have HER2 recptor cells then they grow more aggressively. This test thus helps in treatment plan to block these HER2 receptor cells, with Herceptin or Tykerb.