Tuesday, November 19, 2013

Explaining My Diagnosis

Based on the biopsy of the tumor after surgery, my specific diagnosis is IDC, Grade III "poorly differentiated", ER/PR positive, HER2 unamplified, 2.2 cm, Stage IIA or IIB.  My diagnosis was slightly worse after surgery; the pre-surgery biopsy was Grade 2, 1.7 cm, ER/PR positive.  I know that is probably a bunch of confusing gibberish to many of you, so I will do my best to explain what it all means!

Invasive Ductal Carcinoma (IDC) is the most common form of breast cancer with about 80% of all breast cancers being this type.  The definition of IDC is a cancer that initially formed inside a milk duct, but has broken through the wall of the duct and begun to invade the surrounding breast tissue.  It is sometimes also referred to as "Infiltrating Ductal Carcinoma."

The Grade of the cancer is determined by a pathologist after examining the cancer cells under a microscope.  There are three grades:  Grade I, Grade II, Grade III.  The lower the grade, the more closely the cancer cells resemble normal breast cells, the more slowly they grow, and the less likely they are to spread.  The higher the grade, the more abnormal the cancer cells are in appearance and behavior (the more "wild" they are) and the more likely to grow and spread.  Grade I cells are "well differentiated"--they look and act somewhat like healthy cells.  Grade III cells are "poorly differentiated."   There is one more level within Grade III, and that would be "undifferentiated", which is the worst.  So the Grade of my tumor is bad, but it's not the worst.  I was not surprised about the Grade because typically, the younger you are (pre-menopausal as opposed to post-menopausal), the worse the cancer is.

The Endocrine/Hormone Receptor Assay determines if the cancer cells have receptors for estrogen and progesterone.  If the cells do have these receptors then they are "estrogen receptor positive" (ER+) and/or "progesterone receptor positive" (PR+).  This means that the cancer cells grow in response to estrogen and/or progesterone.  About 75% of breast cancers are ER+, and about 65% of those are also PR+.  Endocrine therapy is standard treatment for ER/PR positive tumors and is supposed to help prevent recurrence by blocking the estrogen receptors on the cancer cells and preventing estrogen from binding to them.  The most common drug given for ER/PR positive tumors is Tamoxifen which is taken for up to five years after initial treatment.    Drugs called aromatase inhibitors actually stop production of estrogen in post-menopausal women; pre-menopausal women cannot take aromatase inhibitors.  Of ER/PR positive tumors, about 60% of them are likely to respond to endocrine therapy.  If the cells do not have these receptors, they would be ER/PR negative; only 10%-15% of these tumors respond to endocrine therapy, and ER/PR negative cancers are more rare and more serious than ER/PR positive cancers.  My diagnosis is ER/PR positive.

Twenty to twenty-five percent of breast tumors produce too much of a protein called HER2/neu.  These cancer cells also have too many HER2 receptor sites on the cell surface, which causes the cells to  pick up too many growth signals.  These tumors tend to be much more aggressive and fast-growing.  Standard treatment for HER2 positive cancers is a drug called Herceptin which is supposed to reduce recurrences and is given along with chemotherapy.  Herceptin blocks the cell receptors so they don't pick up as many growth signals.  Tykerb is another drug used if Herceptin fails.  Tykerb interferes with HER2 activity from inside the cell by limiting the amount of energy the cells have for growth and multiplication.  My diagnosis is HER2 "unamplified" which means it was indeterminate--neither clearly positive nor negative.

Triple Negative breast cancers (ER/PR negative, HER2 negative) make up roughly 10%-17% of all breast cancers, and generally the prognosis is poorer than for other types of breast cancer; this is a rare and aggressive cancer.  There are no targeted drug therapies for Triple Negative breast cancer, but they can respond to chemotherapy.

Size of the tumor helps in staging the cancer.  Generally, a tumor measuring less than 2cm would be Stage I; a tumor measuring 2-5cm would be Stage II; and a tumor measuring more than 5cm would be Stage III.  My diagnosis is a tumor measuring 2.2cm, so it would be at least Stage II.

Cancer staging involves many factors, but the three main factors are the size of the cancer, whether it is invasive or non-invasive, and whether it is in the lymph nodes.  Stage 0 is non-invasive--no cancer cells have broken out of the part of the breast in which they started and invaded nearby normal tissue.  Invasive cancers are always at least Stage I.  Stage IA is when the invasive tumor is less than 2cm, has not spread outside the breast, and no lymph nodes are involved.  Stage IB is when either no tumor is found in the breast but small groups (less than 2mm) of cancerous cells are found in the lymph nodes; OR when the invasive breast tumor is less than 2cm and the lymph nodes are involved.  Stage IIA is when there is no tumor but small groups of cells measuring more than 2mm are found in 1-3 axillary (under arm) lymph nodes or in the lymph nodes near the breastbone; OR the tumor is 2cm or less and has spread to the axillary lymph nodes; OR the tumor is larger than 2cm but less than 5cm and has not spread to the lymph nodes.  Stage IIB is when the invasive tumor is more than 2cm but less than 5cm and small groups of cancer cells less than 2mm are found in the lymph nodes; OR the tumor is larger than 2cm and less than 5cm and the cancer has spread to 1-3 axillary lymph nodes or lymph nodes near the breastbone; OR the tumor is larger than 5cm but has not spread to the axillary lymph nodes.  Stage IIIA is when no tumor is found in the breast or a tumor is of any size and cancer is found in 4-9 axillary lymph nodes or lymph nodes near the breastbone; OR the tumor is larger than 5cm and small groups of cancer cells less than 2mm are found in the lymph nodes; OR the tumor is larger than 5cm and cancer has spread to 1-3 axillary lymph nodes or lymph nodes near the breastbone.  Stage IIIB is when the invasive tumor can be any size and cancer has spread to the chest wall and/or skin and caused swelling or an ulcer; AND may have spread to up to 9 axillary lymph nodes OR spread to lymph nodes near the breast bone.  Stage IIIC is when there can be no sign of cancer in the breast or any size tumor which has spread to the chest wall and/or skin of the breast; AND the cancer has spread to 10 or more axillary lymph nodes; OR the cancer has spread to lymph nodes above or below the collar bone; OR the cancer has spread to axillary lymph nodes or lymph nodes near the breastbone.  Stage IV (advanced/metastic) is when the cancer has spread beyond the breast and nearby lymph nodes to other organs such as lungs, liver, brain, skin, bones, or distant lymph nodes.  My diagnosis is Stage IIA or IIB because the invasive tumor is more than 2cm, but we don't know if it has spread to any lymph nodes.  There are no outward signs of cancer in my axillary lymph nodes (i.e. swollen nodes or swelling under my arm); however I wouldn't be surprised if there is cancer in some lymph nodes just because of the location of the tumor (this thought is my personal opinion, not anything a doctor has told me).  The tumor was in my right breast located at about 10 o'clock (looking at the breast from the front) and very close to my armpit.

The prognosis statistics for Stage IIB cancer are significantly worse than those for Stage IIA.  This is definitely something to keep in mind; however, statistics are just that...statistics.  They are generalizations based on the results of thousands of women with the same diagnosis.  It is important to remember that not every woman falls into neatly divided statistical categories; each individual woman, each case is unique.  What works for the statistical majority may not work for every woman; likewise, if the statistical outlook is bleak, there are some women who defy the odds and outlive the statistics. 

Looking at statistics alone can cause undue fear...or undue overconfidence.  I have chosen to arm myself with as much knowledge as I can and make educated, logical decisions based on that knowledge.

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