The Role of Histology in the Breast Cancer
Breast cancer is an uncontrolled growth of breast cell that can be benign, not dangerous, but it can also metastasize and invade different and distant tissues in our body. Breast Cancer is the most common cancer in female of any age and although the risk increases, as you get older, many different factors affect the chance of a woman to get breast cancer. I chose this specific topic because breast cancer is something that I’ve dealt with in my personal life. My grandmother was diagnosed with cancer when I was around 7 years old and although I didn’t quite understand what was happening, I could see the trauma it had caused my grandmother and my entire family. Due to an early detection, my grandmother fully recovered and is currently in remission. But yearly mammogram and talk about the BRCA 1 and 2 genes became a normal conversation for the woman in my family. In this paper, I want to understand how histology and histopathology has helped breast cancer treatment and well as the prevention of breast cancer. I also want to find out how histology aided in the diagnosis of breast cancer.
As stated earlier, breast cancer can benign as well as malignant. Breast cancer is considered a heterogeneous disease with different morphological appearances, molecular features, behavior and response to therapy. (Rekha Et al. 2010) There are 3 major types of breast cancer and they include Ductal carcinoma in Situ (DCIS), invasive ductal carcinoma and invasive lobular carcinoma. There are many important features that are used like diagnosing as well as preparing a course of treatment for breast cancer. Such feature involves the size of the tumor, histologic grade, tumor necrosis, DNA content, vascular invasion etc.
Due to increased mammograms in United States, detection of breast cancer as increased dramatically. On suspected patients, along with the mammogram, a biopsy is also taken and went to a pathologist. A pathologist looks at four distant histological features for prognosis. They are tumor size, necrosis presence, nuclear grade and width of surgical margin. Due to the fact that pathologist looking at specific types of feature, a correct approach for removing biopsy of breast is important. First of all, wide, local excision specimen is very important because margins are looked at. This is done by dying the specimen before slicing.
This is also especially important in staging of the breast cancer. Histologically, DCIS are divided into comedo (cysts that open directly to the surface such as blackheads) and noncomedo subtypes while Lobular Carcinoma in Situ show expansion of lobule. Both of these types of breast cancer do not metastasize. Meanwhile, invasive carcinoma is the most commonly diagnosed breast cancer and has no histologic characteristic other than invasion through the basement membrane of a breast duct. (Rekha Et al. 2010) These specific types of features found in the cells of breast tissue makes histology an important factor of diagnosing the cancer.
Pathologist rely hugely on the histology of breast cancer for not only identifying the cancer but also for staging the cancer. Usually an examination of lymph nodes may also be necessary as lymph nodes are frequently involved in breast cancer that has metastasized. The pathologist classifies the breast cancer into grade 1, grade II and grade III depending on the urgency and the aggressiveness of the treatment that is needed. Higher grade relates to less survival rates of patients. For example if a patient is diagnosed with grade I, the five year survival rate is over 80% meanwhile for grade II and III the five year survival rate is 64% and 50% respectively. (Hanby et al. 2005)
As previously stated, establishing an accurate breast cancer size is fundamental for treatment and diagnosis of breast cancer. Tumor histology has been a very important part of this process; In 2004 a research question the influence of breast cancer histology of the relationship between ultrasound and pathology of tumor size. For this particular analysis, ultrasound and pathology receptor were retrospectively review for 204 women and 210 invasive breast cancers including ductal, lobular and mixed pattern ductal and lobular carcinomas for each tumor, the largest pathology and ultrasound dimensions were compared. (Pritt et al. 2004) In the results, ultrasonography consistently underestimated pathologic tumor size especially for lobular carcinomas. The size difference was so much so that it could actually affect the staging of the cancer. The results of this study signified and reinstated the continued benefit of tumor histology in cancer especially breast cancer.
As we as humanities advance more in technology and medicine, the role of histology in cancer diagnosis and treatment is changing as well. Although histology has been used an gold standard to diagnosis, new avenues such as immunohistochemical makers are making their mark on the cancer community. Pathologists along with oncologist have used the immunohistochemical markers to predict the outcome and how responsive the patient is going to be for the treatment. (Potter et al. 2005) Immunohistochemistry is the process of identifying and labeling individual proteins found in breast cancer. This is done by using protein based stain, which “marks” the receptors that are found in breast cancer cells. These tests are called immunohistochemical staining assay or immunohistochemistry (IHC). The most common one being estrogen and progesterone receptors. Estrogen receptors are present in 80% of all breast cancer patients but are only detected in the nucleus of malignant cancer cells. The progesterone level is highly depending on estrogen and a breast cancer is very rarely progesterone positive and estrogen negative. There are many other histoimmunomarkers that may also be present and detected by pathologist including Cyclin D, Cyclin E, ERbeta, and HER2 etc. This is an important part of treatment for the patient as hormonal therapy may be used to help slow or stop the growth of hormone-receptor positive breast cancer. (Potter et al. 1998) The treatment of cancer has now shifted to making a individualized treatment for the cancer rather than the “one size fit all” approach that has widely been used in the earlier years.
Histology can also used in various different aspects of breast cancer research as well. In a study the tumors from people with different ethnic background were studied. The specific background included Caucasians, Americans, Hispanics, Asians etc. The main purpose of the study was to investigate the association of race/ethnicity and histologic types of breast cancer. The study found the ductal carcinoma was most common in overall. Caucasian women having the highest rate of breast cancer, ductal and lobular breast cancer. In African American women, ductal carcinoma was twice that of lobular carcinoma compared with Caucasians women. This study was possible by using histopathlogical tools, thereby once again proving the importance of histology in identification of cancer. (Klonoff-Cohen et al. 1998).
There are new technologies that have shown possible replacement for histopathology, these include things, which will basically “tumor barcode”. Genome-wide microarray- is another way of categorizing tumors of breast cancer. Although this isn’t fully used yet, undergoing studies are have shown microarray to show improved prognostic and predictive tool for clinical practice. Although microarray has done shown great results, the cost of microarray will far more expensive than the cost of traditional methods such as histopathology of breast cancer. (Rekha et al. 2010) But it is more than likely that histopathology will remain the gold standard and histology will more than likely aid these development.
All in all, through out this research I found out that histology and histopathology has played a huge role in not only the diagnosis but also the treatment of breast cancer. It has aided several different researches. Advanced histological techniques that uses biomarkers has made it possible for patient have individualized treatment rather than “one size fits all” technique. As different methods of identifying cancer have come into the medical market, one of them being ultrasonography, histology has proved itself to cost effective and more efficient. As we as society advance in modern technology and medicine, histology may eventually need to take a back seat but for now and the near future it will remain as a gold standard for not only breast cancer but many different diseases, new researches, tumors etc. With it’s cost effective and accuracy in identifying and staging the cancer histopathology has changed how the medical community handles cancer as a whole. Personally, it was only after me taking histology and my other biology classes I have begun to understand medicine. I would sit in my parent’s doctor meeting and understand exactly what the doctor was saying. I’ve learned more and more about how a little microscopies cell can make a huge difference. My mom and dad suffer from hypothyroidism and diabetes respectively and it ‘s due to histology that I’ve have gotten insight into the development of these diseases.