Breast Cancer and Stem Cells
Breast cancer is a disease which involves uncontrolled growth of breast cells. There are several types of breast cancer depending upon the kind of cells in the breast that turn into cancer. Breast cancer can begin in distinct parts of the breast. Breast is consists of three major parts:
- lobules:glands which produce milk.
- ducts: thin tubes that transfer milk from the breast lobules to the nipple.
- connective tissues,
that consist of fibrous and fatty tissue that surrounds and holds everything together.
Majority of breast cancers start in the ducts or lobules and can also later metastasize (spread to the other parts of body) via lymph vessels and blood vessels. Breast cancer can be divided into two categories:
- Invasive ductal carcinoma:
It involves the development of cancer cell outside the ducts into other parts of the breast tissue. It is capable of metastasizing to other parts of the body.
- Invasive lobular carcinoma:
It involves the dispersion of cancer cells from the lobules to the breast tissues that are close by. It is also capable of spreading to other parts of the body.
According to the report published by American Cancer Society (ACS), breast cancer accounts for 25 % of all new cancer diagnoses in women worldwide. In 2012, approximately 1.7 million new patients were diagnosed globally. In 2012, Belgium had the highest number of breast cancer cases in the worldwide, with 111.9 cases per 100,000 adult women. In countries with advanced medical care, the survival rate of breast cancers is 80%–90% in early stages diagnosis and comes down by 24% for breast cancers when diagnosed at advanced stage. Overall, the incidence rate of breast cancer, or the number of cases per 100,000 women, is still lesser in developing countries compared to West, while mortality rate from the disease is higher. This may be associated with the later diagnosis and poor access to treatment
Management of breast cancer
Breast cancer can be treated in several ways depending on its stage and type. Treatment can be categorized as local & systemic:
This method includes Surgery and Radiation therapy, which can treat the tumor without affecting the other parts of the body.
In this method drugs are used to treat cancer as these drugs can target cancer cells nearly anywhere in the body. Drugs can be administered directly into the bloodstream or can be given orally depending upon the type of breast cancer. Systematic treatment involves chemotherapy, hormonal therapy and targeted therapy.
Usage of stem cells on breast cancer
Hematopoietic stem cell transplantation (HSCT) defined as the transplantation of hematopoietic stem cells from a donor into a recipient, can be either autologous or allogeneic. Since the early 1980s, HSCT from both autologous and allogeneic stem cell sources has been employed in the treatment of metastatic Breast cancer.
However, Allogeneic HCT for metastatic breast cancer has two curative potential advantages compared to autologous HCT— a cancer free graft and Immune-mediated graft-vs-tumor (GVT) effect from the donor’s cells. Number of clinical observation supported the significance of these interactions between immunocompetent donor T lymphocytes and normal and tumor cells of host origin in mediating an antitumor response. Published clinical studies have suggested that allogeneic HCT can generate a GVT effect in metastatic breast cancer. In conclusion, a GVT effect does exist against metastatic breast cancer and play a vital role in tumor response which might be included in the armamentarium treatment for breast cancer.
Mesenchymal stem cells are multipotent stromal progenitor cells majorly present in the bone marrow, which can further differentiate in most cell types of mesodermal, ectodermal and endodermal cell lineages. MSCs in solid cancer have shown the following benefits:
- their potential to home to area of tumorigenesis, providing a mean for effective delivery of anticancer drugs
- to inhibit local inflammation, which bears a capability for suppressing tumor stimulating inflammation, a hallmark of primary tumor microenvironment and relapse
- to promote damaged tissue repair and regeneration, deprived of any toxicity and immunogenicity to the host.
Several studies demonstrate the effective therapeutic potential for Mesenchymal stem cell in breast cancer. For example, adipose tissue-derived MSCs (ADMSCs) cultured at high density down regulate the growth of MCF-7 human breast cancer cells via an IFN-β-dependent mechanism. The use of human umbilical cord blood derived MSCs (hUCMSCs) are supposed to be safe and Practicable. In a same way, in a co-culture study of human breast cancer cells and bone marrow-derived MSCs (BM-MSCs) also showed the suppression of growth of breast cancer cells. In conclusion, MSCs possesses the ability to deliver anticancer therapeutics to tumor sites and also have potential for tissue repair. Several studies reported the role of hUMSCs for inhibiting tumor growth in breast cancer. Therefore, the hUMSCs transplantation is expected to become a new approach for tumor therapy and the safety profile of human umbilical cord derived mesenchymal stem cells is satisfactory as well. Several studies have recognized the potential of HSC and MSCs in the treatment of breast cancer, stating they can be used as effective therapeutic tools, recommending them to be part of approved clinical trials.