# Anti-Breast Cancer Activity of Essential Oil:
## 3 Result
### Breast Cancer  
Breast cancer is the most common cancer with a high mortality in women [3]. The malignant illness which causes this cancer starts in the breast cells. Factors including  
Figure 1: Flowchart of the methodology.  
the population structure, lifestyle, genetics, and the environment, can increase the risk of acquiring this cancer, similar to other malignant tumors [1; 2; 25].  
According to breast cancer oncology, neoplastic cells are different from other normal body cells. Normal tissues in the body have limited growth regulation keeping their structure and function working as usual. Cancer cells, however, have prolonged and chronic proliferation without external stimulation [26]. A breast tumor usually begins with ductal hyperproliferation which will develop into a benign tumor or metastatic carcinoma if stimulated continuously by various carcinogenic factors. The tumor microenvironment, such as the influence of the stroma or macrophages, also plays an important role in the initiation and progression of breast cancer [27; 28; 29].  
The two theories put forth as the basis for the initiation and progression of breast cancer are the cancer stem cell theory and the stochastic theory (Figure 2). According to the cancer stem cell theory, all tumor subtypes develop from the same stem cell or progenitor cell. Different phenotypes of a tumor are caused by genetic and epigenetic alterations that are acquired in stem cells or progenitor cells. The stochastic theory describes that each tumor subtype originates from a single type of cell (stem cells, progenitor cells, or differentiated cells). Any breast cell may progressively develop random mutations, and if these mutations result in malicious behavior, the breast cells are categorized as tumor cells.  
According to the cancer sites, there are many types of breast cancer, including invasive and non-invasive cancer. When abnormal cells originating from milk ducts or lobules spread out closer to the breast tissue, invasive carcinoma develops [30]. These type of cancer cells can pass through the breast tissue and migrate to various parts of the body by the immune system or through systemic circulation [31]. The most frequent malignancy in women is invasive breast cancer. Non-invasive breast cancer, on the other hand, refers to cancer that has not spread from the lobules [32]. Atypical cells can form and progress into invasive breast cancer, even when they have not yet spread to other tissues outside of the lobules or ducts.  
Treatment of breast cancer currently consists of three methods, including surgical therapy, radiation therapy, and chemotherapy. Every technique has positives and negatives aspects, starting with surgical therapy, which aims to prevent, diagnose, stage, and remove malignant tissue. In the case of radiation therapy, the irradiated rays can often kill more than 40% of cancer cells. If chemotherapy is used, it can lessen the quantity of cancer cells and stop them from spreading. However, each approach has a number of disadvantages, such as pain, infection, bleeding, blood clots, and gastrointestinal issues for surgical therapy. The mechanism of action for radiation is typically harmful to normal cells, which can occasionally be destroyed by the delivery of high radiation doses throughout the radiation process. Chemotherapy, on the other hand, is not selective and also has a negative effect  
Figure 2: Stem cell and stochastic model.  
on healthy cells [6]. In addition, the limitations of chemotherapy are side effects and multiple drug resistance issues, prompting researchers to explore treatments utilizing natural compounds such as essential oils. Essential oils are plant-defense compounds (secondary metabolites), which contain active components with therapeutic action, one of which is anti-radical; hence, they can be used as an alternative cancer treatment.