Cancer Treatment

2018 mortality data on deaths and death rates was reported by Ministry of Health and Welfare. In 2018, the first leading cause of death was still cancer, followed by heart disease and pneumonia. The 3 leading causes of cancer death in 2018 were (1) lung cancer; (2) hepatobiliary cancer ; (3) colorectal cancer. Cancers cause about 85% of death for the population aged 55 and over. Early diagnosis of cancer generally increases the chances for successful treatment by focusing on detecting symptomatic patients as early as possible and the doctor-patient relationship.

The TNM Classification of Malignant Tumors was developed by the Union for International Cancer Control (UICC) and the American Joint Committee on Cancer (AJCC) in 1980. The TNM is a globally recognized standard for classifying the anatomical extent of a cancer, called cancer stage, prognostication and treatment strategies.

T describes the size of the primary tumor and invasion nearby tissue
N describes regional lymph nodes
M describes distant metastasis

TNM stage groups：

Stage I: tumors localized to the organ of origin
Stage II: extent of a cancer with locally extensive spread
Stage III: localized spread to regional nodes
Stage IV: distant metastasis

For most types of cancer, doctors use TNM staging information to choose optimal treatment options and to predict a person’s prognosis.

Types of staging：

Clinic staging:

This is an assessment of the extent of the cancer based on past medical history, physical exams, imaging tests, including ultrasound, X-rays, CT scans, MRU and PET-CT. The clinical staging plays an important role in the evaluation of cancer and decision of the treatments.

Pathologic staging:

Surgical removal of cancers and nearby lymph nodes revealed the pathological staging.

Cancer can be treated by different approaches including surgery, radiation therapy, chemotherapy, targeted therapy and immunotherapy such as monoclonal antibody and immune cell therapy, depending on the type and location of cancer and physical medical condition of patient.

Surgery：

Complete removal of the cancer and nearby tissue during an operation is the ideal for patients with early-stages disease.
Types of surgery

Primary surgery
Debulking
Palliation

Surgery is most commonly used to remove the tumor and some of the nearby healthy tissue. However, some cancer cells around the tumor is difficult to be detected. Pathologists will examine the margin closely to make sure there are no cancer cells at the cut edge of the tissue. In order to increase cure rate, it may be used with other treatments, such as chemotherapy or radiation therapy.

Radiation therapy：

Radiation with high high-energy X-rays or other particles makes small breaks in the DNA inside cells to destroy cancer cells and slow tumor growth and dividing without harming nearby healthy tissue. Nearby normal cells can also be affected by radiation, but most recover and go back to working the way they should. The radiologic dose depends on the location and severity of the tumor and is at the discretion of the oncologist and radiologist responsible for therapeutic decisions. Radiologic doses are divided into multiple smaller doses five times a week for a total period of five to eight weeks. This treatment strategies treat the cancerous cells effectively, whilst leading to less damage that affects normal tissues.

Chemotherapy：

Chemotherapeutic drugs are cytotoxic by means of interfering with cell division and proliferation. Usually a combination of multiple chemotherapeutic drugs is used to kill cancer cells effetely and avoid drug resistance. The chemotherapeutic dose, options and interval depend on the location and severity of the tumor and physical condition of patients. Chemotherapeutic drugs damage cell that divide rapidly, including normal cell: cells in the hair follicles, digestive tract and blood. The severity of side-effects varies widely depending on drug class and individual body. Most side effects subside when treatment is over.

Treatment strategies：

Neoadjuvant chemotherapy is given to shrink a tumor before surgery or radiation therapy.
Adjuvant chemotherapy is given to help kill any cancerous cells in the body after surgery or radiation therapy.
Palliative chemotherapy is given to decrease tumor load simply and increase life expectancy.

Method of administration：

Intravenous administration:
Chemotherapeutic drugs are delivered into the bloodstream and absorbed rapidly in larger amounts by cancer cells.
Oral medications:
Oral medications are taken by mouth and absorbed by stomach into the bloodstream to kill the cancer cells.
Intra-Arterial administration
Intra-arterial administration of chemotherapeutic drugs is based on the "First Pass" effect, injecting directly into the artery supplying the tumor via a pre-embedded arterial catheter. This is suitable for solid cancers localized to the primary site of the body and locally advanced.

Targeted therapy：

Targeted therapy can “target” these proteins or enzymes of cancer cells without affecting normal cells. Due to molecular biologic development and human genomic analysis. Based on the molecular biologic development and human genomic analysis, new therapeutic targets associated with surface proteins, signal-transduction pathways and growth factors are identified and used in order to inhibit cancer development. Targeted therapy has fewer side effects in comparison with traditional chemotherapy.

Classification of targeted therapies:

Small-molecule drugs are small enough to enter cancer cells easily. They are used to target a specific substance inside the cancer cell and block it, including tyrosine kinase inhibitor, ALK inhibitor, BRAF inhibitor and MEK inhibitor.
Monoclonal antibodies, also known as therapeutic antibodies, are designed to mark to specific targets on cancer cells, including vascular endothelial growth factor(VEGF), epidermal growth factor receptor (EGFR) and Human Epidermal Growth Factor Receptor 2 (HER-2) in order to stop cancer cells from growing or cause them to self-destruct.