Survey on Therapeutic Advances in Oncology

Introduction

Cancer is a disease in which some body cells grow abnormally and spread to other body regions. Cancer can be benign ( does not spread/non-cancerous) or malignant ( spread/ cancerous). It is a hereditary disease which means that cancer is caused by specific alterations to genes. Proto-oncogenes, tumor suppressor genes and DNA repair genes are the primary gene groups that are typically affected by the genetic alterations that cause cancer. The study of diagnosis and treatments of cancer is known as ‘Oncology.’ It comprehends medical oncology (chemotherapy, hormone therapy, drugs to treat cancer), radiation oncology (radiation therapy to treat cancer) and surgical oncology (surgery and other procedures to treat cancer). There are more than one hundred types of cancer.

Scientists have discovered that specific mutations occur in a variety of cancer forms as they learn more about the molecular changes that cause cancer. Now there are a wide range of cancer treatments available that focus on target gene alterations found in cancer. Some of these treatments are used by anyone with a cancer, regardless of where it started growing in the body.

Objective

A wide range of treatment options are available for the patients due to the advancement in the research and development platforms, the discovery of novel targets and development of new technologies. In this review, we provide an overview of therapeutic advancement in treatments of breast cancer and lung cancer.

Breast Cancer

Breast cancer is the most common type of cancer in women. The stage of breast cancer at diagnosis is the most important factor in determining the survival outcome. But during the past three decades early detection, better screening and increasing awareness have improved the survival rate. The base of breast cancer treatment is chemotherapy, surgery, hormone therapy, radiation, and targeted therapy.

Breast cancer was considered a local disease and was primarily treated with radical surgery (mastectomy). Over the time, radiation combined with lumpectomy (removal of lumps from breast) has increasingly been used as the main therapy. Some chemotherapy drugs, such as, Taxanes, anthracyclines and platinum, have been approved by FDA. Instead of administration of the standard treatment schedule of every three weeks, a combination of doxorubicin, cyclophosphamide and paclitaxel administered every two weeks with high density have reduced cancer growth and increased survival without causing any additional negative side effects.

Screening of breast cancer includes 3-D mammography. 3-D mammography is a process in which x-rays are used to take a series of images of the inside of the breast from various angles. These x-rays are used to create 3-D images of the breast on a computer. This process is used to analyze for breast cancer and other changes in the breast (abnormal lumps, cysts, calcifications). It might enable doctors to visualize breast tissue, including dense breast tissue, more clearly compared to 2-D mammography. This might make it easier to detect breast cancer or other changes in the breast.

 Following includes some of advanced techniques for treating breast cancer.

Targeted radiation: In the past it was recommended that most cancer patients get radiation therapy on a daily basis for 7 weeks. Extensive radiation therapy was necessary to meet the required results. In contrast with targeted radiation therapy, the patient, and the tumor, both influenced the treatment plan. Prior to the initiation of this therapy, a picture of the tumor is created using a 3-D computer planner. The tumor is analyzed using this image, and a precise treatment plan in created. This technique reduces the impact of radiation on the surrounding internal organs. As a result, treatment days are reduced.

Genetic Testing: Cancer treatments can be much easier if identified before time. Testing for hereditary cancer in an individual’s genetics can be extremely useful in determining the risk factor even before it occurs. Genetic testing can be used to assess the possibility of breast cancer recurrence and the effectiveness of chemotherapy.

Drugs approved by FDA: Following are some of the drugs that are approved by FDA,

·         Pembrolizumab (Keytruda), a drug approved for treating cancer with numerous gene mutations in its cells. This drug is recommended to treat metastatic triple-negative breast cancer(TNBC).

·         Sacituzumab govitecan-hziy (Trodelvy) is another drug which is approved to treat TNBC patients.

·         Palbociclib (Ibrance), ribiciclib (Kisqali), and everolimus (Afinitor), all these drugs have been approved for the treatment of advanced or metastatic breast cancer when used with hormone therapy.

 

Lung Cancer

Lung cancer, one of the common malignant tumors that poses a major threat to human life due to its high mortality rate and high occurrence. Lung cancer is primarily categorized into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

Lung cancer is the second most prevalent cancer in US. Additionally, it is also the main cause of death from cancer. Lung cancer can be successfully treated if diagnosed earlier before its spread. Screening test for lung cancer is advised to specific people who smoke or used to smoke but do not exhibit any symptoms. If a person has lung cancer but does not show any symptoms, then there is an opportunity to detect the cancer early.

Screening methods include low dose CT scan (LDCT). People with a history of heavy smoking can be screened for lung cancer using LDCT scans. LDCT scans assist in finding abnormal areas in the body that might be cancerous. According to research, annual LDCT scans to screen those with a higher risk of lung cancer can save lives, compared to chest X-rays. These individuals should undergo LDCT scans before the symptoms appear to help reduce their risk of developing lung cancer.  

Lung cancer treatment approaches are surgery, radiation, chemotherapy, targeted therapy, immunotherapy, and combinations of these treatments.

Immunotherapy: Immunotherapies assist the body’s immune system to fight cancer by collaborating with it. New immunotherapy combinations, either with or without chemotherapy, are currently the subject of clinical trials to treat lung cancer. A drug known as an immune checkpoint inhibitor blocks proteins on immune system cells, enabling those cells to fight cancer. These inhibitors specifically target the PD-L1 and PD-1 proteins to strengthen immune responses against cancer. For advanced lung cancer, a number of immune checkpoint inhibitors have recently been approved, namely, Atezolizumab, Cemiplimab, Durvalumab, Nivolumab, and Pembrolizumab.

Targeted Therapies: Targeted therapies identify and kill specific cancer cell types while causing less damage to healthy cells. For advanced lung cancer, numerous targeted therapies have become available, and more are currently being developed. Some of the treatments are:

·          Anaplastic lymphoma kinase (ALK) inhibitor – Target the cancer-causing mutations in ALK gene (5% lung cancer patients with ALK gene alterations)

·         EGFR inhibitors – blocks the activity of protein EGFR (Epidermal Growth Factor Receptor)

·         ROS1 inhibitors – In small % of NSCLC patients, altered forms of ROS1 gene present.  (ROS1 gene makes ROS1 protein which is responsible for cell signaling and cell growth.)

Lung cancer requires a variety of treatments due to its high molecular heterogeneity and complexity, as well as early detection methods. Although new techniques like molecular targeted therapy and immunotherapy have altered the treatment landscape, chemotherapy is still the most common form of the treatment.