By Akshaya Tallapally
Introduction
Cancer is a disease with a profound impact on society as the second leading cause of death worldwide. From lung cancer to breast cancer to leukemia, there are over 100 variations of cancer. But what exactly is cancer and what are possible ways to treat it?
What is Cancer?
Cancer is marked by the abnormal, uncontrollable division of cells. Under normal conditions, cells go through the cell cycle– a series of stages and checkpoints that mediate the growth and division of cells. When cells become damaged and old, they die through a process known as apoptosis– the controlled death of cells. However, the cell cycle and apoptosis don’t always work as intended. In cancer patients, cells rapidly grow without any control, despite chemical signals from the cell, and spread DNA damage through excessive cell division. Without containment, these abnormal cells spread throughout the body and destroy human tissue.
National Cancer Institute. (2021).
These cancerous cells in the tissue clump together to create tumors. These tumors are categorized into two types: malignant (cancerous) and benign (not cancerous). Malignant tumors spread to other regions of the body in a process called metastasis. These tumors are harder to extract from the body. Benign tumors, on the other hand, don’t spread to new areas but do pose a threat due to their large size. Once removed, though, most benign tumors don’t grow back. Tumors are lethal as they can block the function of vital organs in the body. The organ that the cancerous cells mainly affect, such as the lungs or brain, determines the type of cancer. Cancer is also organized into stages based on the severity of the cancer.
How does Cancer develop?
Gene mutations, or changes in DNA, are the main reason for the development of abnormal cells in cancer patients. Genes are the main controls of how the cell functions, especially cell division and growth. Changes in these genes result in rapid and uncontrollable cell division. Gene mutations are either inherited, due to errors during the cell cycle, or are due to environmental factors such as excessive ultraviolet light exposure. As cancer cells grow and further divide, more mutations are created along the way. Cancer mutations most often target three specific genes: proto-oncogenes, tumor suppressor genes, and DNA repair genes.
National Cancer Institute. (2021).
Cancer Genes
Proto-oncogenes are genes that are in charge of normal cell growth and division. Genetic changes, however, can transform proto-oncogenes into oncogenes. Oncogenes are activated when they shouldn’t be which causes excessive cell growth and division, ultimately leading to the development of cancer.
Tumor suppressor genes, as the name implies, contain cell growth and mediate apoptosis to prevent the formation of cancerous cells. Mutations in the tumor suppressor genes interfere with the function of the genes resulting in the rapid growth of cells. Without the control of the tumor suppressor genes, cancerous cells develop.
DNA repair genes are in charge of ensuring the proper replication of DNA during the cell cycle, which occurs before the division of the cell. If there are mutations present in the repair genes, DNA damage cannot be fixed and will go unchecked as the cell continues to divide. This sets off a chain of genetic changes which can lead to unruly cell growth.
National Cancer Institute. (2021).
Treatments
While doctors aren’t sure of a definite cure for cancer, there are numerous treatments available. Some treatments focus on providing a possible cure for a specific type and stage of cancer. Other treatments work to eradicate cancerous cells from the body. These treatments are referred to as primary treatments and are generally cancer surgery. Primary treatments, however, don’t always remove every trace of cancer from the body. Instead, adjuvant treatments are needed to remove those excess cancer cells. These therapies include chemotherapy, hormone therapy, or radiation therapy. In some cases, a cure or removal of cancer isn’t possible. Instead, patients receive palliative treatment: treatments to help relieve the symptoms and suffering caused by the cancer. These include primary and adjuvant treatments, as well as medications to relieve pain.
Cancer is a complex disease with many different causes and variants that have a significant impact on many lives. However, recent discoveries and technologies are allowing scientists to come up with numerous new and effective treatments to help cancer patients thrive. Over the past 50 years, cancer survivors have increased from 3 million to 18 million, an impressive jump that may soon increase further.
References:
American Cancer Society. (2022). Oncogenes, tumor suppressor genes, and DNA repair genes. American Cancer Society. https://www.cancer.org/cancer/understanding-cancer/genes-and-cancer/oncogenes-tumor-suppressor-genes.html#:~:text=Proto%2Doncogenes%20are%20genes%20that,it’s%20now%20called%20an%20oncogene.
Mayo Foundation for Medical Education and Research. (2022, December 7). Cancer. Mayo Clinic.https://www.mayoclinic.org/diseases-conditions/cancer/diagnosis-treatment/drc-20370594
National Cancer Institute. (2021). What is cancer?. National Cancer Institute. https://www.cancer.gov/about-cancer/understanding/what-is-cancer#types
NBCUniversal News Group. (2022, September 21). Cancer death rates continue to fall, driven by new treatments and improved screening. NBCNews.com. https://www.nbcnews.com/health/cancer/cancer-death-rates-continue-fall-driven-new-treatments-improved-screen-rcna48647
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