Cancer is a word that most people think of to be a death sentence. It is one word that nobody wants to hear in a doctor’s office. Sadly, over the past decades, cancer prevalence has continued to rise. It was thought to be more common in elderly people but now it is becoming a lot more common in younger adults and even in children. There are many types of cancer that can develop throughout the body. Luckily, cancer is curable in some cases with treatment. People can be saved at all stages of cancer but sadly, not every person survives. It is a battle that scientists and doctors have been fighting for decades. Cancer is very complex and to get a better understanding of it, first one must have a general idea of what it is, the origin and what causes it.
Cancer is abnormal cell growth within the body. It is when normal cells become mutated and then these mutated cells continue to reproduce. Cancer cells do not differentiate, have abnormal nuclei, and do not undergo apoptosis. What this means is unlike the other cells in our body, cancer cells do not die. They rapidly produce and their nuclei is enlarged. Keep in mind that there are also other abnormal cell growths that can occur within the body and it doesn’t mean that every abnormal cell growth is cancerous. The abnormal cell growth will eventually form tumors. Not all tumors are cancerous. There are two types of tumors; benign and malignant. Benign tumors are noncancerous and malignant tumors are cancerous. Abnormal cells multiply rapidly and cluster up together to form a tumor. Another thing to note is that different kinds of cancers have different mutational signatures (Mike Adams et al.) This is why cancer in general is hard to cure because there are so many types and each type differ from one other in regards to their cells.
The development of cancer isn’t something that happens overnight either. The development of cancer can take years. There are multiple steps or stages that these cells go through to become cancerous. First, the formation of the tumor will occur. Then this tumor will undergo metastasis, which means the tumor will break off into fragments and spread to other parts of the body. Next these tumors will undergo angiogenesis, which is where blood vessels are formed in the tumor and nutrients and oxygen can now be supplied to the tumor. Even though the cancer has spread to different parts of the body from the original starting point, it would still be considered one type of cancer. For example, if a person had a tumor in their pancreas and the cancer spread to the bones or lymph nodes, this cancer would still be called pancreatic cancer because it originated in the pancreas. Knowing this information will make understanding the different stages of cancer much easier. There are technically five stages of cancer and they are: stage 0, stage I, stage II, stage III, and stage IV (‘Stages of Cancer’, 2018). Stage 0 means that the cancer hasn’t spread, it is sedentary in one part of the body. Stage I means that it has started to spread into nearby tissues, but isn’t deep rooted anywhere. Stage II and stage III have spread deeply within the nearby tissues and possibly the lymph nodes. Stage IV is the worst stage of cancer and this means that the cancer has spread to other parts of the body.
The origin of cancer comes from mutated genes. An experiment was performed with mice in an attempt to prove this. Scientists focused on a liver cancer called fibrolamellar hepatocellular carcinoma or fibrolamellar for short. Scientists found that all of the patients with this cancer had the same mutations in their tumor cells. A piece of DNA was missing. This missing DNA is supposed to be between these two genes: DNAJB1 and PRKACA. The deletion of this DNA causes seven other genes to be deleted and a protein to fuse the genes DNAJB1 and PRKACA together. This fusion is call chimera. The formation of chimera is what causes the cancer. This can be clarified by the experiments used on mice. Scientists took the genes of adult mice and mutated their genes. They created the same deletion of DNA missing between DNAJB1 and PRKACA that is found in fibrolamellar patients. After a few months, the mice developed the cancer. Scientists then took another group of mice and added just an extra piece of DNA with the chimera on it and this group of mice also developed the same cancer. These two experiments justify that the formation of chimera in the genes is the cause of fibrolamellar. This is just one example. Referring back to chapter nine, these mutated genes are called ‘oncogenes’. There is another gene called ‘tumor suppressor genes’. An oncogene is a mutated proto-oncogene. This is what can lead to cancer. It basically tells the cells to keep growing and dividing and there is no off switch so a tumor is created. The tumor suppressor genes regulate cell division and reproduction. They tell the cell to stop growing and dividing but if it becomes inactive due to mutation, it can also lead to cancer.
The cause of cancer can be traced back to a number of things. A lot of times doctors can’t even specifically say what caused it because they do not know. It is obvious in some cases; a person who has been diagnosed with lung cancer and also has a vast history of smoking. We are not always that lucky, though. There are many risk factors that have the possibility to lead to cancer. As stated by the National Cancer Institute, some of these factors include: age, diet, sun light, genetics, alcohol, obesity, and etc. Cancer is a lot more common in elderly people. “The median age of a cancer diagnosis is 66 years old. This means that half of cancer cases occur in people below this age and half in people above this age. One-quarter of new cancer cases are diagnosed in people aged 65 to 74” (National Cancer Institute, 2015). Drinking alcohol in excess for long periods of time can possibly lead to the development of multiple cancers such as cancer in the breast, liver, and throat. When it comes to genetics causing cancer, it is because the person has inherited the same genetic mutation that a family member has. Just because the person inherited this genetic mutation does not mean that the person will have cancer. They just have a high risk of getting it or passing on this risk to future offspring. There is some bittersweet hope in this field. If a family has a known history of cancer (not self-induced such as smoking or drinking), genetic testing can be done. The test can tell a person how high the percentage is that they may get cancer. The positive side is that a person can know what to expect but the negative side is there is no preventing it. All one can really do is monitor with regular visits to the doctor and hopefully stop it in time when the time comes. Tobacco is also another leading cause of cancer. When it comes to smokers, not only does the smoker have a high chance of getting cancer but whoever is around that person getting secondhand smoke also has a high chance of developing cancer as well. Tobacco can cause the same cancers as drinking alcohol and more examples also include these cancers: lung (most common), kidney, pancreas, and cervix.
There are some interesting myths when it comes to cancer as well. One myth is, if a person gets cancer, they are going die. Even though a lot of people think of cancer as a death sentence, that is not always the circumstance. Although in some cases it is, depending on how advanced the cancer is. It can reduce a person’s lifespan to numbered years. “Five-year survival rates for some cancers, such as breast, prostate, and thyroid cancers, now are 90 percent or better. The 5-year survival rate for all cancers combined is currently about 67 percent” (National Cancer Institute, 2015). This is very encouraging seeing that the survival rate is increasing. Also, another myth that I myself believed to be true is, eating sugar makes cancer worse. It has not been proven to make cancer worse but the misconception is that eating a lot of sugar all the time can lead to obesity and obesity can lead to several types of cancer. I think this is where people (including myself) mix up sugar worsening cancer. Another big myth that people (including myself) believe to be true is artificial sugars cause cancers. All of the artificial sugars that are used in the United States have been approved by the Food and Drug Administration. Which means that these artificial sweeteners were approved after being evaluated and tested by researchers. There was no evidence that they are linked to cancer. This is why it is important to always check labels of foods when buying especially when they are not fresh foods.
The biggest question is ‘Why isn’t there a cure for cancer yet?’. As I have talked about above, there are many types of cancer and each type of cancer has its own genetic mutation. Since every type of cancer has its own genetic mutation, a cure has to be found for every single type of genetic mutation. In other words, a cure must be found for every type of cancer. Another tricky thing is there can be thousands of genetic mutations within a certain type of cancer. Let’s say two people both have colon cancer; one person may have a different genetic mutation from the other person so generic medication prescribed for colon cancer may not work for both people due to the different genetic mutations. Since this is so common, chemotherapy and radiation are common treatments for cancer. These methods are commonly used because of the many genetic mutations but also if the tumor gets cut out, it may grow back. These treatments can stop potential tumors from growing back. There is also another treatment option called genome sequencing. Scientists test the genes of the cancer cells to determine a specific treatment plan such as developing medications that can combat specific genetic mutations in the genes to stop the cancer. This form of treatment is very helpful compared to chemotherapy and radiation because these treatments are very invasive and have many harmful side effects.
Overall, cancer is a very scary disease to think about or even discuss. However, it should not be something that we live in fear of. We know it can be terminal but we also know it can be treated and managed. It is not something that a person can mentally plan for, even if their chances of becoming diagnosed are high. Even though there isn’t really a preventive measure to getting cancer, a person can get evaluated by a physician regularly and if the cancer does occur, it can be caught in the early stage and hopefully terminated. Living a healthy life free of alcohol and tobacco can help lower the risk of cancer developing in your body. If diagnosed, it does not have to be something that alters the way we live our lives. There is still so much to learn about all the different types of cancers and the genetic mutations that come along with them. I believe that research will have to continue and progress for many years due to the complexity of cancer. I think in the future genome sequencing will become more advanced and hopefully scientists will be able to get rid of the mutated genes that lead to cancer. This could be the cure for cancer we have been searching for. It is only a matter of time before the cure for all cancers is found.
References
- https://www.nature.com/scitable/ebooks/essentials-of-cell-biology-14749010/122997842/
- https://www.cancer.net/navigating-cancer-care/diagnosing-cancer/stages-cancer
- https://www.pnas.org/content/pnas/114/50/13076.full.pdf
- https://www.cancer.gov/about-cancer/causes-prevention/risk
- https://www.cancer.gov/about-cancer/treatment/types