Cancerous Tumours and where to find them

In this post I will answer two questions you possible might have after reading the title of this blog post; Yes, the title is a play on the movie title “Fantastic beasts and where to find them” which btw is an awesome movie. And yes, in this post we are going to overview some methods for finding out if a certain person has cancer or not.  

In a previous blog post (“What is cancer?” by Leticia and Pablo) we explored what a cancerous tumour (as we simply will note by tumour henceforth) is; a mass of cells that divides uncontrolled e.g., due to malfunctioning control mechanisms for cells in the body. We learnt that there are basically six hallmarks or capabilities of cancerous cells to help them survive even though they shouldn’t belong in the body; evading control mechanisms, evading growth suppression, evading normal cell death, ‘unlimited’ cell divisions, being in favourable (for growth) environments and being good at invading other parts of the body. We also learnt that tumours come from mutations of cells, and that there are a lot of different cancer types which makes it really difficult to treat although much progress and research is currently occurring.  

But ok, that is what cancer is but how can we find out if someone actually has cancer or not? Let’s say you suspect you or someone close to you have cancer, or let’s say you want to know if you or your children might get cancer in the future.  Well, they are different issues so let’s take them one at a time. 

Being a detective; symptoms, history and viewing the crime scene 

But you believe you have symptoms, you might (but not necessarily) also know that a relative has / had cancer with similar symptoms (even a distant one). Then it is time to call the specialist / the doctor / the crime scene detective. He or she will review the symptoms and patient history and also run some tests (what this post is supposed to be mainly about, except when I am beating around the bush) to get more information to finally determine if you have cancer or not. These tests yet again vary depending on the cancer that you have, for instance skin cancer is on your skin and you can more easily sample some cells but that is not the case for breast cancer. Here I will mention a few of them which can be used maybe not for all cancer types but for many or a few.  

Laboratory tests 

Some cancers affect for instance different liquids in your body, like your urine or blood. So one way to know if you have that type of cancer or not is study for instance irregularities in the blood. Leukemia is such a case, where the disease affects the number of white blood cells in your blood and thus is a indicator that you might have Leukemia. Some different tests listed and some cancers they can be used for: 

• CTC (circulating tumor cell) test – Metatstatic breast and prostate cancer 
• CBC (complete blood count) test – leukemia and anemia 
• Flow cytometry – breast, prostate and bladder cancer 
• CA-125 (biomarker for many cancers) test – Ovarian, Endometrial, Pancreatic, Stomach, Liver, Breast and Lung cancer 

Imaging

Cancerous tumours usually form chunks or ‘lumps’ of cells and sticks to organs in the body. This due to the rapid and uncontrolled growth and divisions of the cells. Let’s say this happened in the lung, e.g. you got lung cancer, then that would imply that you have a big lump of tissue or cells at a place where you usually don’t have one. So if the doctor or specialist were to check if you have a tumour in the lung then they would check if such a lump exists. The doctor could cut you open and look for it, but that is both impractical and bad for the patient. Instead, the doctor could use imaging techniques like MRI-, CT- or PET scans to take images of the inner part of your body and view the images for irregularities. Taking good quality images is difficult and very complex, and often it might be difficult for the doctor to see the tumour in the image even if it is there. Interestingly, here computers can perform better than humans in many cases. Computer programs (this goes in to the field of machine learning or artificial intelligence) can be written to find irregularities in images, even if the tumours are small in size (barely detectable for humans) or if the images are of low quality. These programs have repletely shown to perform better or similar to humans. 

The imaging area is rapidly advancing; both the images get better (increased quality) and methods to process them performs better and better.  This is mainly due to the non-invasive characteristics of the imaging which is both a fast way to receive information and also not harming the patient, thus being attractive as a pre-treatment screening method. It is also attractive in the sense that computer scientists (popular science field) can take a heavy load in development, and that it is easy to share knowledge around the globe.  

Biopsy 

Well, this is the one we kind of want to avoid. Biopsy is when we get a sample of cell from the tumour by cutting in the patient or doing a surgery. Biopsy is sadly not always unavoidable, but methods which are replacing biopsies are increasingly being developed and/or improved.  

No symptoms, but still wanna know? 

Ok next case; you don’t have any symptoms but maybe one of your parents had cancer, or maybe you have it and want to know if it will be passed on to your children. Well, from here forth we are going to discuss your genes, because they are the villains in this case.  

Cancer is unfortunately genetic and about 5 to 10 percent of all cancer types are mayorly inheritable from parents. Many genes for instance related to cell growth have and are being studied, and scientists have found several which, if is dysfunctional, might cause cancer. For instance, gene TP53 produces a protein which usually limits or supresses growth of tumours and if not working properly then tumours will have a bigger platform to grow on. So how do we actually know If a gene is dysfunctional e.g. if it is wrongly constructed, and what can we gain from it?  

One method is DNA sequencing. By taking a sample of e.g. blood or saliva from both a normal and cancerous cells, and then comparing the DNA sequences we may know if something is not in order. There are different methods on how to determine the DNA sequence (nucleotides sequence), one new method is called new generation sequencing (NGS) which can sequence whole genomes which is very cool. I will leave the details for another post, but this helps in finding the correct biomarkers to use and thus which treatments are possible. Some treatments, like immunotherapy may only be used if the receptor or patient have certain biomarkers.  

Without side tracking too much, if we know that you have a specific dysfunctional gene, then treatment can start faster. If we also know that it is inheritable, e.g. the modified cells are present in the germ cells (sperm or eggs cells), then prevention and treatment plans can be established early for your children.  

Last note 

Cancer is a ‘sad’ disease, and the best way to treat it is to start the treatment as early as possible. If you believe you have symptoms, go check them up. It is better to go one time more than one time less.  Also check if you have inheritable genes, it might help your children in the future. 

Cheers 

Robin   

[1]https://www.mayoclinic.org/diseases-conditions/cancer/diagnosis-treatment/drc-20370594 

[2]https://www.cancercenter.com/diagnosing-cancer/lab-tests 

[3] https://www.cancer.gov/about-cancer/causes-prevention/genetics 

[4] https://www.cancer.gov/about-cancer/treatment/types/biomarker-testing-cancer-treatment 

[5] https://www.nature.com/articles/d41586-020-03157-9