Cancer FAQ

How does cancer start?

Cancer starts when some cells of our bodies grow uncontrollably. In a healthy scenario, our genes can control the growth and division of our cells, ensuring that normal cells are created to replace ageing or damaged ones. What happens with cancer is that, due to changes to the genes, cells start to replicate uncontrollably and do not mature as a normal cell would. 1,2

What exactly is cancer?

When cells start to grow (proliferate) uncontrollably, they can add up and form tumours, which might be cancerous (malignant) or non-cancerous (benign). The main difference between these two types of tumours is that cancerous tumours can invade other tissues and can spread to other parts of the body, while non-cancerous tumours cannot invade or spread to other tissues. 1,2

Why is cancer called that?

Cancer is called that because the “Father of Medicine”, the Greek physician Hippocrates, described tumours as “carcinos”, which means crab in Greek. It is believed that the word crab was used because of the similarities between the shape of a crab and the way that cancer spreads through various projections. 

How do you know when cancer is starting?

Cancer can start with many signs and symptoms. However, none of them are exclusive to cancer and might be caused by several other conditions. If you experience any signs or symptoms, especially if they do not get better or they are worsening, you should consult with your general practitioner and share your concerns. Many conditions may be causing you discomfort and only a doctor can specify the cause and treat it if necessary. 

Some of the signs and symptoms that may be caused by cancer are: 3

  • Unexplained fatigue
  • Appetite loss
  • Unexplained weight loss
  • Fever or night sweats
  • Trouble swallowing
  • Persistent heartburn or indigestion
  • Persistent bloating
  • Swelling or lumps
  • Unexplained and/or persistent pain
  • Skin changes (e.g., skin or eyes turning yellow, a sore that takes longer than usual to heal, a new mole, or a change in an existing mole)
  • Persistent cough, chest pain, croaky voice, or breathlessness
  • Changes in the size, shape, or feel of your breast
  • Changes in bowel habits for three weeks or more (e.g., constipation, diarrhoea, abdominal pain, blood in your poo, changes in how your stool/poop looks)
  • Bleeding in your urine, from the anus, when you cough, in your vomit, vaginal bleeding between periods, after sex, or a year or more after entering menopause

However, it is important to emphasise that these are only some of the signs and symptoms that cancer can cause, and many other signs and symptoms may appear due to cancer. If you have any concerns, consult with your doctor. If it is cancer, an earlier diagnosis can make a big difference in your treatment. If it is not cancer, it might be another condition that requires treatment. 

How do you deal with cancer emotionally?

Being diagnosed or having a close person diagnosed with cancer can be very emotionally challenging. There are many ways that can help you deal with cancer if you are struggling: 

  • Find the support that best works for you; talking to someone other than family and friends can be helpful. This can happen through clinical social workers, support groups, or therapists. Seek help and find out the best type of support for you.
  • Express your emotions; being diagnosed with cancer comes with a lot of emotions. Expressing these feelings might be extremely helpful for your well-being.
  • Be as active as you can; maintaining your daily activities as much as possible and keeping active is good for your well-being.
  • Make use of relaxation techniques; try out different relaxation techniques, such as meditation and mindfulness exercises, and find the one that better works for you.
  • Focus on what you can control; there are many things about cancer that are out of your control, so focus on what you can control, such as keeping a healthy routine and taking care of your mental well-being.

Is cancer a family thing?

The minority of all cancers – around 5 to 10% - are caused by genes inherited from a parent. Most cancers are caused by a combination of other factors, including older age, smoking, a sedentary lifestyle and an unhealthy diet. 

In general, people have a higher chance of possessing a cancer gene in the following situations:

  • When at least two close relatives on the same side of the family have the same type of cancer.
  • In cases of specific types of cancer (e.g., types of breast and ovarian cancer).
  • In cases of cancer occurring at younger ages (below 50 years of age).
  • Having a close relative that had two different types of cancer. 4  

Consult with your general practitioner about the possibility of having an increased risk of developing cancer to get proper counselling on this matter.

What is the latest treatment for cancer?

There is no specific “latest” treatment for cancer since the choice of cancer treatment depends on many factors, such as the site, type and stage of cancer and the patient’s general health and preferences. Cancer treatment options often include surgery, chemotherapy, radiotherapy, bone marrow transplant, immunotherapy, and hormone therapy. More recent types of cancer treatment include targeted drug therapy, cryoablation, and radiofrequency ablation. Only by discussing all options available with your doctor, can you decide what treatment is the best for you.

What is cancer family syndrome?

Cancer family syndrome, also called inherited cancer syndrome or hereditary cancer syndrome, is a condition in which mutations in genes that can cause cancer are passed from parents to their children, increasing the risk of developing certain types of cancer. Examples of this condition are hereditary breast and ovarian cancer syndrome, Lynch syndrome, and Li-Fraumeni syndrome. 4

Where does cancer normally start?

Cancer can start in any part of the body, which is why there are over 100 types of cancer. The types of cancer are often named by the body part in which it started. For example, breast cancer starts in the breast, bone cancer in the bone, and so on. 1,2

Can blood tests detect cancer?

Simply put, no, a blood test cannot directly detect cancer. However, blood tests are often used to guide cancer diagnosis, since they provide clues about what might be happening in your body and are therefore often used in combination with other diagnostic tests for cancer.

These include blood tests for tumour markers, which can be increased in certain types of cancers, and give clue on cancer’s origin. However, these markers are not specific to cancer and can also be increased in other conditions. 


  1. What Is Cancer? [Internet]. National Cancer Institute. 2022 [cited 17 September 2022]. Available from:
  2. [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006. How do cancer cells grow and spread? 2013 Nov 6 [Updated 2019 Jun 19]. Available from:
  3. National Cancer Institute. Symptoms of Cancer. Updated May 16, 2019. Accessed November 6, 2020.
  4. Rahner N, Steinke V. Hereditary cancer syndromes. Dtsch Arztebl Int. 2008;105(41):706-714.

Juliana Lima Constantino

Medical Doctor and Master Student in Epidemiology, University of Groningen, Netherlands

Juliana completed her studies in Medicine in Brazil in 2019, during which she studied a year abroad in The Netherlands at Vrije Universiteit Amsterdam and took a Medical Elective in England at Oxford University.

After graduating, she worked as a general practitioner and as an emergency doctor in the frontline against COVID-19 in Brazil. In 2021, she moved to the Netherlands to do her Master in Epidemiology.

She is currently working on her Master Thesis in the Global Health Department, with a focus on maternal and child health. She is passionate about medical writing as it serve as a way of spreading trustworthy knowledge to everyone. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
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