Question: what is different from cancer compared to other diseases?

Hi nadun! Good to hear from you again and it was good to talk to you again today.
Cancer is different to many common diseases because it doesn’t have a single cause, and it isn’t always caused by a pathogen – that is, an organism that causes disease, like parasites, viruses and bacteria. Cancers are cells that are permanently malfunctioning – their DNA is mutated, all the proteins that normally control growth and repair errors in DNA don’t work,the cells divide rapidly. Many of the more common diseases we’re affected by are due to infections by parasites, bacteria or viruses. If there is a treatment for the pathogen, removal of the pathogen generally means curing the disease. The immune system helps the body to recognise when it’s being invaded and mount a response.

But in cancer, it’s different. The immune system can’t always detect a cancer, because the immune system is trained to recognise foreign organisms and to leave “self” or cells of the body, alone. But cancer is a disease thar arises from cells of the body, so it’s not seen as “non-self” by the immune system.

However, we can use treatments to induce the immune system to help us fight cancer.

One more thing – some cancers *are* caused by pathogens – the human papilloma virus (HPV) can help induce cancers. It’s why we have a vaccine for ovarian cancer, directed at HPV. But the HPV itself alters a cell to cause cancer, so if you were able to treat HPV, it doesn’t mean that the cancer can be treated as the cell has already changed.