Hi. You're right. Since you don't normally have every one of your organs periodically checked (that would be very expensive!), cancer is usually diagnosed when some abnormal symptom appears which makes us suspect the presence of malignancy. Such symptoms include unexplained weight loss and fever, blood in the stools, breast lumps etc.
I am not looking for a particular cancer. I was just curious on how you know if you have it, going about everyday life. I am 25 year old male so i wouldnt normaly have a colonoscopie or a prostate checkup. So basicaly other parts of your body that you can get cancer on i am talking about. I guess symptoms right? I would assume if you had skin cancer you would notice something on your skin etc..Like how could you tell if you had cancer on an organ if you do not normally get each one checked out?
Hi. Diagnosing cancer in a person who does not have symptoms is what is called "cancer screening". The type of screening procedure would depend on the type of cancer you're looking for. For example, breast cancer screening involves doing a breast examination (by palpating the breasts) and mammography. Prostate cancer screening would entail digital rectal examination and prostate specific antigen (PSA) determination. Colorectal cancer screening involves doing periodic colonoscopies.
Basically, screening procedures are concerned with finding direct evidence of tumors and other suspicious looking lesions. Serum tumor markers such as PSA or alpha fetoprotein may also be used in certain instances to screen for tumors, but the evidence provided by these tests are more indirect (only suggest the presence of cancer) and positive results need to be confirmed either by imaging procedures or biopsy.
Maybe you can tell us what particular cancer you are concerned about, so we can give you a more specific answer. Hope to hear from you soon.