How does cancer kill you?
Death-defying are consequences of tumor growth which depend on many reasons and on tumor type. Most frequent reason of death is joined infection (quite often, pneumonia) connected with a tumor caused oppression of the immune system. This phenomenon is well described, but the reasons are not entirely clear.
In case of leukoses (sometimes incorrectly called “blood cancer”), tumor cells replacing normal ones in marrow are not capable of performing protective functions that leads to decrease in immunity and development of infections. Radiotherapy and chemotherapy negatively affect also healthy cells that also undermines body resistance to infections. Acute gemorragiya, blood clots and pulmonary insufficiency can also lead to death almost at 20% of oncological patients.
Invasion and, as a result, tissue destruction (in bones, liver, brain, etc.) lead to death at 10% of patients. Some tumors, for example, colon malignoma, can cause heavy and sometimes fatal anemia because of chronic hemorrhage, i. e. constant blood loss. Popular belief that people dry out (cachexia) because of malignant tumour is truly only in some cases, and only in every 100-th case it can lead to death.
Prostate cancer at men is on the top of incidence in connection with aging of the population and also improvement of early diagnostics. There is an opinion among oncologists that all men risk to have this malignant tumour type, but not all live till it appears. In confirmation to this view it's shown that about 80% of men by 80 years have prostate cancer. Breast cancer (generally at women though sometimes it happens also at men) is on the second place.
Among tumors which are not connected with gender, lung malignoma is on the first place. Colon and rectum malignoma are further two widespread types of malignant tumour.
Lung carcinoma is the most frequent murderer (more than 150,000 death cases in the USA in 2010), the second place takes colon and rectum malignoma, then mammary gland, pancreas, prostate malignoma, leukosis etc. The most widespread oncological diseases of children are leukoses, brain tumors and lymphoma.
Pancreatic carcinoma is the most difficult for treatment. Only 5% of the patients live longer than 5 years. However, in general most of all patients perish from lung malignant tumour, first of all because of its prevalence. Malignant brain tumors are also very difficult to treat, the people with this diagnosis can live from 3 months to 3 years long. Treatment of metastases of the majority of tumors is also usually ineffective.
Some skin carcinoma types (bazalioma) do not spread practically, and it's easy to cure them by an usual surgical removal. As it was already mentioned above, Berkitt's lymphoma, generally widespread in Africa and also choriocarcinoma and Hodgkin's disease are easy to treat. Usual classical chemotherapy is effective in these cases. It's important to know that many malignant tumors have high probability of full treatment at early stages (I-II), in particular, breast carcinoma.