Cancer is a disease characterized by uncontrolled multiplication of cells that form a mass called a tumor. It is typically divided into two types: malignant or cancerous cancer and benign or non-cancerous cancer. Cancer typically starts in either the lining of the colon or in the tissues around the rectum. The cause of cancers is not fully understood, but they are believed to be the result of some combination of genetic error and environmental factors.\n
The exact cause of cancer is unknown, but there are a range of factors that may increase the risk of developing cancer. It is clear that diet and exercise have a protective effect, whereas smoking is both a cause of lung cancer and a risk factor for many benign forms of cancer. A positive family history and early age at first pregnancy increases the risk of breast cancer, as does exposure to ionizing radiation.
Symptoms that need to be addressed include blood in the urine, blood in the stool, abdominal pain, itchiness of the skin, unexplained weight loss, and tiredness. The symptoms of cancer may be similar to common and benign conditions; therefore, diagnostic tests may be done if a person presents with these symptoms.\n
The American Cancer Society estimates 235,800 new cases of cancer will be diagnosed in 2022. About 19,000 of these cases will be attributed to tobacco use.
Cancer can be cured but not in all disease stages or in all disease types. The extent of cure depends on the stage at diagnosis and the disease type of the [prostate cancer](https://www.withpower.com/clinical-trials/prostate-cancer). The extent of cure is probably better when compared to other forms of cancer.
Many cancer treatments cause harm, only lead to temporary relief of symptoms, and not much difference in survival. Common interventions are: surgery or radiotherapy only, surgery and radiotherapy, or no therapy at all. All such options are not optimal treatments and have little effect on survival. Newer treatments for cancer aim to maximize survival and quality of life, rather than just symptom and PSA control. As cancer progresses, there is no cure. Common treatment options for cancer are chemotherapy, radiotherapy and targeted therapy for cancer, which are not effective.
More recent research is published in the field of cancer, but much of the evidence cannot be applied clinically because it is of poor quality and its applicability is questionable.
The pur001-pemetrexed combination therapy may increase the median OS and the overall efficacy by more than 3-fold in the treatment of advanced non-small-cell lung cancer patients.
At a population level, cancer patients are generally not considered to be severely compromised. For a given sex, diagnosis of cancer causes death for half as many men as it does women. Although some aspects of the disease are more life-threatening for men, on average men have a longer life expectancy post-diagnosis than women. The effect of cancer diagnosis on quality of life may, however, vary by gender and the particular disease. Women with breast cancer and ovarian cancer can have severely reduced quality of life as diagnosed and treated. Oncology nurses can help cancer patients address the psychological stresses associated with cancer and its treatment.
pur001 is one of a group of compounds called purines or purines derivatives. As of 1998 the National Cancer Institute had no evidence to confirm or to disprove any therapeutic use for pur001, but in 1997 a group of scientists began investigating pur001 because of several observations made during preclinical studies by other scientists who were in various stages of cancer therapy. A preclinical study by J. F. Stanger of the University of Colorado, a series of studies by others, and then an observational study of pur001 in cancer patients by G. N. Palanias concluded that pur001 was useful in the treatment of a small group of patients.
The hypothesis of an inherited component in cancer risk cannot be ruled out in any particular population. However, these findings could be due to shared familial environmental factors influencing both cancer risk and mortality.