What Is Cancer?
Cancer is a group of diseases in which cells grow uncontrollably failing to die. The abnormal cells can continue to spread. If the spread is not controlled, it may result in death. Cancer is caused by internal factors (inherited mutations, hormones, immune conditions, etc.) and external factors (tobacco, chemicals, radiation, etc.). Cancer is treated by surgery, radiation, chemotherapy, hormones, and immunotherapy.
Can Cancer Be Prevented?
The American Cancer Society estimates 729,000 new cases in 2018 are potentially avoidable. 19% are cased by smoking, 18% are caused by excess body weight, physical inactivity, excess alcohol use, and poor nutrition.
What Percentage of People Survive Cancer?
In 1975-1977, the 5-year relative survival was reported to be 49%. In 1987-1989, the survival rates increased to 55%. And, in 2007-2013 the 5-year relative survival rates rose to 69%. These improvements demonstrate improved treatments, and earlier detection at earlier stages. Survival varies greatly by cancer type and stage at diagnosis.
Regular screening exams by a health care professional can result in the detection of cancers of the breast, colon, rectum, cervix, prostate, oral cavity, and skin at earlier stages, when treatment is more likely to be successful. A heightened awareness of breast changes or skin changes may also result in detection of these tumors at earlier stages. If all of these cancers were diagnosed at a localized stage, 5-year survival rates would increase to about 95%.
Who is at Risk of Developing Cancer?
Anyone can develop cancer. Since the occurrence of cancer increases with age, most cases affect adults. Nearly 87% of all cancers are diagnosed at age 50 and older. Cancer researchers use the word “risk” in different ways. Lifetime risk refers to the probability that an individual, over the course of a lifetime, will develop cancer or die from it. In the US, men have a 1 in 2 risk of developing cancer; for women the risk is 1 in 3.
How Many New Cases are Expected to Occur This Year?
About 1.7 million new cancer cases are expected to be diagnosed in 2018. These estimates do not include carcinoma in situ (noninvasive cancer) of any site except urinary bladder, and do not include basal and squamous cell skin cancers. More than 1 million cases of basal and squamous cell skin cancer are expected to be diagnosed this year.
How is Cancer Staged?
Staging is the process of describing the extent or spread of the disease from the site of origin. Staging determines the choice of therapy and assessing prognosis. A cancer’s stage is based on the primary tumor’s size and location in the body, and whether it has spread to other areas of the body. Many different staging systems are used to classify tumors. The TNM staging system assesses tumors in three ways: extent of the primary tumor (T), presence of regional lymph nodes (N), and presence of distant metastases (M). Once the T,N, and M, are determined, a stage of I, II, III, or IV is assigned. Stage I being is the early stage and IV the advanced stage. Summary staging (in situ, local, regional, and distant has been useful for descriptive and statistical analysis of tumor registry data. If cancer cells are present only in the layer of cells they developed and they have not spread, then the state is in situ. If cancer cells have spread beyond the original layer of tissue, the cancer is considered invasive.
* Information provided by American Cancer Society, Surveillance Research