The cancer death rate in the United States has fallen by 27% since 1991. According to the American Cancer Society, which compiled the data over a 25-year period from 1991 to 2016, a total of 2.6 million fewer individuals have died from cancer in the United States. This remarkable decrease, which is a trend observed in both males and females, is attributed to a number of factors. The most notable factors are (1) the continual awareness and dissemination of information about the link between lung cancer and tobacco smoking, resulting in large reductions in the number of individuals who smoke; (2) advancements in early screening and detection methodologies; and (3) more effective cancer treatments and chemotherapies. In addition, there has been overall increased awareness on the part of individuals to avoid exposure to a multitude of other cancer risk factors. For example, individuals are more prone than those in the past to avoid certain carcinogens in their diet and to limit their exposure to the Sun's ultraviolet (UV) rays in order to maintain a healthier lifestyle. See also: Cancer; Chemotherapy and other antineoplastic drug treatments; Death; Nutrition; Oncology; Tobacco; Ultraviolet radiation (biology)

Cancer deaths in the United States since 1930. There has been a steady decline in the number of deaths since 1991 for both males and females. Overall, this reduction amounts to a mortality rate decrease of 27%. (Credit: Based on data compiled by the American Cancer Society)

Cancer is a serious medical condition that develops when the orderly relationship of cell division and cell differentiation becomes disordered, leading to the development of neoplasms (tumors). Neoplasms are new growths and can be divided into benign and malignant types. Malignant neoplasms invade surrounding structures and metastasize (spread) to distant sites. If undetected or if too much harm has been caused, the cancer can be fatal. Presently, cancer is the second leading cause of death both globally and in the United States; only heart disease is responsible for causing more deaths. See also: Cell biology; Cell differentiation; Cell division; Heart disorders; Tumor

The most prevalent types of cancer in the United States are lung, breast, prostate, and colorectal cancers. Survival rates for all of these cancers have increased by as much as 50%. Still, tobacco smoking remains the leading cause of cancer deaths, accounting for about one-third of all cases. In addition, not all of the news with regard to cancer in the United States is positive. There are ever-present disparities related to socioeconomic status, with wealthier individuals having better and earlier access to cancer detection and care compared to less wealthy individuals. Moreover, obesity, which is also related to socioeconomic status and which is becoming more widespread in the United States, is considered to be a risk factor for certain cancer types. As the rates of obesity continue to rise, investigators have observed a similar increase in the rates of cancer in obese individuals. Thus, information, education, and vigilance are needed on the part of patients and clinicians. See also: Breast cancer and other breast disorders; Colorectal cancer increasing in young adults; Medicinal mushrooms and breast cancer; Neoadjuvant systemic therapy for breast cancer; Obesity; Public health