Cancer statistics, 2015

Incidence and Mortality Data

Mortality data from 1930 to 2011 were obtained from the National Center for Health Statistics (NCHS).1 Forty-seven states and the District of Columbia met data quality requirements for reporting to the national vital statistics system in 1930. Texas, Alaska, and Hawaii began reporting mortality data in 1933, 1959, and 1960, respectively. The methods for abstraction and age adjustment of mortality data are described elsewhere.2, 3

Population-based cancer incidence data in the United States have been collected by the National Cancer Institute's (NCI's) Surveillance, Epidemiology, and End Results (SEER) Program since 1973 and by the Centers for Disease Control and Prevention's National Program of Cancer Registries (NPCR) since 1995. The SEER program is the only source for long-term, delay-adjusted, population-based incidence data. Long-term incidence and survival trends (1975-2011) were based on data from the 9 oldest SEER areas (Connecticut, Hawaii, Iowa, New Mexico, Utah, and the metropolitan areas of Atlanta, Detroit, San Francisco-Oakland, and Seattle-Puget Sound), representing approximately 9% of the US population.4 As of 1992, SEER data have been available for 4 additional populations (Alaska Natives, Los Angeles county, San Jose-Monterey, and rural Georgia) that increase the coverage of minority groups, allowing for stratification by race and ethnicity.5 Delay-adjusted data from these (SEER 13) registries, which represent 14% of the US population, were the source for the annual percent change in incidence from 1992 to 2011. The SEER program added 5 additional catchment areas beginning with cases diagnosed in 2000 (greater California, greater Georgia, Kentucky, Louisiana, and New Jersey), achieving 28% population coverage. Data from all 18 SEER areas were the source for cancer stage distribution, stage-specific survival, and the lifetime probability of developing cancer.6 Much of the statistical information presented herein was adapted from data previously published in the SEER Cancer Statistics Review, 1975-2011.7

The North American Association of Central Cancer Registries (NAACCR) compiles and reports incidence data from 1995 onward for cancer registries that participate in the SEER program and/or the NPCR. (Five states receive funding from both programs). These data approach 100% coverage of the US population in the most recent time period and were the source for the projected new cancer cases in 2015, incidence rates by state and race/ethnicity, and the 5-year average annual percent change in incidence rates by race/ethnicity and for childhood and adolescent cancers.8, 9 Some of the data presented herein were previously published in volumes 1 and 2 of Cancer in North America: 2007-2011.10, 11

All cancer cases were classified according to the International Classification of Diseases for Oncology except childhood and adolescent cancers, for which the International Classification of Childhood Cancer (ICCC) was used.12 The lifetime probability of developing cancer was calculated using NCI's DevCan software (version 6.7.1).13 All incidence and death rates were age-standardized to the 2000 US standard population and expressed per 100,000 population, as calculated by NCI's SEER*Stat software (version 8.1.5).14 The annual percent change in rates was quantified using NCI's Joinpoint Regression Program (version 4.1.1).15

Whenever possible, cancer incidence rates presented in this report were adjusted for delays in reporting, which can occur because of a lag in case capture or data corrections. This adjustment is only available for data from the 13 oldest SEER registries because historic patterns of case ascertainment are required to anticipate future corrections to registry data. Delay adjustment has the largest effect on the most recent years of data for cancers that are frequently diagnosed in outpatient settings (eg, melanoma, leukemia, and prostate cancer) and provides a more accurate portrayal of the cancer burden in the most recent time period.16 For example, leukemia incidence rates adjusted for reporting delays are 13% higher than unadjusted rates in the most recent data year.4 Delay-adjusted rates were obtained from SEER*Stat databases.17, 18

Projected Cancer Cases and Deaths in 2015

The most recent year for which incidence and mortality data are available lags 3 to 4 years behind the current year due to the time required for data collection, compilation, quality control, and dissemination. Therefore, we project the numbers of new cancer cases and deaths in the United States in the current year in order to provide an estimate of the contemporary cancer burden. These 4-year-ahead projections are not useful for tracking cancer occurrence over time because they are model-based and because the methodology varies over time as we continually strive to achieve the most accurate estimates by taking advantage of improved modeling techniques, increased cancer registration coverage, and updated covariates.

A 3-step spatio-temporal model was used to estimate the number of new invasive cancer cases that will be diagnosed in 2015 based on high-quality incidence data from 49 states (Minnesota data were unavailable) and the District of Columbia during 1995 through 2011. Case coverage represents approximately 89% of the population because, in addition to lacking Minnesota, many states did not achieve high-quality data standards every year. In the first step, complete incidence counts were estimated for each county from 1995 through 2011 using geographic variations in sociodemographic and lifestyle factors, medical settings, and cancer screening behaviors as predictors of incidence.19 Then these counts were adjusted to account for delays in cancer reporting and aggregated to obtain national- and state-level estimates. Finally, a temporal projection method (the vector autoregressive model) was applied to the last 15 years of data to estimate counts for 2015. This method cannot estimate numbers of basal cell or squamous cell skin cancers because data on the occurrence of these cancers are not required to be reported to cancer registries. For the complete details of the case projection methodology, please refer to Zhu et al.20

To estimate the number of cases of female breast carcinoma in situ and melanoma in situ diagnosed in 2015, we first estimated the number of cases occurring annually from 2002 through 2011 by applying age-specific NAACCR incidence rates (data from 44 states with high-quality data every year) to the corresponding US population estimates provided in SEER*Stat.8, 14 SEER 13-based delay-adjustment ratios, accessed from NCI's Cancer Query System,21 were applied to in situ breast cancer counts to account for delays in reporting. (Delay-adjustment ratios are not available for in situ melanoma.) Then the total number of cases in 2015 was projected based on the average annual percent change in case counts from 2002 through 2011 generated by the joinpoint regression model.15

We estimated the number of cancer deaths expected to occur in 2015 in the United States overall and in each state using the joinpoint regression model based on the actual numbers of cancer deaths from 1997 through 2011 at the state and national levels as reported to the NCHS. For the complete details of this methodology, please refer to Chen et al.22

Other Statistics

The estimated number of cancer deaths averted in men and women due to the reduction in overall cancer death rates was calculated by first estimating the number of cancer deaths that would have occurred if death rates had remained at their peak. The expected number of deaths was estimated by applying the 5-year age-specific cancer death rates in the peak year for age-standardized cancer death rates (1990 in men and 1991 in women) to the corresponding age-specific populations in subsequent years through 2011. The difference between the number of expected and recorded cancer deaths in each age group and calendar year was then summed. Averted deaths by state in 2011 were calculated similarly using state- and age-specific average annual crude rates for 5 age groups during 1990 through 1992. An aggregate rate was used instead of a single year because peak years varied across states, with a majority of states reaching peak rates during 1990 to 1992.

Expected Numbers of New Cancer Cases

Table 1 presents the estimated numbers of new cases of invasive cancer expected in the United States in 2015 by sex. The overall estimate of 1,658,370 new cases is the equivalent of more than 4,500 new cancer diagnoses each day. In addition, about 60,290 cases of female breast carcinoma in situ and 63,440 cases of melanoma in situ are expected to be diagnosed in 2015. The estimated numbers of new cases by state for selected cancer sites are shown in Table 2.

Figure 1 indicates the most common cancers expected to occur in men and women in 2015. Prostate, lung and bronchus, and colorectal cancers will account for about one-half of all cases in men, with prostate cancer alone accounting for about one-quarter of new diagnoses. The 3 most commonly diagnosed cancers in women will be breast, lung and bronchus, and colorectum, accounting for one-half of all cases in women. Breast cancer alone is expected to account for 29% of all new cancers in women.

Expected Numbers of Cancer Deaths

Table 1 also shows the expected numbers of deaths from cancer in 2015. It is estimated that about 589,430 Americans will die from cancer this year, corresponding to about 1,600 deaths per day. The most common causes of cancer death are cancers of the lung and bronchus, prostate, and colorectum in men and cancers of the lung and bronchus, breast, and colorectum in women. These 4 cancers account for almost one-half of all cancer deaths (Fig. 1), with more than one-quarter (27%) of all cancer deaths due to lung cancer. Table 3 provides the estimated numbers of deaths in 2015 by state for selected cancer sites.

Lifetime Probability of Developing Cancer

The lifetime probability of being diagnosed with an invasive cancer is higher for men (43%) than for women (38%) (Table 4). The reasons for increased susceptibility in men are not well understood, but to some extent likely reflect differences in environmental exposures, endogenous hormones, and complex interactions between these influences. Recent studies suggest that height may also be a factor.23, 24 For adults aged younger than 50 years, however, cancer risk is higher for women (5.4%) than for men (3.4%) because of the higher occurrence of breast, genital, and thyroid cancers in young women. The current cancer incidence rate among individuals aged birth to 49 years is 78.6 (per 100,000 population) in males and 125.1 in females, compared with 1732.8 and 1188.9, respectively, among adults aged 50 years and older.8 The estimated probability of developing cancer is based on the average experience of the general population and may over- or underestimate individual risk because of differences in exposure (eg, smoking history), medical history, and/or genetic susceptibility.

Trends in Cancer Incidence

Figures 2 and 3 illustrate long-term trends in cancer incidence rates for all cancers combined and for selected cancer sites by sex. Cancer incidence patterns in the United States reflect behavioral trends and improvements in cancer prevention and control, as well as changes in medical practice. Trends in overall incidence are heavily influenced by the 4 major cancers (lung, breast, prostate, and colorectal). For example, the steady increase in incidence rates in men from 1975 to the early 1990s (Fig. 2) was driven by a surge in prostate cancer incidence largely due to the increased detection of asymptomatic disease, first through the use of transurethral prostatectomy and then through widespread prostate-specific antigen (PSA) testing (Fig. 3).25, 26 The increase in incidence in women during the 1980s reflects the increase in lung cancer as a result of the tobacco epidemic and the increase in breast cancer because of changes in female reproductive patterns, as well as increased detection of asymptomatic disease during the rapid uptake of mammography screening.27

Table 5 presents the annual percent change in delay-adjusted incidence rates in the SEER 13 registries during 1992 through 2011 based on joinpoint regression analysis. Joinpoint is a tool used to describe and quantify trends by fitting observed rates to lines connected at “joinpoints” where trends change in direction or magnitude.7, 28 During the past 5 years for which there are data (2007-2011), the overall incidence rate remained stable in women and declined by 1.8% per year in men. The decrease in men is driven by the rapid declines in colorectal (3.6% per year), lung (3.0% per year), and prostate (2.1% per year) cancers. Among women, although the recent rates of decline for colorectal and lung cancers have been similar to those in men, breast cancer incidence rates remained flat and thyroid cancer incidence rates increased dramatically, by an average of 4.5% per year from 2007 to 2011. Although thyroid cancer incidence is also increasing rapidly in men, the 3-fold higher rates in women have a larger influence on overall trends.8

The long-term declines in colorectal cancer incidence rates since the mid-1980s have been attributed to both changes in risk factors and the introduction of colorectal cancer screening.29 However, the rapid declines in recent years (4.0% or greater per year from 2008-2011) likely reflect the increased uptake of screening, primarily in the form of colonoscopy, which can prevent cancer by allowing for the removal of precancerous lesions.30, 31 Among adults aged 50 to 75 years, colonoscopy use increased from 19.1% in 2000 to 54.5% in 2013.32

Lung cancer incidence rates began declining in the mid-1980s in men and in the late 1990s in women as a result of reductions in smoking prevalence that began decades earlier. Contemporary differences in lung cancer incidence patterns between men and women (Fig. 3) reflect historical differences in tobacco use. Women took up smoking in large numbers decades later than men, first initiated smoking at older ages, and were slower to quit, including recent upturns in smoking prevalence in some birth cohorts.33, 34

The decline in prostate cancer incidence rates that began in the mid-1990s likely reflects the diminishing proportion of men receiving an initial PSA test.35 Routine screening with the PSA test is no longer recommended because of growing concerns about high rates of overdiagnosis, estimated at 23% to 42% for screen-detected cancers.36 PSA testing rates may have declined in recent years among men aged younger than 50 years, as well as in those aged 75 years or older, but remain high for older men with a limited life expectancy.37-39

In contrast to the stable or declining trends for most cancers, incidence rates in the SEER 13 registries increased from 2007 through 2011 among both men and women for cancers of the small intestine, anus, liver, pancreas, soft tissue (including the heart), and thyroid; melanoma of the skin; myeloma; and leukemia.7, 17 In addition, incidence rates increased in men for breast cancer, non-Hodgkin lymphoma, and human papillomavirus-positive oropharyngeal cancers and in women for esophageal adenocarcinoma and uterine cancer. The largest annual increases were for cancers of the thyroid (5.3% and 4.5% in men and women, respectively) and liver (3.6% and 2.9% in men and women, respectively) (Table 5).

Trends in Cancer Survival

There have been notable improvements in survival over the past 3 decades for most cancer types in both blacks and whites (Table 6). The 5-year relative survival rate for all sites combined has increased 19 percentage points among whites and 23 percentage points among blacks. Progress has been most rapid for hematopoietic and lymphoid malignancies due to improvements in treatment protocols, including the discovery of targeted therapies. For example, the 5-year survival for acute lymphocytic leukemia increased from 41% during the mid-1970s to 70% during 2004 to 2010. The use of BCR-ABL tyrosine kinase inhibitors (eg, imatinib) doubled survival for patients with chronic myeloid leukemia in less than 2 decades, from 31% in the early 1990s to 60% in 2004 through 2010.40

In contrast to the steady increase in survival for most cancers, advances have been slow for lung and pancreatic cancers, for which the 5-year relative survival is currently 18% and 7%, respectively. These low rates are partly because more than one-half of cases are diagnosed at a distant stage, for which 5-year survival is 4% and 2%, respectively. There is promise for improving lung cancer survival rates because of earlier detection through screening with spiral computed tomography, which has been shown to reduce lung cancer deaths by 16% to 20% among adults with at least a 30-pack-year smoking history.41, 42 However, it is important to realize that screening, as well as other changes in detection practices, introduces lead time bias in survival rates, thereby reducing their usefulness in measuring progress against cancer.43 Advances against cancer are best measured using age-standardized mortality rates.

Trends in Cancer Mortality

The overall cancer death rate rose during most of the 20th century, peaking in 1991. This increase was largely driven by rapid increases in lung cancer deaths among men as a consequence of the tobacco epidemic. Over the past 2 decades, however, there has been a steady decline in the cancer death rate as a result of fewer Americans smoking and advances in cancer prevention, early detection, and treatment. The 22% drop in cancer death rates from 1991 (215.1 per 100,000 population) to 2011 (168.7 per 100,000 population) translates into the avoidance of an estimated 1,519,300 cancer deaths (1,071,600 in men and 447,700 in women) that would have occurred if peak rates had persisted.

Although cancer death rates have declined in every state, there is much variation in the magnitude of the declines. Table 7 shows the relative decline in cancer death rates by state from the early 1990s to 2011 and the estimated number of cancer deaths averted in 2011 as a result. The decline was calculated from an average annual baseline rate during 1990 to 1992 because the death rate did not peak in 1991 in all states. Declines ranged from 9% in Oklahoma to 33% in the District of Columbia, and were generally largest in northeastern states. The declines of 25% to 30% in Maryland, New Jersey, Massachusetts, New York, and Delaware resulted in 29,000 fewer cancer deaths, collectively, in 2011. Almost 20,000 deaths were averted in California because of a 25% drop. In general, Southern states had the slowest declines and the highest current death rates, whereas western states had the lowest death rates (Fig. 4). For example, 2011 cancer death rates ranged from 125.6 (per 100,000 population) in Utah to 200.9 in Kentucky. The large geographic variation in cancer death rates and trends reflects differences in risk factor patterns, such as smoking and obesity, as well as disparities in the national distribution of poverty and access to health care, which have increased over time.44, 45

Figure 5 depicts trends in cancer death rates since 1930 among men and women overall and for selected cancer sites by sex. In contrast to male cancer death rates, which rose continuously prior to 1990, female cancer death rates fell from the late 1940s to the mid-1970s (Fig. 5A). It is also interesting to note that prior to 1941, death rates were higher in women than in men due to the high death rate for uterine cancer (uterine corpus and uterine cervix combined), which was the leading cause of cancer death among women in the early 20th century. Uterine cancer death rates declined by more than 80% between 1930 and 2011, largely due to the widespread uptake of screening for the prevention and early detection of cervical cancer. A similarly dramatic decline occurred for stomach cancer, which accounted for 30% and 20% of male and female cancer deaths, respectively, in the 1930s, but just 2% for each in 2011. Although reasons for the decline in the United States and most other parts of the world are complex and not completely understood, contributors are thought to include a lower prevalence of Helicobacter pylori because of improved hygiene and lower salt intake and a higher consumption of fresh fruits and vegetables because of advances in food preservation techniques (eg, refrigeration).46 Recent studies indicate that incidence rates for certain subtypes of stomach cancer are increasing for some subsets of the US population.47, 48

During the most recent 5 years for which data are available, the average annual decline in cancer death rates was slightly larger among men (1.8%) than women (1.4%) (Table 5). These declines are driven by continued decreases in death rates for the 4 major cancer sites (lung, breast, prostate, and colorectum). Lung cancer death rates declined 36% between 1990 and 2011 among males and 11% between 2002 and 2011 among females due to reduced tobacco use as a result of increased awareness of the health hazards of smoking and the implementation of comprehensive tobacco control.7, 49 Researchers recently estimated that tobacco control efforts adopted in the wake of the first Surgeon General's report on smoking and health in 1964 have resulted in 8 million fewer premature smoking-related deaths, one-third of which are due to cancer.50, 51 Death rates for female breast cancer are down 35% from peak rates, and those from prostate and colorectal cancers are each down 47% as a result of improvements in early detection and treatments.7, 29, 52, 53

In contrast to declining trends for the major cancers, joinpoint analysis indicates that death rates are rising in both sexes for cancers of the oropharynx, anus, liver, pancreas, and soft tissue (including the heart).7 Death rates are also increasing for tonsil cancer and melanoma in men and for uterine cancer in women. Thyroid cancer death rates also increased, but only slightly, from 0.51 (per 100,000 population) in 2007 to 0.52 in 2011 among men and from 0.48 to 0.49 among women.

Recorded Number of Deaths in 2011

A total of 2,515,458 deaths were recorded in the United States in 2011, of which 576,691 (23%) were from cancer. Overall, cancer is the second leading cause of death following heart disease, which accounted for 24% of total deaths. However, cancer is expected to overtake heart disease as the leading cause of death within the next several years. In 2011, cancer was the leading cause of death among adults aged 40 to 79 years and was the first or second leading cause of death in every age group among women (Table 8).

Table 9 presents the number of deaths from all cancers combined and from the 5 most common sites for each 20-year age group by sex. More cancer deaths occur in men than in women except for those aged 20 to 39 years and 80 years or older. Breast cancer is the leading cause of cancer death in women aged 20 to 59 years, but is replaced by lung cancer in women aged 60 years or older. Among men, leukemia is the leading cause of cancer death for those aged 20 to 39 years, whereas lung cancer ranks first among men aged 40 years or older.

Regional Variations in Cancer Rates

Tables 12 and 13 depict current cancer incidence and death rates for selected cancers by state. The largest geographic variation in cancer occurrence by far is for lung cancer, reflecting the large historical and continuing differences in smoking prevalence among states.49 For example, lung cancer incidence rates in Kentucky, which has historically had the highest smoking prevalence, are 3.5 times higher than those in Utah, which has the lowest smoking prevalence. There is a 2-fold difference for prostate cancer incidence rates, which range from 100.9 (per 100,000 population) in Arizona to 198.2 in the District of Columbia, likely reflecting both state differences in PSA testing prevalence and population demographics.26 In contrast, state variations for other cancer types are smaller in both absolute and relative terms. For example, breast cancer incidence rates range from 109.8 (per 100,000 population) in Arkansas to 143.4 in the District of Columbia, a relative difference of just 23%. Some of this variation is attributable to differences in mammography prevalence.65 State variation in cancer incidence rates reflects differences in the use of screening tests and diagnostic practices in addition to differences in the prevalence of risk factors, while the variation in death rates reflects differences in cancer occurrence and survival.