This “Annual Report to the Nation” is the first to document a statistically significant decrease in lung cancer incidence and death rates among women from 2003 to 2007 ( and ), more than a decade after the rates began to decrease in men. Although cigarette smoking peaked in men who served in World War II and were born in the early 1920s, it peaked in women born in the late 1930s (32
). The decrease in lung cancer rates in women that we are seeing now reflects the later uptake of cigarette smoking among women. The decrease in lung cancer rates in women can be expected to continue for at least two decades as women in the older generations with higher lung cancer risk are replaced by the subsequent younger generations with lower risk. But trends may be interrupted as women born around 1960, who have higher lung cancer and smoking rates, enter the high-risk age groups (11
). In contrast to women, lung cancer rates in men are expected to continue to decrease in the subsequent younger generations (11
In addition to lung cancer, death rates in the most recent period (2003–2007) showed a statistically significant decrease for seven of the remaining 14 leading cancers among both men and women (cancers of the colorectum, kidney, stomach, brain, leukemia, non-Hodgkin lymphoma, and myeloma) as well as for prostate and oral cancer among men and cancers of the breast, ovary, and bladder among women. As a result, death rates from all cancers combined continued to decrease among both men and women and in all racial and ethnic groups, except among AI/AN women. These decreases indicate real progress in cancer control, reflecting a combination of primary prevention, early detection, and treatment (2
). However, death rates continued to increase for cancers of the pancreas and liver among men and women, and for uterine cancer in women, cancers for which there are no established screening tests. Among men, death rates also increased for melanoma, for which population screening is not recommended but prevention and early detection strategies are available (36
). Among children, long-term (1975–2007) trends in death rates continued to decrease, although at a slower pace during the recent decade than in earlier years.
The overall cancer incidence rates showed a statistically significant decrease during the most recent period (2003–2007) in women, but the decrease was not statistically significant in men. These trends are driven largely by trends in the most common cancer sites (lung, colorectal, prostate, and female breast), accounting for more than 50% of the overall rates in both men and women (38
). Incidence rates decreased for cancers of the lung, colorectum, and oral cavity in both men and women; for breast, cervix, uterine, and bladder cancers in women; and for stomach and brain cancers in men. In contrast, incidence rates increased for kidney and pancreatic cancers and melanoma in both men and women, for liver cancer in men, and for thyroid cancer and leukemia in women. Prostate cancer rates showed a non-statistically significant increase. Factors that contribute to these trends were discussed previously (4
) and include changes in risk factors, screening modalities, and diagnostic practices.
Of the leading cancers, prostate cancer and breast cancer are of special note because they are the most frequently diagnosed cancers and second leading cause of cancer death among men and women, respectively. Prostate cancer incidence has fluctuated through the years, decreasing during 1992–1995, increasing during 1995–2001, decreasing during 2001–2005, and increasing again during 2005–2007, albeit non-statistically significantly (). Prostate cancer death rates have decreased substantially over time (39
), but the contribution of prostate-specific antigen screening to this decrease and the risks and benefits for individual men remain uncertain (40
Trends in breast cancer incidence over time reflect long-term changes in reproductive and other risk factors, introduction and prevalence of mammography screening, and use of hormones among postmenopausal women (45
) ( and Supplementary Table 1
, available online). Breast cancer incidence rates stabilized from 2003 to 2007 (46
) after decreasing sharply between 2002 and 2003, which was temporally associated with the dramatic decrease in the use of postmenopausal hormonal replacement therapy (47
). The stabilization of the rates after the sharp decrease between 2002 and 2003 may in part reflect the role of hormonal replacement therapy as a promoting agent rather than as an initiating agent in the development of breast cancer (DeSantis et al., unpublished data). Meanwhile, breast cancer death rates continued to exhibit a statistically significant decrease. Mammography screening generally is accepted to reduce breast cancer mortality and has been recommended for some time, although recommendations have varied among organizations with respect to age at initiation for average risk women, screening intervals, and screening modalities, especially for high-risk women (49
Of concern is the long-term increase in cancer incidence rates among children, which may be because of larger increases in incidence rates for the lymphoid leukemias and proportionately smaller increases for other childhood cancers (56
). Considerable progress has occurred for many types of childhood cancers, resulting in decreases in cancer death rates among children since 1975, although the rate of decrease has slowed since the mid-1990s. These decreases have resulted from refinements in treatment that substantially improved survival for many childhood cancers. However, for some types of childhood cancer, including some brain tumors, progress has been more modest and current treatments remain inadequate (56
Differences in rates and trends in incidence and death rates for specific cancers for different racial and ethnic groups and for men and women suggest differences in risk behaviors, socioeconomic status, and access to and use of screening and treatment (57
). It is particularly important to monitor these trends to identify opportunities and set priorities for cancer control interventions. Where possible, it is important to examine multiple indices and risk indicators at the national, state, and local level. In addition, although not always feasible in national reports, it is important to recognize that categorizing the population by broad racial and ethnic categories may mask important differences within and among populations.
We provided a comprehensive evaluation of the incidence and mortality for all primary (malignant and nonmalignant) brain and ONS tumors, as well as trends in incidence and survival on a national level. This report expands on the descriptive epidemiology of primary brain tumors presented by the Central Brain Tumor Registry of the United States in its annual statistical report (16
). Collection of nonmalignant (benign or uncertain behavior) tumors began nationwide in diagnosis year 2004, allowing for 4 years of data (2004–2007) to be presented here. Nonmalignant tumors accounted for the majority of all brain tumors, representing two-thirds of all adult and one-third of all childhood (aged 0–19 years) brain tumors. Capturing surveillance data on nonmalignant brain tumors has demonstrated that meningioma is the most common form of brain tumor in the United States. Differing patterns by race, sex, and age were seen for different types of malignant and nonmalignant brain tumors. Although the reasons for these differences have not been elucidated, they may prove important for discovering differences in the etiology of these diverse tumors.
An important finding of the current analysis is the relative stability of the long-term incidence trends of malignant tumors of the neuroepithelial tissue. During the 27-year (1980–2007) time period studied, an increase of 1.9% per year during 1980–1987 was counterbalanced by a decrease of 0.4% per year during the remaining 20 years, resulting in nearly identical incidence rates at the beginning and end of the study. However, marked differences in trends were observed for histological groups within this category of tumors. As with many cancers, trends may be influenced by a number of factors, including changes in diagnostic techniques and changes in coding and classification. The introduction of computed tomography scans in the 1970s and magnetic resonance imaging scans and stereotactic biopsy in the mid-1980s (59
) has led to less invasive methods for diagnosing these tumors and contributed in part to fluctuations in the incidence rates over time. Revisions in the World Health Organization’s histological classification of ONS tumors and the ICD-O
also occurred during the period of the study, along with changes in the multiple primary rules for malignant brain tumors and the introduction of multiple primary rules for nonmalignant brain tumors. Brain and ONS tumors have been particularly difficult to diagnose pathologically because they often are heterogeneous histologically, genetically, and therapeutically (17
). However, progress in understanding the molecular pathogenesis of malignant gliomas has begun to allow for better classification of these tumors (61
In contrast to tumors of neuroepithelial tissue, marked changes in the incidence of lymphomas of the brain have been observed, likely because of increases in AIDS-related lymphomas in the 1980s, followed by decreases in AIDS-related lymphomas after the introduction of highly active antiretroviral therapy in the 1990s (64
). The short time period for which data on nonmalignant brain tumors are available in the United States precluded analysis of temporal trends.
Modest improvements in survival for many types of brain and ONS tumors likely result from improvements in diagnostic and surgical techniques, radiotherapy, chemotherapy, biological therapy, and the use of multimodality therapy (65
). Despite improvements in treatment, major prognostic factors include the histology of the tumor, whether complete surgical resection is achieved, and the age of the patient at diagnosis (66
). Late effects of therapy for childhood brain tumors are substantial and include neurocognitive deficiencies, hormone deficits, growth impairment, second primary brain tumors, and ototoxicity related to platinum chemotherapy (67
Several reviews of risk factors for brain tumors have been published recently (70
). The relatively low variation in incidence and death rates for cancer of the brain and ONS nationally and internationally suggests that environmental risk factors do not play a major role in this disease (70
). In fact, other than hereditary tumor syndromes (17
) and increased familial risk without a known syndrome (79
), the only known modifiable causal risk factor for brain tumors is exposure to ionizing radiation (71
). Variability in age at onset and molecular tumor characteristics suggests that risk factors for brain tumors may differ by histological type (16
). An example is the mostly consistent inverse association that has been observed between history of atopic disease, including allergies and asthma, and risk of glioma (72
) and possibly meningioma (78
); but no association with nerve sheath tumors has been found (84
Several reviews summarize studies evaluating exposure to cellular phones and the risk of brain tumors (78
). Short-term (<10 years) exposures to cellular telephones appear to have no association with risk of brain tumors. However, the association with long-term (>10 years) use remains unclear, primarily because of the relatively recent adoption of widespread use of cellular phones, as well as issues of bias and study design. Acoustic neuromas are of particular interest with regard to cellular phone use because of the proximity of these tumors to the phone. However, studies that have examined this association have mixed results and limited numbers of long-term users; further studies with longer term follow-up will be needed to evaluate whether there is an increased risk of acoustic neuromas associated with the use of cellular phones (99
). A recent study using data from SEER 9 registries for 1977–2006 found decreasing or stable brain cancer incidence rate trends for whites in most age groups except among women aged 20–29 years in 1992–2006, which was driven by a rising incidence of frontal lobe cancers (103
). We examined age- and sex-specific trends in overall malignant brain cancer incidence rates among whites in the SEER 13 registries from 1992 to 2007 and NAACCR data for 1995–2007 (Supplementary Table 8
, available online). Although the short time period for which non-malignant data are available in the United States precludes analysis of temporal trends, the relatively large number of acoustic neuromas identified in the first 4 years of data collection suggests that etiologic studies will be possible in the future.
High-quality cancer surveillance data now cover 93% of the US population for incidence and the entire population for mortality; however, certain limitations in data sources, data collection, and analyses may have influenced the findings of this report. First, state and national population estimates are provided annually by the Census Bureau to estimate intercensal populations. Differences between the numerator (incidence data) and denominator (US Census population data) can occur in the designation of race and/or ethnicity, place of residency, age, single vs multiple races, and the like. Every effort is made to ensure that the definition of the numerator and denominator are the same. Intercensal population estimates based on numbers updated by birth and death data are more subject to error than the estimates based on the actual count. Although these population estimates are believed to be the most accurate available, errors in the estimates may increase as time passes from the original recording of Census data. The NCI developed modifications to these Census estimates to attempt to account for changes in 2005 county-level populations because of displacement of people after Hurricanes Katrina and Rita in the most-affected counties of Louisiana, Mississippi, Alabama, and Texas. Censal and other data are used to classify the incidence cases, and census definitions are used to determine residency for the incidence cases. Race and ethnicity, however, generally are self-reported, but for the incidence cases, this information may come from a wider group of sources (patient, relative, nurse, doctor, coroner, funeral director). To enhance race and ethnicity, determination for the incidence cases, special studies and algorithms are used. For example, a match of incidence cases to IHS rosters is undertaken to correct the possible underreporting of AI/ANs, and NAACCR has developed guidelines and algorithms for enhancing Hispanic-Latino and API identification. Consistency over time in definitions for both census and incidence data is an issue, and efforts have been made to bridge single race and multiple race reporting (more information available on http://www.cdc.gov/nchs/nvss/bridged_race.htm
). Second, joinpoint models were used to describe long-term (1992–2007) and short-term (1998–2007) trends. The AAPC, a summary measure of a trend over a prespecified fixed interval based on an underlying joinpoint model, was used to describe all trend data. The joinpoint model is preferable to single linear regression when a sufficient number of years are available for analysis because it enables identification of recent changes in magnitude and direction of trends. However, it may mask the underlying data and give an impression of a continuous increase or decrease over time when this is not the case. In addition, although methods have been adapted recently to adjust for delayed reporting of aggregated data similar to earlier published methods used for incidence from the nine oldest SEER registries (30
), methods have not been tested on data from registries outside of SEER and were employed in our analysis only for SEER 9 and SEER 13. Delayed reporting may affect the most recent joinpoint segments, overestimating recent decreases and underestimating recent increases.
Third, US Department of Veterans Affairs (VA) hospitals traditionally have been a major source of data for cancers diagnosed among veterans, representing approximately 3%–8% of cancer diagnoses among men. A 2007 policy change regarding the transfer of VA cancer data to state central cancer registries has resulted in incomplete reporting of VA hospital cases in some but not all state registries. This change has affected reporting from the third quarter of the 2004 diagnosis year through the current time period. As a result, cancer incidence rates among men for 2005–2007 are thought to be underestimated by 0.8%–2% for all cancers combined, according to independent statistical analyses conducted by the CDC and SEER. The level of underreporting varied from 0.5% to 4% according to cancer site, race, and age group (14
). The amount of underestimation also may vary by local VA facility reporting patterns and the VA’s contribution to the total number of cancers. Progress in collecting VA data has been made in many states with the enactment of special data-sharing agreements with the VA. Over time, as cancer registries receive these missing VA cases, national cancer incidence estimates will be more complete and accurate.
Fourth, as routinely noted in the Annual Reports to the Nation (1
), the broad racial and ethnic groups categorized for our analyses may mask variations in the cancer burden by country of origin; for example, Chinese and Vietnamese in the API group (105
) and Cubans and Mexicans in the Hispanic group (9
), or by other unique characteristics of high- or low-risk populations (107
). Also, cancer rates for populations may be limited by difficulties in ascertaining race and ethnicity information from medical records, death certificates, and census reports (25
The observed decreases in overall cancer incidence and death rates in nearly all racial and ethnic groups are highly encouraging. This progress could be accelerated by comprehensively applying existing cancer control knowledge of cancer prevention, early detection, and treatment to public health and clinical practices. Unfortunately, at this point in time, not all cancer sites are amenable to cancer control practices, and innovative methods to study these cancers and rare tumors must be developed. For example, the relative rarity of brain tumors, including many histological subtypes, has required investigators to establish consortia and pooled studies, especially for studies of genetic risk factors and gene–environment interaction (70
). Many advances are being made in the molecular characterization of brain and ONS tumors and many other types of cancer. Tumor biospecimen banking linked with treatment and outcome information will be particularly important in studying the prognostic and predictive value of such markers and in developing targeted therapies (115
) to improve effectiveness, lessen toxicity, and measure response to therapy more quickly. It is too early to assess the impact of some treatment advances or the progress in targeted therapy that is expected to emerge in future years.
The US population aged 65 years and older is expected to double in size by 2030 (about 71 million persons) compared with the number reported in the 2000 census (118
). Improvements in health and welfare also mean that individuals are expected to live longer, often with a range of health conditions that include the diagnosis of cancer. Even with declining cancer incidence rates, the absolute number of individuals diagnosed with cancer will continue to increase because of these population changes, leading to increased demand for cancer-related medical services through the spectrum of diagnosis, active treatment, and posttreatment medical management. Effective management of the cancer burden will require the application of sound cancer control strategies in prevention, detection, treatment, and survivorship, as well as resources to provide good quality of care. Continued utilization of quality population-based data systems and translation of evidence-based clinical and basic research findings to public health practices are essential to the development of public policies for cancer.