Cancer Survivors --- United States, 2007

As a result of advances in early detection and treatment, cancer has become a curable disease for some and a chronic illness for others; persons living with a history of cancer are now described as cancer survivors rather than cancer victims (1). From 1971 to 2001, the number of cancer survivors in the United States increased from 3.0 million to 9.8 million (2). To update those data, published in 2004, the National Cancer Institute (NCI) and CDC analyzed cancer incidence and follow-up information from nine Surveillance, Epidemiology, and End Results (SEER) programs to estimate the number of persons in the United States ever diagnosed with cancer who were alive on January 1, 2007. This report summarizes the results of that analysis, which indicated that the number of cancer survivors increased from 9.8 million in 2001 to 11.7 million in 2007. Breast, prostate, and colorectal cancers were the most common types of cancer among survivors, accounting for 51% of diagnoses. As of January 1, 2007, an estimated 64.8% of cancer survivors had lived ≥5 years after their diagnosis of cancer, and 59.5% of survivors were aged ≥65 years. Because many cancer survivors live long after diagnosis and the U.S. population is aging, the number of persons living with a history of cancer is expected to continue to increase. Public health and health-care professionals should understand the potential long-term needs of cancer survivors, engage in health promotion (e.g., urging cancer screening and smoking cessation), and ensure coordination of follow-up care for this growing population.

For this report, data on persons with malignant cancer diagnosed during 1975--2006 were obtained from the SEER Program at NCI. Persons who had diagnoses of in situ cancer or nonmelanoma skin cancer were excluded. The SEER Program consists of cancer registries throughout the United States and has been collecting information on tumor characteristics, patient demographics, and follow-up since January 1, 1973. The estimates in this report are based on information from the nine SEER registries* that have provided data continually since 1975; these registries cover approximately 10% of the U.S. population.

To estimate the number of persons in the United States ever diagnosed with cancer who were alive on January 1, 2007, a three-step analysis was performed (3). First, SEER statistical software† was used to estimate the proportion of persons enrolled in the nine registries who were alive on January 1, 2007, and who received a diagnosis of cancer during 1975--2006. Next, using NCI software,§ these prevalence estimates were extrapolated to the entire U.S. population,¶ while controlling for age, sex, and race. Finally, to adjust for underascertainment of cases that occurred before 1975, another NCI software** was used to apply a completeness index (based on incidence and survival estimates) to the 1975--2006 prevalence estimates. The final results are estimates of the number of persons ever diagnosed with cancer who were alive on January 1, 2007, regardless of how long ago the diagnosis was made, and are characterized by patient age and sex, years since diagnosis, and cancer type.

The number of cancer survivors in the United States increased from an estimated 3.0 million in 1971 (1.5% of the U.S. population), to 9.8 million in 2001 (3.5%), and to 11.7 million in 2007 (3.9%) (Figure 1). Female breast (22.1%), prostate (19.4%), and colorectal (9.5%) cancers were the most common types of cancer diagnosed, accounting for 51.0% of diagnoses among persons who were alive on January 1, 2007 (Table). Among all cancer survivors, 54.3% were female, and 45.7% were male.

An estimated 59.5% of cancer survivors on January 1, 2007, were aged ≥65 years; 35.2% were aged 40--64 years, 4.5% were aged 20--39 years, and <1% were aged ≤19 years (Table). The largest numbers of survivors with female breast cancer were aged 65--84 years (1,227,283) and 40--64 years (1,038,976). The largest numbers of survivors with prostate (1,549,851) and colorectal cancer (625,129) were aged 65--84 years. The largest numbers of survivors with melanoma (393,133), thyroid (250,824), and cervical cancer (127,519) were aged 40--64 years. Among survivors aged 0--19 years, 33,001 (31.1%) had leukemia.

Among cancer survivors on January 1, 2007, an estimated 64.8% had lived with a diagnosis of cancer for ≥5 years; of those survivors, 57.2% were females (Figure 2). Among those who had lived with a diagnosis of cancer ≥15 years, 67.5% were females. Approximately 1.1 million of the 11.7 million cancer survivors had lived with a diagnosis of cancer for ≥25 years; of those survivors, 75.4% were females.

Reported by

JH Rowland, PhD, A Mariotto, PhD, CM Alfano, PhD, Div of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland. LA Pollack, MD, HK Weir, PhD, Div of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion; A White, PhD, EIS Officer, CDC.

Editorial Note

Updating the 2004 report that showed an increase in cancer survivors from 1971 to 2001 (2), the findings in this report indicate that the population of cancer survivors continued to grow, both in number and as a percentage of the U.S. population, from 2001 to 2007. This growth can be attributed to multiple factors, including earlier detection, improved diagnostic methods, more effective treatment, improved clinical follow-up after treatment, and an aging U.S. population (1,4). If these trends continue, the number of cancer survivors is expected to increase further (4,5).

Similar to previous reports, this analysis found that the majority of cancer survivors are females and persons aged ≥65 years (2,6,7). Women are more likely to be survivors because cancers among women (e.g., breast or cervical cancer) usually occur at a younger age and can be detected early and treated successfully; in addition, women have a longer life expectancy than men. Among men, a substantial number of cancer survivors had prostate cancer, which is diagnosed more commonly among older men. The large proportion of cancer survivors aged ≥65 years reflects the increase in cancer risk with age (7) and the fact that more persons with diagnoses of cancer are surviving ≥5 years.

The findings in this report are subject to at least four limitations. First, to calculate national estimates of cancer survivors, race- and age-specific proportions from SEER were extrapolated to the U.S. population, and the data do not account for other prognostic factors (e.g., smoking status or comorbidities). In addition, compared with the U.S. population, the SEER population is more urban and includes more persons who are foreign-born (8), which might limit generalizability. Second, because of the methods used, these cancer prevalence estimates might be lower than those obtained through self-reported cancer in national surveys because self-reported cancer cases in surveys tend to be overreported and are not confirmed diagnostically, whereas this study uses cancer registry data derived from medical record review (9). Third, persons with multiple primary tumors were categorized according to their first tumor; therefore, the number of survivors for certain cancer types is underestimated (10). Finally, the data do not permit specifying whether a cancer survivor is cured, in active therapy, living with a chronic cancer-related illness or disability, or dying from cancer.

Healthy behaviors such as smoking cessation, healthy eating, and regular physical activity can reduce the risk for cancer, and early detection of cancer can improve the quality of life and increase the likelihood of survival. With a steady increase in the number of cancer survivors during the past 40 years, additional research is needed to identify those survivors at risk for recurrence, secondary disease, or late effects (e.g., nerve damage or infertility) from cancer and its treatment (e.g., chemotherapy or radiation). Further study also is needed to address the disparate burden of cancer among the medically underserved and the special needs of older cancer survivors, and to develop, test, and deliver measures to prevent or mitigate these adverse effects on survivors.

NCI and CDC are actively pursuing a better understanding of cancer survivorship. NCI's Office of Cancer Survivorship supports research to identify, examine, and prevent or control adverse effects associated with cancer and disseminates information to enhance the quality of life of survivors.†† CDC works with state, territorial, tribal, and local partners to address various aspects of cancer survivorship, including development of cancer-control strategies, education of survivors and health-care providers regarding survivorship, and evaluation of the use and effectiveness of resources for cancer survivors and their families.§§

References

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