Cancer and Public Health

Cancer’s Impact on Public Health and Why Addressing It Is Important

Cancer and the many issues associated with it have a significant impact on public health in the United States. The years of life lost due to premature deaths, the economic burden due to lost productivity and the costs associated with illness and therapy, and the long-term effects of cancer and its treatment on the quality of life of survivors take a toll at a population level. Moreover, cancer’s impact on public health will continue to grow as the U.S. population ages and some cancer incidence rates rise.

Researchers are addressing this reality by studying cancer and its burden on a population-wide scale. This research includes:

• maintaining large registries of information about people diagnosed with cancer that can be used to identify important trends or issues that affect cancer patients and survivors
• investigating behavioral patterns that can influence cancer risk or cancer recurrence (such as tobacco use, diet, and screening practices)
• identifying how inherited genetic factors and occupational, environmental, medical, and other exposures contribute to cancer risk
• analyzing patterns of cancer care in different health care settings
• analyzing the economics of cancer and how the health care system affects screening practices, access to care, and post-treatment behaviors
• studying ways to improve cancer control programs

Although cancer affects individual patients and their families in different ways, studying its impact on large populations can provide important information that influences practices, policies, and programs that directly affect the health of millions of people in the United States each year.

Opportunities in Cancer-Related Public Health Research

Given the expected growth in the number of cancer cases, population-based cancer research offers many important opportunities to improve public health.

One of the most notable examples from the past several decades is the success in reducing the number of people who smoke. This achievement was made possible, in large part, by the many studies that documented the numerous health risks posed by tobacco use. These studies provided the evidence needed to implement programs and policies, such as the addition of warning labels, public smoking bans, smoke-free workplace policies, and smoking cessation programs, that have helped reduce smoking rates and, in turn, prevented hundreds of thousands of cases of cancer.

Areas that present opportunities for improving cancer-related public health include those that:

• develop and test behavioral interventions that reduce cancer risk (such as smoking cessation, cancer screening, and cancer vaccination programs)
• develop and test interventions that improve access to and delivery of cancer care
• assess cancer risks associated with environmental exposures so as to inform regulatory decisions to limit such exposures
• identify policies and programs that can make cancer care more efficient and cost less
• develop better tools and study designs for conducting population-based studies
• identify and test methods for more effectively disseminating cancer prevention, risk, screening, prognosis, and treatment information to specific population groups
• test ways to meet the needs and challenges of a growing population of cancer survivors

Technology is already playing a significant role in much of this research, and its impact will likely grow in the future. Mobile phones, for example, can be used to help reinforce efforts to quit smoking or track dietary information, and wearable sensor technologies can be used to collect and analyze behavioral information and provide real-time feedback. Social media platforms can be used to disseminate information about cancer control and public health (including recommended screenings and healthy behaviors) tailored to specific populations and to collect data on how this information affects health-related behaviors.

Cancer registries are also offering a more robust assortment of information by capturing more data on patients and their care, such as cancer subtypes and specific treatments received. This will allow researchers to better understand issues such as access to and quality of care and treatment outcomes.

Challenges in Cancer-Related Public Health Research

Conducting research that involves studying large groups of people comes with inherent challenges, as does translating the findings from population-based research into practices and policies that can improve public health.

There are, for example, limitations in the tools used to conduct population-based studies. Surveys rely on respondents accurately recalling their family and medical histories or prior behaviors (such as eating habits, physical activity, or the date of cancer screenings), and patient registries and medical records may be missing important information about medical history and other data.

The logistics associated with conducting population-based studies can also be complicated. For example, maintaining long-term follow-up on large numbers of participants can be challenging and costly. And population-science researchers are still learning how to effectively integrate “big data”—large electronic sets of data from genomic, clinical, and other research—into their work.

From an implementation perspective, developing innovative ways to further reduce smoking rates is a major public health challenge, particularly in populations whose rates remain stubbornly high. The growing use of electronic nicotine-delivery products, particularly among teens, and smokeless tobacco and alternative tobacco products, such as mini-cigars, also pose significant challenges for the public health community.

In the health care setting, cancer screening rates and vaccination rates against viruses that cause cancer still fall short of desired levels. Targeted research and community initiatives to improve screening and vaccination rates and reduce disparities could further reduce cancer morbidity and mortality.

Helping patients and families deal with the escalating costs of cancer care is another major public health concern. Studies show that the costs of cancer therapy affect access to care and patient adherence to treatment. Finding effective ways to address the socioeconomic and other factors thought to be largely responsible for disparities in cancer incidence and mortality among certain population groups also continues to be a major issue.

NCI’s Role in Cancer-Related Public Health Research

NCI supports a diverse array of research that is helping to address issues in cancer-related public health, including many programs supported by NCI's Division of Cancer Control and Population Sciences (DCCPS).

In addition to providing resources and tools to help people quit smoking, NCI continues to place a priority on tobacco-related research, including tracking the use and impact of smokeless tobacco products and nicotine-delivery products such as e-cigarettes. This research is essential to protecting the public health gains achieved with the reduction in smoking rates and to making further gains against all tobacco-related diseases.

To help address the low rate of vaccination against human papillomavirus (HPV) in the United States, NCI is supporting research to identify ways to improve and accelerate HPV vaccine uptake and research on the efficacy of reducing the number of HPV vaccine doses from the current recommendation of three doses.

The Surveillance, Epidemiology, and End Results (SEER) program in DCCPS collects data on cancer incidence and survival from cancer registries that cover more than one-quarter of the U.S. population. Because of its broad coverage, SEER data are used by many researchers to identify important cancer-related trends, such as increases or decreases in the incidence of or mortality from specific cancers or cancer subtypes and factors associated with better or worse prognosis or the risk of secondary cancers. 

These studies can identify trends that often would not be apparent otherwise, spurring important new research and helping to inform decisions and policies on cancer control. SEER data are a critical source for reports that capture long-term cancer-related trends, such as the Annual Report to the Nation on the Status of Cancer, which is produced jointly by NCI, the Centers for Disease Control and Prevention, the North American Association of Central Cancer Registries, and the American Cancer Society.

The SEER program also includes the SEER-Medicare linked database, which links SEER data with Medicare beneficiary claims data. The Medicare data covers care received by beneficiaries from the time they enroll until their death, providing valuable insights into the care of a population who, because of their advanced age, is most at risk for cancer.

Epidemiologic and genomic studies led by the Division of Cancer Epidemiology and Genetics (DCEG) and studies supported by DCCPS continue to document important factors that affect cancer risk, such as workplace and environmental exposures (such as medical radiation and diesel exhaust), infectious diseases such as those caused by human papillomavirus (HPV) and HIV, and genetic changes. 

Through DCCPS’s Healthcare Delivery Research Program and the NCI Community Oncology Research Program (NCORP), the institute also supports studies on the delivery of cancer care, such as those that look at whether patients are receiving the most effective treatments or at factors that influence patterns of treatment among populations. These studies can provide important information that has the potential to improve overall cancer care.

Similarly, NCI supports studies that look at the economics of cancer and its impact on patients, their families, and survivors. Studies of “financial toxicity” can help clinicians work with their patients to better understand the costs of treatment and educate policymakers as they consider new laws and regulations that affect treatment costs and payment policies. NCI's PDQ Adult Treatment Editorial Board has published an evidence-based summary reviewing the published literature on Financial Toxicity and Cancer Treatment among American cancer patients and survivors.

DCCPS’s CISNET program uses statistical modeling to improve the understanding the population-wide impact of cancer control interventions, from screening to treatment. CISNET studies, for example, have been used by the U.S. Preventive Services Task Force to inform their recommendations on breast cancer screening and the Centers for Medicare and Medicaid Services on coverage policies for lung cancer screening.

Behavioral research is also critical to public health. DCCPS supports numerous programs that study behavior and cancer from a wide variety of perspectives. For example, the division funds research on how depictions of smoking in the media or online influence smoking behavior. Other studies examine the factors that influence how population groups perceive their cancer risk and how it influences their behavior, such as decisions about cancer screening or whether parents decide to have their children vaccinated against HPV.

The DCCPS-supported Transdisciplinary Research on Energetics and Cancer Centers study the relationships between obesity, energy balance, nutrition, physical activity, and cancer risk.

The number of people who have survived cancer is expected to grow to 19 million by 2024, and so it is critically important to understand and develop interventions that address the unique health needs of this population. NCI-supported studies have identified long-term physical, psychological, and economic issues cancer survivors often face. 

DCCPS’s Office of Cancer Survivorship maintains a robust research portfolio devoted to helping survivors of adult and pediatric cancers address their unique needs and improve both their quality of life and their long-term survival. These studies are looking at ways to improve physical activity and diet among survivors, help survivors manage psychological issues such as depression and anxiety, and to manage physiologic effects such as lymphedema and sexual dysfunction.

And DCEG conducts a number of studies to identify risk factors—related to treatment, lifestyle, and genetics—for the development of second primary cancers. This research can point to possible interventions for reducing that risk, such as suggesting ways to alter treatments without sacrificing efficacy and guiding the follow-up care of cancer survivors.

Results from several large clinical trials led by NCI’s Division of Cancer Prevention have contributed to major changes in public health practice. For example, based on findings from the National Lung Screening Trial, the U.S. Preventive Services Task Force recommended that people at high-risk be offered a low-dose helical CT scan screening for lung cancer. The Centers for Medicare & Medicaid Services (CMS) now covers the cost of lung cancer screening with LDCT once a year for Medicare beneficiaries who meet the same criteria as NLST participants. Analysis of data from large trials such as NLST continue to contribute valuable insights about related issues, such as patient-reported symptoms, quality of life, and population differences.