Spotlight: Cancer Research
March 2015
According to the American Cancer Society, more than 1 million Americans are diagnosed with cancer each year, and approximately 40,000 1 of those are Veterans. Cancer, however, is not one specific condition—it's a general name for a group of more than 100 diseases that have varying treatments and outcomes.
While types of cancers may vary, all start the same way: abnormal cells grow out of control. Any normal, healthy cell can become a cancer cell as a result of damage to the cell's "instructions" or DNA (deoxyribonucleic acid). In a normal cell, when DNA is damaged, the cell repairs the damage or dies. In cancer cells, however, the damaged DNA is not repaired and the cell doesn't die—instead, it continues making new cells. Over time, those cells may form a tumor that may crowd out and replace the surrounding, healthy tissue. Some cancers, like leukemia, do not form solid tumors, but instead affect the blood cells.2
Damage to cell DNA is frequently a result of exposure to external factors. Certain viruses, cigarette smoking, sun exposure, and long-term inhalation of asbestos fibers have all been connected to certain cancers. However, some cancers (such as certain types of breast or colon cancer) are the result of genetically inheriting abnormal DNA. Regardless of type, a cancer diagnosis has far-reaching impact—from treatment options to care delivery to long-term side effects associated with certain medications.
Within the VA healthcare system, clinicians and researchers provide treatment and conduct research to improve care for Veterans diagnosed with cancer, and studies funded by VA's Health Services Research & Development Service (HSR&D) are part of that effort. The following investigations represent just some of the work being done by HSR&D investigators on behalf of our nation's Veterans.
- Screening for Hepatocellular Cancer. Over the past 40 years, the incidence of and mortality from liver cancer (hepatocellular carcinoma, or HCC) have increased internationally. While screening for HCC via imaging tests may identify patients with early-stage disease—and there are several potential options for treatment—recommendations for HCC screening remain controversial, in part because of several concerns, including: quality and lack of existing evidence; over-diagnosis and potential patient harms from screening itself; and the impact of side-effects from treatment for early-stage HCC. This study sought to review the benefits and harms of HCC screening in patients with chronic liver disease by conducting a literature review. Of more than 13,000 citations, 22 studies met the study inclusion criteria.
Results indicated that while screening for hepatocellular cancer can identify more patients with earlier stage disease who are candidates for potentially curative treatments, there is very limited evidence upon which to draw firm conclusions about the balance of health outcome benefits and harms of using routine screening to identify HCC. For example, in 18 observational studies, screened patients had earlier stage HCC and longer survival after diagnosis than those clinically diagnosed with HCC, but lead- and length-time bias prevent concluding that mortality was reduced by screening. Therefore, the body of evidence that serves as the basis for current recommendations for screening has substantial shortcomings.
Authors of a separate editorial accompanying the study results emphasized that screening should be paired with efforts to collect better data, including baseline characteristics and long-term outcomes in both screened and unscreened patients. They also noted that in VA and other integrated healthcare systems with electronic records and cancer registries, most of these data can be collected as part of routine clinical care. Given the high mortality from HCC and the high costs of delivering a truly effective program of early detection and treatment, better evidence is imperative.
Citation: Kansagara D, Papak J, Pasha A, et al. Screening for Hepatocellular Cancer in Chronic Liver Disease: A Systematic Review. Annals of Internal Medicine. August 19, 2014;161(4):261-69.
- Increase in Thyroid Cancer among Veterans Linked to Increases in Diagnostic Testing. From 1975 to 2009, the incidence of thyroid cancer in the United States nearly tripled. While some studies suggest that these trends represent an actual increase in the number of cases, several population-based studies suggest that the increase in thyroid cancer incidence is related to increases in screening, more sensitive diagnostic methods, and an increase in thyroid tumors found incidentally on non-thyroid imaging studies. Investigators in this national cross-sectional study used VA data to examine the number of Veterans who were diagnosed with thyroid cancer in the VA healthcare system between 2000 and 2012, as well as the utilization of thyroid ultrasound (US) and fine needle aspiration (FNA). Results indicated that during the 12-year study period, the incidence of thyroid cancer among Veterans within the VA healthcare system nearly doubled (from 10.3/100,000 persons to 21.5/100,000.) Of the nearly 11 million Veterans who received healthcare during the study period, 8,870 were diagnosed with thyroid cancer.
Investigators also found that among Veterans receiving a thyroid cancer diagnosis, 69% underwent a thyroid US, 32% underwent a thyroid FNA, and 30% did not have either test in the VA healthcare system. Data regarding usage rates of each diagnostic test indicated that US rates increased nearly fivefold (from 125.6/100,000 to 572.1/100,000), and FNA usage rates increased nearly sevenfold (from 7.0/100,000 to 46.2/100,000).
Findings suggest the increase in thyroid cancer incidence may reflect over-diagnosis of subclinical disease due to increased thyroid US and FNA utilization, although these findings do not rule out a true increase in thyroid cancer incidence.
Citation: Zevallos J, Hartman C, Kramer J, Sturgis E, and Chiao E. Increased Thyroid Cancer Incidence Corresponds to Increased Utilization of Thyroid Ultrasound and Fine Needle Aspiration: A Population-Based Study in the Veterans Affairs Healthcare System. Cancer. March 1, 2015;121(5):741-46.
- Informed Decision Making for Veterans Considering Lung Cancer Screening. Lung cancer is the most common cause of cancer-related death in the United States with an annual incidence of more than 226,000 and a 5-year survival rate of only 16%. Veterans face a significant burden of disease from this condition due, in part, to higher numbers of former and current smokers in comparison to the general population. To date, lung cancer control has focused primarily on smoking cessation; however, this approach is changing. A recent randomized clinical trial found that screening with low-dose computer tomography (LDCT) was associated with a 20% reduction in lung cancer mortality. But despite the strength of this evidence, questions remain regarding how this screening might be used in an every day clinical setting; for example, how will individuals weigh the benefit, potential harms, and uncertainties associated with lung cancer screening?
In this soon-to-be completed study, investigators are looking at how to develop a patient-centered approach to the implementation of a lung cancer-screening program. Investigators enrolled primary care patients in clinics at the Philadelphia VA Medical Center who were between the ages of 55 and 74 and who had a history of smoking equivalent to 20 pack-years or more, and who are currently involved with a Patient Aligned Care Team. Investigators expect the study to provide preliminary data regarding the feasibility and acceptability of communication strategies and the use of a preference assessment tool within VA. Investigators also expect study results to advance the goals of patient-centered care, cancer diagnosis, and cancer treatment for Veterans.
References
- Veterans Administration National Cancer Registry, 2007.
- ACS website: Cancer basics. http://www.cancer.org/cancer/cancerbasics/what-is-cancer
