ST. PETERSBURG, Florida-As cancer survival increases, outcomes research must focus on both quality of life and length of survival, and must define and quantify late effects of cancer treatment, Noreen Aziz, MD, PhD, MPH, said at the Late Effects of Normal Tissues (LENT) IV workshop on late effects criteria and applications.
ST. PETERSBURG, FloridaAs cancer survival increases, outcomes research must focus on both quality of life and length of survival, and must define and quantify late effects of cancer treatment, Noreen Aziz, MD, PhD, MPH, said at the Late Effects of Normal Tissues (LENT) IV workshop on late effects criteria and applications.
"The remarkable progress over the last few decades in cancer detection and early treatment is a success story that comes with a challenge: how to treat the effects of cancer treatment seen in survivors," said Dr. Aziz, program director of the Office of Cancer Survivorship, National Cancer Institute (NCI). "Our mandate and goal for professionals dealing with cancer survivors is to enhance the quality as well as the length of survivorship."
Cancer has become for many a curable or chronic illness. There are currently 8.9 million cancer survivors in the United States facing delayed toxicity now or in the near future (see Figure 1). Statistics suggest that by 2010, one of every 250 adults aged 20 to 29 will be a survivor of childhood cancer. Apart from other causes of death, 5-year survival from cancer is now 61% for adults and nearly 75% for those under age 19 at diagnosis.
Cancer survivorship research attempts to identify, examine, prevent, and control adverse effects related to cancer diagnosis and treatment outcomes, and to provide a knowledge base allowing optimal health after cancer therapy. Since 1996, Dr. Aziz’s group has stimulated such research at the NCI and also collaborated with the Department of Defense and various institutes at the National Institutes of Health.
"How do we enhance research in this field?" Dr. Aziz asked. "First we articulate our gaps in knowledge." Missing pieces of the puzzle include cancer types that are common but not well studied, outcomes research specific to age and cultural disparities, and appropriate assessment instruments.
The best studied primary cancer is breast cancer, accounting for about 41% of survivorship grants, while about 22% of research dollars are spent on multiple or mixed cancers (see Figure 2). Although colorectal cancer is the third most prevalent cancer, it receives only 3% of research funding, and very little is known about long-term effects, Dr. Aziz said.
Other primary tumors, even common ones like prostate cancer, are also understudied. Greater long-term survival in head and neck and hematologic cancers now demands more survivorship research in these areas as well.
Defining different adverse outcomes helps target and ameliorate them, she said, noting that some specific interventions may help ameliorate physiologic sequelae such as cardiac or pulmonary toxicity, renal function following treatment for testicular cancer, and neurocognitive impairment following chemotherapy.
Education, support and communication can improve psychosocial outcomes including quality of life, coping and resilience, fear of recurrence or of treatment effects, family adjustment, and spiritual growth, Dr. Aziz said.
She noted that the emphasis needs to shift from descriptive to prospective and analytic research. Effective intervention models could be disseminated to the community and could help educate both the survivors and the doctors about what they can do to help.
Development of assessment instruments to monitor follow-up and surveillance issues, economic outcomes, and family and caregiver burden are also important to optimal quality of care.
"A thought-provoking question is whether both late and long-term effects in childhood survivors are similar to those in adults," Dr. Aziz said. "The impact of cancer treatment on adults may be quite different and needs to be examined."
Most existing long-term survivor research has studied children and adolescents. Late and long-term adverse effects may differ by age of diagnosis. About 59% of survivors are over age 65, and 34% are age 40 to 64. Although fertility issues concern adolescents and young adults, vascular disease and other comorbidities assume primary importance in middle-aged and elderly survivors.
Other gaps in knowledge concern different outcomes based on health care disparity. Most research focuses on white upper-class patients who get optimal health care, not underprivileged minority groups. Important questions, Dr. Aziz said, are whether lifestyle changes, education, or activities influence late effects and to what degree should these interventions be culture specific.
"The evolving paradigm of cancer survivorship research is moving more toward a clinical disease spectrum with better outcomes after treatment," Dr. Aziz said. "We should shift away from a medical deficit or dysfunction model and toward one that optimizes health in the context of the survivor’s life rather than considering effects in isolation."
For more information, see the Office of Cancer Survivorship website located at http://survivorship.cancer.gov.