Newer treatments, closer monitoring may improve longevity, say researchers
Lisa Diller, MD
Although more children today are surviving cancer than ever before,
young patients successfully treated in the 1970s and '80s may live a
decade less, on average, than the general population, according to a
study from Dana-Farber Cancer Institute and the Harvard School of Public
Depending on the type of cancer, the estimated loss of life
expectancy ranges from four years to more than 17 years, the scientists
report in the April 6 issue of the Annals of Internal Medicine.
Causes of the premature deaths include recurrences of the initial
cancer, new cancers caused by drug and radiation therapy, and other
delayed complications from cancer treatments.
The study, based on a computer model, is the first to estimate the
lifetime toll of childhood cancer and the grueling but increasingly
successful treatments for diseases such as kidney and bone cancers,
leukemia, and brain tumors. About 10,000 children and adolescents are
diagnosed with cancer annually, and the five-year survival rate has
risen to about 80 percent overall.
Jennifer Yeh, PhD, a Research Fellow at the Harvard School of Public
Health (HSPH) Center for Health Decision Science and first author of the
report, said she was surprised when the analysis projected a 10-year
average loss of life expectancy. "For a group of patients fortunate
enough to have survived their initial cancer, to still have this
considerable extra risk is disheartening," she said.
However, Lisa Diller, MD,
Clinical Director of Pediatric Oncology at Dana-Farber and Children's
Hospital Boston, who is the senior author of the paper, said that recent
changes in treatments and the increasing use of less-toxic "targeted"
therapies may lead to better long-term outcomes in the future.
"The study is based on how children were treated in the 1970s and
early 1980s," said Diller, who directs the Perini Family Survivorship
Center at Dana-Farber. "It is our hope that when we see data from more
recent cohorts of patients, there will be improved life expectancy as a
result of some changes that pediatric oncologists have made."
For example, pediatric cancer doctors have been tweaking treatment
regimens to minimize harm to normal tissues and organs while assuring
that treatments remain effective for cancer control. Radiation beams are
being more tightly focused on the cancer, oncologists are avoiding
chemotherapy agents that can damage particular organs, and some children
are receiving drugs aimed at preventing toxicity to these organs along
with their cancer drugs.
Yeh said there is often a "disconnect" when young patients, following
successful treatment, switch to a primary care physician for adult
care. "Many times the primary care physicians aren't as familiar with
the history of the treatments and the higher risks" of serious
complications their patients face, she said.
Diller added that because most physicians will see very few patients
with a history of childhood cancer, they may not be alert to symptoms
that could signal a recurrence or a new cancer. For example, she said,
the common complaint of heartburn would normally not be cause for great
concern in someone without a prior history of cancer, but in a survivor,
it should be investigated as a possible indicator of stomach cancer.
"It is not reasonable to expect a primary care doctor who has one
childhood cancer survivor in his or her practice to know about all the
prior treatments used and their long-term after-effects," said Diller.
"As pediatric oncologists we should be arming the patient transitioning
to adult primary care with personalized information about their
treatment, and creating a survivorship care plan for them."
The additional risks of illness and death conferred by childhood
cancer and its treatments have been studied previously, but findings
were not translated into estimated life expectancy, said the scientists.
Their new research drew on data collected in the Childhood Cancer
Survivor Study (CCSS) on individuals who were under age 21 when
diagnosed with cancer between 1970 and 1986, and who survived at least
five years. Those patients have been followed only for 20 to 30 years,
Yeh said, so lifetime outcomes aren't yet known.
The HSPH and Harvard scientists and their collaborators used a
mathematical simulation model that converted the excess mortality risk
estimates from the CCSS into estimated life expectancies for the
survivors compared to the general population. Among their projections
For all types of cancer, life expectancy was decreased by an average
of 10.4 years, or 17.1 percent, ranging from 4.0 years (6.0 percent) for
kidney cancer survivors to about 17.8 years (28.0 percent) for
survivors of brain and bone tumors.
One in four survivors would die from recurrences of the original
cancer or from new cancers developing as a result of treatment. One in
20 would die from non-cancer-related causes such as heart and
respiratory damage caused by cancer therapy.
The risks of premature death are highest in the first few decades
after diagnosis and treatment, leveling off in later years. "These
results suggest that recognition and treatment of illnesses associated
with late effects in the first 35 years after therapy for childhood
cancer will probably result in improved longevity," the authors wrote in
Patients treated in the more recent years of the CCSS study fared
better than those treated earlier, giving hope that changes in cancer
therapies will lead to longer lives.
In 2007, the CCSS began recruiting a new cohort of childhood cancer
survivors treated between 1987 and 1999. When the results become
available, the authors plan to estimate how improved methods of
delivering cancer treatment may reduce the impact of cumulative
long-term effects on survivor life expectancy.
"This study highlights the potential for comprehensive survivorship care,"
said Yeh. "We are hopeful that this care, including appropriate
screening and greater awareness among primary care physicians, can
reduce the mortality risks associated with a history of childhood
Other authors of the study are Larissa Nekhludov of Harvard Medical
School, Sue J. Goldie of HSPH Center for Health Decision Science, and
Ann C. Mertens of Emory University. The research was funded by the
National Cancer Institute.