An estimated 12 million cancer survivors are alive today in the United
States alone, and approximately 15% of these survivors were
diagnosed 20 or more years ago. The average 5-year survival rate for
all cancers combined has risen consistently, and is now at 68% for
adults, and 80% for children and adolescents3.
These survival statistics reflect major advances in detecting cancers
earlier and in better treatments. As these patients are living longer, we
are also becoming increasingly aware that cancer therapies can lead
to physical, emotional, and psychological problems which might not
become apparent in a cancer survivor until 10, 20, or even 30 years
after their initial diagnosis and treatment.
Long-term and late effects of radiation include second cancers,
endocrine system and thyroid problems, heart disease, and infertility.
A person’s likelihood of developing these problems depends upon the
specific cancer, where the radiation was delivered, and the total
radiation dosage received. There are also numerous long-term and
late effects of chemotherapy, such as fatigue, infertility, cardiac
toxicity, muscle weakness, and cognitive problems.
Perhaps one of the most difficult and serious problems for a cancer
survivor is the development of a second cancer. According to the NCI,
more than 10% of all invasive cancers that occur each year are
second cancers, and some individuals may go on to develop even
Given the spectacular success rate for treating many childhood
cancers, there has been a great deal of interest in understanding the
long-term effects that this particular group of survivors faces. The
largest study of adult childhood cancer survivors, the federally funded
Childhood Cancer Survivor Study, found that adults who have survived
childhood cancer are 3 times more likely than their siblings to develop
a later, chronic health condition.
Among this group, 9.6% developed new primary tumors unrelated to
their original cancers, and about 30% of this group developed third
tumors. This long-term study began in 1993 and has involved more
than 14,000 survivors originally diagnosed between 1970 and 1986 at
26 participating research centers in the United States and Canada.
Investigators plan to expand the number of participants involved in this
study, as well as continue to follow the existing group of survivors as
As cancer therapy continues to improve and cancer survivors live
longer after diagnosis, the number of persons living with a history of
cancer will continue to increase. While middle-aged cancer survivors
are most common, in the last 30 years there has been a marked
increase in survivorship among the young and old. A new area of
research focused on cancer survivorship aims to optimize the health
and well-being of men and women living with a history of cancer.
Survivorship research must focus on the relationship between aging
and cancer, the characterization of the chronic and late effects of
cancer therapy, and the development and improvement of patient
metrics and care for survivors of all ages.
In addition to behavior modification, increased screening,
and preventive surgery, research has given us a new
prevention tool, called chemoprevention. Our ability to
associate detailed information, including molecular
information, about the patient and tumor, with an increase in
cancer risk has given rise to the field of chemoprevention,
which aims to treat at-risk individuals with a targeted drug
to reduce their risk.
One example, although not molecularly based, is in non-small cell lung carcinoma where the cytotoxic
chemotherapeutic pemetrexed (Alimta) is an effective
maintenance therapy only for those patients that have the
non-squamous cell form of lung cancer. Identifying the
molecular details about this patient population can only
further enhance the precision of this chemopreventive
In breast cancer, however, the molecular understanding that
the hormone, estrogen, drives at least 65% of breast
cancers has provided an excellent chemopreventive tool.
Two FDA-approved drugs that block the effect of estrogen
on its receptor, tamoxifen (Novadex) and raloxifene (Evista),
reduce the chance of developing breast cancer by about
50%, or by 38% in women at increased risk, respectively.
Further the protective effect can last for years.
Likewise, the non-steroidal anti-inflammatory drug,
celecoxib (Celebrex), is FDA-approved to prevent and reduce
the formation of colorectal polyps in patients with a high-risk
AACR Cancer Progress Report 2011