April 11, 2006

By Lynette Grouse

Posted in: survivorship

Tags: care plan, internet, passport, QOL, quality, survivor, survivorship, treatment

The long-awaited day has arrived: you have finished chemotherapy and radiation treatments, and your cancer is in remission. For millions of patients with cancer each year, ths day has become a reality. The number of cancer survivors has been increasing every year for decades.

Although the acute side effects of cancer therapy — nausea, anemia and hair loss — are well known, possible late or chronic complications resulting from cancer are not clearly defined. As cancer survivors live longer, the effects of cancer treatments and additional health risks become apparent. The most serious side effect is development of a second cancer.

Second cancers now account for approximately one in six of all new cancer diagnoses in the United States. A second cancer is different from the original tumor and is not the result of the first tumor spreading to other parts of the body (known as metastatic disease). It may appear months or even years after treatment. In the past, second cancers were primarily seen in survivors of pediatric cancers and young adults treated for more curable forms of cancers; but today, the diagnosis of multiple cancers is being made in survivors of many types of cancers.   

“It is a great day when a patient with cancer finishes therapy, but we must continue to follow these patients,” said Julia Rowland, Ph.D., director of the Office of Cancer Survivorship at the National Cancer Institute (NCI). “We must evaluate patients, not just for recurrence of their primary disease, but for development of second cancers that may or may not be related to their prior tumor.” 

Many survivors are living longer as a result of earlier diagnosis, prevention and more effective cancer treatments such as radiotherapy and chemotherapies. These cancer treatments, however, have been associated with an increased risk of developing second cancers. Researchers are now examining these therapies and underlying predispositions to determine risk factors that may be related to the incidence of additional cancers. One group being studied for late effects of therapy is long-term survivors of Hodgkin’s lymphoma — a blood-borne cancer. Second cancers are now the leading cause of death in this group.  

In the late 1960s, new treatments changed Hodgkin’s lymphoma from a fatal disease to one that was curable. “Early treatments involved intense chemotherapy, as well as high doses of radiation to large areas of the body,” said Lois Travis, M.D., senior investigator in NCI’s Division of Cancer Epidemiology and Genetics. “In one large, population-based survey, we found significantly increased risks of cancer at many sites, with excess cancers of the stomach, female breast, and uterus persisting for 25 years or longer after treatment in these patients.”

Current treatment of Hodgkin’s lymphoma includes shorter treatment schedules with reduced doses of radiation to smaller areas of the body. Advanced technologies also permit focused radiation treatment that spares normal tissue from exposure.

“Treatments are being developed to keep cure rates high but also to produce fewer side effects,” said Travis. “It is important to understand that the research on second cancers in patients with Hodgkin’s lymphoma is only possible because of the many long-term survivors of this disease.”

Therapeutic options for treating second cancers are often compromised. Female patients who have survived Hodgkin’s lymphoma found that when they were later diagnosed with breast cancer, their treatment choices were limited. “For many of us who received high doses of chest radiation for the initial diagnosis of Hodgkin’s disease, a lumpectomy followed by more radiation is not always an option. While mastectomy, with or without breast reconstruction, seems to be the most frequently offered surgery, wound healing may also pose a challenge,” said Susan Leigh, who was diagnosed with breast cancer in 1990 after surviving Hodgkin’s lymphoma in the early 1970s. “Decision making can be complex for the long-term survivor since there are no guidelines for managing these new occurrences of cancer.”

“When survivors develop secondary cancers, it may not be due entirely to prior cancer treatment, but may be related to risk factors contributing to the initial cancer — for example, smoking, alcohol use, diet, hormones, environmental exposures, and genetic susceptibility,” continued Travis.  “The role of gene-environment interactions may also be a factor in predisposing some patients to multiple tumors.”

The majority of genetic alterations that cause cancer occur after birth. However, approximately five percent of cancers may be caused by inheriting a mutated gene. This occurs, for example, in the Li-Fraumeni syndrome due to inheritance of a mutated p53 gene — a gene that normally suppresses tumors. Families with this mutation are prone to tumors in the breast, brain, bone and soft tissues, as well as leukemia. Most patients with this gene mutation develop cancer at an early age and continue to suffer from multiple cancers throughout their lives.

“We need more research on long-term survivors to document the late effects of cancer and determine how patients who develop second or multiple cancers are different from those who do not,” concluded Rowland. “We are working on follow-up guidelines that go beyond surveillance for recurrence and evaluate the effects of cancer therapies and other contributing factors on survivors’ subsequence health. This may lead to recommendations that will reduce treatment-related or behavioral risks and minimize their adverse impact on cancer survivorship outcomes, including risk for second cancers.”