Cancer Prognosis Improves with Time for Survivors

The risk of death from cancer is usually greatest in the first few years. Many studies have focused on five-year survival rates at diagnosis, but these numbers do not apply to individuals who have survived for several years after initial treatment.

Larry F. Ellison and colleagues at Statistics Canada and associated organizations performed an analysis of conditional survival estimates for 26 common types of cancer. The data are from the July 2010 version of the Canadian Cancer Registry.

Pancreatic cancer shows the most improvement in prognosis with time. At the time of diagnosis, only 6 percent of patients can expect to survive for five years. For those who do survive for five years, 88 percent can expect to survive for another five years.

Chronic lymphocytic leukemia shows the least improvement in prognosis with time. At the time of diagnosis, 77 percent can expect to survive for five years. Those who make it to the five-year mark have a 78 percent chance of survival for another five years. Other cancers with little improvement in prognosis with time are breast cancer, larynx cancer, and multiple myeloma.

Ellison listed seven cancers that have at least a 95 percent chance of five-year survival for those who have already survived five years past diagnosis:
1. Thyroid
2. Prostate
3. Testis
4. Skin melanoma
5. Uterine (corpus)
6. Hodgkin lymphoma
7. Cervical
8. Colon

Breast cancer is close, with a 93 percent chance of five-year survival after five years. All the statistics are presented as relative survival rates, which means they are compared to the general population with no cancer diagnosis.

All cancers studied except multiple myeloma had five-year survival rates of at least 75 percent after five years. The observed trends were similar for males and females. Ellison reported that the Canadian results are similar to U.S. data from the Surveillance, Epidemiology and End Results (SEER) study.

Cancer types with five-year survival rates of 90 to 94 percent after five years are those affecting the breast, bladder, kidney, soft tissue, rectum, and stomach, as well as leukemia, other than chronic lymphocytic leukemia.

Ellison cautioned that his data represent population averages rather than predictions for any individual patient. “Even so,” he concluded, “the figures are a useful update of the initial prognosis for a number of cancers, and are generally a cause for optimism.”

References:
1. Ellison LF et al, “Conditional survival analyses across cancer sites”, Health Reports 2011 June; 22(2): 21-5. http://www.ncbi.nlm.nih.gov/pubmed/21848129
2. National Cancer Registry. Surveillance Epidemiology and End Results. Web. Oct. 24, 2011.
http://seer.cancer.gov/csr/1975_2007

Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.
Reviewed October 31, 2011
by Michele Blacksberg RN
Edited by Jody Smith

http://www.empowher.com/cancer/content/cancer-prognosis-improves-time-survivors