Over the past 30 years, cancer research efforts have spurred the translation of scientific discoveries into improved methods of preventing, detecting, diagnosing, and treating cancer, according to the American Association for Cancer Research’s (AACR) Cancer Progress Report 2013.
The report, published on September 17, 2013, is a comprehensive educational tool that illustrates the return on investment in cancer research and biomedical science.
AACR Reports on Great Strides in Cancer Research
According to the third annual report, the number of cancer survivors continues to increase. The latest data show that 13.7 million cancer survivors in the United States were alive on January 1, 2012. The report states that in 1971 only one in 69 Americans was a cancer survivor; however, today that number is one in 23. The authors of the report say these findings offer oncologists the information they need to effectively counsel their patients about treatment options and their odds of survival.
“The overall landscape of cancer mortality has improved slightly, but I feel the most dramatic improvements are being seen in cancers like melanoma, which only a few years ago had dismal outcomes,” said Elaine Mardis, PhD, Professor of Genetics and Molecular Microbiology at Washington University School of Medicine, St. Louis, MO.
“With the advent of targeted therapies like vemurafenib, and checkpoint blockade therapies, like ipilimumab, being combined in patients, dramatic and durable responses are in evidence. Both drugs are now FDA [Food and Drug Administration]–approved in melanoma use, and clinical trials in other cancer types with the checkpoint blockade therapies in particular showing dramatic promise,” Mardis added.
Mardis, who was a co-author on the report, said large projects to decode the cancer genome are changing the way that oncologists now think about cancer. She added that these genomic alterations are paving the way to the development of new therapeutics that are more potent, but with lower risk for treatment-related toxicities.
The report notes that one of the greatest advances in cancer research has been the discovery that cancer can be the result of permanent mutations in genetic material in a normal cell. These mutations can lead to protein abnormalities that disrupt normal cell behaviors. This knowledge has enabled researchers to develop anticancer drugs that target specific abnormal proteins.
According to the report, the FDA approved 11 new drugs to treat a variety of cancers, between September 1, 2012, and August 1, 2013; three new indications for previously approved cancer drugs and three new imaging technologies were also approved in this time frame. Approximately half of the new anticancer drugs approved in 2013 by the FDA target specific defects in cancers.
In many cancer cells, patterns of DNA methylation and histone acetylation are altered. The FDA has approved the DNA methylation inhibitors azacitidine (Vidaza®) and decitabine (Dacogen®),1 both of which are approved for the treatment of myelodysplastic syndrome. In addition, the histone deacetylase inhibitors romidepsin (Istodax®) and vorinostat (Zolinza®) have now both been approved for the treatment of certain lymphomas.1
“I think the most important take-home message for oncologists and their patients is that we are making great strides in understanding the cancer genome and the cancer biology that these mutations determine. We are, as a consequence, better able to design therapies that are more specific,” Mardis told ChemotherapyAdvisor.com.
Taking a Different Approach
More than 100 years of fundamental discoveries in immunology have led to the development of anticancer immunotherapies that are now yielding remarkable, long-lasting patient responses. A recent advancement in personalized cancer medicine has led to a whole new approach to treatment that involves the use of mouse avatars—patient-derived xenografts that are derived by implanting portions of a patient’s tumor into several mice. The report states that a large number of potential therapies can be tested on mice for their ability to destroy the patient’s tumor before the therapies are administered.1
Currently, avatar screening is showing considerable promise, although there are many challenges to using patient-derived xenografts. The report states that, so far, the success rate for implanting human tumors in mice has been rather low. In addition, it can take more than 6 months to develop patient-derived xenografts and screen potential therapies. However, this drug-screening approach may result in improved outcomes in some specific tumor types.
“We are quite excited about these avatars. At least in breast cancer, they may provide the ideal surrogate for testing targeted therapy regimens. To be clear, not all tumors will xenograft successfully, so it’s not a perfect scenario. More aggressive tumors are more successful in getting established in the mouse. This is true for pancreatic xenografts, which have a very high success or ‘take’ rate,” said Mardis.
There are many obstacles that must be overcome before patient-derived xenografts are widely available; however, they may become an important new tool for oncologists. A major concern in 2013 is that cancer-related deaths will be increasing in the coming years as the segment of the population older than 55 continues to age. The report suggests that, as a result, cancer will soon become the leading disease-related killer in Americans.
Aging Baby Boomers Expected to Increase Cancer Incidence
Even with the latest advances in cancer research, it is projected that more than 1.6 million Americans will be diagnosed with cancer in 2013 and more than 580,350 Americans will die from some form of cancer.1 According to the report, more than 75% of cancer diagnoses occur in individuals age 55 and older. Currently, this segment of the population is growing in size, and so the report projects that the number of cancer-related deaths will rise significantly over the next 30 years.1
Compounding this issue is the increasing prevalence of obesity and the continued use of tobacco products by nearly one in every five Americans. According to the report, obesity is linked to an elevated risk for eight different cancers, whereas tobacco use is associated with an elevated risk in 18 cancers. Type-2 diabetes rates are also continuing to rise in the United States. Studies show that persons with type-2 diabetes are at increased risk for developing several different types of cancer, including certain forms of lymphoma.1
“One person will die of cancer every minute of every day this year. This is unacceptable. If we are to accelerate the pace of progress toward our goal, we must continue to pursue a comprehensive understanding of the biology of cancer,” said Charles Sawyers, MD, who is President of the AACR and Chair of the Human Oncology and Pathogenesis Program at Memorial Sloan-Kettering Cancer Center, New York, NY, as well as a co-author on the report.
Since the growing number of Americans over the age of 65 will live longer, may likely develop cancer, and need treatment over the next 20 years, the AACR notes that greater investments in scientific research are more important than ever. “We continue to make research count for patients by saving and enhancing the quality of many lives,” said Margaret Foti, MD, PhD, Chief Executive Officer of the AACR. “However, we need more progress, more hope, and more lives saved.”
1. Sawyers CL, Abate-Shen C, Anderson KC, et al. Cancer Progress Report 2013. Clin Cancer Res. 2013 Sep 16. [Epub ahead of print]