Cancer; Discovery; Prevention
Precision medicine, immunotherapy drive largest single-year drop in cancer deaths
January 15, 2020
Nearly 50 years after America declared “war on cancer,” the country has reached a remarkable milestone: Cancer deaths decreased by 272,450 from 2016 to 2017, the largest single-year percentage drop on record, according to the American Cancer Society’s annual report.
The most dramatic shifts came in lung cancer and melanoma (skin cancer) survival. The total decrease in cancer mortality from 2016 to 2017 was 2.2%.
While it is too soon to claim victory, steady progress has resulted in 2.9 million fewer deaths since 1991. This success – and the unprecedented one-year swing – points to three crucial areas of advancement that have altered the cancer landscape:
- Prevention: intercepting cancer before it can form, which includes population health efforts to reduce smoking and obesity, as well as genetic testing and research on cancer biology
- Early detection: amazing improvements in imaging technology and screening protocols
- Treatment: notably, immunotherapy and targeted therapies that seek out and block the growth of cancer cells
At UT Southwestern’s Harold C. Simmons Cancer Center, our team relies on these three pillars of precision medicine to personalize our patients' care. By exploring genetic abnormalities, promoting early detection, and delivering targeted therapies, we believe the impact on our patients can be dramatic.
3 fundamentals of precision medicine for cancer
From the research lab to the bedside and into survivorship, precision medicine has expanded the medical community's understanding of cancer biology. But it requires a multidisciplinary approach – physicians and scientists, surgeons and radiation oncologists all working as a team – particularly as more advanced therapies are approved for a larger population of patients.
1. Prevention strategies and research
The decline in cancer deaths since 1991 began two decades prior. In a 1971 Nixon administration campaign dubbed "the war on cancer," the National Cancer Institute (NCI) was restructured to carry out a national effort against the disease – including a greater emphasis on prevention.
The best example of its success has been the major reduction in U.S. smoking rates – down 67% since 1965. Quitting smoking can reduce the risk of dying from lung cancer by 50% of a current smoker's risk within 10 years. While smoking is still a public health concern – with vaping hot on its tail – recent measures such as proposals to ban flavored vape cartridges and increase the legal smoking age to 21 might be a step in the right direction.
Mapping nicotine addiction
Researchers at UT Southwestern continue to search for breakthroughs in helping smokers kick the habit. Several years ago, they discovered a 3D structure of a microscopic protein that holds answers to how nicotine addiction occurs in the brain.
In the lab, prevention looks much different. Over the last 20 years, researchers have focused intently on how cancer develops, grows, and spreads, all in hopes of intercepting the disease process before it can begin.
In the last decade alone, collective knowledge of genetic mutations and cancer risk factors has soared. We've learned that up to 10% of cancers are driven by inherited gene mutations, as well as more than 50 hereditary cancer syndromes.
We also know certain populations are at increased risk of cancer due to family history. For example, patients who carry the BRCA1 or BRCA2 mutations are at increased risk for breast and ovarian cancer. These patients can benefit from earlier or more frequent screenings.
At UT Southwestern, we have studied the preventive effects of modifying lifestyle factors such as obesity. We also conduct extensive clinical studies through our NCI lung cancer Specialized Programs of Research Excellence (SPORE) grant.
'From the research lab to the bedside and into survivorship, precision medicine has expanded the medical community's understanding of cancer biology. But it requires a multidisciplinary approach – physicians and scientists, surgeons and radiation oncologists all working as a team – particularly as more advanced therapies are approved for a larger population of patients.'
As an NCI-designated Comprehensive Cancer Center, Simmons Cancer Center conducts fundamental research that leads to changes in early detection protocol, as well as breaking new ground in treatment using novel drugs and combination therapies. Our team has even partnered with NASA to translate data from radiation exposure in astronauts to the clinical setting.
Related reading: Game-changing lung cancer treatment may be at hand
2. Early detection screening with advanced imaging
Imaging technology today is downright futuristic compared to even 30 years ago. Advancements in CT, MRI, PET, and ultrasound mean we are no longer limited to static images of large tumors that have spread.
Today, we can get real-time visualization of small tumors tucked inside an organ. For example, the advent of low-dose CT screening can potentially reduce the risk of death by 20% due to detection of early-stage lung cancer. However, there is work to be done to educate the public. Research suggests less than 2% of eligible patients get screened.
Advanced imaging also allows us to see how tumors interact with certain substances, such as sugar solutions. If we can determine which substances tumors actively consume, we can use them to help detect cancers, deliver medication, and plan personalized treatment for early and late-stage lung cancer and melanoma.
3. Treatment advances: Immunotherapy, radiation therapy, and surgery
In the last five to 10 years, we've seen remarkable improvements in the effectiveness of cancer drugs, as well as control of side effects.
Immunotherapy became a beacon of hope for patients with metastatic melanoma that could not be cured with surgery. These patients essentially went from no options to a panel of drugs with proven effectiveness in just a few years.
For melanoma, several immunotherapy and targeted therapy drugs have proven effective. Examples include ipilimumab (Yervoy®), which enlists the patient's own immune system to treat cancer, and vemurafenib (Zelboraf®), a targeted therapy that blocks abnormal cell functions in metastatic melanoma.
After the approval of these drugs in 2011, first year survival rates of metastatic melanoma increased 13% from 2010 to 2015. The overall death rate dropped 7% a year from 2013 to 2017 for patients age 20 to 64. Interestingly, the death rate dropped 5% to 6% a year for patients 65 and older, whereas it was previously increasing.
Immunotherapy also has been a game changer for lung cancer. Along with prevention and screening advancements, immunotherapy drugs such as pembrolizumab (KEYTRUDA®) helped drive the unprecedented decline in lung cancer deaths between 2016 and 2017, totaling 5% for men and 4% for women.
High-dose radiation therapy such as stereotactic body radiation therapy (SBRT) allows more precise treatment with fewer sessions and no increase in side effects. In some cases, radiation therapy is effective enough that patients can avoid systemic treatments such as chemotherapy.
In lung cancer, SBRT damages the tumors’ cellular DNA, causing them to stop dividing. The tumor shrinks and dies, which can cure the cancer. Research has shown that 95% of primary lung tumors treated with SBRT are eliminated – they cease to be harmful – which is a marked improvement over the 50% rate with previous types of radiation therapy.
The GammaPod: A breakthrough in breast cancer treatment
UT Southwestern is the only institution in Texas and one of only two in the world to have The GammaPod, the first SBRT optimized for treating breast cancer with precisely focused radiation.
Robert Timmerman, M.D., Vice Chair of the Department of Radiation Oncology, helped develop the SBRT method and directs training courses in stereotactic radiotherapy at UT Southwestern and nationally. Our radiation oncology department also continues to seek new ways to treat cancer using advanced imaging techniques. More precise imaging yields more precise treatment – this will likely become a significant area of research in the next decade.
Related reading: 3 skin cancer treatments that might stop melanoma in its tracks
Minimally invasive surgery
Surgery has long been considered the best curative option for lung cancer. Using imaging, we can perform more accurate and less invasive surgery, including minimally invasive lung cancer surgery.
In the precision medicine model, surgeons and radiation oncologists collaborate to shrink the tumor prior to surgery. This approach allows for a less invasive procedure, disturbing less healthy tissue and potentially allowing for easier recovery.
In the future, surgeries like this might become so precise that patients can avoid additional immunotherapy or chemotherapy altogether.
Precision medicine on the horizon
Even with the remarkable progress of the previous decade, we've only scratched the surface of what precision medicine and immunotherapy might offer patients in the future. As we celebrate these advancements, we must temper our enthusiasm with appropriate expectations.
Even though cancer mortality rates have gone down dramatically, the number of cancer diagnoses will continue to climb in the U.S. The American Cancer Society estimates 1.8 million new cancer diagnoses in 2020 – an increase of 200,000 from 2016.
As people live longer, their risk of developing cancer increases. We have also improved our ability to detect smaller, earlier stage tumors, which increases the total number of diagnoses. After heart disease, cancer is the second leading cause of death in the U.S.
So clearly, there is more work to be done. But we do have more resources at our disposal than ever before.
Many cancer treatments are now available in oral form, which is more convenient for patients. We continue to work on novel immune therapy approaches, and our patients have access to the most advanced medical technology, such as the GammaPod, the first SBRT optimized for treating breast cancer.
With a precision, multidisciplinary approach, the Harold C. Simmons Comprehensive Cancer Center is prepared for the future – and to help patients live healthier lives after cancer.