Image source: National Cancer Institute.
According to the Centers for Disease Control and Prevention, cancer is the second leading cause of death in the United States. It trails only heart disease and is fully expected to surpass it to become the leading cause of death within the U.S. in the near future.
The projections offered by the World Health Organization paint an even more terrifying picture. WHO suggests that cancer incidence rates will rise by nearly 60% over the coming two decades to 22 million diagnoses per year. With few actual cures, the CDC's and WHO's statistics and projections are downright scary.
Statistics from a recent study that were reported on by the Associated Press during the summer paint a picture that's seemingly disappointing when it comes to the occurrence of second cancers -- but stick with me and I'll show you how there's good news to be found.
A catch-22 in second cancer incidence rates
A second cancer is the occurrence of a new type of cancer, or the growth of a similar type of cancer on new tissue. It does not include the regrowth of an original tumor. The study showed that between the 1970s and today, the prevalence of second cancer diagnoses had grown by approximately 300%, whereas initial cancer diagnoses jumped by roughly 70% over the same time span. In total, in the 1970s, second cancer diagnoses occurred in 9% of cancer patients. Today, this had more than doubled to 19% of people that have had an initial cancer diagnosis.
Image source: Pixabay.
It's not the news we want to hear. We're well aware that cancer diagnoses are on the rise, but the prevalence of second cancer occurrences is an unwelcome surprise. If a patient beats cancer, it can be demoralizing to find out at some point in the future that they have to face a potentially similar battle again.
Still, there is actually good news hidden in this data. Because old age is one of the biggest across-the-board risk factors for cancer, a rising incidence rate of second cancers suggests that first cancers are being treated more effectively -- and people are living longer than ever. It's a testament to the drug developers that are working hard to unlock the secrets to fight cancer, and to diagnostic developers and physicians for ensuring patients receive the best treatment plans available.
The "2015 Facts and Figures" report from the American Cancer Society seems to be in agreement that improved physician and patient education, as well as more effective medicine, have improved five-year survival rates for a lot of cancer types. For instance, breast and prostate cancer, the two most commonly diagnosed cancer types, have moved from a five-year survival rate of 75% and 68%, respectively, in the 1975-1977 period to 91% and greater than 99%, respectively, between 2004 and 2010. Other cancer types demonstrated strong five-year survival improvement as well, including non-Hodgkin lymphoma, kidney cancer, and leukemia.
Cancer drug innovation spurs patient survival
What's behind the improvement in cancer therapy effectiveness? Look no further than drug developers of all sizes attacking cancer from new and unique angles.
Image source: Bristol-Myers Squibb.
The biggest shift in cancer treatments recently has been the introduction of cancer immunotherapies. Unlike traditional chemotherapies that either attack cells indiscriminately, or aim to stop the proliferation of new cells, immunotherapies work to suppress the ability of cancer cells to go undetected by the immune system. Making cancer cells visible to immune activators can aid a patient's defenses against cancer in as natural a way as possible.
The two leading checkpoint inhibitors currently on the market are Merck's (MRK +3.13%) Keytruda and Bristol-Myers Squibb's (BMY +2.13%) Opdivo. Both are approved to treat a form of metastatic melanoma and had their labels expanded this year to treat advanced non-small cell lung cancer, or NSCLC.
It's within NSCLC that we've really been able to see the potential of these immunotherapies. For advanced NSCLC patients, a typical response rate might be in the mid to upper 20th percentile. In the case of Keytruda and Opdivo, advanced NSCLC patients who highly expressed PD-L1 had response rates of around 60%. That's incredible for advanced lung cancer, and it demonstrates how far researchers' thinking has come in terms of fighting cancer.
Another relatively new and novel approach is to attack certain types of cancers, such as acute myeloid leukemia, with the use of IDH-mutant inhibitors.
Image source: National Cancer Institute.
Under normal circumstances, IDH enzymes break down nutrients and provide energy for cells. Mutations to IDH lead to the rapid proliferation of immature cells. Companies such as Agios Pharmaceuticals (AGIO +0.63%), which is partnered with Celgene (CELG +0.00%), believe the inhibition of mutated IDH1 or IDH2 could have a beneficial effect on patients with cancers that express these mutations.
Although IDH-mutant inhibitors are still relatively early in their development process, the initial efficacy for IDH2-inhibitor AG-221, which was announced at the annual European Hematology Association Congress in June, was encouraging. In ongoing phase 1 dose-escalation trials for the treatment of for advanced hematologic malignancies, AG-221 generated an overall response rate of 40% in the 158 response-evaluable patients, and a complete response rate of 16%. For patients with advanced acute myeloid leukemia, a 40% response rate (assuming AG-221 proves safe in clinical studies) could be good enough to make it a new standard of care treatment.
Taking the good with the bad (and remaining hopeful)
Sometimes we just have to take the good news with the bad when it comes to cancer statistics. Although we would all prefer to see falling cancer incidence rates overall, the simple implication that survival rates are improving suggests we're on the right track to improving the quality and length of life for cancer patients. I can only hope that we continue to push forward to new and effective treatments.
