Source: University of Michigan Medical School via Flickr.
There may be more commonly diagnosed forms of cancer – breast, prostate, and melanoma of the skin – but when it comes to being lethal there is no greater cancer-related killer than lung and bronchus cancer.
According to 2013 estimates from the American Cancer Society lung and bronchus cancer killed three times as many men as the next deadliest cancer type, prostate cancer, despite prostate cancer diagnoses outnumbering lung cancer diagnoses in men by a factor of two-to-one. For women, lung and bronchus cancer led to nearly twice as many deaths as breast cancer. The estimated 159,480 lives lung and bronchus cancer were expected to take in 2013 is as much as prostate, breast, pancreatic, and colon cancer deaths combined.
Although the dollar figures are probably a bit dated now, the ACS in collaboration with the Livestrong Foundation released a study in 2010 that noted the global economic loss (i.e., the indirect costs of cancer due to premature death and removal from the workforce) totaled $895 billion for cancer, with lung cancer topping the list at $188 billion. Note, these costs didn't include the arguably high costs of treating lung cancer patients. It's also probably safe to assume these figures have risen even more since 2010.
10 U.S. states where lung cancer incidence is the highest
Within the United States, lung cancer incidence tends to occur at a rate of 61 incidences per 100,000 people according to figures from the Centers for Disease Control and Prevention as of 2011. However, there are a number of states which have lung cancer incidence rates well in excess of the national average.
The following 10 states all have incidence rates of 70 per 100,000 people, or higher:
- Kentucky (93.1 incidences per 100,000 people)
- West Virginia (79.2)
- Arkansas (75.2)
- Tennessee (74.8)
- Delaware (74.3)
- Mississippi (73.2)
- Indiana (72.5)
- Missouri (72)
- Alabama (71)
- Oklahoma (70.2)
Age-adjusted lung and bronchus cancer incidence rate per 100,000 people. Source: Centers for Disease Control and Prevention.
Geographically the map above has to raise some eyebrows with regard to lung cancer occurrence, as the highest states appear to be clustered within one region of the country. However, the truth of the matter is that researchers aren't able to identify, at least with any certainty, why some people develop lung cancer and others don't.
Don't get me wrong, though; researchers do have a pretty good idea what the prime risk factors for lung cancer are. Per the CDC, smoking and secondhand smoke rank very high on the list of risk factors, with your genetic makeup and exposure to radon gas also playing some role in increasing your chances of developing lung cancer in your lifetime.
Source: Flickr user Sabrina's Stash.
A ray of hope
Even though lung cancer remains the most lethal cancer killer, we're also seeing some promising trends that would suggest we're making some headway in improving patient survival and their overall quality of life.
Based on ACS statistics (link opens PDF), five-year survival rates for lung cancer have jumped from just 12% as of 1975-1977 to 17% as of 2002-2008. Make no mistake about it; we still have a long way to go when it comes to developing better and more effective lung cancer treatments, but this is evidence that steps are being taken in the right direction to hopefully, one day, cure this terrible disease.
Some of this improvement can certainly be attributed to improved education regarding the risk factors of lung cancer, and a better than 50% reduction in the number of U.S. adult smokers over the past 50 years. However, pharmaceutical companies' strive to create a healthier society and improve patients' quality of life has played a strong role as well. Let's take a brief look at a few of the drugs responsible for this improved survival rate as well as note a developing treatment pathway that may hold a world of promise for lung cancer patients.
Source: Flickr user James Jordan.
Baby steps in the right direction
As ACS data shows, the key to having the best chance of treating lung cancer is to catch it early. If localized, just slightly more than half of all patients live five years or longer. If the cancer has metastasized to other regions of the body this five-year survival rate disappointingly falls to just 4%. This is why most pharmaceutical products on the market today target late-stage lung cancer in an effort to give those patients improved survival opportunities and better quality of life.
One therapy delivering these improvements, albeit in the baby step variety, is Abraxane, made by Celgene (CELG). Abraxane is given with carboplatin to patients with non-small cell lung cancer (NSCLC), the most common type of lung cancer, and when approved in 2012, boosted the overall response rate relative to using carboplatin by itself by 8% to 33%, while almost delivering a 0.9 month median progression-free survival improvement.
Roche (RHHBY 1.58%), which is probably focused on more cancer treatments than any other pharmaceutical company around the world, has a number of therapies that are also commonly used to treat NSCLC. The most common of those therapies is Avastin, a drug which was approved in 2006 and is given in combination with carboplatin and paclitaxel. Overall, Avastin boosted median overall survival to 12.3 months from 10.3 months relative to the control arm.
Understandably these figures aren't improving by leaps and bounds, but they are headed in the right direction, which is good news for lung cancer patients and their families.
Keep your eye on this new treatment pathway
However, what really has me intrigued (because I would really love to see lung cancer cured since I lost my mother to it four years ago) is the potential for cancer immunotherapies to play a curative role.
Without getting too technical, cancer immunotherapies retrain your immune system to recognize and destroy cancer cells. The way cancer cells are comprised allows many of them to go undetected by your immune system. By genetically altering your immune response to recognize these cells the idea is that you can focus your immune response solely on cancer cells, keep healthy cells intact, and potentially reduce adverse side effects since pharmaceutical companies are utilizing cells from your own immune system.
Specifically, I have two types of cancer immunotherapies that I'm watching closely, which I believe could have a big impact on fighting lung cancer.
Source: Bristol-Myers Squibb.
First, I'm keeping a watchful eye on anti-PD-1 inhibitors such as Merck's (MRK 0.53%) Keytruda or Bristol-Myers Squibb's (BMY 2.45%) Opdivo. Though both drugs are first geared toward melanoma, they hold a world of promise in treating lung cancer patients.
Anti-PD-1 inhibitors work disallowing PD-L1 and PD-L2 ligands from binding with PD-1 receptors. This linkage is what's believed to mask cancer cells from our immune system. In other words, by blocking these receptors our immune system should be able to recognize and attack these lung cancer cells which had previously gone undetected. Survival rates in late-stage melanoma have been very impressive for both therapies, so I'm excited to see if it can have a sizable impact on lung cancer patients' overall survival.
The other therapy I'm eyeing is Peregrine Pharmaceuticals' (NASDAQ: PPHM) bavituximab. Again, without getting too technical, bavituximab is a monoclonal antibody that targets a molecule that's located on the outside of cells that line tumor blood vessels and makes them undetectable by the immune system. By suppressing this molecule bavituximab aims to alert your immune system to a solid tumors' presence so it can attack those invading cells.
Currently bavituximab is in a critical late-stage trial known as SUNRISE. Its midstage study had a few third-party data bumps in the road, but the end result was a better-than-doubling in median overall survival to 12.1 months from 5.6 months. Obviously this late-stage study will be critical, but its sheer outperformance of the control therapy has me excited that we're on the cusp of seeing a large leap in lung cancer patients' quality of life.
Here's the only thing that matters
Ultimately, it doesn't really matter which pathway helps cure this terrible disease as long as progress continues to be made. Baby steps may not be what the public wants to see, but as long as the combination of improved education and better quality pharmaceutical products boosts long-term survival chances, then all we can do is hope the trend continues. I, for one, really look forward to the day when lung cancer is curable, and I've got my hopes high that I'll be able to see this happen during my lifetime.
