Lung Cancer

Alright, this is when all of my smoking friends (and there are many of you lovely people in my life) start to hate the fact that I'm going to medical school. This week is "Lung Cancer" week in our Pathology/Oncology curriculum, and after a learning much about cancer, its causes, its prognosis, and our paltry attempts at its treatment, I feel compelled to share some of the things I've learned.

Current statistics say that one in 2-3 people will be diagnosed with cancer during their life time, and 30% of those cancers could have been prevented. Obviously, smoking is one of the most potent and preventable causes of cancer, and when combined with alcohol and bad diet, it gets further increased. Tobacco is responsible for 30% of all cancer deaths and increases the risk of cancer ten fold. Alcohol - I know this one sucks! - increases tobacco risk, up to 5x. Obesity is another one (2-fold increase), as is a sedatory lifestyle. But we all kind of know that. What is really scary, especially for those of us sitting in lecture (watching autopsy images of cancer destroying people's lives, learning what happens to cells and tissues on a microcopic level, and absorbing all the newest information on diagnosis, treatment, and prognosis) is the sad reality of how little we will be able to do for our patients and loved ones when they are diagnosed with certain types of cancers.

Lung cancer is the worst. Though breast and prostate cancer rates still outnumber lung cancer rates in women and men, lung cancer is the number one killer. Often there is little that can be done for it once it is diagnosed, and sadly, as we saw in slide after slide today, by the time the many of the different lung cancers have grown big enough to be symptomatic or visible on films, they have likely also metastasized to other places in the body (most often bone, brain and liver). One of those random, useless facts (except maybe for shock value), is that if a jetliner with more than 400 people on board crashed every day, that would be equal to the number of daily deaths from lung cancer.

Maybe what's even sadder and more frustrating and scary is that almost all - about 95% - of lung cancers are preventable. Before smoking became popular, lung cancer was so rare that medical schools would assemble their students together to witness an autopsy of a patient who had died of lung cancer. As one quote from 1919 said, "the condition is so rare you might never see another case." Twenty years later, there was an epidemic of lung cancer patients - solidiers from WWI, who had become heavy smokers after cigarettes were handed out on the front lines.

As we learned in our carcinogenesis lectures last quarter, cancer is an evolving event. It takes years of repeated chemical/radiation exposure to turn a cell into a malignant one. One gene has to be deleted, another activated, another mutated, etc, before all the safety nets of our biological systems are defeated. Smoking, as our professor stressed today, is an ongoing chemical carcinogensis experiement on lung cells. It is the repeated assult on a damaged surface that makes it so horribly destructive.

Fortunately, if there is a silver-lining to all of this, lungs can often regerate and heal if given the chance. Most damage done by smoking can be reversed within 10-15 years, even for smokers who have smoked for as long as 20 years. Significant changes can be seen after even 1 year. Sadly, this was not the case for Peter Jennings, who died today of a lung cancer though he had quit smoking twenty years ago, but it can be true for thousands of others. Additionally, early detection of all cancers, even lung cancer, is key to survival, and researchers all over the world are looking for markers that would help us detect cancer at a treatable phase.