SMOKING : SLOWLY TAKING YOUR BREATH AWAY
LUNG CANCER : KENTUCKY ’ S CURSE AUTHOR Alexander Gavsyuk & Goetz Kloecker , MD
A
hundred years ago lung cancer was so rare that professors advised their students that they would likely not see two patients with lung cancer in their working lives . Nowadays lung cancer is the cancer that kills the most people worldwide , approximately 1.8 million , which accounts for 18 % of total cancer deaths ( Sung 2020 ) and is commonly seen in all areas of the care of adults .
However since 1991 the tide has turned in the US , and the number of lung cancer deaths has been decreasing . Because of the huge number of lung cancer patients in the US , 228,820 new cases per year ( Siegel 2020 ), this has been major in decreasing the overall mortality of cancer in the US . When I ( Dr . Goetz Kloecker ) started seeing lung cancer patients in clinic 20 years ago , most of our patients had advanced stage by the time of diagnosis . Our imaging and treatment modalities were limited . We only distinguished small cell and non-small cell lung cancer and our treatments were chemotherapies that barely made a dent in survival beyond one year , at the cost of significant toxicity . Doctors of earlier eras can testify that the diagnosis was itself a death sentence .
Twenty years later , lung cancer has become an example of how fast and far modern medicine can take us into a future that was unimaginable just a few years ago . In 2011 the landmark National Lung Screening Trial ( NLST ) - regarding the value of screening - proved that annual CT screening of 30 pack year smokers over 55
years old saved lives . It created a new standard that shifted the stage distribution and decreased lung cancer mortality by 20 %.
In the early years of this century , the Human Genome Project taught us to detect oncogenes and mutations that drive cancer growth . Not long after , the first targeted therapies to block the effect of oncogenes were developed . We learned to sequence the genome of cancer cells in a day for an ever decreasing and affordable cost . Targeted therapies are now approved and available at an explosive speed . Just this year , the most common cancer oncogene KRAS became “ druggable ” adding to the longer and longer list of “ actionable ” oncogenes .
Liquid biopsies taking blood samples to detect cancer DNA in plasma are becoming a new standard to guide therapies . This technology alone opens up new ways of detection and surveillance for a cancer that often is hard to biopsy . Even if the biopsy contains cancer cells , how do we know this small sample reflects the heterogeneity of all the cancer cells in the patient ? Consider that the human body has 37 trillion cells ( Bianconi 2013 ) and 1cm 3 tumor alone has 100 million cells ( Narod 2012 ). Many biopsies however contain only hundreds or thousands of cancer cells .
During the last decade , one of the biggest revolutions in oncology has been the discovery of how to harness our immune system to make cancer go into remission and sometimes disappear altogether .
( continued on page 10 ) NOVEMBER 2021 9