Lung cancer is suspected most commonly when someone notes a persistent cough, begins to cough up blood, or develops other common symptoms of lung cancer such as shortness of breath or chest pain. Sadly, when these symptoms are present, many of these tumors have already progressed to a stage where a cure is not possible. Studies are in progress to find a way to screen for early stage lung cancer, but the benefits versus risks of this remain highly controversial. Are there any other symptoms those with a history of smoking may want to watch for – to perhaps catch lung cancer at an earlier stage?

A recent study suggests that “monoarthritis,” that is, arthritis confined to only one knee, may be an early sign of lung cancer in some people. This study looked at over 6000 individuals that were seen in a rheumatology clinic. In 1.7% of these patients, arthritis confined to one knee was the first sign of non-small cell lung cancer. All of these patients were diagnosed at a stage when their tumor could be treated with surgery. It should be noted that all of these individuals had been heavy smokers, and quitting smoking remains the single most important goal in avoiding lung cancer.

Though these researchers did not leave us with any practical tips for early detection based on this study, I think anyone with a history of smoking should consider discussing pain in a knee, or for that matter any unexplained symptom, with their health care provider. Have any of you, or your loved ones with lung cancer, had symptoms that are not considered typical for lung cancer?

_{Source:
Isolated knee monoarthritis heralding resectable non-small cell lung cancer. A paraneoplastic syndrome not previously described. 2007. Cantini, F. et al. Ann Rheum Dis. Doi: 10.1136.ard.2007.075333.}