Having isolated arthritis in one knee could be an early warning sign for lung cancer, Italian researchers suggest. “Knee monoarthritis as an early manifestation of lung cancer has never been described previously,” says Fabrizio Cantini from the Hospital of Prato in New York, US. He noted that knee trouble in such cases appears very early, “with the consequent possibility of surgical removal of the cancer.”
The researchers reviewed the medical records of everyone with isolated knee arthritis seen at their centre over a six-year period, and reported their findings in the ‘Annals of the Rheumatic Diseases’. During the study period, 6,654 patients were seen for various rheumatic disorders, including 296 with isolated knee arthritis. In five of these patients (1.7%), the arthritis appeared to be the first sign of lung cancer.
These five patients were all middle-aged men and each had a long history of heavy cigarette smoking. In all five men, the cancer could be completely removed surgically, and the patients were in good condition after an average follow-up period of 41 months. The arthritis totally disappeared in all cases after lung cancer surgery, confirming that the two were linked. Based on these observations, Cantini advises doctors to order a chest X-ray “every time you see a heavy smoker who presents (with) mild knee arthritis.”