When I was a boy, tobacco advertisements on television were ubiquitous. I remember sitting in front of our black and white set, watching the Marlboro man drive his herd on horseback through the dust. At some point he’d lean back in the saddle, reach a pack of Marlboros to his lips and extract a cigarette. He was the epitome of a man’s man, masculine to the core.
Such ads worked to introduce millions of young people to the smoking habit. It is perhaps less well known that three of the Marlboro man actors eventually succumbed to lung cancer in their early 50s.
During those years Chesterfield brought out a new cigarette one millimeter longer than the conventional brands. It was christened “101,” and marketed as “a silly millimeter longer.” To this day I can still recall the jingle inside my head.
What difference does one millimeter make after all? In the world of contemporary tobacco sales one millimeter counts for little (the brand was retired long ago), but in the world of medical science a millimeter is anything but silly.
The other morning I read a case presentation of a young woman of twenty years who consulted her dermatologist for a 5 millimeter lesion on her upper back of two month’s duration. The dome-shaped lesion was round, smooth, with regular borders—all of the characteristics usually associated with a benign growth. Because it bothered the patient, the dermatologist excised the lesion. Unfortunately, the pathology studies showed malignant melanoma, with invasion of the dermis to a depth of 3.5 millimeters. At the time of diagnosis this cancer had already spread to two of five sentinel lymph nodes.
Five-year survival rates for patients with malignant melanoma correlate with the depth of the lesion at time of diagnosis. Anything less than 1 millimeter carries an excellent prognosis. Survival rates shrink appreciably as the lesion expands below 2 millimeters—a silly millimeter lower. For the patient with malignant melanoma, morbidity and mortality are determined by millimeters.
Synapses in the brain are measured in nanometers, 1/1,000,000th of a millimeter. These microscopic gaps are bridged by neurotransmitters which trigger the impulses that facilitate thought processes and coordinate motor movement. Yet in the patient with Parkinson’s disease, pathologic processes dictate otherwise. Metaphorically speaking, these minute gaps might as well approach infinity.
Few of us outside scientific research pause to consider the implications of such minutiae in our world, unless we become one of those unfortunate patients who develop such illnesses. Only then, for us, do minute measurements take on cosmic significance.