Cancer is on everybody's mind these days. Many pharmaceutical companies are devoted solely to finding new cancer treatments. In 2016, President Obama called on scientists to "end cancer as we know it." and signed a $6.3 billion bill to fund drug treatment. But cancer is far from new. Queen Mary (aka "Bloody Mary") died from what is thought to have been ovarian cancer in the year 1558. But that is nothing to some older, notable cancer cases. The oldest recorded case we have was discovered in Egypt from 3000 BC The earliest evidence of cancer in hominids comes from the toe of a 1.7 million-year-old human relative found in South Africa.
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Yet cancer has been around for far longer than hominids roamed the earth. Scientists in Germany recently detected a highly malignant tumor in the fossilized leg bone of a stem turtle. Drs. Nadia Fröbisch, Ph.D., of The Museum of Natural History at the Leibniz Institute, and Bruce M. Rothschild, MD, of the Carnegie Museum of Natural History in Pittsburgh, collaborated on the project that revealed the oldest evidence of cancer to date. It was a malignant tumor found in a 240 million-year-old turtle bone. This suggests that cancer has been around at least since the Triassic Period, some 250 million years ago. The findings were recently published in JAMA Oncology.
The researchers used paleopathology, the study of ancient disease, to study cancer across the phylogenetic tree. This is done as a means to understand potential underlying causes; which species are more susceptible to cancer than others; and how the prevalence of cancer has changed over the course of evolution. This last point is particularly informative since there has been an increase in human cancer compared to the cases of cancer found fossil record. The increase in human cases has been attributed to environmental and genetic changes.
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An interesting theory that helps explain why the number of cancer cases has increased is that humans are just living longer. Many cancers do not show up until old age. When the average lifespan for a human was 30 to 35, there were fewer cases of cancer because we just did not live that long for the disease to manifest. In essence, something else would kill you off first. The fact that rates of cancer are increasing is a testament to how much we have expanded the average lifespan through modern medicine, the neutralization of predation, and a lower (on average) child mortality rate.
Unfortunately, this data from the fossil record indicates that we are dealing with a very old malady. This may be why cures for cancer have eluded us for so long. As we have evolved, so has it. As many oncologists are keenly aware, cancer is a moving target. Our ancient lineage has thus endowed us with genes that contain the capacity for cancer. And our modern lifestyle choices (food, exercise, stressors) may exploit this potential and turn those ancient genes on.