As this week's NEJM journal roundup reports, a new study on the heterogeneity of cancer shows that tumors may be more complex than previously thought. At Not Exactly Rocket Science, Ed Yong says this study underscores that "cancer is really, really hard" and a "puzzle of staggering complexity." It's already known that cancer itself is made up of more than 200 different types, all of which have their own "individual quirks," Yong says, and that cancer evolves. What this new study shows is that even a single tumor can be "a hotbed of diversity," he adds. The various mutations within a single tumor can affect a patient's prognosis, the efficacy of a treatment, and even the potential for metastasis. In addition, Yong says, this study throws the issue of biomarkers into the air once again. "The biomarker might only be relevant to a tiny bit of a tumor, rather than the whole thing," he says. And the same goes for treatments, which could also explain why certain cancers become resistant to treatment after a while.
However, there is a bit of good news, Yong adds. "Even though cancer is maddeningly complicated, survival rates are still going up. At the moment, half of all cancer patients will survive for at least five years after their diagnosis. Cancer seems like an unbeatable adversary, but we are beating it," he says. All studies like the one in NEJM show is that "victory will not come in one decisive strike, but through a thousand shallow cuts," he adds. "It will take a lot of time and effort."