Cancer overtakes heart disease as leading cause of death in richer countries

A recent study shows that cancer is starting to overtake heart disease as the biggest killer, but only in certain countries, specifically higher income countries.
The analysis of the causes of death among middle-aged individuals across the world, published in the medical journal The Lancet, shows that, in recent years, deaths from cancer are now more common than deaths from cardiovascular disease in certain high and medium income countries like Chile, Argentina, Sweden, Poland, Tukey ... and Canada. On the other hand, deaths in lower income countries in Africa and Asia are more likely to result from cardiovascular disease than cancer. Separate studies within the United States suggest a similar trend among poorer and richer regions.
The studies are not definitive, merely illustrative, and they make no attempt to analyze quite why the change might be happening, but it seems like cancer is becoming more of a rich person's disease.