China is expected to have diagnosed 4.3 million new cancer cases in 2015, and 2.8 million people are expected to have died from the disease, according to a major new study. That amounts to 204 deaths per 100,000 people, significantly higher than the US’s rate of 171 deaths per 100,000.
The new analysis, published in CA: A Cancer Journal for Clinicians, also shows that while the number of cancers diagnosed among Chinese men remained stable between 2000 and 2011, they “increased significantly” among women. China’s cancer data has been spotty at best, but the report—authored by researchers in China, the US, and Australia—gives one of the most comprehensive pictures of the threat to date.
Between 2000 and 2011, the cancer rate in Chinese men rose by just 0.2% per year. But female cancer rates increased by 2.2% per year over the same period. The largest increases in cancer rates among women were found in the thyroid (which saw a 20% increase between 2003 and 2011), the cervix (4.1% between 2007 and 2011), and the breast (3.9% between 2000 and 2011).
The report suggests that such increases could be a result of leading a more “Westernized” lifestyle. “Increases in the prevalence of obesity and physical inactivity” were among the potential causes cited in the report. But that doesn’t explain why women in China have much higher rates of some cancers, like of the stomach.
Environmental differences could also play a part in the rate at which cancer is being detected in China, the report says. ”Outdoor air pollution, […], indoor air pollution through heating and cooking using coal and other biomass fuels, and the contamination of soil and drinking water,” expose people in China to a high number of carcinogens, the report says.
Looking ahead, it is likely that the burden on China’s healthcare system is expected to grow. The risk that any individual will suffer from cancer rises as they get older, and China’s population has been aging fast.
To increase the chances of survival from cancer, earlier detection is essential. Many women in China are not routinely tested for common cancers; only one in five women in China report having ever had a pap smear, which tests for cervical cancer. China also has no national program to encourage mammograms, which detect breast cancer.
But the report suggests better public health awareness could also help curb the number of new incidences. Just 12 cancer types made up three quarters of all cancers diagnosed in China, it found. Each of those 12 are closely linked with smoking.