Cancer prevention and breakthroughs in cancer treatment have helped lower the nation’s cancer death rate, but an annual report by the American Association for Cancer Research found the number of cancer cases is growing, particularly among people under the age of 50.

“Since the 1990s, fewer people are actually dying from cancer … overall cancer deaths rates are down by one third since 1991, which means that about 4.1 million cancer deaths are happening across the United States,” said Dr. Cynthia Yoshida, the medical lead of UVA Cancer Center’s Colorectal Cancer Screening Program.

Among the progress is a 42% reduction in breast cancer deaths over the past 30 years and, in the past decade, the Food and Drug Administration approved 16 new therapies against breast cancer.

Cancer deaths are also down because of screening, early detection and improvement in cancer prevention, such as reductions in smoking rates.

But cancer rates are increasing, including for people younger than 50. Researchers cite many factors including unhealthy diets, obesity, chemicals in the environment, antibiotics, sedentary behavior and increased use of alcohol.

“It’s not only colorectal cancer that’s rising in young people but also breast cancer, stomach cancer and certain blood cancers,” Yoshida said. “What this shows is that GenXers and millennials are going to have higher rates of cancer compared to prior generations and their chance of developing cancer is even higher than their grandparents.”

To guard against cancer, Yoshida recommended people pay attention to signs or symptoms that can signal cancer and participate in recommended cancer screenings. These include breast cancer screenings, which are recommended for those turning 40, and colorectal cancer checks at age 45.