WEDNESDAY, Jan. 12 (HealthDay News) -- By 2020, the annual cost of cancer care in the United States is expected to reach at least $158 billion -- a 27 percent jump from 2010, according to a report from the U.S. National Cancer Institute.

The surge in cost will be largely driven by an aging population that is expected to develop more cases of cancer in the near-term. And projected costs could go even higher if the price tag for care rises faster than expected.

"This reflects only the aging and growth of the U.S. population," said lead researcher Angela Mariotto, chief of the Data Modeling Branch in the National Cancer Institute's Division of Cancer Control and Population Sciences. She described the 2020 cost estimate as "on the low side."

Cancer is a disease of aging and the population of elderly Americans is expected to rise from 40 million in 2009 to 70 million by 2030. Improvements in screening mean cancer is becoming more identifiable and treatable, but therapies are becoming increasingly expensive.

"If the trend in incidence, survival and cost continue as they have been, then the estimates could be as high as $207 billion by 2020," Mariotto said. "That's an assumption that the cost of treatment will grow annually at a 5 percent rate," she added.

The report is published online Jan. 12 and in the Jan. 19 print issue of the Journal of the National Cancer Institute.

To estimate the cost of cancer treatment, Mariotto's team looked at data on 13 cancers in men and 16 in women. Tracking the rate of these cancers and the current costs to treat them in 2010, they were able to project costs in 2020. In these calculations they assumed that costs would rise by only 2 percent a year.

The largest increases in cost over the period will be for breast cancer at 32 percent and prostate cancer at 42 percent, simply because more people will be living longer with these diseases, the researchers noted.

For example, while the cost of treating breast cancer remains relatively low (compared to other tumor types), by 2020 this cancer will incur the highest costs -- about $20.5 billion -- since there are expected to be many more women living with the disease.

The new projections do not take into account other costs associated with cancer, such as screening and other prevention measures, Mariotto noted.

"These rising costs raise a challenge for both the federal government and for the private sector," she believes. The new data could help policymakers set priorities for managing new treatments and diagnostic technologies, she added.

Commenting on the study, Elizabeth Ward, the national vice president for Intramural Research at the American Cancer Society, said that "a big component of the rise in cost is just the growth and aging of the population. We are just going to have more people developing cancer and under treatment for cancer," she said.

And while many new treatments do cost more, there's debate on whether the cost is always worth the benefit, Ward said.

"Most individuals in our society value human life enough to say it's probably worth it," Ward said. "I think where you get more debate, if a treatment only extends life only four weeks [for example]. That's on the borderline," she said.

More information

For more information on the cost of cancer, visit the U.S. National Cancer Institute.