The number of new cancer cases diagnosed each year will jump 45 percent in the next two decades to 2.3 million up from 1.6 million in 2010, affecting many more older adults and minorities, U.S. researchers predicted on Wednesday.

Using demographic trends, researchers at the University of Texas project a 67 percent increase in the number of adults 65 and older will be diagnosed with cancer in 2030, rising to 1.6 million in 2030 from 1 million in 2010.

And they foresee a doubling in the number of non-whites who will be diagnosed with cancer by then, rising to 660,000 cases a year from 330,000.

The data assume that rates of cancer would remain about the same. "This is basically saying how will our population changes impact the number of people getting cancer," Dr. Ben Smith of the university's M.D. Anderson Cancer Center, said in a telephone interview.

"In 2030, 70 percent of all cancers will be diagnosed in the elderly and 28 percent in minorities, and the number of older adults diagnosed with cancer will be the same as the total number of Americans diagnosed with cancer in 2010," he said.

Smith said that the number and types of cancers expected to increase -- such as liver, stomach and pancreas -- are especially deadly.

"Currently, we don't have the health care infrastructure to be able to accommodate the expected surge in cancer diagnoses," Smith, whose findings appear in the Journal of Clinical Oncology, said in a telephone interview.

He pointed to data from the American Society of Clinical Oncology that suggests 40 percent of cancer specialists in the United States are 55 and older and many will retire in the next decade or so.

"The rate of new oncologists is not sufficient to keep pace with the rate of retirement," Smith said, adding that by 2030, there will be a shortage of 3,800 oncologists. "That is a great concern."

Shift in Disease

For the study, Smith and his team used current the United States Census Bureau statistics and cancer incidence rates to look at how changes in the population will affect the number of people getting cancer.

He found a major shift in new cancers being diagnosed in older adults and minorities -- segments of the population projected to grow rapidly.

"Both older adults and minorities are segments of the patient population that are particularly vulnerable to receiving sub-optimal medical care," Smith said.

He said minorities are more likely to be diagnosed with cancer at a later stage, and death rates, especially for black Americans, are significantly higher compared to white Americans.

Given these statistics, Smith said, screening and prevention become all the more vital.

Cancer remains the No. 2 killer of Americans, with about 560,000 deaths annually, topped only by heart disease.