While cancer survival rates are at an all-time high for many groups, doctors say that people from age 15 to 39 who get cancer are more likely to die than 25 years ago, according to the Lance Armstrong Foundation.

It's now estimated that two of three people diagnosed with cancer will be alive in five years, according to the American Cancer Society. But the numbers aren't as good for people under 40.

"Clearly this group is caught in the middle. Both in terms of diagnosis and prognosis, there hasn't been a lot of progress," said Dr. Mike Caliguiri of Ohio State University.

Researchers have noted separately that five-year survival rates also are going up because increased screening has led to more cancers being found that would not have threatened health within five years if left undetected.

Caliguiri said part of why patients in that group don't do as well is that they're not studied as often. People in other age groups are more likely to volunteer for research, he said.

Besides slim access to appropriate clinical care, inadequate insurance, youthful feelings of invincibility, and delayed or missed clinical diagnoses, a new report also lists several other reasons for the dilemma:

A lack of awareness that cancer is the fourth leading cause of death -- after homicide, suicide and unintentional injury -- among people aged 15 to 39

Many in this age group are students or professionals who don't have primary care providers or take the time to visit them

These patients are often referred to inappropriate medical specialists and are therefore less likely to benefit from advanced therapies.