"Draconian cuts to biomedical research will slow our progress at the moment of greatest scientific potential and increasing need worldwide," Dr. Sandra Swain, president of the American Society of Clinical Oncology, said at the opening of the group's annual meeting.
The National Institutes of Health's budget has been slashed by 20 percent and is now at its lowest level since 2001, Swain said.
That funding needs to be restored if researchers are going to be able to expand on the significant progress made in recent years developing new treatments and diagnostic tools.
More than 7.6 million people worldwide will die from cancer this year and that number is expected to rise to over 12 million by 2030.
In addition to undermining more theoretical research, the cuts could also limit the number of cancer patients able to participate in clinical trials which could extend their lives.
"Even before the most recent budget cuts our clinical research didn't have the strong federal funding it needed," Swain told reporters.
"Our federally funded clinical trials system has achieved remarkable advances that have improved survival and quality of life for millions of people with cancer, but this progress is occurring under the cloud of federal budget slashing."
Public spending on US clinical trials for cancer research come in at around $243 million a year while pharmaceutical companies spend $6 billion, said Monica Bertagnolli, chair of the Alliance for Clinical Trials in Oncology.
"Cancer treatment is not just drugs," Bertagnolli said, warning that important but "unprofitable" areas of research are not being sufficiently pursued.
Some 30,000 cancer specialists are expected to attend the society's annual meeting in Chicago, where over 4,700 studies will be presented.