Global spending on cancer drugs is closing in on $100 billion, according to a new report issued Tuesday by a major drug research institute.

The IMS Institute for Healthcare Informatics announced that global spending on cancer drugs – including those used for supportive care – reached $91 billion in 2013, up from $71 billion in 2008. The U.S. dominates oncology spending with 41 percent of the cancer treatment pie. That translated to $37.2 billion spent in 2013.

According to the report, recently approved oncology treatments (i.e., “branded” drugs), now run about $10,000 a month in the U.S., up from an average cost of $5,000 a month ten years ago. In addition, the report found that more costs are being shifted to patients with the increasing burden “linked to declining therapeutic adherence potentially resulting in drug discontinuation and higher overall total costs of care.”

These findings piggyback onto another IMS Institute study issued mid-April that focused on consumers’ use of health care, including visits to the doctor, hospital admissions and prescription drug use.

All of the above went up in 2013 thanks to an improved economy, but so did the costs of prescription drugs for cancer patients.

While nearly 60 percent of all retail prescriptions carry an average out-of-pocket cost of $5 or less, the report said prices for specialty drugs, particularly those used for diseases like cancer and hepatitis C, were continuing to burgeon. Thirty percent of total patient out-of-pocket costs relate to just 2.3 percent of prescriptions.

“These reports and the media coverage around them highlight the fact that drug costs are again soaring, largely fueled by the rising costs of specialty drugs with new cancer drugs leading the pack,” said Fred Hutch’s Dr. Gary Lyman, co-director of the Hutchinson Institute for Cancer Outcomes Research (HICOR). “For many, the indirect and out-of-pocket expenses of cancer care are more than they can handle leading to interruption or even cessation of potentially lifesaving treatment. “