With the cost of some lifesaving cancer drugs exceeding $100,000 a year, more than 100 influential cancer specialists from around the world have taken the unusual step of banding together in hopes of persuading some leading pharmaceutical companies to bring prices down.

Prices for cancer drugs have been part of the debate over health care costs for several years — and recently led to a public protest from doctors at a major cancer center in New York. But the decision by so many specialists, from more than 15 countries on five continents, to join the effort is a sign that doctors, who are on the front lines of caring for patients, are now taking a more active role in resisting high prices. In this case, some of the specialists even include researchers with close ties to the pharmaceutical industry.

The doctors and researchers, who specialize in the potentially deadly blood cancer known as chronic myeloid leukemia, contend in a commentary published online by a medical journal Thursday that the prices of drugs used to treat that disease are astronomical, unsustainable and perhaps even immoral.

They suggested that charging high prices for a medicine needed to keep someone alive is profiteering, akin to jacking up the prices of essential goods after a natural disaster.