"They took out a golf-ball-sized tumor," Marks said. "I don't think there's any question it's going to come back."
A real estate developer in California, Marks talked on his cell phone about an hour a day for 23 years.
"There's no question what caused it," Marks said of his cancer. "It was my cell phone."
Twenty years ago, there were only about two-and-a-half million cell phone subscribers in the U.S. Today, that number is a quarter billion, and each subscriber spends close to three hours a week on their cell phone, reports CBS News correspondent Jim Axelrod.
Marks's condition is why his wife Ellen Marks traveled cross-country this week to appear before Maine state legislators and urge them to approve a bill requiring a warning label on all cell phones sold in the Pine Tree State.
"I'm going to watch my husband die from this," Ellen Marks said.
Democratic state Rep. Andrea Boland is behind the bill, which would require phones to carry a label saying, "Warning: this device emits electromagnetic radiation, exposure to which may cause brain cancer."
It's common sense to her: we all walk around pressing these radiation-emitting devices to our heads.
"The cell phones have never been proven safe," Boland said, "and that's the obligation of the manufacturers."
Warning labels on cell phones would put the Maine legislature ahead of the National Cancer Institute on the issue. The center says studies have not shown any consistent link between cell phone use and cancer but that more research is needed before any firm conclusions can be drawn.
State health officials want more than just Boland's "common sense." They want conclusive evidence.
"You go back 20 or 30 years, there's no increase in these cancer rates during this time," said Dr. Dora Anne Mills of the Maine Center for Disease Control and Prevention.
Radiation produced by cell phones is stronger than an FM radio signal but just one-billionth the intensity of an X-ray and considered to be a completely different type of radiation altogether.
If there's no threat, advocates for a warning want to know why some manufacturers advise users to keep the phones an inch away from the body unless carried in an approved holster.
"People don't read those tiny little print labels," said Dr. Devra Davis of the Mount Sinai Medical Center in New York City and founder of Environmental Health Trust. "That's why I think it's a good idea to put the warning label on the phone so you'll think about it when you use the phone."
Still, legislators in Maine just haven't seen enough proof. A skeptical health committee pushed the bill to the House floor but recommended it not pass.
"The research is not there," said one Maine legislator. "I'm sorry."
A federal study examining possible links between cell phones and cancer is due out in the next few years. Until then, people deciding how much to use their cell phones will be left to their own devices.