The hours spent sitting in doctors' waiting rooms, in line for the CT scan, watching chemotherapy drip into veins: Battling cancer steals a lot of time — at least $2.3 billion worth for patients in the first year of treatment alone.

So says the first study to try to put a price tag to the time that people spend being treated for 11 of the most common cancers.

Even more sobering than the economic toll are the tallies, by government researchers, of the sheer hours lost to cancer care: 368 hours in that first year after diagnosis with ovarian cancer; 272 hours being treated for lung cancer, 193 hours for kidney cancer.

That doesn't count the days spent home in bed recovering from surgery or weak from chemo, just time spent actively getting care — chemo or radiation therapy, blood tests or cancer scans, surgery or checkups, driving to medical appointments and waiting your turn.

It's a study, to be published Wednesday in the Journal of the National Cancer Institute, that sheds new light on the human costs of cancer.

"What we see here is a measure of the patient's burden of commitment," wrote Drs. Larry Kessler of the Food and Drug Administration and Scott Ramsey of the Fred Hutchinson Cancer Center, in an accompanying editorial.

"Cancer is more than the just the dollars and cents for the medicines and the treatments and the doctors. It's also the lost opportunities for the patients," added Dr. Len Lichtenfeld of the American Cancer Society, who praised the research for attempting to quantify that often overlooked reality.

How much a disease costs society plays an important role in policy-making, such as how much to invest in medical research, but it's hard to calculate the value of a patient's time spent getting care.

NCI epidemiologist Robin Yabroff and colleagues culled the records of 763,000 cancer patients covered by Medicare, the government's insurance program for those 65 and older, and estimated the time involved in traveling to, waiting for and receiving both in-hospital and outpatient care. They compared the results to time spent in medical care by 1 million other Medicare recipients without cancer.

Although most of these patients were retired, the researchers assigned a monetary value to their time — $15.23 an hour, the median U.S. wage rate in 2002. Then they estimated the national toll by including the number of patients diagnosed with cancer in 2005.

It is almost certainly an underestimate, the researchers said, noting that younger cancer patients often receive more intensive treatment.

Whatever the dollar figure, the study showed something important to patients' day-to-day lives, Lichtenfeld noted: Cancers that often are diagnosed early, when they're more curable, require less treatment time.

Men with prostate cancer spent 55.3 more hours getting medical care in the first year after diagnosis, compared with similar people without cancer. Breast cancer patients spent 66.2 hours. Also, both groups spent about four days in the hospital.

Compare that to cancers with worse survival rates, largely because they're usually caught late: Ovarian cancer patients struggled the most, spending about 21 days in the hospital that first year, and 368 extra hours getting care. Gastric cancer and lung cancer patients fared almost as badly, spending about 21 days and 15 days in the hospital, respectively, and 351 and 272 hours in treatment.

The difference shows that investing in research for better early detection of cancer "has real benefits," Lichtenfeld stressed.

The study also highlights the importance of newer "targeted" cancer treatments that promise fewer severe side effects and often allow patients to be treated with pills at home instead of in a clinic, added Kessler and Ramsey. The pair called on manufacturers to do research on patients' time toll, and for insurers to better cover new drugs that reduce it.

One puzzling finding: The shortest treatment time was for melanoma, the deadliest form of skin cancer, at 17.8 hours the first year. Early-stage melanoma can be surgically removed with good survival, but it's often discovered late. The study didn't address if the shorter treatment time was because melanoma patients had fewer treatments to try, or some other reason.

Differences in patients' treatment times persisted during their last year of life, largely because of increased hospitalization, longest for gastric, lung and ovarian cancers — 35.4, 32.4 and 31.9 days, respectively.