Are you due for a cancer screening test? Don't let cost stand in the way.

Yes, it would be easier to schedule such tests if you have insurance, a regular doctor who can refer you to screenings and money in your checking account to foot the bill.

But with some digging, you can often find free or low-cost cancer detection tests that could just save your life.

A study published in June in CA: A Cancer Journal for Clinicians found that about 650,000 deaths from cancer were avoided or delayed between 1990 and 2005. That decline is at least partially attributable to early detection, says Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society.

There are a number of cancer detection tests available, but the cancer society specifically recommends three for which there is the strongest evidence of benefit, Lichtenfeld says.

They are:

Colonoscopies: At $1,200 or more, these tests are costly.

Occasionally, medical practices and hospitals offer free screenings, but these often fill up and the sites rarely take walk-ins. Contact area hospitals to see if they have any free screenings coming up.

You're more likely to find an economical test through community health centers, which provide care at no cost or low cost based on income. Some facilities that offered the colonoscopies may no longer do so because of budget cuts, says David Bowman, a spokesman for the federal Health Resource Services Administration (HRSA), which supports thousands of the centers.

Find a center by calling (888)275-4772, or looking online at wwwfindahealth center.hrsa.gov. Expect to wait a few weeks or longer before a test date opens up.

Prepare to do some traveling: The test center available could be out of your neighborhood.

Mammograms and tests to detect cervical cancer: In California, women 40 and older who meet income eligibility guidelines and are uninsured or under-insured (for example, they have Medicare hospitalization coverage but not coverage for care outside the hospital) may be eligible for free mammograms through a program called Cancer Detection Programs: Every Woman Counts. In L.A. County, call (800) 303-1131; staff can take your information over the phone and let you know if you qualify.

Coverage for cervical cancer testing -- the Pap smear -- starts at age 25. If your income is too high to qualify for free tests, you can schedule them at free or nominal cost depending on income through the community health center system, at the website and number listed above. (Starting age for cervical cancer testing may be earlier at community health centers.) As with colonoscopies, there could be long waits because of recent budget cuts in California. For example, the Cancer Center at UCLA recently had to cancel its mammogram van, which traveled to underserved communities, because of lack of funding.

Many women enrolled in Medicare Part B, which provides non-hospital care such as doctor visits and many routine tests, are unaware that the program covers much of the cost of an annual mammogram. Mammograms typically cost about $100-$150 and Medicare covers about 80% of its approved charge. Find out more at www.medicare.gov/ health/mammography.asp.

October is National Breast Cancer Awareness Month, and some facilities may offer free mammograms, though you may have to show proof of income. Call the American Cancer Society, beginning in September, to see if there are any free test sites in your area: (800) ACS-2345. Susan G. Komen for the Cure, a breast cancer resource group, may also be able to direct you to free or low cost mammograms during October. Contact them at www.komen.org or by phone at (877)465-6636.

Skin and oral cancer: Many cancer experts recommend annual checks of your body and your mouth to look for skin cancer, the most common form of cancer in the U.S., and oral cancer, which is on the rise. If you regularly see a primary care doctor and a dentist, they generally do these checks as part of a routine checkup. But if cost has kept you away from routine care, you'll want to find free screenings for both.

The American Academy of Dermatology does free screenings, but is most likely to do them in May. Go to www.aad.org and click on "Find a Skin Cancer Screening" on the left side of the home page. You can also sign up for an e-mail alert for when a local screening is available.

The AAD also has online guides for self checks at www.aad.org/public/exams/ abcde.html and www.aad.org/ public/exams/self.html. If you see something suspicious, contact a community health center to see how quickly they can schedule a test with a dermatologist. Or call a local hospital to find out about low-cost or free dermatology clinics.

Many community health centers have dermatologists available to see patients, says Bowman of the Health Resource Services Administration. Since not all do, don't just ask about a center in your neighborhood. Ask specifically where and when you can see a dermatologist, Bowman says.