Treating childhood leukemia

Editor's note: CNN's Dr. Sanjay Gupta answers medical questions submitted by e-mail on "Your Health," which airs at 2:30 p.m. ET Saturdays. Questions and answers are posted on CNN.com after the show.

Q: How common is childhood leukemia?

A: Approximately 3,250 children in the United States are diagnosed with leukemia each year, according to the National Cancer Institute. The most common type is acute lymphoblastic leukemia – also known as ALL. Fortunately, this is one of the most treatable forms of childhood cancer. The treatment may consist of chemotherapy, various drugs, and in some cases, radiation or bone marrow transplant.

Acute myelogenous leukemia, or AML, is less common and less treatable. It occurs in both children and adults and progresses rapidly. It also is treated with chemo. Bone marrow transplantation is much more likely with this type of leukemia.

There is also CML, chronic myelogenous leukemia, which accounts for less than 5 percent of all childhood leukemia.

Q: Can condoms prevent all sexually transmitted diseases? -- Ranjan Jayasinghe

A: Unfortunately, no public health strategy can guarantee perfect protection. Condoms are effective barriers at blocking the transmission of HIV, herpes simplex, cytomegalovirus (CMV), hepatitis B, chlamydia and gonorrhea, to name a few.

When used perfectly, condoms are also 97 percent effective in preventing unwanted pregnancies, according to research by the Planned Parenthood Federation of America. However, condoms must be used correctly and consistently to be effective.

"Ask Dr. Gupta" is not intended to address specific questions concerning individual cases. CNN does not directly or indirectly practice medicine or provide medical advice, and nothing contained in the responses of CNN through its correspondents is a substitute for medical advice, diagnosis or treatment. Always contact your doctor if you need medical advice or treatment, or have any questions regarding a medical condition.