CHICAGO (Reuters) Nearly half of colorectal and cervical cancers and a third of breast cancers in the United States are diagnosed in the late stages, even though screening tests are available to detect them early on, a report by US health officials said recently.

They said more work is needed to ensure people get screened for these cancers, which could lead to early detection and more lives saved.

This report causes concern because so many preventable cancers are not being diagnosed when treatment is most effective, Dr Marcus Plescia of the US Centers for Disease Control and Prevention said in a statement.

Researchers at the CDC studied rates of breast, cervical and colorectal cancer by stage and demographic characteristics in different US states. They also used national data on new cancer cases collected through different registries at the CDC.

They found rates of late-stage colorectal cancer increased with age and were highest among black men and women.

Rates of late-stage breast cancer were highest among women aged 70 to 79 and among black women, the team reported in the CDCs weekly report on death and disease.

And they said rates of late-stage cervical cancer were highest among women aged 50 to 79 and among Hispanic women.

Where people live also plays a role in the frequency of screening and the diagnosis rate, the CDC said.

Cases of late-stage colorectal cancers were highest in Connecticut, Delaware, Illinois, Iowa, Kentucky, Louisiana, Maine, Nebraska, New Jersey and Pennsylvania.

Cases of late-stage breast cancer were highest in Alabama, the District of Columbia, Kansas, Louisiana, Mississippi, New Jersey, Oklahoma, Pennsylvania, Tennessee and Washington.

Cervical cancer rates were highest in Arkansas, the District of Columbia, Illinois, Kentucky, Louisiana, Mississippi, Nevada, New Mexico and Oklahoma.