(Reuters Health) - Whether it's colon cancer, breast cancer, or ovarian cancer, survival rates in the U.S. are lower for black people than for white people, three new studies show.

All three were published in the journal Cancer. In one, Dr. Arica White from the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, and her team looked at colon cancer survival rates in 2001-2003 and 2004-2009.

Overall, the proportion of patients still alive five years after diagnosis improved slightly between those two periods, from 63.7 percent to 64.6 percent. But five-year survival was lower among blacks (54.7 percent for 2001-2003 and 56.6 percent for 2004-2009) than among whites (64.5 percent and 65.4 percent, respectively).

Furthermore, survival rates among blacks diagnosed in 2004-2009 were lower than survival rates among whites diagnosed 15 to 20 years earlier when fewer treatments were available.

“While colon and rectal cancer survival has improved over time, black men and women continue to have lower survival than white men and women, and survival varied by state,” White told Reuters Health by email. “This suggests that access to and/or use of screening and treatment services varies by race and location. We need continued efforts to ensure that screening and high-quality treatment services are available and utilized universally.”

“Screening for colorectal cancer is one of the most effective preventive services available,” she said. “We strongly encourage all eligible adults to talk with their doctor about which test is right for them, and to not put it off if they are aged 50-75. Screening can reduce the number of people diagnosed at a late stage, which means that treatment will be more effective and survival will increase.”

Results were similar when Dr. Jacqueline W. Miller from the CDC and colleagues studied breast cancer survival among nearly 1.4 million women diagnosed between 2001 and 2009 in 37 states.

Throughout this period, breast cancer survival in black women was more than 10 percentage points lower than in white women. In the later period (2004-2009), for example, five-year survival was 89.6 percent for white women versus 78.4 percent for black women.

Black women were 60 percent more likely than white women to be diagnosed after their breast cancer had already spread to other parts of their body.

“While some racial disparities will exist due to differences in tumor types, improving early diagnosis and providing specific treatment based on tumor characteristics in a timely fashion would result in reducing breast cancer disparities,” Miller said by email.

“The key to improving survival is early detection and appropriate treatment,” Miller added. “CDC’s National Breast and Cervical Cancer Early Detection Program (NBCCEDP), provides low-income, uninsured, and underserved women access to timely breast and cervical cancer screening and diagnostic services. Currently, the NBCCEDP funds all 50 states, the District of Columbia, 6 U.S. territories, and 13 American Indian/Alaska Native tribes and tribal organizations to provide screening services for breast and cervical cancer.”

In the third study, the CDC's Dr. Sherri L. Stewart and her team examined racial disparities in ovarian cancer survival.

Between 2001-2009, ovarian cancer was much more common among white women than among black women. More than half of all cases were diagnosed after the cancer had spread.

Five-year survival was at least 10 percent lower in black women than in white women throughout this period. (In 2004-2009, only 31 percent of black women survived for five years, compared with 42 percent of white women).

“Recognizing early symptoms of ovarian cancer and seeking timely care may help lead to detection of the cancer at an earlier stage, where treatment is likely to be more effective,” Stewart told Reuters Health by email. “Symptoms, such as abdominal and back pain, feeling full quickly after eating, and frequent urination, are often present among women with ovarian cancer. Women should talk with their doctors if they experience any of these symptoms for two weeks or longer and the symptoms persist or worsen.”

Dr. Michele L. Cote from Wayne State University School of Medicine and Karmanos Cancer Institute Population Sciences and Disparities Research Program, Detroit, Michigan, also has examined ovarian cancer disparities. She told Reuters Health by email, “Getting women of all racial and ethnic groups into clinical trials and other types of research is critical to better understand and treat this disease. The majority of the research has been performed in white women.”