MONDAY, Feb. 22, 2016 (HealthDay News) -- The gap in cancer deaths among blacks and whites in the United States has narrowed for most cancers, but disparities remain for two common cancers, a new report from the American Cancer Society says.

For deaths from breast cancer in women, the gulf between blacks and whites has widened, the report noted. For deaths attributed to colon cancer in men, the racial divide has remained the same. This imbalance is likely caused by inequalities in access to care, screening and treatment, the researchers said.

"There is good news. Cancer death rates among black women are decreasing for all of the top cancers, but compared to whites not as much progress has been made -- particularly for breast cancer," said lead researcher Carol DeSantis, an epidemiologist with the cancer society.

In men, the death rates for colon cancer have remained 50 percent higher for blacks than whites, she said. "For all of the major cancers, deaths are higher for blacks than whites," she added.

Reductions in overall cancer deaths since the early 1990s have saved more than 300,000 black lives over the past 20 years, the report said.

Deaths from cancer are declining because improved screening detects many cancers earlier, and improvements in care have made treatments more effective, DeSantis said. "The disparities remain because not everyone is getting access to the best cancer therapies," she said.

The disparity in care is more economic than racial, DeSantis said. "It's just that there are more poor blacks," she said.

The report was published Feb. 22 in CA: A Cancer Journal for Clinicians.

Cancer death rates have dropped faster among blacks than whites for all cancers combined, and for lung, prostate and colon cancer in women, the researchers found.

Other highlights from the report:

• In 1990, the cancer death rate for men was 47 percent higher in blacks than in whites, but dropped to 24 percent higher in 2012. Among women, the disparity decreased from 19 percent higher in 1991 to 14 percent in 2012.
• Since 1990, deaths from breast cancer dropped 23 percent among black women and 37 percent among white women, widening the racial disparity. In 2008-2012, breast cancer deaths were 42 percent higher in black women than white women, despite historically lower breast cancer rates overall. Researchers said the higher death rates among black women are likely due to a number of factors, such as differences in cancer progression at diagnosis, obesity, other chronic illnesses, tumor type and access to care.
• From 2003 to 2012, colon cancer deaths dropped faster among black women than white women (3.3 percent versus 2.9 percent per year). But the drop was slower among black men than white men (2.5 percent versus 3.0 percent). The racial gap is narrowing in women, but since 2005, rates in men have remained about 50 percent higher in blacks than in whites.
• For most cancers, fewer blacks than whites survive five years. Much of this difference is due to limited access to "timely, appropriate and high-quality care," according to the report. These barriers result in later diagnosis, when treatment choices are limited and often less effective.
• Obesity increases the risk for cancer, and black women have the highest obesity rates of any group. In 2013-2014, nearly six in 10 black women were obese, compared with about four in 10 white women. The prevalence of obesity is similar in black and white men (38 percent and 35 percent, respectively).

Dr. Christopher Flowers is chair of the Health Disparities Committee for the American Society of Clinical Oncology (ASCO). He said, "There is some promising news that there is a narrowing of the gap in cancer disparities, but [this study] also raises the concern that there still is a gap between black and white patients in terms of cancer deaths."

Flowers added that ASCO is trying to develop new ways to educate doctors and improve the quality of care in hospitals that "serve traditionally underserved populations."

He said Medicaid reform might help to address the racial disparities in cancer care, and added that that's another area where ASCO is working to make changes.

DeSantis noted that changes in insurance access will likely help. In particular, she said, the Affordable Care Act (known as Obamacare) may help narrow the gap between blacks and whites, because more people will have health insurance. "That's a huge step," she said.

More information

For more on cancer, visit the American Cancer Society.