High lung, cervical cancer rates in indigenous people point to need for prevention

The high rates of lung and cervical cancers among indigenous peoples in Canada, the U.S., Australia and New Zealand highlight the need for better, targeted screening and prevention, researchers say.

Indigenous peoples share a history of disproportionately worse health, lower life expectancy and greater levels of poverty compared with their non-indigenous counterparts in the wealthiest countries, previous research suggests.

Investigators led by World Health Organization's the International Agency for Research on Cancer (IARC) used cancer registry data from 2002 to 2006  from Alberta, the U.S. and three states in Australia to study the cancer burden among indigenous people compared with non-indigenous people.

The most commonly occurring cancers among indigenous men, irrespective of jurisdiction, were lung, prostate, and colorectal cancer. 

Among indigenous women, breast cancer was the most frequent cancer, followed by lung and colorectal cancer.

Colorectal cancer was the most common cancer in men in Alberta, the researchers reported in Wednesday's issue of The Lancet Oncology.

"The high incidence of several common and largely preventable neoplasms, including cervical and lung cancer, shows the need for better health surveillance and targeted prevention, early detection, and vaccination programs in Australia, New Zealand, Canada and the USA," Dr. Suzanne Moore, the lead author, and her co-authors said.

Smoking, a major risk factor for lung cancer and cancers in the oral cavity, head and neck, esophagus , stomach and cervix, appeared to be very common in indigenous communities in all four countries compared with their non-indigenous counterparts, said Dr. Freddie Bray at IARC, a lead author of the paper.

Cervical cancer is considered largely preventable through screening.

Associate Prof. Diana Sarfati, the director of the Cancer Control and Screening Research Group at Otago University in New Zealand, wrote a journal commentary, titled "Equitable cancer cancer: better data needed for indigenous people."

"In all four countries included in this study, there are documented cancer survival inequities; indigenous people who are diagnosed with cancer have poorer survival than non-indigenous people," Sarfati wrote. "This finding suggests that disparities in early detection, access to optimum care, and effective management of co-morbidities need to be monitored."

Since data were limited in timeliness, availability and span, the researchers said they weren't able to investigate patterns of death and incidence trends over time.

They also called for more reliable cancer data to implement and assess cancer control measures in indigenous communities.

The research was funded by the International Agency for Research on Cancer — Australia Fellowship.