Georgetown Study Highlights Opportunities for Liver Cancer Interventions in Thailand

Posted in News Release  |  Tagged bile duct cancer, global oncology, liver cancer, pesticide use, Thailand

WASHINGTON (August 28, 2025) — Safer pesticide practices, clean drinking water, and effective community health programs could help reduce liver and bile duct cancer risk in Thailand, according to a new study by researchers at Lombardi Comprehensive Cancer Center at Georgetown University.

The study used a medical anthropology approach to learn about the attitudes and lifestyles of rural villagers and could be used to guide new cancer prevention interventions. The work was sponsored in part by the National Institutes of Health’s National Cancer Institute and published August 1 in the journal Asian Pacific Journal of Cancer Prevention (“A Medical Anthropology Assessment of Community Liver Cancer Risks: Qualitative Comparisons of Two Villages in Nan Province, Thailand”).

The study builds on years of previous research, including a large epidemiological study and urine testing, aimed at understanding why Thailand has one of the highest rates of liver cancer in the world, and the world’s highest rate of bile duct cancer.

“With the addition of this qualitative information fleshing out the story, I think we have a much better understanding of where to go from here,” said Christopher Loffredo, PhD, professor of oncology and biostatistics and director of the Office of Global Oncology at Georgetown Lombardi.

The new study compared two rural Thai villages — one with high cancer rates and another where rates are significantly lower. Researchers identified several key differences that helped explain the discrepancy.

The first was a lowland village made up of ethnic Thai families engaged in low-income subsistence farming. The second village, which is located in a mountainous area, was populated by Mian, a different ethnic group with their own language. Families in the mountain village farmed cash crops, like coffee, and the village had a strong health system, with a community clinic and network of social workers.

While previous research by the Georgetown Lombardi team identified unsafe pesticide use as a contributing factor to high cancer rates, interviews with local farmers helped explain the extent of the problem. Loffredo noted that because farmers in the lowland village relied on subsistence crops like rice, they struggled to control diseases and pests as a matter of survival, resulting in unsafe pesticide practices he called “really alarming.”

Some of the risky practices included pouring many different pesticides into a single container, using pesticides off-label and not following instructions. Many farmers were not literate and therefore unable to read the instructions on the containers’ labels. For those who could read, instructions were ignored.

“In some cases the thought is, ‘If the label says I need a capful per gallon of water, well then two or three capfuls must be even better,’” Loffredo said.

Contaminated drinking water was another factor driving cancer risk. Loffredo noted that pesticide overuse led to runoff that contaminated surface water sources, which the lowland villagers relied on for drinking water. However, the mountain village was upstream of the contamination, leading to a safe water supply.

Diet also was a key difference, with lowland villagers eating freshwater crabs that they harvested by pouring insecticide into the water and gathering crabs that floated to the surface. Researchers noted that the crabs had potentially high risk of contamination.

But the study wasn’t all bad news. In addition to highlighting risks, researchers also identified strengths that could be expanded to improve cancer prevention efforts.

Loffredo noted that the rural health care system of the mountain village played a pivotal role in improving overall health and reducing cancer deaths. In particular, a network of social workers was engaged in checking on local families, referring villagers to the clinic for screening or follow up care, and providing health education.

“That was completely absent in the lowland village,” Loffredo said.

Similar systems could be expanded and leveraged to support future cancer interventions and education campaigns throughout the country, he said.

Loffredo said a key takeaway from the study was the need for more education about cancer prevention.

“There were some people in very strong denial that the farming, their lifestyle or pesticides had anything to do with their cancer,” Loffredo said, noting that one villager explained that his cancer had been caused by “weak cells” in his body.

“That was shocking to me,” Loffredo continued. “To me, it points to a need for more education to bring people up to speed about what’s really known about the causes of liver cancer.”

The study was funded by the NCI’s Center for Cancer Research (Z01BC010313) and the Chulabhorn Research Institute in Thailand.

In addition to Loffredo, study authors include Judy Huei-yu Wang of Georgetown Lombardi; Panida Navasumrit, Benjarath Pupacdi, Siritida Rabibhadana and Mathuros Ruchirawat of Chulabhorn Research Institute, Bangkok, Thailand; Kannika Phornphutkul of Rajavej Hospital, Chiang Mai, Thailand; and Curtis Harris and Xin Wei Wang of the National Cancer Institute.