New research suggests that infection with bacteria from the Chlamydia family may play a role in the development of a type of lymphoma that affects the tissue around the eye, raising hopes that antibiotics may one day prove to be an alternative to chemotherapy or radiation.
The study, presented Monday at the European Cancer Conference, is the latest to link infection with cancer, following the establishment of the human papilloma virus as the major cause of cervical cancer and the bacteria Helicobacter pylori as a cause of stomach cancer.
“This is sensational,” said Dr. Dieter Hossfeld, a professor of oncology at the University of Hamburg, Germany, who was not involved with the research.
“It was first noted in Italy and now it’s been confirmed on the other side of the world in Korea, and we’ve heard that there are similar findings in the United States, so it’s not a regional disease and is obviously a valid thing,” Hossfeld said.
The bacteria in question, Chlamydia psittaci, can be contracted from infected birds such as parrots. Scientists also suspect it can come from household cats because they also carry it. Chlamydia psittaci is known to cause a lung infection called psittacosis.
In the study, Dr. Changhoon You from the Asan Medical Center in Seoul, South Korea, compared chlamydia infection in 33 people with ocular adnexal lymphoma, or OAL, and 21 people with a comparable but non-cancerous condition called non-neoplastic ocular adnexal disease.
He found the Chlamydia psittaci strain was present in 78 percent of the cancer patients, but only in 23 percent of those in the comparison group.
In a previous study conducted in Italy, the bacteria were found in 80 percent of people with the lymphoma and in none of those in a comparison group of healthy people.
“In the future, eradication of the (germ) could be a common treatment method for low-grade lymphoma, replacing current cytotoxic chemotherapy or radiation,” You said.
The Chlamydia family of bacteria has been linked to cancer before. Scientists already have shown that another strain, Chlamydia trachomatis, is linked to the development of cervical cancer. Another, Chlamydia pneumoniae, has been linked to lung cancer.
Ocular adnexal lymphoma belongs to a group of lymphomas where cellular changes result from immune system responses gone awry. Scientists say it makes sense that infections such as chlamydia could contribute to the development of the disease.
“It makes biological sense, but whether it will translate into anything practical, and for how many patients, this is the question,” said Dr. Joachim Yahalom, a lymphoma specialist at Memorial Sloan-Kettering Cancer Center in New York who was not connected with the research.
In many of these types of lymphoma, an infection can start the process, but at some point the cancer becomes independent of the infection. So unless the infection is treated early, antibiotics may not be enough, Yahalom said.
The next step, Yahalom said, is to see whether antibiotics can reverse the cancer.
“I think for some patients it may work,” he said.
Hossfeld said he was optimistic antibiotics would work because the cancer is a slowly developing one.
“It remains localized for a long period of time. This gives us a good chance to try bacteria eradication first, before radiotherapy or chemotherapy,” Hossfeld said.