By Mary Engel
Researchers from Fred Hutchinson Cancer Research Center and the Uganda Cancer Institute are launching a clinical study in the Uganda, that could change the way breast cancer in sub-Saharan Africa is diagnosed and treated.
The study will test a diagnostic tool that is already widely available throughout the continent to see if it performs as well as the method used in wealthier countries for determining a tumor’s hormone receptor status and other factors that guide treatment options.
The study also will assess the feasibility of a three-drug chemotherapy regimen that patients will be able to take orally rather than intravenously.
Both the alternative tool and the oral therapy could have “potentially widespread application” in countries that are making gains against malaria, HIV/AIDS and other infectious diseases but have limited resources for diagnosing and treating cancer, said oncologist Dr. Manoj Menon.
A researcher with Fred Hutch Global Oncology, Menon will co-lead the study with UCI director and oncologist Dr. Jackson Orem. Results are expected in about three years.
The study also seeks to use genetic sequencing to look for mutations that may explain why breast cancer in sub-Saharan Africa tends to strike younger women and to be especially aggressive — characteristics also seen in breast cancer in African-American women. Tumor tissue samples will be sent for analysis to the laboratory of University of Washington breast cancer geneticist Dr. Mary-Claire King, who discovered the “breast cancer gene,” BRCA1.
“Breast cancer is a huge problem in sub-Saharan Africa, but we don’t know much about the biology,” Menon said.
Sub-Saharan Africa continues to struggle with communicable, or infectious, diseases, but international and regional efforts at prevention and treatment over the last decade have halved malaria deaths, and a rollout of antiretroviral drugs has begun to stem HIV deaths. Now cancer is emerging as a public health threat.
A cancer divide
Breast cancer is one of the three most common cancers in sub-Saharan Africa, along with cervical and prostate cancers, and the second-leading cause of cancer deaths in women after cervical cancer, according to the World Health Organization. Fewer than half of those diagnosed with breast cancer in sub-Saharan Africa are still alive after five years, compared with almost 90 percent in the United States.
The UCI-Fred Hutch study will test an alternative diagnostic tool — reverse transcription polymerase chain reaction, or RT-PCR — which already is used throughout the continent as part of international and regional efforts to test and treat HIV. Smaller studies have compared RT-PCR testing against immunohistochemistry to test for breast cancer receptor status. The two tests resulted in identical results about 90 percent of the time.
The study will enroll 100 Ugandan women with newly diagnosed breast cancer to undergo additional analysis of receptor status. Their tumor samples will be processed in the laboratories of the UCI-Fred Hutch Cancer Centre in Kampala.
The study will also seek to understand at the molecular level why breast cancer in Uganda is so aggressive and why it so often affects young women.
“We do know that breast cancer tends to be more aggressive in Uganda,” Menon said. “But there are other differences too. The average age of a breast cancer patient at UCI is in the 40s, where in the U.S., it is 61. There’s likely something different in the pathogenesis of the disease. Hopefully this study will help to clarify some of the differences.”