Breast cancer is the most common cancer worldwide, according to the World Health Organization, and the leading cause of cancer death among women. While in high-income countries like the U.S., the five-year survival rate for breast cancer is over 90 percent, in low- and middle-income countries (LMICs), breast cancer survival rates are much lower — between 60 to 40 percent. That’s because in many LMICs, women are diagnosed at later stages of the disease and have less access to optimal health care.
That’s the case in Tanzania, where breast cancer is the second most lethal cancer among women. While breast cancer rates in Tanzania are not as high as they are in Europe or the U.S., it can be more difficult for women to get a timely diagnosis and treatment.
“In Sub-Saharan Africa, like in other resource-constrained settings, there is a large shortage of pathologists as well as a shortage of the tools needed for cancer diagnostics,” said Katherine Van Loon, MD, MPH, professor of medicine at the UCSF School of Medicine and director of the Global Cancer Program at the UCSF Helen Diller Family Comprehensive Cancer Center. “In many cases, women are lost to follow up due to the long turn-around-times for pathology results.”
Recently, Van Loon and her collaborators at UCSF, Memorial Sloan Kettering Cancer Center and Muhimbili University in Tanzania published a paper in Lancet Oncology describing a new biopsy technique that can not only help women get diagnosed with breast cancer faster, but can also result in more precise breast cancer treatment.
Biomarkers Are Key to Successful Breast Cancer Treatment
Not all breast cancers are the same. Each woman with breast cancer has unique biomarkers, molecules on her tumors that make them more or less susceptible to different types of treatment. Detecting these biomarkers and optimizing treatment can make a significant difference in a woman’s life expectancy. Unfortunately, it can also be extremely expensive.
“Currently, in Tanzania, women are often given treatment without a proper assessment of their breast cancer biomarkers,” said Asteria Kimambo, MD, a pathologist at Muhimbili University of Health and Allied Sciences (MUHAS) and one of the coauthors of the study. “This may impact the patient’s prognosis since they may not be given the most effective treatment.”
The researchers took fine-needle aspiration biopsies from women with breast masses, which involved using a thin and inexpensive needle to extract a small sample of cells from the tumor. The team then ran these samples through a molecular diagnostic system called GeneXpert, which can detect these biomarkers and deliver same-day results. The result: a fast, accurate way for women to get diagnosed with breast cancer, including biomarkers.
“This is a transformative technology because now practitioners can deliver breast cancer diagnostics and biomarker information at point-of-care,” said Van Loon. “Women can then quickly start the appropriate treatments, which are often lifesaving.”
Repurposing a Common System
The GeneXpert diagnostic system is already widely used in health care settings around Sub-Saharan Africa to diagnose infectious diseases such as tuberculosis and malaria. This means that health care systems are already familiar with the technology, and many health care providers are already trained on its use.
“GeneXpert as a whole has increased access to molecular testing for infectious diseases and select cancers,” said Dianna Ng, MD, a pathologist at Memorial Sloan Kettering Cancer Center and a co-author of the study. This specific test, she says, is also automated and requires less training and fewer chemical substances, called reagents, compared to typical tests.
However, while a clinic health care worker like a nurse could theoretically be trained to do the fine needle aspiration, Van Loon said, a pathologist is still needed to diagnose the cancer — and that’s something that is in short supply in Tanzania. The vast majority of pathologists work at Tanzania’s four referral hospitals, which provide the country’s highest level of health care — but not outside the city centers where many women live. In preparation for this study, team members from UCSF and MUHAS worked together to train pathologists in the new skills they would need to diagnose cancer from a fine needle aspiration. That training would need to be done on a larger scale before this new technology can be more widely deployed, the study authors said.
“This is going to require additional training to decentralize diagnostic resources outside of the national referral centers,” Van Loon said. “The most impact will be if we can successfully deploy technologies for cancer diagnosis into more remote sites. This could be transformative.”
Banner photo: Dianna Ng, MD (left), and Asteria Kimambo, MD (right), during a workshop teaching ultrasound guided fine needle aspiration