Detecting lung cancer early is critical to a patient's survival, but how early is early enough?
Florida International University math professor and researcher Deborah Goldwasser is uncovering new findings that could identify the mathematical tipping point between a curable cancer and terminal cancer. Her work could change how doctors determine the best timing for lung cancer screening by correcting statistical biases that may be over-estimating the window for curing aggressive cancers. Goldwasser's research focuses on what she calls the "cure threshold," which refers to the point at which an aggressive lung cancer progresses from being curable through surgical removal before becoming inoperable. The study appears in Cancer Epidemiology, Biomarkers & Prevention, a flagship journal of the American Association for Cancer Research.
Earlier models estimating how lung cancer progresses and when it can still be cured were based largely on chest X-rays and cancer registry data. Newer, more sensitive low-dose CT (LDCT) scans are giving researchers a much clearer picture. Because LDCT can detect very small cancers earlier, researchers are finding some fast-growing aggressive tumors at smaller sizes than traditional models predicted, particularly on annual screenings. Goldwasser's work accounts for this, providing more accurate estimates of how long these fast-growing cancers may remain curable.
Current lung cancer screening guidelines primarily focus on determining whether a lung nodule is likely to be cancerous and ignore the cure threshold.
"If every lethal cancer you detect before the cure threshold is contributing to mortality reduction, that's where you're getting a benefit of screening," Goldwasser said.
Once a tumor progresses beyond that point, the ability of screening to improve survival is significantly reduced.
Earlier studies using chest X-rays failed to demonstrate a survival benefit, leading many physicians to question the effectiveness of routine screening. That changed in 2010 when the National Lung Screening Trial found that LDCT screening reduced lung cancer deaths by approximately 20 percent. Now Goldwasser is building on those findings by determining which screening regimens provide the greatest benefit? Her mathematical framework could optimize future screening recommendations.
Unlike many researchers who study lung cancer through biology or medicine, Goldwasser approaches the disease through mathematics. Her research uses mathematical modeling to understand how lung nodules grow over time and how that growth relates to the likelihood of a cure.
The findings could support more personalized screening schedules, allowing patients at higher risk of developing fast-growing tumors to be monitored more frequently while reducing unnecessary screenings for others. Ultimately, Goldwasser hopes the work will help physicians detect cancer not only earlier, but at the moment when treatment is most likely to save a patient's life.
