A modeling study demonstrated that breast cancer mortality may increase by 0.52% by 2030, but effects of delays during the COVID-19 pandemic may be mitigated by making up screenings sooner than later.
Delayed mammograms and breast cancer diagnoses during the COVID-19 pandemic may have a small long-term impact on breast cancer mortality rates up to 2030, according to results of a study with simulation modeling.
Findings from this study published in the Journal of the National Cancer Institute highlight the importance of continuing breast cancer screenings and evaluations in symptomatic women.
“Some women simply skipped their mammogram if they were scheduled to undergo a mammogram during the pandemic,” said Oguzhan Alagoz, who holds a PhD in industrial engineering and is a professor of industrial and systems engineering at University of Wisconsin-Madison, in an interview with CURE. “What we are suggesting is rather than skipping the mammogram and waiting for your next mammogram — whether it is in two years or next year — this suggests you need to make up that missed mammography exam as soon as possible. That’s the primary means of undoing the impact of the pandemic.”
When the COVID-19 pandemic first started, screening mammography and diagnostic mammography declined up to 80%, according to the study’s introduction. There were also changes in breast cancer treatment protocols, which led to treatment delays and lower rates of chemotherapy administration.
“In this short term, there was a huge reduction in the number of screenings (and) diagnoses,” Alagoz said. “The concern is if we have these short-term declines in breast cancer control activities, what will be the impact in the long term? Breast cancer is an interesting disease, … where if you delay mammography, you’re not going to see the full effect of it in six months or 12 months. Sometimes, some of these effects are seen in five years, 10 years.”
To assess the potential long-term impact of breast cancer control disruptions during the COVID-19 pandemic, researchers used three established breast cancer models to simulate reductions in mammogram screenings, delays in the diagnosis of cancer in symptomatic patients and reductions in chemotherapy treatments for women with early-stage breast cancer. These scenarios were assessed within the first six months of the pandemic, when reduced screening rates were observed, following a return to patterns similar to before the pandemic.
Alagoz provided the reason as to why researchers only focused on the first six months of the pandemic rather than the entire pandemic.
“By the end of the summer of 2020, many practices, clinics and health systems actually made up all of the missed mammography exams,” Alagoz said. “We have seen the screening volumes basically reach almost 100% capacity back in the summer. I (spoke) with our radiologist collaborators, (who) are telling me that they scheduled additional weekend and weeknight mammographic screenings.”
Based on the model projections, researchers found that by 2030, there could be 950 cumulative excess breast cancer deaths related to reduced screenings during the COVID-19 pandemic. In addition, there could be 1,314 deaths from the delayed diagnosis of symptomatic patients and 151 deaths linked with reduced chemotherapy in women with hormone-positive, early-stage cancer. Collectively, there may be an estimated 2,487 excess breast cancer deaths, which represents a 0.52% increase in deaths by 2030 compared with models indicating breast cancer deaths without the effect of the COVID-19 pandemic.
Although any increase in mortality rates isn’t ideal, Alagoz mentioned that these results were a “pleasant surprise” for his research team.
“Before I started this study, I was really expecting a significant number of breast cancer mortality over the next 10 years due to the pandemic,” Alagoz said. “Fortunately, the impact is actually relatively small (in magnitude). I was expecting maybe 10,000 additional deaths, 15,000 additional (deaths), but our modeling suggests that we are going to see an additional 2,500 deaths over the next 10 years due to the pandemic.”
He mentioned that these lower-than-expected increases in mortality rates are a somewhat positive finding of the study.
“I think the silver lining in this unfortunate paper is that the impact is not as high as I was scared it would be, which is good news,” Alagoz said. “Primarily, that is because many practices — after the initial shock of the pandemic — and many patients were able to actually make up the exams and did resume the normal operations within a six-month period.”
Alagoz added that delays during the COVID-19 pandemic did not greatly affect women who were already diagnosed with breast cancer.
“Our findings show that disruptions didn’t affect (these women) too much,” Alagoz said. “In other words, anybody who was supposed to get surgery, radiotherapy or chemotherapy, they already got the treatment. Oncologists aware of the really terrible potential effect of delaying the treatment or stopping the treatment didn’t really change treatment practices very much. The patients who were already diagnosed with breast cancer prior to the pandemic, the effect of the pandemic on their care or mortality, we found, is limited.”
Although there are some effects of the COVID-19 pandemic that can be undone, such as making up missed mammograms sooner rather than later, Alagoz said there are some consequences that cannot.
“For example, … many women during their self-exam (or) during their annual physician visit, they observe a palpable lump in their breast and then they go and visit the clinic,” Alagoz said. “And those cases dropped significantly during the pandemic. There is very little we can do to undo those effects. Those women already came for a delayed diagnosis, maybe like three months (or) six months later, and, unfortunately, there is not much we can do to undo that. But at least for the screening mammography exams that women (missed), we can certainly mitigate the impacts of the pandemic.”
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