Liz O’Riordan: Debunking Fears About Covid and Lung Metastases in Breast Cancer

Liz O’Riordan, Breast Surgeon with Breast Cancer and an Advocate for Cancer Awareness, shared a post on LinkedIn, about recent study by Shi B Chia et al. published in Nature:

“Have you been scared by these headlines claiming that Covid causes lung Metastases after breast cancer?

I’m here to put your mind at ease. The study, published in Nature, looked at mice with HER2+ve breast cancer. Their lungs were seeded with hibernating breast cancer cells that weren’t actively growing. The mice were infected either the Flu or Covid. In a couple of days the dormant cells started to grow and multiply and form nodules in the lungs. But two weeks later, the cells went back to sleep again. We don’t know if the mice would have died more quickly because of these lung deposits because they were euthanised for the study. The scientists found that an inflammatory cytokine called IL-6 was largely responsible for the increase in growth. When they genetically engineered mice that didn’t have IL-6, the growth was a lot slower.

So IL6 could be a target for future cancer treatment. They also saw that both Covid and the Flu weakened the immune system and stopped it killing the cancer cells. Now while this is fascinating, we can’t extrapolate it to humans. And remember that these were mice that already had cancer cells in their lungs. The second part of the study analysed the US Flat Iron Health database (almost 37k women).

We only know they had breast cancer. We don’t know any of the details about their age or treatment. Women infected with Covid were twice as likely to get lung metastases. Sounds scary? I know. But this database was collected before we had vaccines, and there are lots of other factors that could have contributed to this increase. The vaccine could actually reduce the risk of developing lung mets. But what about that scary number – Covid doubling the risk of lung mets If we group every breast cancer together, the risk of getting any stage 4 disease is 20-30%, and 25-30% of those will be lung mets.

That means that the LIFETIME risk of lung mets is 4-8%, or 0.3-0.6% per year for the first fifteen years of follow-up. Thats up to 6 in 1000 women with breast cancer getting lung mets each year. And getting Covid or the flu if you’re not vaccinated increases that yo 12 in 1000 women. Still really small numbers. So what can we really say about this study and how it impacts you? This is a fascinating insight into how breast cancer metastases develop in mice. If the same effect is seen in humans, then IL-6could be a target for future research. If you had Covid or the flu, please don’t worry, as the increase in you developing lung mets is small. But to be on the safe side, get your Influenza and Covid vaccines every year.”

Title: Respiratory viral infections awaken metastatic breast cancer cells in lungs

Authors: Shi B Chia, Bryan J Johnson, Junxiao Hu, Felipe Valença-Pereira, Marc Chadeau-Hyam, Fernando Guntoro, Hugh Montgomery, Meher P Boorgula, Varsha Sreekanth, Andrew Goodspeed, Bennett Davenport, Marco De Dominici, Vadym Zaberezhnyy, Wolfgang E Schleicher, Dexiang Gao, Andreia N Cadar, Lucia Petriz-Otaño, Michael Papanicolaou, Afshin Beheshti, Stephen B Baylin, Joseph W Guarnieri, Douglas C Wallace, James C Costello, Jenna M Bartley, Thomas E Morrison, Roel Vermeulen, Julio A Aguirre-Ghiso, Mercedes Rincon, James DeGregori

Read the Full Article at Nature.

Proceed to the video attached to the post.

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