It’s not a new idea that viruses can cause or accelerate cancer. But it will probably be years before answers emerge about COVID and cancer.
Kashyap Patel enjoyed his team's Friday lunches, where doctors from his oncology practice gathered in an open-air courtyard under a magnolia tree to catch up. The atmosphere was typically lighthearted, but in 2021, a year into the coronavirus pandemic, Patel was troubled. He had just seen a patient in his 40s with cholangiocarcinoma, a rare and deadly bile duct cancer usually found in people in their 70s and 80s. His colleagues reported similar unusual cases, and within a year, the office recorded seven such instances.
“I’ve been in practice 23 years and have never seen anything like this,” said Patel, CEO of Carolina Blood and Cancer Care Associates. Asutosh Gor, another oncologist, shared his concern, noting the unusual increase in multiple rare cancer diagnoses and cases involving multiple simultaneous cancers.
This surge in aggressive, late-stage cancers since the pandemic's onset has been corroborated by early national data and large cancer institutions. While many experts attribute this trend to healthcare disruptions beginning in 2020, not everyone is convinced.
The link between viruses and cancer isn't new; since the 1960s, scientists have recognized that certain viruses can cause or accelerate cancer, with an estimated 15 to 20 percent of all cancers worldwide originating from infectious agents like HPV, Epstein-Barr, and hepatitis B.
While conclusive answers about the coronavirus's role in cancer might take years, Patel and other scientists urge the U.S. government to prioritize this research due to its potential implications for millions of cancer patients.
“We are completely under-investigating this virus,” said Douglas C. Wallace, a University of Pennsylvania geneticist. However, there is currently no real-world data linking SARS-CoV-2 to cancer, and some scientists remain skeptical.
John T. Schiller of the National Institutes of Health noted that viruses known to cause cancer typically persist in the body long-term, whereas respiratory viruses like the coronavirus usually do not linger. David Tuveson, director of the Cancer Center at Cold Spring Harbor Laboratory, agreed there’s no evidence the coronavirus directly transforms cells into cancerous ones, but speculated it could act like an environmental stressor.
“Covid wrecks the body, and that’s where cancers can start,” Tuveson explained, citing studies showing prematurely aged tissue in COVID-19 autopsy reports.
Public health officials had predicted a surge in cancer cases due to delayed or skipped care during the pandemic. A Lancet Oncology paper and data from institutions like Baptist Health Miami Cancer Institute and UC San Diego Health showed increases in late-stage cancers.
Xuesong Han from the American Cancer Society attributed this rise to healthcare delays and socio-economic factors but acknowledged possible biological mechanisms of SARS-CoV-2.
Afshin Beheshti, president of the COVID-19 International Research Team, has been exploring the virus's potential role in cancer, noting studies showing widespread inflammation and impact on organs vulnerable to cancer stem cell development. Patel and Beheshti hosted a symposium concluding that compelling evidence suggests links between the coronavirus and cancer.
Wallace is researching how COVID-19 affects cell energy production and cancer vulnerability, while a University of Colorado team studies whether COVID-19 reactivates dormant cancer cells in mice. Their findings showed that SARS-CoV-2 and the flu virus could proliferate dormant cancer cells in mice lungs.
Ashani Weeraratna of Johns Hopkins Bloomberg School of Public Health, though surprised by the Colorado study's results, emphasized the importance of mitigating infection risks for cancer patients. She also noted that recent studies focus on COVID-19 infection or long COVID, not the vaccine.
Patel, conducting his own research, theorizes that cumulative coronavirus infections and pandemic-related stress might increase cancer risks. He has collected data from nearly 300 patients and aims to create a national registry.
Patients like Bob and Bonnie Krall, who endured multiple cancers between them despite no family history or genetic predisposition, illustrate Patel’s concerns. Both had high coronavirus antibody levels, although the connection to their cancers remains uncertain.
“Maybe if we didn’t get covid …” Bonnie wondered, reflecting the uncertainty many patients feel about the pandemic's long-term health impacts.
