A systematic review of 69 studies identified safety signals for leukemia, lymphoma, breast and lung cancer. The paper identified mechanisms — including the spike protein and DNA contamination found in some COVID-19 vaccine types — that might be responsible for triggering cancer.

A systematic review of 69 studies and reports on COVID-19 and cancer identified a possible safety signal linking COVID-19 vaccines and SARS-CoV-2 to certain types of cancer.

The study identified safety signals for leukemia, lymphoma, breast and lung cancer. The authors of the paper, published last week in the journal Oncotarget, said their findings suggest the need for further research.

The paper identified mechanisms — including the spike protein and DNA contamination found in some COVID-19 vaccine types — that might be responsible for triggering cancer.

The authors also addressed "several recurrent themes" in the studies they examined:

• The "unusually rapid progression, recurrence, or reactivation" of preexisting conditions.

• The "atypical" appearance of cancers near the point of vaccination.

• The reactivation of dormant tumors.