U.S. District Judge Vince Chhabria said Tuesday that plaintiffs could present expert testimony linking the product to the cancer, the Associated Press reported.
While evidence that glyphosate -- the active ingredient in Roundup -- can cause Hodgkin's lymphoma is "rather weak," the opinions of the three experts are not "junk science" that should be excluded from a trial, Chhabria ruled.
While the decision means the lawsuits can move forward, the judge noted that it could be a "daunting challenge" to convince him to allow a jury to hear testimony that glyphosate was responsible for individual cancer cases, the AP reported.
Lawsuits allege that Roundup maker Monsanto long knew about the cancer risk associated with the week killer but did not warn people. There are hundreds of lawsuits in state and federal courts, and Chhabria is handling more than 400 of them.
"Moving forward, we will continue to defend these lawsuits with robust evidence that proves there is absolutely no connection between glyphosate and cancer," Monsanto Vice President Scott Partridge said in a statement. "We have sympathy for anyone suffering from cancer, but the science clearly shows that glyphosate was not the cause."
Many government regulators say there is no link between cancer and glyphosate, the AP reported.