A Supreme Court ruling this week could have a "chilling effect" on the many lawsuits filed in St. Louis claiming talcum powder causes a deadly form of cancer in women, including cases under appeal in which stricken women and their survivors have been awarded more than $300 million, experts said Tuesday.

Justices ruled 8-1 Monday that hundreds of out-state-residents can't sue Bristol-Myers Squibb Co. in California state court over adverse reactions to the blood thinner Plavix. It followed a similar ruling in May related to out-of-state injury claims against BNSF Railway Co. Both were seen as wins for companies opposed to "venue shopping," in which those filing suit seek out favorable state courts.

Almost immediately after the Supreme Court ruling, St. Louis Circuit Judge Rex Burlison declared a mistrial in a Missouri state court case in which three plaintiffs, two from out-of-state, sued Johnson & Johnson, claiming its talcum powder caused ovarian cancer.

More than 1,000 others have filed similar lawsuits in St. Louis against Johnson & Johnson, but most don't live in Missouri. Five trials have already taken place over the past 16 months. In four of those cases, jurors awarded more than $300 million combined.

Johnson & Johnson believes that the Supreme Court ruling "requires reversal of the talc cases that are currently under appeal in St. Louis," spokeswoman Carol Goodrich said in an email. She said the ruling "makes it clear that Johnson & Johnson was wrongfully forced to defend itself in multiple trials in Missouri, a state with no connection to the plaintiffs."

Jim Onder, whose suburban St. Louis-based law firm is representing many women and survivors who filed suit, said Missouri is a proper venue because Johnson & Johnson, though based in New Jersey, uses a factory in Union, Missouri, to package and label talcum products.