June 10 (Reuters) - A woman who claimed in a lawsuit that GSK's discontinued heartburn drug Zantac caused her breast cancer dropped her case shortly before it was set to go to trial in Illinois state court on Monday, the company announced.

GSK said in a statement that it did not settle with the woman, Eugenia Kasza. A lawyer for Kasza did not immediately respond to a request for comment.

Kasza's case would have been the second over Zantac to go to trial, after the first ended last month with a victory for GSK and Boehringer Ingelheim, which also sold Zantac. Another case was dismissed by a judge shortly before a trial was set to begin on May 23.

More than 72,000 lawsuits remain pending over Zantac against companies that sold the drug, which also include Pfizer and Sanofi. Sanofi has settled about 4,000 cases, and the Financial Times reported last month that Pfizer had settled more than 10,000 cases.

A Delaware judge earlier this month ruled that the cases could go forward, rejecting a bid by GSK and other drugmakers to stop plaintiffs from offering expert testimony that the drug can cause cancer. The drugmakers have said they will appeal.

First approved in 1983, Zantac became the world's best selling medicine in 1988 and one of the first to top $1 billion in annual sales. It was originally marketed by a forerunner of GSK and later sold successively to other companies.

In 2019, some manufacturers and pharmacies halted Zantac sales after a chemical called NDMA, which is known to cause cancer, was detected in some pills. Some tests showed that Zantac's active ingredient, ranitidine, could degrade into NDMA over time or when exposed to heat.

The U.S. Food and Drug Administration asked manufacturers to pull the drug off the market in 2020. In the face of mounting lawsuits, the drugmakers have maintained that there is no evidence Zantac exposed users to harmful levels of NDMA.

The companies notched a significant win in 2022, when another judge rejected about 50,000 lawsuits making similar claims that had been consolidated in federal court in Florida. Some plaintiffs are appealing that ruling. (Reporting By Brendan Pierson in New York, Editing by Alexia Garamfalvi and Bill Berkrot)