A defect was discovered in a test performed on hundreds of patients in Israel.

Medical drama in Israel: On October 26, the Ministry of Health announced a defect found in the test kit of the pharmaceutical company Roche for detecting hormone receptors in cancer tumors. The problem is that patients, especially those with breast and reproductive cancers, did not receive the antihormonal treatment needed for their form of the disease. At the end of August, Roche issued a notice about a defect in the test kits, but only now the Israeli Ministry of Health informed the general public about the problem.

Currently, the company and the Ministry of Health are not aware of a single case in which a patient was harmed due to this defect. Roche has recommended that use of these kits be discontinued immediately and inventories destroyed. The Ministry of Health subsequently instructed all laboratories to re-examine cases in which the problematic kits were used and, if necessary, conduct examinations of patients.

“Our main concern is that there are treatments that can reduce the risk of recurrence of the disease, and those who could have received certain drugs may not have received them,” Dr. Hagar Mizrahi, head of the health ministry’s medical division, said at a briefing for reporters on October 26. However, she emphasized that we are not talking about a test that determines whether a person has cancer or not, but only about an analysis for the presence of specific receptors, which determine the nature of the treatment.

Roche estimates that 300 patients were tested with the problematic test kit. “We are not sure about this, so we ask professional institutions to report in an orderly manner so that we can understand how many people were tested using defective batches of test kits,” Dr. Mizrahi explained.

When asked by Ynet why the public announcement was late, Dr. Mizrahi explained that it was difficult to formulate the right plan and the ministry was keen to avoid causing panic. According to her, the use of the defective batches was initially stopped and later professional consultations were held with various specialists. “The solution to the problem is very complex. There have been quite a few discussions on this topic with some of the most respected experts. We believe that we will be able to retest everyone who was tested using the defective kits,” she said.

Estrogen receptor (ER) and progesterone receptor (PR) testing for breast cancer, female reproductive system tumors and other types of cancer is one of the most important tests for determining the type of tumor and selecting appropriate treatment. The test is performed on a tissue sample from the tumor (obtained by biopsy or surgery) using immunohistochemistry (IHC). “We are talking about a defect in the kit that detects receptors in malignant tumors,” explained Dr. Mizrahi.

►Less “toxic” treatment than chemotherapy

“The receptor is located on the surface or inside the cell. The estrogen receptor is found mainly in tumors of the reproductive system and breast. It stimulates cell division and proliferation. When the receptor is on the surface of a malignant cell, it affects its physiology and the rate of division, and we have known for many years how to block it with drugs. In other words, if a woman has a breast tumor, and we found out that it has such receptors, then we have a drug that blocks them and thus suppresses the growth and development of the tumor,” said Dr. Mizrahi.

Dr. Mizrahi explained that the goals of hormonal therapy are to reduce the risk of relapse after initial treatment, slow or stop the growth of metastatic disease, and improve overall survival. It is a less toxic treatment than chemotherapy, especially for older women or those with underlying medical conditions. The risk of relapse after treatment remains, but to a lesser extent. She points out that these receptors are very common in breast tumors, as well as endometrial tumors and even other cancers that are not necessarily related to the reproductive system.

According to Dr. Mizrahi, the test involves applying a substance to the cells that stains and identifies the receptors. “This allows for a score of 0 to 3. The defect in the test is such that the staining becomes weaker. In other words, there may be patients with a score of 3, but as a result of the defect the tumor is scored as a 2 or less,” she says. However, she emphasizes that beyond the specific test, there are many factors that help the doctor determine treatment, including the stage of the disease, the patient’s age, and whether the tumor is localized or widespread. “There are many clinical factors that form a professional basis for determining treatment, not just this test,” said Dr. Mizrahi. “It is possible that some patients, despite weaker staining, received hormonal therapy due to the decision of the treating physician based on clinical parameters.”

As already mentioned, the company has informed that it is necessary to stop using the defective batch of test kits. “We have studied this issue in depth and believe that simply stopping use is not enough,” Dr. Mizrahi explained. Health Ministry officials consulted the Association of Pathologists and the Association of Breast Oncologists on this issue to study the medical significance of the findings. An inaccurate result could lead to poor treatment decisions, such as providing unnecessary treatment or withholding hormonal therapy that could be beneficial, experts say. Accordingly, laboratories and clinicians are instructed to re-examine cases in which problematic kits were used, causing the examination result to be insufficiently reliable, and re-examine if necessary. The laboratory report will be updated accordingly and the treating physician will inform the patient of any changes. Within a month, each laboratory is required to submit a summary report on the measures taken to the Ministry of Health.

Dr. Mizrahi wanted to emphasize to patients that doctors will contact them if necessary. “This process will take time. Patients do not need to contact us, doctors will do it themselves,” she said.