How a patient with kidney cancer overcame several metastases against all expectations (Temsirolimus)

Medical Xpress / The Spanish National Cancer Research Centre / International Journal of Cancer ^ | June 14, 2023 | Juan M. Roldán‐Romero et al

[ConservativeMind]

15 years ago, a woman in her thirties was diagnosed with metastatic kidney cancer. The oncologist, José Pablo Maroto, decided to treat her with the drug temsirolimus, which worked much better than expected. The patient beat the cancer. Nine years later, bone metastasis was detected, but temsirolimus was once again effective.

Now, we know why temsirolimus proved so effective in this case and in that of two other patients. This finding will allow clinicians to identify other kidney cancer patients for whom temsirolimus will likely be the ideal treatment. At the moment, drugs like temsirolimus—so-called mTOR inhibitors—are only used when others have failed.

"Currently, drugs within the temsirolimus family are not usually the first option in kidney cancer, but this result indicates that in some very specific patients, they should be because they work so well. We now know how to identify these patients," says Cristina Rodríguez-Antona.

Mutations in a protein involved in autophagy

The key is some very rare mutations in the USP9X protein, which regulates cellular processes critical for tumor growth. Roldán-Romero's research shows that these mutations override the function of USP9X, and when that happens the cell does not recycle its waste properly and dies. Temsirolimus acts on a different molecular pathway but has a similar effect; in patients in whom USP9X does not work, the impact of this drug is enhanced.

Rodríguez-Antona explains, "To understand the effect of USP9X mutations, we developed cell models and did proteomic assays that indicated that tumor cells without USP9X had an alteration in cell autophagy [the process by which the cell recycles its waste products]. Temsirolimus also alters autophagy, which causes a synergistic effect, making tumors respond better to this treatment."

[ConservativeMind]

If you can have get tested for the USP9X mutation, you may find you can eradicate your metastatic kidney cancer with help from Temsirolimus, which is available today as a generic drug. For those patients, this should be the first-line therapy—not the last.

[ConservativeMind]

The “Take Charge Of Your Health” Ping List
This high volume ping list is for health articles and studies which describe something you or your doctor, when informed, may be able to immediately implement for your benefit.

Email me to get on either the “Common/Top Issues” (20 - 25% fewer pings) or “Everything” list.