Patients with prostate cancer who undergo to androgen-deprivation therapies are prone to have a suppressed adaptive immune response, which may lead to a relapse, according to researchers UT Southwestern Medical Center. Findings were published last week in the journal Science Translational Medicine.
Androgen-deprivation therapies (ADTs) are anti-hormone therapies that reduce the levels of male hormones called androgens, to stop them from stimulating cancer cells to grow, said the American Cancer Society. However, hormone therapy is usually combined with other treatments like immunotherapy.
As a consequence of suppressed immune responses caused by ADTs, immunotherapies may be stopped from working if the combination of treatments is not sequenced properly, said researchers after analyzing mouse models. That said, ADTs are the most common non-surgical treatment for prostate cancer.
“Medical ADTs have been used for a half-century to treat prostate cancer, and promising clinical results for cancer immunotherapy have led to attempts to combine it and other standard-of-care therapies with immunotherapy to treat the disease,” said senior author Dr. Yang-Xin Fu, Professor of Pathology and Immunology.
Relapse of prostate tumors is still a major problem
Dr. Fu has explained that even when castration or surgical ADT works well alongside immunotherapy, some androgen receptor antagonists could reduce the response of the T-cell to face prostate cancer.
In other words, patients may be prone to develop an early tumor relapse, due to suppressed immune responses caused by medical ADTs that reduce the effects of immunotherapy, wrote researchers in a press release issued Thursday last week.
A theory suggests that even when these treatments attack tumors in the short term, they do not kill every cancer cell. If the immune response of the patient is not mobilized, the tumor could relapse hostilely.
Researchers propose that physicians should carefully regulate the timing, types and dosage of anti-androgens used with immunotherapy, in order to enhance the “antitumor” effects of the combination of treatments.
“We hope that our findings will cause physicians to think twice before starting chemotherapy or radiation on their cancer patients, to consider the best way to combine them with immunotherapies” Said Dr. Fu.
He added that the objective is to kill the tumor, but always considering that ADTs can suppress or activate the immune system.
Which is the impact of prostate cancer in the United States?
Prostate cancer is the most common cancer among men in the country, including all races, after non-melanoma skin cancer, said the Centers for Disease Control and Prevention (CDC). Most cases are diagnosed in men aged 65 or older.
The American Cancer Society calculates that there will be nearly 181,000 new cases of prostate cancer in the country, and about 26,000 deaths due to the same disease in 2016. However, most men diagnosed do not die from it. As a preventive measure, elderly adults should get screened every certain time, said the CDC.
New prostate cancer drug arrives soon to Mexico and Europe
A “revolutionary drug” called Tookad Soluble, which is delivered with an injection and then activated by laser light, has been approved by Mexico’s health authorities while it is in trials in Europe and Israel.
According to Israel21, once the drug is activated, it circulates to target the tissue and destroy the tumor’s blood vessels and tumor cells. After nearly four hours of action, the drug is eliminated, leaving no toxic traces.
Drugs activated by laser light may be the beginning of therapies used to attack cancer cells, using procedures that are not invasive. Specially, for patients diagnosed with early-stage prostate cancer.