Prostate cancer resistant to conventional treatment could be all but wiped out by a therapy that boosts the immune system , claim researchers . Tests carried out in combination with chemotherapy drugs achieved almost complete remission in mice . The US scientists used low doses of the drug oxaliplatin , which has a unique ability to activate cancer-killing immune cells in small tumours but works less well in large , aggressive tumours . Tests of new drug oxaliplatin , carried out in combination with chemotherapy drugs , achieved almost complete remission in mice . Each year in the UK around 41,000 men are diagnosed with prostate cancer and 11,000 die from the disease . The problem is partly caused by immune system ‘ B-cells ’ that put a brake on the body ’ s defences in prostate and other cancers . In their study , the researchers found a way of blocking the development or function of these B-cells , or removed them entirely before using oxaliplatin . The prostate tumours were ‘ almost completely destroyed ’ by the mice ’ s own immune cells , the team said . Lead scientist Shabnam Shalapour , of the University of California at San Diego , said : ‘ The presence of such B-cells in human prostate cancer calls for clinical testing of this novel therapeutic approach. ’ Because of the effect of the immune system , advanced and aggressive prostate cancer does not typically respond to chemotherapy , researchers said . B-cells also undermine the effectiveness of promising new drugs called checkpoint inhibitors which ‘ unmask ’ cancer cells allowing them to be recognised by the immune system . Prostate cancer cells . There are currently few options for men with aggressive drug-resistant prostate cancer that has started to spread . But researchers also managed to get a checkpoint inhibitor – combined with chemotherapy – to work after wiping out the B-cells in one test . Each year in the UK around 41,000 men are diagnosed with prostate cancer and 11,000 die from the disease . While early treatment is often highly successful , there are few options for men with aggressive drug-resistant prostate cancer that has started to spread . B-cells play a number of vital immune system roles , including the production of antibodies . They can also tell the immune system to slow down when it is getting overheated , but this can be counter-productive in cancer treatment . Professor Michael Karin , study co-author and also from the University of California at San Diego , said there might be implications for the treatment of other types of cancer . The William Pereira designed Geisel Library at the University of California San Diego . Researchers there have made this new prostate cancer breakthrough . ‘ Similar immunosuppressive B-cells can be detected in other human cancers , ’ he added . ‘ This indicates that B-cell-mediated immunosuppression might be the reason several other cancers are also unresponsive to checkpoint inhibitors , raising the hope that chemoimmunotherapy will have broader applications for many cancer types. ’ Symptoms of prostate cancer include the need to urinate more frequently , especially at night , painful ejaculation and blood in the urine or semen . Men may also have pain or stiffness in the lower back , hips or thighs . However , not all men with the disease will have symptoms and often the cancer is spotted only in a routine check-up . Early diagnosis is crucial – up to 98 per cent of men who are diagnosed when the cancer is still contained within the gland will live for more than five years . That drops to just 30 per cent if the cancer has spread .
US scientists used drug oxaliplatin to fire up cancer-killing immune cells . Drug blocks ‘ B-cells ’ that put a brake on body ’ s defences against cancer . There are currently few options in cases of aggressive prostate cancer .