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Ejaculating reduces prostate cancer risk

PHOTO:AFP

*Chemotherapy causes tumour to spread, grow back even more aggressive, new study finds
*Treatments tailored to person’s individual mutations train immune system to attack disease

Can ejaculating at least 21 times a month significantly reduces a man’s risk of prostate cancer?
A new research by Harvard University, United States (U.S.), has found confirmed this compared to those who release just four-to-seven times every four weeks.The researchers say the findings are true regardless of whether men achieve orgasm through masturbation or sex.Researchers did not speculate on why ejaculation protects against prostate cancer, however, past research suggests it helps to rid the gland of cancer-causing substances and infections.

Ejaculation may also help to ease inflammation, which is a known cause of cancer. Researchers from Harvard University analyzed 31,925 healthy men who completed a questionnaire about their ejaculation frequency back in 1992. Monthly ejaculation frequency was assessed in men aged 20-to-29, 40-to-49 and the year before the questionnaire was completed.

Ejaculation was defined broadly and could be as a result of sex or masturbation. The men were then followed until 2010. Some 3,839 of the study’s participants were diagnosed with prostate cancer during the investigation.

Results revealed that ejaculating at least 21 times a month significantly reduces the risk of prostate cancer in men aged 20-to-29 and 40-to-49. This is compared to ejaculating just four-to-seven times a month.

The researchers wrote: “We found that men reporting higher compared to lower ejaculatory frequency in adulthood were less likely to be subsequently diagnosed with prostate cancer.” The findings were published in the journal European Urology.

Meanwhile, new research claims chemotherapy could cause cancer to spread and become more deadly. The treatment is often regarded as the first option for breast cancer patients to shrink tumors and even blitz the disease altogether.

However, scientists at New York’s Albert Einstein College of Medicine have found evidence that this is only a short-term solution.Their research suggests that, while shrinking the tumours, chemotherapy simultaneously opens a gateway for tumors to spread into the blood system, making it easier to grow back stronger.

Cancer becomes incredibly difficult to treat – often fatal – once it spreads to other organs; it is then classified as Stage 4.Lead author Dr. George Karagiannis says the findings, published on Wednesday, should not deter patients from seeking treatment, but suggests we could create a way to better monitor tumor movement in patients undergoing chemotherapy.

Also, vaccines tailored to match a person’s particular constellation of cancer mutations seem to have fended off tumours in a handful of patients, two small clinical trials show. The vaccines are described in papers published in Nature on July 5. The studies are the first to report that the approach — which is gaining support in academia and industry — could combat cancer in humans. They also provide hints about ways to boost the vaccines’ power by combining them with treatments that target the immune system, called immunotherapies.

“It is potentially a game changer,” says Cornelis Melief, a cancer immunologist at Leiden University Medical Centre in the Netherlands, and author of a commentary accompanying the papers. “The two papers really strongly indicate that the patients experienced clinical benefit.”In principle, the vaccines are similar to those used against infectious diseases: unique components of a foreign invader — cancer cells, in this case — are mixed with agents that stimulate an immune response. The mixture is injected into the patient, in the hope of triggering an immune attack strong enough to vanquish the invader.

But for personalized cancer vaccines, the components are tailored to each patient and are administered after the cancer has already appeared — rather than aiming to prevent occurrence. In the studies, researchers began by sequencing the genes that encode proteins in each patient’s tumour. They selected mutant proteins that were most likely to generate an immune response and used these as the basis for their vaccines.

One group, led by Catherine Wu at the Dana-Farber Cancer Institute in Boston, Massachusetts, treated six people with melanoma, a type of skin cancer. For each person, they formulated a vaccine that contained up to 20 protein fragments corresponding to the mutations in their tumours1. The participants, who received surgery to remove their tumours, had been deemed at high risk for cancer recurrence. But they were not due to receive further treatment unless their cancer came back. Recurrence typically occurs in about half of all such melanoma patients, says Wu.

Two years later, four of those patients had not seen their tumours return. And although tumours did grow in the remaining two participants, both experienced a complete remission when subsequently treated with a drug that rouses the immune system by blocking a protein called PD-1.

The second group, led by Ugur Sahin, a physician who studies tumour immunology and cancer genomics at the University of Mainz in Germany, treated 13 melanoma patients with vaccines that contained RNA encoding up to 10 mutated proteins in each patient2. The eight patients who had no visible tumours at the time of vaccination remained tumour-free more than a year later.

The remaining five participants’ tumours had spread by the time they received the vaccine. Tumours shrank in two of them, but later resurged in one patient. A third experienced a complete remission after subsequent treatment with a PD-1 inhibitor.

Personalized cancer vaccines had already been shown to provoke immune responses in humans. But the new trials are the first to evaluate whether these immune responses can successfully battle tumours. The numbers are small and the trials lacked a control group, but the results are encouraging, says Robert Schreiber, a cancer immunologist at Washington University in St Louis, Missouri. Larger trials in academia and industry are ongoing, he notes, and researchers are particularly interested in combining the vaccines with PD-1 inhibitors. “I’m convinced that personalized vaccines are a way to go,” he says.

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EjaculationProstate Cancer


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