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By Nancy Lapid

Feb 6 (Reuters) - Hello, Health Rounds Readers! Today we feature a very early-stage clinical trial that has achieved remarkable results in patients with advanced renal cancer. We also share news of an at-home test that might improve screening for prostate cancer, and a treatment that helps keep nearsightedness from worsening in children.

Experimental vaccine shows promise against kidney cancer

Patients with advanced kidney cancer who received an experimental vaccine after their tumors were removed were still cancer-free years later in a small early-stage trial, researchers reported in Nature.

These were patients "where you know the risk of the cancer coming back is very high," said Dr. Toni Choueiri of Dana-Farber Cancer Institute in Boston, who helped lead the study. "And after a median follow up of almost four years, none of the nine vaccinated patients has experienced a recurrence from their kidney cancer."

Standard treatment for stage III or stage IV clear cell renal cell carcinoma is surgery followed by immunotherapy with Merck's MRK.N Keytruda. In most patients, however, the cancer recurs, typically within three years, and there are no good treatments at that point.

The new vaccine is "personalized," meaning it is designed to train the patient's immune system to recognize and eliminate any remaining cells of that person's cancer.

Using tumor samples removed during surgery, the researchers identified neoantigens, which are tiny fragments of mutant proteins that exist in the cancer but not in any other cells in the body. Then they determined which of these neoantigens to include in the vaccine based on the likelihood that the immune system would respond strongly to them.

"We pick targets that are unique to the cancer and different from any normal part of the body, so the immune system can be effectively 'steered' towards the cancer in a very specific way," study co-author Dr. David Braun of Yale School of Medicine in New Haven, Connecticut said in a statement.

Working with Merck, the researchers are now testing a similar kidney cancer vaccine in a randomized trial with 272 patients.

In the meantime, Choueiri said, "We're very excited about these results."

At-home urine test screens for prostate cancer

A simple at-home urine test is highly accurate at screening for prostate cancer, according to researchers.

Traditional prostate cancer screening starts with a blood test to measure levels of prostate-specific antigen $(PSA)$, a protein produced by the prostate gland. But the results are frequently unreliable, often leading to biopsies that turn out to have been unnecessary because no cancer was present.

The new test, which analyzes 18 genes associated with prostate cancer, "is highly accurate for ruling out the presence of clinically significant prostate cancers - those that merit treatment - so that patients with a negative test result can confidently avoid having to undergo MRI or biopsy," study leader Dr. Jeffrey Tosoian of Vanderbilt University Medical Center in Nashville, Tennessee, said in a statement.

Tosoian and colleagues had previously validated the urine test in men who also underwent digital rectal exams to detect prostate cancer. The new study found the test - MyProstateScore 2.0, from biotechnology startup Lynx Dx of Ann Arbor, Michigan - was just as accurate on its own, they reported in The Journal of Urology.

"Rectal exams are no fun," Tosoian said. "These findings will increase the impact of the (urine) test, as it can now be used for at-home testing."

In the study of 266 men, including 103 with at least grade group 2, or moderately aggressive, prostate cancer, the noninvasive urine test "would have allowed patients with an elevated PSA to avoid 34-53% of unnecessary biopsies," Tosoian said.

If the test is eventually proven to be similarly accurate in patients being monitored for progression of low-risk prostate cancers, it could potentially "eliminate or reduce the need for prostate biopsies during active surveillance," Tosoian said.

Contact lenses keep nearsightedness from worsening in kids

Nearsighted children and teens who wear bifocal contact lenses to prevent their vision impairment from worsening do not lose the benefits of the treatment once they stop wearing the lenses, according to new research.

Normally, eye length grows quickly in early childhood, then slows down until it stops around age 12. In myopia, or near-sightedness, the eye's axial length grows too quickly and can continue to grow into the late teens. Slowing this elongation can control myopia.

In an attempt to keep their nearsighted eyes from growing too much, the 235 youngsters in the study, ages 11 to 17, wore soft multifocal contact lenses with a high level of correction for near vision for two years.

The lenses significantly curbed abnormal lengthening of the eyes, and slowed or prevented worsening of the children's near-sightedness. But the researchers wondered whether discontinuing the treatment might cause a rebound of faster-than-normal eye growth that would wipe out the benefit.

During a third year when the children switched to wearing single-vision contact lenses, the researchers saw no evidence that the treatment effect declined, they reported in JAMA Ophthalmology.

"You don't lose the benefits that you gain with this treatment," study leader Dr. Jeffrey Walline of the Ohio State University said in a statement.

The treatment landscape for nearsighted children "is a burgeoning area," Walline said. "The standard of care has switched from providing kids with single-vision glasses or contact lenses to things that slow down the progression of myopia, or the growth of the eye," such as contact lenses or atropine eye drops.

With regard to these new treatments, an editorial published with the study noted that "the fundamental question remains: will myopia control treatments in childhood decrease the lifetime risk of visual impairment from sequelae, such as retinal detachment and myopic macular degeneration?"

"If so, then we will know that these interventions are truly impactful," it added.

(Reporting by Nancy Lapid; editing by Will Dunham)

((Nancy.Lapid@thomsonreuters.com))