Cochrane does a U-turn on prostate cancer screening

Hello Nature readers,
This week, we hear that Cochrane has done a U-turn on prostate cancer screening, discover that stiffer cancer cells make better targets for immune cells and hear that the US has approved a first-in-class drug for advanced breast cancer.

Cochrane U-turns on prostate screening

Cochrane, an influential group that reviews medical evidence, has reversed its position on prostate cancer screening. In two prior reviews, published in 2006 and 2013, the group found that the prostate-specific antigen (PSA) blood test did not reduce mortality. The latest review, based on data from nearly 800,000 people, found a small benefit, with two fewer deaths from prostate cancer for every 1,000 people screened and “little to no difference” in the number of adverse effects. “For the first time, we are saying in a fairly authoritative way that prostate cancer screening does reduce prostate cancer mortality,” says urologist and review co-author Philipp Dahm.

Stiffer cancer cells make better targets

Making the membranes of cancer cells stiffer lets T cells latch onto them more strongly and improves T-cell efficacy in mice. Cancer cells tend to be softer than healthy cells in both humans and mice, but a compound called methyl β-cyclodextrin can firm them up by drawing cholesterol out of the cell membrane. Mice with melanoma given CAR T cells engineered to fight cancer and an immunotherapy drug that boosts the cancer-killing abilities of T cells lived longer if they were also given methyl β-cyclodextrin instead of saline. “It’s a completely new concept,” says bioengineer Yi Sui. “It’s really tackling a medical problem from a physical point of view. I think it’s highly promising.”

Immune cell mix predicts chemo response

Immune cells called macrophages might determine whether people with an aggressive form of breast cancer respond to chemotherapy or not. After examining tissue samples from more than 100 people with triple-negative breast cancer, researchers identified eight distinct cellular communities, or ecotypes, in tumours. “Some macrophage subtypes are associated with good response to chemotherapy, while others are associated with poor response — they play a dual role,” says biologist and co-author Nicholas Navin. “This is important in triple-negative breast cancer where most of the focus on immune cells has previously been on the T-cell populations.”

One patient’s poop is ‘lightning in a bottle’

Forty people with non-small cell lung cancer will soon take a pill containing about 50 strains of bacteria isolated in the stool of a 76-year-old woman with stage 4 colorectal cancer who went into remission after taking the immunotherapy Keytruda (pembrolizumab). Her unique microbiome is thought to be the reason for her strong response to the drug. “We captured that lightning in a bottle to immortalize the best parts of her microbiome and reverse-engineer it into a therapy,” says Matt Cheng, the CEO at biotech startup Kanvas Biosciences, which is running the trial.