Prostate cancer study raises new questions over NHS testing

Prostate cancer screening is as good as breast cancer screening, according to a German study that has reignited the row over how the NHS tackles the disease. Researchers compared data from Germany’s Probase prostate screening trial with the country’s breast cancer screening programme. They found that both identified invasive cancers at similar rates (discovering about seven in 10 cancers), and similar proportions of men and women were referred for biopsies to investigate lumps (about 1%).

However, prostate screening led to more wrong diagnoses with about 40% false positives compared with 10% for mammograms. Both types of screening identified substantial numbers of cancers that turned out to be non-aggressive – 22% for women and 26%-31% for men. But fewer men were referred for biopsies unnecessarily.

The research from the German Cancer Research Centre, unveiled on Sunday at the European Association of Urology Congress, comes after the UK’s National Screening Committee (NSC) decided not to recommend a national prostate screening programme last year, after a review found that screening might do more harm than good.

Around 55,000 men a year are diagnosed in the UK, and there are 12,000 deaths, but although some cases are aggressive, many tumours grow slowly and do not need treatment. Surgery to remove the prostate usually leads to long-term incontinence and impotence.

However, the Prostate Specific Antigen (PSA) blood test is often inaccurate and diagnosis needs to be confirmed by an MRI scan. Last year’s NSC review found that although two lives would be saved for every 1,000 men screened, another 12 would have unnecessary treatment.

The new German study compared data from 39,392 men aged 45 or 50 taking part in the Probase trial with 2.8 million women aged 50 to 69 who were screened for breast cancer.

Dr Sigrid Carlsson, who led the German research, said it was impossible to make a like-for-like comparison between the trial and the national breast cancer programme but “informed assumptions” showed that “if prostate cancer screening were extended to the wider population, then the outcomes are likely to be very similar to breast cancer”.

“Although our study used German data, the findings are applicable to other countries,” she said.

UK researchers provided a mixed response. Dr Sam Hare, a consultant radiologist and former adviser on imaging to NHS England, said the trial added “further weight” to “a risk-stratified, PSA and MRI based approach to screening for prostate cancer”. He said that the high false positive rate might be reduced using AI and second opinions.

Dr Lennard Lee, a cancer researcher at the University of Oxford, said screening technologies were evolving. “There is a strong case for piloting modern prostate cancer screening programmes in real healthcare systems and assessing outcomes regionally,” he said, “rather than waiting decades for randomised trials that may not fully represent how screening works in practice, and not give results for decades.”

Dr Alastair Lamb of Barts Cancer Institute said the study showed prostate screening delivered too many false positives.

“Breast cancer screening is an odd benchmark given that not many experts would claim breast screening as a success,” he said. The big difference between the diseases was that breast surgery rarely caused harm, apart from the aesthetic and psychological impact, “whereas pretty much all prostate cancer treatment can cause many functional harms” to the bladder, bowels or cause erectile dysfunction.

Simon Grieveson from Prostate Cancer UK, which is funding a £42m trial on the effectiveness of population-wide screening that began last year, said the study was interesting but did not provide enough evidence to prove screening would save lives without causing harm.

Photograph by Getty Images