State of the evidence: Evidence level: selected extension of an earlier single-arm study, rather than independent confirmation or proof of a survival benefit.
A new publication is not always a new trial
The 2023 report continues an earlier six-month study. Forty-six participants without initial progression were eligible, seven withdrew consent and 39 continued. At 18 months in total, 33 met the authors' composite response definition.[1] These figures describe a selected continuation group, rather than a new, independently recruited sample.
Why selection changes the question
When entry into a second phase depends on meeting conditions during the first phase, the population changes. This does not make the follow-up uninformative; it narrows the question being answered. Instead of showing what every new participant might expect, it describes subsequent observations among people who completed an earlier period in a particular way. Interpretation should preserve that distinction.
Keep the denominator visible
Ask whether a reported percentage refers to everyone initially enrolled or only to those continuing. In a hypothetical study, suppose 20 people are selected from an original group of 100, and 18 meet an outcome. That does not establish a 90 percent outcome rate for the original 100. The example shows why the population behind every percentage must remain visible.
What longer observation cannot fix
Additional observation can describe an individual's trajectory more fully. It does not supply a missing control group. An appropriate comparison is still needed to estimate what would have happened over the same period without the intervention. Likewise, following a PSA-based outcome for longer does not automatically turn it into a direct finding about survival or cancer spread. Duration and endpoint choice remain separate issues.
Read the information about withdrawals
Check how many people left, their reported reasons and whether later information was available. Travel, time commitments, personal preferences and health-related reasons may have different implications. Missing data should not automatically be assumed favorable or unfavorable. The useful question is whether the report explains what happened transparently and shows how the analysis dealt with participants who did not complete follow-up.
A proportionate way to describe the result
Describe this publication as longer observation of a selected group. Counting two reports from the same study as two independent confirmations can exaggerate the amount of evidence available. Before counting citations, count distinct participant groups and meaningful comparisons. This approach recognizes the value of additional follow-up while keeping uncertainty visible. It also helps distinguish a developing research programme from repeated confirmation of a clinical claim.
References
This article provides general health information. Research findings about MCP are not individual recommendations for diagnosing or treating disease. Medicine and supplement use should be discussed with a doctor or pharmacist.
Published and sources assessed: 17 October 2026