CBL Deletion in Stage II Melanoma: Why Statistics Matter Before Calling It a Prognostic Biomarker

A deletion on chromosome 11q has been proposed as one of the most intriguing prognostic markers to emerge from genomic profiling of early-stage melanoma, but a new correspondence in the British Journal of Cancer argues that the statistical foundations beneath this claim deserve far closer scrutiny before the marker is translated into clinical practice. In a letter to the editor published on 21 September 2026, researchers Jingyi Han, Xinger Gao and Wenjun Jiang of the Department of Clinical Laboratory at the First Affiliated Hospital of Dalian Medical University respond to a comprehensive genetic landscape study of stage II melanoma, praising its scale while raising pointed methodological concerns about how a deletion within the CBL gene region was transformed from a genome-wide observation into a candidate biomarker for specific molecular subgroups of patients.

The original study, led by Lindner and colleagues, analysed tumours from 193 treatment-naïve patients with stage II melanoma, a disease stage in which the primary tumour is thick but has not yet spread to distant sites, and in which clinicians urgently need better tools to decide who requires intensive surveillance or adjuvant therapy. Among the many alterations catalogued in that work, one finding stood out: a deletion spanning the chromosomal region 11q23.1-3, which contains the CBL gene, was associated with relapse-free survival in the overall cohort when tested in a rigorous multivariate analysis. The Dalian-based team is quick to acknowledge the strength of that result, describing it as a compelling foundation for exploring CBL loss as a potential prognostic biomarker. Their concerns arise not from the headline finding, but from what happens when that finding is pushed into finer molecular subgroups.

CBL is no incidental passenger. The gene encodes an E3 ubiquitin ligase, a molecular machine that tags proteins for degradation and thereby acts as a critical regulator of signalling pathways driven by receptor tyrosine kinases. Because melanomas are classically stratified by driver mutations in BRAF, RAS and NF1, with a residual group classified as triple wild-type, any genomic alteration that appears to carry prognostic weight within one of these subtypes immediately attracts attention. The Lindner study reported that the 11q23.1-3 deletion showed a prognostic trend within the RAS-mutated subgroup of patients, and it is precisely this subgroup-specific claim that Han, Gao and Jiang dissect in their correspondence.

The heart of their critique concerns the difference between an unadjusted p-value and an adjusted one. In the RAS-mutated subgroup, the original report highlighted an unadjusted p-value of 0.044 for relapse-free survival, a figure that sits just below the conventional 0.05 threshold and therefore appears, at first glance, to signal genuine statistical significance. But when the analysis was corrected for multiple testing, the adjusted p-value rose to 0.178, well above the threshold that most researchers would accept as evidence of a reliable effect. The distinction is far from pedantic. When investigators test many genomic subgroups simultaneously, as happens when BRAF, RAS, NF1 and triple wild-type tumours are each interrogated for prognostic associations, the probability of stumbling across at least one apparently significant result by pure chance rises steeply. This phenomenon, known as a Type I error, is the false positive that multiple-testing adjustments are designed to suppress.

Han and colleagues argue that in exploratory subgroup analyses spanning multiple genomic subtypes, adjusting for multiple comparisons is generally recommended to prevent exactly these spurious discoveries. They point to the influential 2007 New England Journal of Medicine commentary by Wang, Lagakos, Ware, Hunter and Drazen on the reporting of subgroup analyses in clinical trials, a paper that has shaped how statisticians and clinicians interpret claims carved out of broader datasets. That commentary warned that subgroup findings are frequently overinterpreted, particularly when unadjusted significance levels are emphasized over corrected ones. By foregrounding the unadjusted p-value of 0.044 while the adjusted figure of 0.178 tells a more cautious story, the original presentation, the correspondents suggest, risks conveying a degree of predictive confidence in the RAS-mutated subgroup that the data do not yet support.

There is also the matter of sub-stage confounding, a second analytical nuance the letter raises. Stage II melanoma is not a single homogeneous category. Under the American Joint Committee on Cancer eighth edition staging system, refined in the landmark 2017 update by Gershenwald and colleagues, stage II encompasses patients with tumours of markedly different thicknesses and ulceration statuses, and these features themselves carry powerful prognostic information. When a cohort is subdivided first by molecular subtype and then examined for survival associations, imbalances in tumour thickness, ulceration or other clinicopathological variables between patients with and without the CBL region deletion can masquerade as genuine biological effects. Disentangling whether the deletion independently forecasts relapse, or merely travels alongside known risk factors that happen to cluster within the subgroup, demands careful covariate adjustment and transparent reporting of how residual confounding was handled.

The correspondents anchor their argument in established reporting standards, invoking the REMARK guidelines, the Reporting Recommendations for Tumor Marker Prognostic Studies published by McShane and colleagues in 2005 in the Journal of the National Cancer Institute. REMARK was developed precisely because biomarker prognostic studies have historically been plagued by small samples, selective reporting and optimistic interpretation, leading to markers that fail repeatedly upon validation. The guidelines call for complete documentation of statistical methods, prespecified hypotheses, transparent handling of multiple testing and honest characterisation of exploratory versus confirmatory findings. Emphasising adjusted p-values, Han, Gao and Jiang contend, aligns with these norms and helps readers accurately gauge the robustness of the CBL alteration within specific molecular subsets rather than being swept up in an apparently significant number.

None of this diminishes the value of the underlying discovery. The genomic classification of cutaneous melanoma established by The Cancer Genome Atlas Network in 2015 demonstrated that melanoma biology divides cleanly into the BRAF-mutant, RAS-mutant, NF1-mutant and triple wild-type categories, and subsequent efforts to layer prognostic information onto that framework have been a major research priority. A driver gene and biomarker candidate emerging from a 193-patient cohort of therapy-naïve stage II patients is genuinely noteworthy, particularly for a disease stage in which sentinel lymph node status and tumour thickness remain the dominant but imperfect guides to management. The Dalian team frames its letter as constructive engagement, crediting the original authors with a robust cohort and a rigorous multivariate analysis in the overall population, while urging that subgroup-level claims be contextualised with the statistical caution they require.

The broader lesson radiates well beyond melanoma genomics. Modern high-throughput studies routinely generate dozens or hundreds of candidate associations, and the path from an exploratory signal to a clinically actionable biomarker runs through validation in independent cohorts, replication under pre-specified analytical plans and harmonisation with existing staging and risk models. A deletion at 11q23.1-3 affecting CBL may yet prove to be a genuine driver event with prognostic power, and the original study’s evidence in the overall cohort suggests the hypothesis is worth pursuing vigorously. But as Han, Gao and Jiang make clear, the credibility of that pursuit depends on how the statistics are handled at each step, and on whether the field resists the temptation to treat a subgroup p-value of 0.044 as a verdict rather than a prompt for further, more stringently powered investigation.

For patients with stage II melanoma, the stakes are concrete: biomarkers of this kind could ultimately refine who is monitored most intensively, who is considered for adjuvant intervention and who can be reassured. Ensuring that such tools rest on statistically sound foundations is therefore not an academic quibble but a patient-safety issue. The correspondence, received on 5 June 2026, revised on 14 June and accepted on 3 September before publication on 21 September, stands as a reminder that in precision oncology, the rigour of the analysis is inseparable from the value of the discovery, and that the most important filters between a genomic observation and a clinical biomarker are multiple-testing correction, confounder control and disciplined adherence to reporting guidelines such as REMARK.

Subject of Research: Methodological evaluation of the 11q23.1-3 CBL deletion as a prognostic biomarker in stage II melanoma

Article Title: Methodological considerations in defining CBL as a prognostic biomarker in stage II melanoma

Article References: Methodological considerations in defining CBL as a prognostic biomarker in stage II melanoma. (n.d.). https://doi.org/10.1038/s41416-026-03628-2

Image Credits: AI Generated

DOI: 10.1038/s41416-026-03628-2

Keywords: stage II melanoma, CBL, 11q23.1-3 deletion, prognostic biomarker, RAS-mutated melanoma, multiple testing adjustment, REMARK guidelines, subgroup analysis, relapse-free survival, AJCC staging, melanoma genomics, statistical methodology