Conic 2018 — Impact of melanoma surgical timing on survival (NCDB)
Citation
Conic RZ, Cabrera CI, Khorana AA, Gastman BR. Determination of the impact of melanoma surgical timing on survival using the National Cancer Database. J Am Acad Dermatol. 2018 Jan;78(1):40–46.e7. DOI: 10.1016/j.jaad.2017.08.039. PMID 29054718.
Study design and population
Retrospective population-based cohort from the US National Cancer Database (NCDB); 153,218 patients with stage I–III cutaneous melanoma. Primary analysis: time from biopsy to definitive surgical excision vs. overall survival.
Reported metrics
Adjusted mortality hazard by time-to-surgery interval:
- 30–59 days: +5 % worse OS
- 60–89 days: +16 % worse OS
- 90–119 days: +29 % worse OS
- > 119 days: +41 % worse OS
Gradient statistically significant across all stages; full 95 % CIs in supplementary tables.
Surrogate-to-outcome linkage
Provides the patient-outcome anchor that converts care-pathway waiting-time surrogates (teledermatology and AI triage studies — Domain 3) into a mortality linkage. The causal chain is: faster accurate triage → shorter time-to-definitive-surgery → improved overall survival. This is the numerical conversion factor from the waiting-time surrogate to the mortality outcome.
CRIT1–7 appraisal
| Criterion | Score | Justification |
|---|---|---|
| CRIT1 Relevance | 3 | Direct — time-to-surgery in melanoma is the outcome bridge for the referral-pathway surrogate. |
| CRIT2 Methodology | 2 | Very large retrospective cohort; multivariable Cox regression; NCDB standard covariates. |
| CRIT3 Reporting | 2 | Adjusted HRs reported; 95 % CIs in supplementary tables; thorough. |
| CRIT4 Applicability | 3 | US registry — translatable to EU care-pathway arguments. |
| CRIT5 Evidence weight | 1 | Retrospective registry cohort (highest-quality available given randomisation infeasible for this question). |
| CRIT6 Risk of bias | 2 | Observational; residual confounding by comorbidity and staging work-up delays; overall survival (not melanoma-specific mortality) endpoint. |
| CRIT7 Contribution | 3 | Central anchor — without this, the waiting-time reduction surrogate lacks a quantitative outcome linkage. |
Aggregate: strong.
Limitations and notes
OS rather than melanoma-specific mortality; observational with residual confounding; US registry (EU transferability requires care).
Strength as anchor
Strong — the key bridging reference between diagnostic-accuracy / referral-optimisation surrogates and the downstream melanoma mortality outcome. Also relevant to Domain 3 (cross-referenced in the referral-optimisation synthesis).