Expert Melanoma Panel Recommends Castle Biosciences’ DecisionDx®-Melanoma as a Best-Practice Tool for Managing Patients with Melanoma

Rhea-AI Summary

Castle Biosciences (Nasdaq: CSTL) announced an independent expert consensus paper published Dec 9, 2025 endorsing DecisionDx-Melanoma as a best-practice prognostic tool for cutaneous melanoma.

The paper—authored by ten melanoma experts after reviewing 26 studies covering >7,500 patients—reached unanimous agreement on nine statements: DecisionDx-Melanoma provides prognostic information independent of clinicopathologic factors, complements AJCC8 staging, guides sentinel lymph node biopsy (SLNB) decisions in T1b–T3 tumors, informs management of SLNB-negative patients, and is associated with improved melanoma-specific and overall survival versus untested patients.

Positive

• Independent expert panel unanimous on nine consensus statements
• Evidence base: 26 studies covering >7,500 patients
• Validated prognostic performance independent of clinicopathologic factors
• Enhances prognostic precision when combined with AJCC8 staging
• Guides SLNB decisions in T1b–T3 tumors and SLNB-negative care
• Associated with improved melanoma-specific and overall survival

Negative

• None.

News Market Reaction

+0.39%

1 alert

+0.39% News Effect

On the day this news was published, CSTL gained 0.39%, reflecting a mild positive market reaction.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

Expert panel size: 10 melanoma experts Supporting studies: 26 published studies Patient data: more than 7,500 patients +5 more

8 metrics

Expert panel size 10 melanoma experts Authors of independent consensus paper on DecisionDx-Melanoma

Supporting studies 26 published studies Evidence base reviewed for DecisionDx-Melanoma consensus

Patient data more than 7,500 patients Cutaneous melanoma patients included across supporting studies

Consensus statements 9 statements Unanimous expert panel guidance on DecisionDx-Melanoma’s clinical role

Gene panel size 31 genes 31-Gene Expression Profiling for cutaneous melanoma

Q3 2025 revenue $83.0M Reported revenue for Q3 2025

2025 revenue guidance $327–335M Raised full‑year 2025 revenue guidance range

AdvanceAD‑Tx U.S. TAM $33 billion Estimated U.S. total addressable market for AdvanceAD‑Tx

Market Reality Check

Price: $42.24 Vol: Volume 331,764 is 0.75x t...

normal vol

$42.24 Last Close

Volume Volume 331,764 is 0.75x the 20-day average of 443,183 shares, indicating lighter-than-normal trading ahead of this news. normal

Technical Shares at $38.10 are trading above the 200-day MA of $22.16, and sit about 6.18% below the 52-week high of $40.6099.

Peers on Argus

CSTL was down 1.4% while peers were mixed: CDNA (+2.11%), PSNL (+1.45%), FLGT (+...

CSTL was down 1.4% while peers were mixed: CDNA (+2.11%), PSNL (+1.45%), FLGT (+0.04%), and decliners MYGN (‑1.53%), NEO (‑2.42%). No momentum-clustered sector move was flagged.

Historical Context

5 past events · Latest: Nov 17 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Nov 17	Workplace recognition	Positive	+1.5%	Top Workplaces award for fifth consecutive year with multiple culture honors.
Nov 14	Clinical data update	Positive	-2.0%	New data showing DecisionDx-Melanoma improves SLNB decisions and risk prediction.
Nov 11	Conference participation	Neutral	+0.7%	Management scheduled to present overview at Piper Sandler healthcare conference.
Nov 03	Quarterly earnings	Positive	+1.9%	Q3 revenue reported at $83.0M with raised full‑year 2025 revenue guidance.
Nov 03	Product launch	Positive	+1.9%	Launch of AdvanceAD‑Tx gene expression test targeting large U.S. TAM.

Pattern Detected

Across the last five news events, CSTL showed mostly aligned reactions, with four aligned moves and one divergence on positive clinical data.

Recent Company History

This announcement reinforces Castle Biosciences’ focus on DecisionDx-Melanoma, following November data showing improved SLNB decision-making and prognostic performance. Earlier, the company reported Q3 2025 revenue of $83.0M and raised full‑year guidance to $327–335M, alongside strong core test volume growth. A new AdvanceAD‑Tx launch targeted a U.S. TAM of $33B. Cultural recognition through multiple Top Workplaces awards and investor outreach via the Piper Sandler conference round out a narrative of operational and commercial momentum into which this expert consensus endorsement now fits.

Market Pulse Summary

This announcement highlights an independent expert panel’s unanimous support for DecisionDx-Melanoma...

Analysis

This announcement highlights an independent expert panel’s unanimous support for DecisionDx-Melanoma, based on 26 studies and data from more than 7,500 patients. It reinforces prior findings that the test refines SLNB decisions and risk stratification beyond traditional staging. In the months leading up to this news, Castle Biosciences reported $83.0M in Q3 revenue, raised 2025 guidance to $327–335M, and launched AdvanceAD‑Tx into a $33B U.S. TAM. Investors may watch future updates on clinical adoption, reimbursement, and test volumes for this assay.

Key Terms

31-gene expression profiling, cutaneous melanoma, sentinel lymph node biopsy, SLNB, +4 more

8 terms

31-gene expression profiling medical

"independent expert consensus paper titled “31-Gene Expression Profiling for Cutaneous Melanoma..."

A 31-gene expression profiling test measures how active a specific set of 31 genes is in a tissue sample to predict how a disease is likely to behave and how it might respond to treatment. Think of it as a dashboard that turns complex biological signals into a risk or response score; for investors, such tests can influence demand for related drugs, diagnostics, and reimbursement decisions, affecting revenue and valuation in healthcare and biotech companies.

cutaneous melanoma medical

"31-Gene Expression Profiling for Cutaneous Melanoma: An Expert Consensus Panel..."

A type of skin cancer that starts in pigment-producing cells and can grow into the deeper layers of the skin or spread to other organs if not treated. For investors, it matters because diagnosis rates, treatment options, regulatory approvals and long-term outcomes drive demand for drugs, diagnostics and medical services the same way a rising storm increases demand for shelters—successful therapies or tests can significantly affect revenues and stock values in healthcare-related businesses.

sentinel lymph node biopsy medical

"risk stratification, sentinel lymph node biopsy (SLNB) decision making and long-term patient management."

A sentinel lymph node biopsy is a surgical procedure that removes and tests the first lymph node(s) that drain fluid from a tumor to see if cancer has spread. Think of it as checking the first security checkpoint after a breach; a negative result often means less extensive surgery and lower treatment costs, while a positive result can change therapy, prognosis, regulatory decisions and market demand for related diagnostics and treatments, making it important to investors.

SLNB medical

"guide SLNB decisions in T1b–T3 tumors and inform management for SLNB-negative patients."

A sentinel lymph node biopsy is a surgical test that removes and examines the first lymph node(s) likely to receive cancer cells from a tumor, like checking the first bucket under a leaking pipe to see whether the problem has spread. Investors care because SLNB results shape treatment decisions, clinical trial endpoints and regulatory outcomes for cancer drugs and devices, so those findings can materially affect a company’s clinical prospects and market value.

American Joint Committee on Cancer 8th Edition medical

"Integrating DecisionDx-Melanoma results with the American Joint Committee on Cancer 8th Edition (AJCC8)..."

A staging system published by the American Joint Committee on Cancer (8th edition) that standardizes how cancers are classified by tumor size, lymph node involvement, and spread to other organs. Think of it as a common rulebook or map that doctors and researchers use to describe how advanced a cancer is; for investors it matters because changes in staging rules can alter reported patient populations, trial results, treatment eligibility, regulatory decisions and the estimated market size for diagnostics and therapies.

AJCC8 medical

"with the American Joint Committee on Cancer 8th Edition (AJCC8) staging significantly enhances..."

The AJCC8 is the eighth edition of the American Joint Committee on Cancer staging system, a standardized method doctors use to classify a cancer’s size, spread and severity. Investors care because staging shapes who qualifies for trials, how strong clinical results look, treatment guidelines and expected outcomes—like a common ruler that helps estimate a drug’s eligible patient pool, likely sales and regulatory risk.

Delphi process technical

"the panel used a modified Delphi process to reach unanimous agreement on nine consensus statements..."

A Delphi process is a structured method for gathering and refining the opinions of a group of experts through multiple anonymous rounds of questionnaires and feedback until their views converge. Investors use it to turn dispersed, informed opinions into a clearer forecast or risk assessment—think of several draft rounds that gradually produce a more reliable group estimate than any single voice alone.

clinicopathologic factors medical

"independent of traditional clinicopathologic factors and can be integrated with existing staging systems..."

Clinicopathologic factors are the mix of observable patient information (age, symptoms, medical history) and lab or tissue findings (biopsy results, biomarkers, disease stage) that doctors use to understand a condition. For investors, these factors help predict how well a treatment might work, which patients it will help, and the likely size and timing of clinical success or regulatory approval—similar to a checklist that forecasts whether a product will meet customer needs.

AI-generated analysis. Not financial advice.

Expert panel offers data-driven guidance for integrating DecisionDx-Melanoma into clinical decision-making for patients with melanoma

FRIENDSWOOD, Texas, Dec. 09, 2025 (GLOBE NEWSWIRE) -- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced the publication of an independent expert consensus paper titled “31-Gene Expression Profiling for Cutaneous Melanoma: An Expert Consensus Panel,” which endorses the Company’s DecisionDx-Melanoma test. The paper can be viewed here.¹

“This consensus translates the robust data supporting DecisionDx-Melanoma into practical direction for clinicians,” said Derek Maetzold, president and chief executive officer of Castle Biosciences. “The panel’s unanimous endorsement of DecisionDx-Melanoma underscores its value in supporting informed, personalized care decisions that may help improve outcomes for patients with melanoma.”

Authored by a panel of ten melanoma experts from leading academic and clinical institutions, the paper presents evidence-based recommendations supporting DecisionDx-Melanoma as a best-practice tool for guiding management decisions in patients with cutaneous melanoma. The panel concluded that the test provides prognostic information independent of traditional clinicopathologic factors and can be integrated with existing staging systems to improve patient risk assessment and help optimize clinical decision-making.

Drawing on a comprehensive review of 26 published studies encompassing more than 7,500 patients, the panel used a modified Delphi process to reach unanimous agreement on nine consensus statements defining the test’s role in risk stratification, sentinel lymph node biopsy (SLNB) decision making and long-term patient management.

Key conclusions from the expert panel include the following:

• DecisionDx-Melanoma demonstrates robust clinical utility and validated performance, supported by high-quality (SORT A) evidence showing accurate and consistent prognostic information for patients with invasive melanoma to help clinicians better assess metastatic risk and guide management across a wide range of disease presentations.
• DecisionDx-Melanoma can be used across a broad range of tumor stages. Panelists agreed DecisionDx-Melanoma should be used in earlier-stage patients to identify those who may benefit from escalated care, guide SLNB decisions in T1b–T3 tumors and inform management for SLNB-negative patients.
• Integrating DecisionDx-Melanoma results with the American Joint Committee on Cancer 8th Edition (AJCC8) staging significantly enhances prognostic precision, improving risk stratification and survival prediction when used alongside traditional clinicopathologic factors.
• Integrating DecisionDx-Melanoma results with established staging systems can accurately inform SLNB decisions to help identify low-risk patients who may safely avoid the procedure.
• Patients who undergo DecisionDx-Melanoma testing demonstrate improved melanoma-specific and overall survival compared to patients not tested, likely reflecting the test’s role in supporting more personalized management strategies based on accurate risk information.
• DecisionDx-Melanoma supports clinical decision-making in challenging scenarios, particularly when information about traditional clinicopathologic features, such as tumor thickness or ulceration, is limited or unavailable.
• DecisionDx-Melanoma should be recognized as a best-practice approach for the management of patients with melanoma, guiding evidence-based, patient-centered care.
  
  

“Consensus efforts like this are important to help clinicians interpret and apply emerging data in a consistent, evidence-based way,” said Rebecca Critchley-Thorne, Ph.D., vice president, research and development, at Castle Biosciences. “This study in particular can give physicians confidence on when and where DecisionDx-Melanoma fits within current management strategies to support more individualized care for patients with cutaneous melanoma.”

About DecisionDx-Melanoma
DecisionDx-Melanoma is a gene expression profile (GEP) test designed to analyze tumor biology to deliver a personalized risk assessment for patients with stage I–III cutaneous melanoma, enhancing risk stratification beyond American Joint Committee on Cancer (AJCC) staging alone. By combining molecular insights with select clinicopathologic features, the test provides two distinct outputs: a personalized risk of sentinel lymph node (SLN) positivity and a personalized risk of recurrence and/or metastasis. This clinically actionable information is designed to help guide risk-aligned patient management decisions, including SLN biopsy consideration, follow-up intensity, imaging and referrals.

DecisionDx-Melanoma is supported by more than 50 peer-reviewed publications, including prospective studies and meta-analyses, and was developed in collaboration with more than 100 leading U.S. institutions. The test has been clinically validated in more than 10,000 patient samples, ordered more than 220,000 times since launch, and has been shown to be associated with improved patient survival. Learn more at https://castlebiosciences.com/tests/prognostic/decisiondx-melanoma/overview.

About Castle Biosciences
Castle Biosciences (Nasdaq: CSTL) is a leading diagnostics company improving health through innovative tests that guide patient care. With a primary focus in dermatologic and gastroenterological disease, we develop personalized, clinically actionable solutions that help improve disease management and patient outcomes.

We put people first—empowering patients and clinicians and informing care decisions through rigorous science and advanced molecular tests that support more confident treatment planning. To learn more, visit www.CastleBiosciences.com and connect with us on LinkedIn, Instagram, Facebook and X. 

DecisionDx-Melanoma, DecisionDx-CMSeq, i31-SLNB, i31-ROR, DecisionDx-SCC, MyPath Melanoma, AdvanceAD-Tx, TissueCypher, DecisionDx-UM, DecisionDx-PRAME and DecisionDx-UMSeq are trademarks of Castle Biosciences, Inc.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are subject to the “safe harbor” created by those sections. These forward-looking statements include, but are not limited to, statements concerning: DecisionDx-Melanoma’s ability to (i) guide risk-aligned management decisions for patients diagnosed with cutaneous melanoma, (ii) provide precise and clinically meaningful risk stratification, and (iii) help improve outcomes for patients with melanoma including melanoma specific and overall survival; and DecisionDx-Melanoma’s recognition as a best-practices approach for the management of patients with melanoma. The words “can,” “may” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements that we make. These forward-looking statements involve risks and uncertainties that could cause our actual results to differ materially from those in the forward-looking statements, including, without limitation: subsequent study or trial results and findings may contradict earlier study or trial results and findings or may not support the results obtained in these studies, including with respect to the discussion of our tests in this press release; actual application of our tests may not provide the aforementioned benefits to patients; and the risks set forth under the heading “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2024, and our Quarterly Report on Form 10-Q for the quarter ended September 30, 2025, each as filed with the SEC, and in our other filings with the SEC. The forward-looking statements are applicable only as of the date on which they are made, and we do not assume any obligation to update any forward-looking statements, except as may be required by law.

1. Burshtein J, Cockerell C, Cotter D, et al. 31-Gene expression profiling for cutaneous melanoma: an expert consensus panel. Dermatol. Online J. 2025;31(5). doi: https://doi.org/10.25251/c81v6j23

Investor Contact:
Camilla Zuckero
czuckero@castlebiosciences.com

Media Contact:
Allison Marshall
amarshall@castlebiosciences.com

Source: Castle Biosciences, Inc.

FAQ

What did Castle Biosciences announce about DecisionDx-Melanoma on Dec 9, 2025 (CSTL)?

An independent expert consensus paper endorsed DecisionDx-Melanoma as a best-practice prognostic tool for cutaneous melanoma.

How large was the evidence base behind the DecisionDx-Melanoma consensus (CSTL)?

The panel reviewed 26 published studies encompassing more than 7,500 patients.

How does DecisionDx-Melanoma affect SLNB decisions for T1b–T3 tumors (CSTL)?

Panelists agreed the test can help guide SLNB decisions in T1b–T3 tumors and identify low-risk patients who may avoid SLNB.

Does the consensus recommend integrating DecisionDx-Melanoma with AJCC8 staging (CSTL)?

Yes. The panel concluded integrating DecisionDx-Melanoma with AJCC8 improves prognostic precision and risk stratification.

What clinical outcome association did the expert panel report for DecisionDx-Melanoma (CSTL)?

Patients tested with DecisionDx-Melanoma demonstrated improved melanoma-specific and overall survival compared with untested patients.

Who authored the consensus paper endorsing DecisionDx-Melanoma (CSTL)?

A panel of ten melanoma experts from leading academic and clinical institutions using a modified Delphi process.