This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Topical Laser-assisted Combination Chemotherapy for Basal Cell Carcinoma- a Clinical Study (NCT03541252), a na phase 1, phase 2 study. The primary outcome is Change in Occurence of Local Skin Reaction (LSR) Side Effects TOTAL COMPOSITE SCORE.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03541252 |
| Phase | Phase 1, Phase 2 |
| Condition | Carcinoma, Basal Cell |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 20 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Merete Haedersdal |
| Results posted | Yes |
2. Clinical Question
Population
Adults with histologically verified superficial or nodular basal cell carcinoma were eligible. The record specifies lesions smaller than 20 mm on the face or scalp and smaller than 50 mm on the trunk or extremities.
Intervention
The intervention was topical cisplatin plus 5-fluorouracil delivered with ablative fractional laser assistance. The study was exploratory and evaluated tolerability as well as tumor clearance.
Comparator
There was no control group or randomized comparison. The study is described as a single-group, uncontrolled, open-label trial, so its outcomes cannot be interpreted as a direct comparison with another treatment or with no treatment.
Primary question
The primary outcome was change in the total composite score for local skin reactions after treatment. A physician assessed local skin findings at Days 1, 3-5, 14, 30 and 3 months. The score was intended to represent overall local skin-reaction severity; lower scores were defined as better. The registry record does not report the observed scores or their change.
3. Trial Design
The registry describes a completed, prospective, uncontrolled, open-label exploratory study, identified as phase I and phase II and characterized in its summary as an exploratory phase IIa trial. It lists an enrollment of 20 and one study group: patients with basal cell carcinoma receiving laser-assisted topical cisplatin plus 5-fluorouracil. Allocation is recorded as not applicable, and masking as none. There is no concurrent control arm, random assignment, or blinded assessment described.
Eligible participants were adults with histologically verified superficial or nodular basal cell carcinoma. The recorded lesion-size limits were smaller than 20 mm on the face or scalp and smaller than 50 mm on the trunk or extremities. The study assessed tolerability and tumor clearance. The primary outcome concerned local skin reactions; secondary outcomes concerned clinical, imaging-based, and histological tumor clearance. The registry record does not report participant-level characteristics or explain how many participants met each eligibility category.
Local skin reactions were assessed by a physician at Days 1, 3-5, 14, 30 and 3 months after laser exposure. The assessment was non-blinded. This design can describe observations within the treated group, but it does not isolate the intervention's effect from other explanations for changes over time. In particular, without a control group, outcome patterns cannot establish what would have happened to comparable participants without this intervention or under another treatment.
The record marks the study completed and gives an enrollment of 20, while the safety summaries list 19 participants at risk. The reason for this difference is not reported in the registry record. It also does not describe follow-up completion, withdrawals, or the analysis population for the primary outcome.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Basal Cell Carcinoma Patients |
|---|---|
| STARTED | 20 |
| COMPLETED | 19 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Basal Cell Carcinoma Patients |
|---|---|
| Withdrawal by Subject | 1 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Basal Cell Carcinoma Patients |
|---|---|---|
| Participants analysed | 19 | |
| Age, Continuous | years | 73 (56 to 89) |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 14 |
| Race and Ethnicity Not Collected | Participants | — |
| Histological Tumor Subtype: Nodular BCC | Tumors | 13 |
| Histological Tumor Subtype: Superficial BCC | Tumors | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Occurence of Local Skin Reaction (LSR) Side Effects TOTAL COMPOSITE SCORE, measured over Days 1, 3-5, 14, 30 and 3 months post treatment.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | score on a scale |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the change in the total composite score for local skin reactions. A physician performed a non-blinded clinical evaluation of erythema, edema, flaking, crusting or scabbing, pustulation, scarring, hypo- or hyperpigmentation, and infection in treated areas. Each listed parameter was graded on a standardized severity scale from 0 to 4, with categories ranging from none to severe. The record describes the overall score as the sum of the parameters, with a minimum of 0 and a maximum of 24; lower scores are better.
The endpoint was assessed at Days 1, 3-5, 14, 30 and 3 months after laser exposure. Repeated assessments can describe the timing and course of local reactions, rather than capturing only a single observation. A composite score also aims to represent overall reaction burden across several local findings. These are general reasons such measures may be used; they do not establish that the score is validated or that it captures every aspect of tolerability in this study.
The registry specifies the median and inter-quartile range as the summary measures. It does not report the observed median, inter-quartile range, or change in score at any assessment. Consequently, the size and precision of the primary endpoint findings cannot be evaluated from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the question and the planned measurement approach, but it does not provide numerical results for the primary endpoint. Although the outcome is described as a change in total local skin-reaction score and specifies assessment times, no observed score, change estimate, median, inter-quartile range, confidence interval, or statistical test is reported. The primary outcome's direction and magnitude therefore cannot be interpreted from this record.
The same limitation applies to tumor clearance. Clinical clearance assessed by a physician, imaging-based complete clearance, and histological clearance are listed as secondary outcomes. The record does not give the observed results for these outcomes, their denominators, or the timing of their assessments. The study's stated interest in clearance should not be mistaken for evidence of a particular clearance result.
The single-group design places an important boundary on interpretation even if outcome values are available elsewhere. Without a concurrent comparator, changes after treatment cannot by themselves distinguish an intervention effect from natural changes in lesions, measurement variation, or other influences. The open-label, non-blinded assessments also mean that the physician knew the treatment context; the registry does not report procedures to reduce the potential influence of that knowledge on scoring.
The primary outcome is summarized using a median and inter-quartile range, which can describe the center and spread of observed scores without assuming a symmetric distribution. Those summaries alone, if reported, would not quantify uncertainty about a treatment effect or establish a comparison. The record provides no confidence intervals or inferential analysis for the primary endpoint. It lists no analysis records, and a statistical analysis plan is not reported in the registry record.
The posted safety summary records 0 participants with serious adverse events and 0 with other adverse events among 19 participants at risk, with 0 deaths. These are counts for the safety categories recorded; they do not supply a detailed account of every possible local reaction. The primary endpoint itself was designed to measure local skin reactions, but its observed scores are absent. Thus the safety counts do not substitute for the missing primary tolerability results.
Overall, the registry supports a description of the study's design, eligible population, intervention, and intended outcome measures. It does not support conclusions about the size, consistency, or precision of observed tolerability or tumor-clearance outcomes. The enrollment and safety denominators also differ, and the reason is not reported in the registry record.
9. Statistical Methods Explained
The study is single-group and uncontrolled. In general, a single-group study can record outcomes after an intervention, but it does not estimate a direct contrast with a concurrent control group. Any observed change can be described in the studied group; attributing that change specifically to the intervention requires caution because other explanations are not ruled out by the design. Here, allocation is recorded as not applicable, masking is none, and the registry describes the study as open-label.
What does the primary summary measure?
The primary endpoint is a composite score for local skin reactions. The record states that the individual findings were graded on a severity scale from 0 to 4 and that a total score was calculated from the findings, with a minimum of 0 and maximum of 24. In general, a composite can condense multiple related observations into one measure, while also making interpretation dependent on how its component findings are combined. The registry record does not provide results for the component findings or describe any additional weighting.
The stated summary is the median with the inter-quartile range. In general, the median identifies the middle of an ordered set of observations, while the inter-quartile range describes the spread of the central half. These measures can be useful when a score's distribution is skewed or contains unusually high or low observations. They do not, on their own, express uncertainty about a population value or quantify a between-group effect. No observed median or inter-quartile range is reported in the registry record.
Why do the assessment times matter?
The physician assessments were scheduled at Days 1, 3-5, 14, 30 and 3 months after laser exposure. Repeated observations can show whether scores vary over follow-up, but interpretation depends on the availability of measurements at each time and on how repeated observations are analyzed. The registry record does not report the number assessed at each time, how within-participant measurements were handled, or whether the primary endpoint refers to a particular time comparison or a summary across time. It therefore does not permit reconstruction of the longitudinal analysis.
What can the design say about comparison?
There is no randomized or control comparison in the described design. General statistical reasoning is that an uncontrolled before-and-after pattern can be affected by time trends, natural history, co-occurring care, and measurement variability. These possibilities are not quantified in the registry record. Because the assessment was non-blinded, observer expectations could also influence clinical scoring in principle. This is a general risk of non-blinded assessment, not evidence that scoring was biased in this study.
What do the planning assumptions mean?
The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. These are planning assumptions, not observed power. In general, a sample-size calculation estimates the number of participants or events needed under specified assumptions; it does not show the probability that a completed study has detected an effect. The two-arm equal-allocation assumptions do not match the described single-group study. The observed effect and calculated participant counts are not reported in the registry record, so the illustration cannot be independently interpreted from this record.
The registry lists no analysis records. It does not report a statistical test for the primary endpoint, a confidence interval, an adjustment for baseline values, or a method for repeated measurements. Those absent details should not be filled in by assuming a conventional approach. The posted results therefore allow the study's measurement plan to be described, but not an independent reconstruction of its statistical analysis.
10. Multiplicity, Missing Data and Analysis Populations
The study measured local skin reactions at multiple follow-up times and listed secondary outcomes for clinical, imaging-based, and histological tumor clearance. Considering several outcomes or time points creates multiple opportunities to observe patterns. In general, multiplicity methods address the increased chance of misleading findings when many statistical comparisons are made. The registry record does not report a multiplicity adjustment, a hierarchy among the secondary outcomes, or which outcomes were intended to support formal statistical claims. It also lists no analysis records, so it is not possible to determine which comparisons, if any, were performed.
Missing-data handling is not reported in the registry record. There is no account of the number of participants measured at each follow-up time, missing scores, withdrawals, or reasons for missing observations. The record does not describe imputation, a complete-case analysis, or another approach. These omissions matter because repeated assessments may not all be available for every participant, and the interpretation of summaries can depend on which observations contribute.
The analysis population is also not reported in the registry record. It is not stated whether the primary endpoint analysis included all enrolled participants, only participants who received treatment, or another defined group. The listed enrollment is 20, while safety outcomes are reported for 19 at risk; the reason for the difference is not given. The record does not clarify how that difference relates to outcome analyses.
In general, a prespecified statistical plan can clarify endpoint priorities, missing-data rules, and how multiple comparisons will be handled. Such a plan is not reported in the registry record. Without these details and without outcome estimates, the extent of selective reporting or the robustness of any analysis cannot be assessed.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Basal Cell Carcinoma Patients | 0 | 19 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Basal Cell Carcinoma Patients | 0 of 19 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Basal Cell Carcinoma Patients | 0 of 19 |
The registry safety summary lists 19 participants at risk for serious adverse events and reports 0 affected. It also lists 19 at risk for other adverse events and reports 0 affected. The death count is 0. These are the recorded counts for the specified categories; they should be read as safety-summary figures, not as a complete description of the local skin-reaction endpoint.
The enrollment is listed as 20, whereas the safety denominators are 19. The reason for this difference is not reported in the registry record. The record does not explain whether the difference reflects treatment exposure, follow-up, or another factor, so no explanation should be inferred from the counts alone.
Zero reported events in these categories does not establish that no local reactions occurred. Local reactions were separately assessed as the primary outcome, but their scores are not reported. The registry also does not provide a detailed listing of non-serious event types, timing, severity, or duration. Accordingly, the safety figures give a narrow account of the event categories and denominators recorded, rather than a full characterization of tolerability.
12. What the Result Does, and Does Not, Mean
The record describes an exploratory, open-label study of laser-assisted topical cisplatin plus 5-fluorouracil in adults with superficial or nodular basal cell carcinoma. It establishes that local skin reactions and several forms of tumor clearance were measured or listed as outcomes. It also identifies the schedule and summary approach for the primary local-reaction score. This is information about what the study set out to assess, not a report of what those assessments found.
The registry record does not provide the observed primary scores, their changes, or the listed clearance outcomes. It therefore does not establish the frequency or severity of local reactions, the extent of tumor clearance, or the precision of any such estimates. The safety summary reports 0 serious adverse events and 0 other adverse events among 19 participants at risk, and 0 deaths, but those counts do not replace the missing endpoint results or describe all local reactions.
The absence of a control group also limits causal interpretation. Even if a change in score or clearance were reported, a single-group observation would not establish how outcomes would compare with another treatment or with no intervention. The open-label design and non-blinded physician assessments are relevant context when interpreting clinical scoring.
These limitations do not mean the study has no descriptive value. Its design and outcome definitions document a clinical investigation of tolerability and tumor response. But the information in the registry record is insufficient to quantify the observed outcomes, assess uncertainty, or draw a comparative conclusion. The record does not report a statistical analysis plan, the analysis population, or missing-data procedures, further limiting independent evaluation of the results.
13. Why This Trial Matters Statistically
This study is statistically notable for the contrast between its outcome ambitions and its design. It assessed both tolerability and tumor clearance, but used a single-group, uncontrolled, open-label structure. That design can document the course of measurements in the treated group, yet it cannot provide a randomized comparison or separate changes over time from other influences. The distinction is essential when interpreting exploratory clinical evidence.
The primary endpoint is a composite of several local findings measured repeatedly after treatment. Composite scores can offer a concise measure of overall burden, while requiring careful attention to their components, scoring rules, timing, and missing observations. Here, the registry supplies a score definition and assessment schedule, but not component-level or overall score results. Readers therefore cannot examine whether any particular finding drove the composite or how scores changed over follow-up.
The record also illustrates why a stated planning approach should not be confused with the analysis of a completed study. Its planning assumptions describe equal allocation between two arms, although the described trial has one group. The planning illustration is not observed power, and the observed effect and calculated counts are not reported in the registry record. Such assumptions should not be read as evidence that the study was powered for its outcomes.
Finally, the safety summary and enrollment do not have the same denominator: enrollment is listed as 20, while safety categories list 19 at risk. With no explanation, outcome-specific denominators, or missing-data account, readers cannot determine how participant availability shaped the reported summaries. These features make transparent reporting of estimates, uncertainty, and analysis populations particularly important for interpreting this exploratory study.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The key limitation for interpreting results is that the registry record does not report numerical results for the primary endpoint or the listed tumor-clearance outcomes. Without estimates and measures of uncertainty, the magnitude, variability, and precision of the observed outcomes cannot be assessed. The record's completed status does not supply the missing results.
The study is described as uncontrolled, single-group, open-label, and non-blinded for clinical assessment. There is no concurrent comparison to contextualize changes over time. A physician who knows the treatment context assessed local skin findings, so observer influence is possible in principle; the registry does not report safeguards or independent review.
The record does not report how many participants contributed measurements at each assessment time, the number of missing observations, withdrawals, or reasons for missingness. It also does not specify the analysis population or how repeated scores were handled. The enrollment of 20 and safety denominator of 19 are not reconciled in the registry record.
The primary outcome combines several local findings into one score. Although the scoring scale and stated score range are described, the record does not give component-level results or explain whether any components were weighted. A composite can conceal variation among its parts, limiting interpretation when only a total score is available; in this record, even the total results are absent.
Multiplicity procedures, a statistical analysis plan, and formal analyses are not reported. The listed planning assumptions use two-arm equal allocation despite the single-group design, and the calculated sample-size results are not reported in the registry record. Together, these gaps restrict assessment of the planned analysis and the strength of any conclusions.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Topical Laser-assisted Combination Chemotherapy for Basal Cell Carcinoma- a Clinical Study — NCT03541252.
- Registry record last updated 2022-04-14; status last verified 2022-03.
- Results first posted 2022-03-15.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry record describes a completed prospective, uncontrolled, open-label exploratory study of laser-assisted topical cisplatin plus 5-fluorouracil for superficial or nodular basal cell carcinoma. It lists enrollment of 20 and identifies local skin reactions as the primary outcome, summarized by median and inter-quartile range across assessments at Days 1, 3-5, 14, 30 and 3 months.
Clinical, imaging-based, and histological tumor clearance are listed as secondary outcomes. Numerical results for these outcomes are not reported in the registry record. The safety summary reports 0 serious adverse events and 0 other adverse events among 19 participants at risk, with 0 deaths; the reason the safety denominator differs from enrollment is not reported. The record lists no analysis records and does not report the analysis population, missing-data procedures, or a statistical analysis plan.