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 Adjuvant Chemoradiation With Weekly Oxaliplatin in Resected Head and Neck Cancer (NCT00256308), a na phase 2 study. The primary outcome is Frequency and Severity of Toxicities.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00256308 |
| Phase | Phase 2 |
| Condition | Head and Neck Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 6 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of California, Irvine |
| Results posted | Yes |
2. Clinical Question
Population
Patients with high-risk resected squamous cell carcinoma of the head and neck region. The registry record identifies head and neck cancer as the condition; further eligibility details are not reported in the registry record.
Intervention
Adjuvant chemoradiation using oxaliplatin 70 mg/m2 intravenously over 120 minutes once a week during radiation, with radiation at 200 centigray per day, Monday through Friday.
Comparator
There was no comparison group. The study is recorded as a single-group design, with no allocation to a control arm.
Primary question
What frequency and severity of toxicities were observed during the study timeframe of 2 years? The registry record says toxicity events were not analyzed for treatment relatedness.
The clinical question is therefore about the safety experience recorded in a small, uncontrolled study, not a comparative estimate of benefit or harm. Because every enrolled participant was in the oxaliplatin group and there was no control group, the study cannot distinguish events associated with the regimen from events that might also have occurred without it. The registry record lists locoregional control, disease-free survival, overall survival and sites of relapse as secondary outcomes, but analyzed results for these outcomes are not reported in the registry record.
The study is described as Phase II and enrolled 6 participants. It was terminated by the funding source for slow accrual. Although data were collected, the registry record states that event relatedness was not assessed at collection and could not be assessed retrospectively because complete patient records were not accessible. Thus, the central safety question is listed as an endpoint, but the record does not contain an analyzed answer to it.
3. Trial Design
This was a Phase II, single-group study sponsored by the University of California, Irvine. The registry record gives enrollment as 6 and describes the study population as patients with high-risk resected squamous cell carcinoma of the head and neck region. The allocation field is recorded as not applicable, and masking is listed as none. Those features are consistent with a study in which participants received the study regimen without random assignment or blinding.
The intervention description specifies oxaliplatin 70 mg/m2 intravenously over 120 minutes once a week during radiation. Radiation was specified at 200 centigray per day using megavoltage equipment with energy of Cobalt 60 or higher, on weekdays from Monday through Friday. The registry record does not report a separate control regimen or a concurrent comparison arm. Details such as treatment completion, dose modifications, and the number of participants who received each component are not reported in the registry record.
The primary endpoint was frequency and severity of toxicities, with a stated timeframe of 2 years. Secondary outcomes listed in the registry record include locoregional control rate, disease-free survival rate, overall survival rate and sites of relapse. Results for these outcomes are not reported in the registry record.
The study began in 2005-02, with primary completion listed as 2010-05. Its status is terminated. The registry explanation says that the funding source ended the study because of slow accrual; upon notification, the institutional review board closure was submitted and research procedures stopped, including completion of any analysis of collected data. The registry record does not report a statistical analysis plan, a sample-size justification, interim analyses, or a prespecified method for summarizing the primary endpoint. No analyzed endpoint results are reported.
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 | Oxaliplatin |
|---|---|
| STARTED | 6 |
| COMPLETED | 4 |
| NOT COMPLETED | 2 |
Reasons for not completing this period:
| Reason | Oxaliplatin |
|---|---|
| Death | 2 |
Analysis population for the primary outcome, as defined in the registry: Although data were collected, events were not analyzed at the time of collection for relatedness to treatment and this analysis cannot be performed retrospectively due to lack of access to complete patient records.
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 | Oxaliplatin |
|---|---|---|
| Participants analysed | 6 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 5 |
| Age, Categorical: >=65 years | Participants | 1 |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 3 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 3 |
| Race/Ethnicity, Customized: American Indian or Alaska Native | participants | 0 |
| Race/Ethnicity, Customized: Asian | participants | 0 |
| Race/Ethnicity, Customized: Native Hawaiian or Other Pacific Islander | participants | 0 |
| Race/Ethnicity, Customized: Black or African American | participants | 0 |
| Race/Ethnicity, Customized: Caucasian | participants | 6 |
| Race/Ethnicity, Customized: More than one race | participants | 0 |
| Race/Ethnicity, Customized: Unknown or Not Reported | participants | 0 |
| Region of Enrollment: United States | participants | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Frequency and Severity of Toxicities, measured over 2 years.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled frequency and severity of toxicities, with a timeframe of 2 years. In general, a toxicity endpoint is intended to describe unwanted events during or after treatment, including how often events occur and how serious they are. Frequency concerns how many people or events are recorded; severity concerns the clinical grade or seriousness assigned under the study's definitions. These are related but distinct dimensions, and a record needs clear definitions and consistent assessment to interpret them.
Such an endpoint is used in a treatment study to characterize the observed safety experience. In a single-group study, the endpoint can describe what was recorded among participants receiving the regimen, but by itself it cannot establish whether the regimen caused an event. A comparison group and a suitable analysis can help estimate differences in event occurrence, while attribution also depends on the study's assessment procedures.
For this study, the registry record explicitly says that events were not analyzed at the time of collection for relatedness to treatment. It also says that retrospective analysis could not be performed because complete patient records were inaccessible. The registry record does not provide analyzed frequency or severity results for the primary endpoint, operational definitions, a grading scale, or a detailed assessment schedule. The safety counts reported separately should therefore not be treated as a completed analysis of the stated primary endpoint or as a determination of causality.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The study was small, single-group and terminated before its planned work was completed. Enrollment was 6. The primary endpoint was toxicity frequency and severity over 2 years, but the registry record states that the relevant events were not analyzed for treatment relatedness and could not be analyzed retrospectively because complete patient records were unavailable. No analyzed primary-endpoint results are reported. Consequently, the central endpoint cannot be interpreted as a quantified estimate of treatment-related toxicity from this record.
The adverse-event fields report 6 participants at risk in the oxaliplatin group, 3 affected in the serious adverse event field, 4 affected in the other adverse event field, and 2 deaths. The record also lists serious adverse event terms with percentages: dry mouth, 33.3%; mucositis, 16.7%; dermatitis, 16.7%; pain, 16.7%; and nausea, 16.7%. These are descriptive entries, not comparative effects. The registry does not establish that the listed events or deaths were caused by study treatment. It also does not report a completed attribution analysis.
There is no control group from which to estimate how the observed counts compare with another treatment or with no study treatment. A single-group count describes the recorded experience in this enrolled group; it does not isolate the effect of the regimen from the underlying disease, other care, or chance variation. The small enrollment also means that the counts summarize few participants. The record does not report uncertainty intervals for these safety figures, so their precision cannot be quantified from the posted results.
The listed secondary outcomes concern disease control, survival and relapse sites, but analyzed results for them are not reported in the registry record. No treatment-effect estimate, hypothesis test, or confidence interval for those outcomes is available in the record. It would therefore be inappropriate to infer an efficacy result from the study title, rationale, intervention description, or safety fields.
In general, a confidence interval describes a range of values compatible with data and a specified statistical procedure; it communicates uncertainty rather than proving that an effect is present or absent. No such interval is reported for the primary endpoint in this record. The record's termination and lack of completed analysis are central to interpretation: the posted safety counts are limited descriptive information, while the intended endpoint analysis remains unavailable. The study does not furnish a comparative conclusion about the regimen.
9. Statistical Methods Explained
In general, trial design determines which questions the data can answer. A randomized comparison can estimate differences between assigned groups under its design assumptions. A single-group study instead describes outcomes among people who received the study regimen. NCT00256308 is recorded as a single-group Phase II study, with no allocation to a comparator and no masking. Its design can document events recorded among enrolled participants, but cannot directly compare their experience with an alternative group.
What does a single-group result describe?
In general, an observed proportion or count in a single group is a description of that group. It is not automatically an estimate of the treatment's causal effect. Participants may experience events related to their illness, background care, or other factors, and without a comparison group those explanations cannot be separated using a between-group contrast. Even a careful causal assessment of individual events would not replace a controlled comparison for estimating relative risk.
For this study, the registry record gives counts for participants at risk and affected in serious and other adverse event fields. These counts can be read as descriptive safety entries. However, the record explicitly says that event relatedness was not analyzed at collection and could not be assessed retrospectively because complete patient records were inaccessible. That limitation prevents interpreting the entries as a completed assessment of treatment-attributed toxicity.
Why does sample size affect interpretation?
In general, estimates based on few observations can change substantially when individual observations differ. Counts from a small enrolled group therefore tend to carry considerable uncertainty, particularly for uncommon outcomes. A confidence interval, when calculated with an appropriate method, can show a range of uncertainty around an estimate. No confidence interval for the primary endpoint is reported in the registry record, and the lack of an endpoint analysis means the uncertainty cannot be reconstructed from the posted results.
Planning calculations are also different from observed evidence. In general, sample-size planning asks how many participants or events might be needed to detect a prespecified effect under stated assumptions. Such calculations do not add information to the observed study results and do not show that a trial had a particular probability of success after it was completed. The registry record does not report the trial's own sample-size justification or statistical planning assumptions. Any planning illustration based on an observed effect would be hypothetical, not a substitute for an analysis, and this study has no reported analyzed primary effect on which to base a trial-specific conclusion.
What does the absence of a reported test mean?
In general, a hypothesis test assesses compatibility between data and a specified null model under assumptions. A p-value is not the probability that a treatment works, and a non-significant result does not establish equivalence or absence of an effect. Interpretation also requires an endpoint definition, analysis population, model, and account of missing data. Those details matter because different reasonable choices can affect both the estimate and its uncertainty.
The registry record reports no analyses and says research procedures stopped before any analysis of collected data was completed. It does not report a statistical analysis plan, an inferential model, a hypothesis test, or a confidence interval for the primary endpoint. As a result, there is no basis in the record for a formal test of toxicity frequency or severity. The lack of a reported test is not evidence that the events did not occur; it reflects the absence of a completed analysis.
Why does event attribution matter?
In general, adverse-event collection and causality assessment are separate tasks. Collection records an event; attribution evaluates whether it may be related to treatment, using clinical information and prespecified procedures. Severity grading is also distinct from seriousness: severity refers to degree, whereas serious-event reporting uses regulatory or protocol criteria. The registry record does not provide the grading rules or event-level assessments needed to interpret severity in detail. Since relatedness was not analyzed, the listed safety terms and counts should be read as reported events, not as confirmed treatment effects.
Over-dispersion is a general concern when count data vary more than a simple statistical model expects. In general, this can make uncertainty estimates too narrow if the model assumes less variability than the data contain. The registry record does not report a count model or enough analyzed data to assess over-dispersion; this concept therefore explains a general modeling issue, not a finding from this study. More broadly, any statistical method would need to respect the study's small single-group design, the endpoint definitions, and the incompleteness of the outcome analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists several secondary outcomes in addition to the primary toxicity endpoint. In general, examining multiple outcomes creates a multiplicity issue: the more separate questions tested, the greater the chance that some results appear unusual by chance if each is judged independently. Researchers may address this through a prespecified hierarchy, adjustment procedure, or clear distinction between confirmatory and exploratory analyses. The registry record does not report a multiplicity strategy, an analysis plan, or completed statistical tests. No multiplicity-adjusted results are reported in the registry record.
The record does not describe the analysis population for the primary endpoint or the secondary outcomes. It does not state whether analyses were intended to include all enrolled participants, only those who began treatment, or another defined group. The number of participants with complete endpoint follow-up is not reported in the registry record. The primary endpoint timeframe is stated as 2 years, but participant-level follow-up and missingness details are not reported.
In general, missing data can affect both the estimated outcome and its uncertainty, especially when the reasons for missingness are related to participants' health or their observed outcomes. Appropriate handling depends on the endpoint, timing, and reasons data are unavailable. The registry record says complete patient records were inaccessible, preventing retrospective analysis of event relatedness. It does not report a missing-data method, sensitivity analysis, or participant-level completeness assessment. Given that data analysis was stopped, the posted record supports no conclusion about how missingness would have influenced an endpoint estimate.
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 |
|---|---|---|---|
| Oxaliplatin | 3 | 6 | 50.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Oxaliplatin | 2 of 6 |
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 |
|---|---|
| Oxaliplatin | 4 of 6 |
Most frequent serious adverse event terms
| Event term | Organ system | Oxaliplatin |
|---|---|---|
| Dry Mouth | General disorders | 2 of 6 |
| Mucositis | Gastrointestinal disorders | 1 of 6 |
| Dermitis | Skin and subcutaneous tissue disorders | 1 of 6 |
| Pain | General disorders | 1 of 6 |
| Nausea | General disorders | 1 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Oxaliplatin |
|---|---|---|
| Red Skin | Skin and subcutaneous tissue disorders | 1 of 6 |
| Elevated Creatinine | Renal and urinary disorders | 1 of 6 |
| Fever | General disorders | 1 of 6 |
| Anemia | Blood and lymphatic system disorders | 1 of 6 |
| Hypomagnesemia | Blood and lymphatic system disorders | 1 of 6 |
| Hypertension | Cardiac disorders | 1 of 6 |
| Constipation | Renal and urinary disorders | 1 of 6 |
| Lymphopenia | Blood and lymphatic system disorders | 1 of 6 |
| Alopecia | Immune system disorders | 1 of 6 |
| Emesis | General disorders | 1 of 6 |
Serious events with the highest arm-level rate: dry mouth (33.3%), mucositis (16.7%), dermitis (16.7%), pain (16.7%), nausea (16.7%).
The registry record lists 6 participants at risk in the oxaliplatin group. It reports 3 affected in the serious adverse event field, 4 affected in the other adverse event field, and 2 deaths. These are separate registry entries and should be read as descriptive counts, not as a comparison between treatments or as proof of causation. The record does not report a control group.
The listed serious adverse event terms are dry mouth at 33.3%, mucositis at 16.7%, dermatitis at 16.7%, pain at 16.7%, and nausea at 16.7%. These percentages are reported as registry entries. They do not by themselves indicate whether an event was attributed to oxaliplatin, how severe it was, or whether it met a specific severity grade. The registry record does not provide event-level detail or an analyzed relationship to treatment.
Seriousness and severity are not interchangeable concepts. In general, seriousness classifies an event according to criteria such as its consequences, while severity describes its intensity. The record's stated primary endpoint includes frequency and severity, but the registry explanation says relatedness was not analyzed and that retrospective review was not possible because complete patient records were unavailable. Therefore, these safety figures should be interpreted as limited descriptive reporting rather than a completed analysis of treatment-related toxicity.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a Phase II, single-group study of adjuvant oxaliplatin with radiation enrolled 6 participants and was terminated by the funding source for slow accrual. It also reports safety counts and selected serious adverse event terms. These details describe the study's conduct and the available safety entries; they do not provide an analyzed estimate of the primary endpoint.
The primary question concerned frequency and severity of toxicities over 2 years. The record says events were not analyzed for relatedness to treatment at the time they were collected, and this could not be done retrospectively because complete patient records were inaccessible. No analysis of collected data was completed after the termination notification. The posted counts therefore cannot be used to conclude that the regimen caused any particular event or death. Nor can they establish that no treatment-related events occurred.
The single-group design also places a limit on causal interpretation. There is no comparator against which to estimate whether an event rate differed from another treatment or from the experience without the study regimen. Counts in a small uncontrolled group are descriptive, and the record does not report uncertainty intervals for the primary endpoint. Secondary outcomes are listed, but their analyzed results are not reported in the registry record.
In general, an inconclusive or unavailable analysis is not the same as evidence of no effect. It means that the available record does not resolve the statistical question. The termination reason and incomplete analysis explain why this study cannot support a comparative estimate, but they do not determine what a completed analysis might have shown. The appropriate interpretation is limited to the registry entries recorded: enrollment, design, termination, and the descriptive adverse-event entries, with no completed primary-endpoint result.
13. Why This Trial Matters Statistically
Statistically, this study illustrates the difference between an endpoint being named and an endpoint being analyzed. The primary endpoint was toxicity frequency and severity, with a 2-year timeframe. Yet the registry record says events were not assessed for treatment relatedness and that a retrospective assessment could not be performed because complete patient records were unavailable. The endpoint's presence in the record should not be mistaken for a result.
The study also demonstrates how design affects inference. A single-group study can document outcomes among enrolled participants, but it cannot produce a randomized between-group treatment contrast. This matters particularly for safety interpretation, where events may have multiple possible causes. The adverse-event counts remain descriptive because there is no comparator and no completed attribution analysis.
Termination for slow accrual and the decision to stop research procedures before analysis left the planned clinical questions unanswered in the registry record. This makes transparent reporting of study status, collected safety information and analytical limitations especially important. Readers can distinguish the observed entries from conclusions that would require a completed analysis, adequate follow-up information, or a comparison group.
In general, small studies can be informative for feasibility and for identifying what was recorded, but the strength of conclusions depends on the design, data completeness and analysis. Here, the record supplies no analyzed efficacy results and no completed primary safety analysis. The statistical lesson is not a claim about the treatment; it is that a study's title, rationale, and collected observations do not substitute for an estimable outcome analysis.
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.
Several limitations specific to this study constrain interpretation. Enrollment was 6, and the design was single-group, with no control arm. As a result, the registry record does not permit a comparative estimate of safety or efficacy. The study was terminated by the funding source for slow accrual, and the record says that research procedures stopped, including completion of any analysis of collected data.
The primary endpoint was frequency and severity of toxicities, but the record states that events were not analyzed for relatedness to treatment. It further states that retrospective analysis could not be performed because complete patient records were inaccessible. The registry record does not report a completed endpoint analysis, an event grading scale, operational definitions, or a detailed account of completeness of follow-up. The stated 2-year timeframe does not by itself establish that every participant had complete observation for that period.
Although adverse-event counts and selected terms are listed, they are descriptive and do not establish causality. The record does not report a statistical analysis plan, sample-size justification, interim analyses, missing-data methods, or multiplicity procedures. It also does not report analyzed results for the listed secondary outcomes. These omissions mean that uncertainty, outcome ascertainment, and the intended inferential framework cannot be evaluated from the registry record.
The registry background describes prior experience with oxaliplatin-containing regimens in other cancers, but that background is not an outcome analysis of this head and neck study. It should not be used to fill gaps in the trial's own results. The specific study record remains limited by its small enrollment, lack of comparison, termination, and absence of completed outcome analyses.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Adjuvant Chemoradiation With Weekly Oxaliplatin in Resected Head and Neck Cancer — NCT00256308.
- Registry record last updated 2018-05-01; status last verified 2018-04.
- Results first posted 2018-05-01.
- 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
NCT00256308 is a Phase II, single-group study titled Adjuvant Chemoradiation With Weekly Oxaliplatin in Resected Head and Neck Cancer. It was sponsored by the University of California, Irvine, and enrolled 6 participants. The intervention description specifies weekly oxaliplatin during weekday radiation. The primary endpoint was frequency and severity of toxicities over 2 years; secondary outcomes included locoregional control, disease-free survival, overall survival and sites of relapse.
The study status is terminated. The registry record attributes termination to slow accrual and states that research procedures stopped before analysis of collected data was completed. It reports that event relatedness was not analyzed and could not be assessed retrospectively because complete patient records were unavailable. Adverse-event counts and terms are present, but no analyzed primary-endpoint result or secondary-outcome result is reported in the registry record. The design and incomplete analysis support descriptive reading only, not a comparative treatment conclusion.