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 Neoadjuvant Chemotherapy With or Without Second-Look Surgery Followed by Radiation Therapy With or Without Peripheral Stem Cell Transplantation in Treating Patients With Intracranial Germ Cell Tumors (NCT00047320), a na phase 2 study. The primary outcome is Response to Induction Chemotherapy.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00047320 |
| Phase | Phase 2 |
| Condition | Brain Tumor, Central Nervous System Tumors, Childhood Germ Cell Tumor |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 104 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Children's Oncology Group |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns patients with newly diagnosed intracranial germ cell tumors. The registry record reports 102 eligible patients and says 85 completed induction chemotherapy with sufficient data for response assessment. Further eligibility criteria and details about the enrolled population are not reported in the registry record.
Intervention
The treatment strategy began with neoadjuvant, or induction, chemotherapy. Listed drugs include carboplatin, etoposide, ifosfamide, and thiotepa. The study title and description also refer to possible second-look surgery and to radiotherapy, with or without peripheral stem cell transplantation. The precise treatment received by each patient is not reported in the registry record.
Comparator
This is recorded as a single-group study, with allocation listed as not applicable and masking listed as none. There is no randomized control group described. The trial therefore does not provide a like-for-like comparison between alternative treatment strategies within a randomized design. Any comparison with another group would require information not reported in the registry record.
Primary question
The primary outcome asks whether patients had a complete or partial response after induction chemotherapy, defined as at least a 65% reduction in tumor size. The assessment timeframe is 18 weeks, and the description says central review was used. The number meeting this response definition, and an estimate of response with uncertainty, are not reported in the registry record.
In practical terms, the study examines a response outcome before radiotherapy within a treatment program that could include additional procedures or treatment. The official title describes the aim as assessing whether neoadjuvant chemotherapy, with or without second-look surgery, could eliminate measurable disease before radiotherapy. The brief summary also names progression-free and overall survival as goals. These stated aims do not establish that the corresponding outcomes were achieved: outcome estimates are not reported in the registry record.
The central statistical question is therefore limited by the available results. The design and response definition can be described, but the primary endpoint cannot be quantified from the registry record. With no randomized comparator, the study is also not designed to isolate the effect of chemotherapy, surgery, transplantation, or radiotherapy against an alternative treatment group. Its question is about response and subsequent outcomes under a treatment strategy, not a controlled estimate of the causal effect of a single treatment component.
3. Trial Design
This is a phase II, single-group study sponsored by Children's Oncology Group. The registry record lists allocation as not applicable and masking as none. It lists enrollment of 104, a start date of 2004-01, primary completion of 2009-02, and status as completed. These record entries describe the trial's registration and design; they do not establish how many participants contributed data to each outcome.
The intervention list includes carboplatin, etoposide, ifosfamide, thiotepa, neoadjuvant therapy, conventional surgery, adjuvant therapy, and peripheral blood stem cell transplantation. The available arm description is titled Radiation Therapy (CR from Induction). It describes six cycles of induction chemotherapy, alternating carboplatin and etoposide with ifosfamide and etoposide, over 18 weeks unless delays occur due to myelosuppression or unanticipated toxicity. The description ends before the full treatment details, so subsequent treatment schedules and decision rules are not reported in the registry record.
The trial title refers to chemotherapy with or without second-look surgery and radiation therapy with or without peripheral stem cell transplantation. These options should not be read as randomized treatment assignments: the registry record classifies the model as single group and does not describe a randomized comparison. It does not give a complete account of which participants received which optional procedures or subsequent treatments.
The primary response population is described separately from overall enrollment. Of 102 eligible patients, 85 completed induction chemotherapy with sufficient data to assess response, using central review. The reason that some eligible patients are not included in this response-assessable group is not reported in the registry record. Nor does the record provide a flow accounting for all enrolled participants across eligibility, treatment, follow-up, and outcome analysis.
Secondary outcomes named in the record include event-free survival, progression-free survival, overall survival, toxic death, and non-hematological grade 4 toxicity. Their estimates, analysis methods, and follow-up details are not reported in the registry record. The single-group design can describe outcomes observed during the study, but by itself does not provide a randomized comparison between treatment options.
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 | Radiation Therapy (CR From Induction) |
|---|---|
| STARTED | 104 |
| COMPLETED | 76 |
| NOT COMPLETED | 28 |
Reasons for not completing this period:
| Reason | Radiation Therapy (CR From Induction) |
|---|---|
| Lack of Efficacy | 8 |
| Lost to Follow-up | 1 |
| Physician Decision | 8 |
| Withdrawal by Subject | 9 |
| Ineligible | 2 |
Analysis population for the primary outcome, as defined in the registry: Of the 102 eligible patients, 85 completed induction chemotherapy with sufficient data to assess response. Central review response assessment is used.
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 | Radiation Therapy (CR From Induction) |
|---|---|---|
| Participants analysed | 104 | |
| Age, Continuous | years | 12 (3 to 23) |
| Sex: Female, Male: Female | Participants | 25 |
| Sex: Female, Male: Male | Participants | 79 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 1 |
| Race (NIH/OMB): Asian | Participants | 8 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 2 |
| Race (NIH/OMB): Black or African American | Participants | 9 |
| Race (NIH/OMB): White | Participants | 72 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 12 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 17 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 85 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 2 |
| Region of Enrollment: United States | participants | 88 |
| Region of Enrollment: Canada | participants | 10 |
| Region of Enrollment: Australia | participants | 5 |
| Region of Enrollment: New Zealand | participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Response to Induction Chemotherapy, measured over 18 weeks.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is response to induction chemotherapy. The registry defines response as a complete or partial response involving a reduction of at least 65% in tumor size after induction chemotherapy. The stated timeframe is 18 weeks, and central review response assessment is used. The response outcome is expressed as a count of participants, but the number who met the definition is not reported in the registry record.
A response endpoint is used to describe whether disease has decreased according to a prespecified criterion at a defined point in treatment. In general, a threshold-based endpoint turns an assessment into a binary outcome: each assessed participant either meets the response definition or does not. This can make a treatment-stage outcome easier to communicate, while the threshold necessarily simplifies the underlying variation in tumor change. The registry description does not state how complete and partial responses were distinguished beyond the stated reduction criterion.
The official title frames the study around eliminating measurable disease before radiotherapy. The brief summary describes response before radiation as an objective, alongside progression-free and overall survival. Those longer-term outcomes address different questions from the induction response endpoint. A response count alone would not establish how long a response lasts or what later outcomes occur. Conversely, survival outcomes cannot be inferred from the response definition.
Because the response count and an uncertainty interval are not reported in the registry record, the primary endpoint cannot be numerically interpreted from this record. The study's endpoint definition and assessable population are described, but the observed response proportion, its precision, and any comparison with a target or external benchmark are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record supplies important design context but not the main numerical primary outcome. It defines response after induction chemotherapy and identifies a response-assessable population of 85 among 102 eligible patients. It does not report how many assessed patients achieved complete or partial response. Consequently, the central quantity needed to characterize the primary outcome is unavailable in the registry record, as is an uncertainty interval around that quantity. The record does not support a numerical conclusion about the frequency or precision of response.
This distinction matters because an endpoint definition is not an endpoint result. A threshold of at least a 65% reduction in tumor size specifies how response is classified; it does not reveal how often that threshold was met. Likewise, identifying central review describes the assessment approach but does not supply the result or explain the agreement between central and local assessments. Such agreement information is not reported in the registry record.
The study is single group rather than a randomized comparison. Any outcomes observed in the study would describe the participants receiving the study treatment strategy, subject to the available follow-up and analysis population. Without a like-for-like control group, differences from an external group could reflect differences in participants, treatment, assessment, follow-up, or other factors. The registry record does not describe an external comparator. The design therefore cannot be interpreted as a randomized estimate of the effect of any one treatment component.
The registry names event-free survival, progression-free survival, overall survival, toxic death, and non-hematological grade 4 toxicity as secondary outcomes. Although the record lists six outcome measures, it reports zero analyses. Outcome estimates, event counts for the survival measures, uncertainty intervals, and analysis details are not reported in the registry record. The listed objectives should not be mistaken for observed findings.
The adverse-event summary records 8 participants affected for the serious-event grouping and 70 for the other-event grouping, each with 102 at risk. The record does not clarify whether these groupings overlap, how events were attributed, or the observation period for these counts. The listed serious-event terms and their percentages provide additional descriptive information, but do not establish comparative safety or explain event severity for each participant beyond the registry categories.
Overall, this record supports a description of the trial question, single-group design, response definition, and selected adverse-event entries. It does not supply the response result or outcome analyses needed to judge the magnitude and precision of the primary outcome or secondary outcomes. No treatment-effect conclusion should be drawn from the design description alone.
9. Statistical Methods Explained
Statistical interpretation begins with the distinction between a design, an endpoint definition, and an observed result. The registry identifies a phase II, single-group study and defines response after induction chemotherapy. Those details say what the study intended to assess and how response was classified. They do not provide the number of responses, the proportion responding, or an estimate of uncertainty. Those primary results are not reported in the registry record.
What does a binary response outcome represent?
In general, a binary outcome places each assessed participant into one of two categories, such as meeting or not meeting a response definition. A count gives the number in a category; a proportion relates that count to the number assessed. A confidence interval describes the statistical uncertainty around an estimate under the chosen method and assumptions. It is not a guarantee that the true value lies within the interval. Here, the registry describes response as a count of participants and identifies 85 with sufficient data for assessment, but does not report the response count or an interval.
Threshold-based response definitions are useful for making a classification explicit, but they discard some detail. Participants just below and well below a threshold may be grouped together as not meeting the response definition, while people meeting it may have different magnitudes of tumor reduction. The registry specifies a reduction of at least 65% and central review. Further details about measurement procedures, handling of unevaluable cases, and adjudication are not reported in the registry record.
Why does the study design affect interpretation?
In general, random assignment can help make treatment groups comparable for estimating the effect of assigned strategies. This study is classified as single group, with allocation not applicable and no masking. It has no randomized comparator described in the registry record. Therefore, the outcome data, if available, would characterize results observed in the studied group rather than a randomized difference between treatment strategies. They would not isolate the contribution of chemotherapy from surgery, radiotherapy, transplantation, or other care.
The title and treatment description refer to treatment options, but the available record does not give a complete account of assignment or actual receipt of each option. It would be inappropriate to infer treatment pathways or compare subgroups on the basis of the title alone. The listed arm description also ends before all treatment details are available in the registry record.
What can planning calculations tell a reader?
General sample-size planning asks how much information a proposed study may need to detect an assumed effect under specified statistical assumptions. The planning assumptions described for calculations associated with this record are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. These assumptions are illustrative, not a description of the trial's single-group design. The record states that the effect to detect is a stated fraction of an observed effect and that time-to-event calculations use total events under a Schoenfeld approach, while other calculations are expressed as participants per arm.
Such planning values are not observed outcomes and are not observed power. They do not show what this trial achieved, nor do they replace a confidence interval for an observed result. Because no primary response count or effect estimate is reported in the registry record, the empirical response result cannot be checked from this record. The trial's own sample-size justification and statistical plan are not reported in the registry record. The illustrative allocation assumptions should not be confused with the actual study design.
How should secondary outcomes be understood?
In general, event-free survival, progression-free survival, and overall survival are time-to-event outcomes. Their interpretation requires information about events, follow-up, censoring, and the analysis method. A time-to-event estimate can make use of information about when events occur and how long participants are followed; it is not equivalent to a simple response count. The registry lists these outcomes but does not report their estimates or analysis details.
The record also names toxic death and non-hematological grade 4 toxicity. These are safety outcomes and require clear definitions, observation periods, and accounting for participants assessed. The available safety summary provides selected counts and terms, but the broader definitions and analytic approach are not reported in the registry record. Across outcomes, an estimate without its denominator and assessment context can be difficult to interpret; a result without an uncertainty measure also gives limited information about precision.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists six outcome measures, including response to induction chemotherapy and secondary measures for event-free survival, progression-free survival, overall survival, toxic death, and non-hematological grade 4 toxicity. It reports zero analyses. The statistical plan, outcome hierarchy beyond the designation of a primary endpoint, and any adjustments for testing multiple outcomes are not reported in the registry record.
In general, examining multiple outcomes or multiple analyses creates more opportunities for chance findings. A prespecified hierarchy or multiplicity adjustment can help explain how evidence across outcomes is interpreted. Without a reported plan, it is not possible to determine which comparisons or time points were prespecified, whether analyses were adjusted, or how any findings were intended to be weighed. No outcome estimates are reported in any case, so multiplicity cannot be assessed from results.
Missing-data handling is also not described. The record states that 85 of 102 eligible patients completed induction chemotherapy with sufficient data for response assessment, but it does not explain why the remaining eligible patients were not assessable, whether their missing response status was related to prognosis or treatment, or how missing outcomes were handled in analyses. This information matters because excluding participants with incomplete assessments can produce a different estimate from an approach that accounts for all eligible participants, particularly if assessability is related to outcome.
The registry does not report a detailed analysis population for each endpoint, rules for censoring survival outcomes, or a statistical plan for handling withdrawals and incomplete follow-up. These details are not reported in the registry record. The distinction between enrolled, eligible, treated, and outcome-assessed participants should therefore be kept in view, and no assumption should be made that the same participants contributed to every outcome.
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 |
|---|---|---|---|
| Radiation Therapy (CR From Induction) | 8 | 102 | 7.8% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Radiation Therapy (CR From Induction) | 70 of 102 |
Most frequent serious adverse event terms
| Event term | Organ system | Radiation Therapy (CR From Induction) |
|---|---|---|
| Neutrophil count decreased | Investigations | 3 of 102 |
| Hypokalemia | Metabolism and nutrition disorders | 2 of 102 |
| Febrile neutropenia | Blood and lymphatic system disorders | 1 of 102 |
| Nausea | Gastrointestinal disorders | 1 of 102 |
| Lymphocyte count decreased | Investigations | 1 of 102 |
| Platelet count decreased | Investigations | 1 of 102 |
| White blood cell decreased | Investigations | 1 of 102 |
| Hyperkalemia | Metabolism and nutrition disorders | 1 of 102 |
| Hypernatremia | Metabolism and nutrition disorders | 1 of 102 |
| Hypophosphatemia | Metabolism and nutrition disorders | 1 of 102 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Radiation Therapy (CR From Induction) |
|---|---|---|
| Neutrophil count decreased | Investigations | 53 of 102 |
| Platelet count decreased | Investigations | 53 of 102 |
| Anemia | Blood and lymphatic system disorders | 51 of 102 |
| White blood cell decreased | Investigations | 48 of 102 |
| Hyponatremia | Metabolism and nutrition disorders | 31 of 102 |
| Hypokalemia | Metabolism and nutrition disorders | 26 of 102 |
| Alanine aminotransferase increased | Investigations | 23 of 102 |
| Hypernatremia | Metabolism and nutrition disorders | 20 of 102 |
| Lymphocyte count decreased | Investigations | 19 of 102 |
| Hyperglycemia | Metabolism and nutrition disorders | 18 of 102 |
Serious events with the highest arm-level rate: neutrophil count decreased (2.9%), hypokalemia (2.0%), febrile neutropenia (1.0%), nausea (1.0%), lymphocyte count decreased (1.0%).
The registry's adverse-event summary records 8 participants affected in the serious-event grouping, with 102 at risk, and 70 affected in the other-event grouping, also with 102 at risk. These are descriptive counts from the record, not a comparison between treatment groups. The record does not explain whether participants could appear in both groupings, how events were attributed to treatment, or the period over which events were collected.
The listed serious-event terms are neutrophil count decreased at 2.9%, hypokalemia at 2.0%, febrile neutropenia at 1.0%, nausea at 1.0%, lymphocyte count decreased at 1.0%, and platelet count decreased at 1.0%. The record does not provide term-specific participant counts, event counts, severity details beyond the listed category, or a description of how the percentages were calculated. These entries should therefore be read as reported summaries, not as a complete account of safety.
In general, adverse-event counts depend on definitions, surveillance, reporting thresholds, and follow-up. A count of participants affected does not indicate how many events each participant experienced, and a listed term does not establish that treatment caused it. The registry record does not provide a comparator group for assessing relative safety. It also does not report the full safety-analysis methods or participant-level event details.
12. What the Result Does, and Does Not, Mean
The study record describes an effort to assess response following induction chemotherapy in newly diagnosed intracranial germ cell tumors, within a broader treatment strategy that could include surgery, radiotherapy, and peripheral stem cell transplantation. It defines a response threshold and states that central review was used. These elements clarify what the primary outcome was intended to measure.
What the record does not establish is the observed response result. The number of participants who met the complete or partial response definition is not reported in the registry record, nor is an estimate with uncertainty. It is therefore not possible from this record to quantify the response frequency or precision. The stated study purpose and endpoint definition cannot substitute for those results.
The registry's secondary outcomes include survival measures and toxicity outcomes, but their analyses are not reported. A response after induction is not itself a measure of long-term disease control or survival. Conversely, a survival outcome would answer a different question and would require its own follow-up and analysis details. Neither type of result can be inferred from the other.
The single-group design also limits causal interpretation. In general, an observed outcome in a single group reflects the experiences of the group under its treatment and care context. Without a randomized comparison, it does not establish what would have happened to comparable participants under a different strategy. The record does not support separating the effects of individual treatment components or comparing optional procedures as if they had been assigned at random.
The safety entries are similarly descriptive. They report selected adverse-event counts and terms, but not comparative risks or a complete account of event timing and attribution. They should not be treated as evidence that any particular treatment component caused, prevented, or changed an event.
Thus, the record is informative about the study's structure and the meaning of its primary endpoint, but limited for judging outcomes. It does not support a conclusion about the size, precision, or comparative effect of treatment. The absence of reported outcome analyses is a limitation of the available registry record, not evidence that an outcome did or did not occur.
13. Why This Trial Matters Statistically
This trial illustrates why statistical interpretation must separate an endpoint's definition from its result. The registry describes a clinically meaningful classification of response after induction chemotherapy, including a specific reduction threshold and central review. Yet without the number of participants who met that definition, the primary endpoint cannot be summarized quantitatively. A clear outcome rule is necessary for interpretation, but it is not a substitute for an estimate.
The study also highlights the role of design in defining the questions that data can answer. A single-group phase II study can describe outcomes in a treatment setting and can inform what further research may be worth considering. It does not provide the same basis for comparing strategies as a randomized study with a concurrent control group. The title's mention of optional procedures does not create a controlled comparison when allocation is listed as not applicable.
Another statistical lesson is that outcome labels do not carry their own evidence. Event-free survival, progression-free survival, overall survival, and toxicity are listed, but the record reports no analyses. Readers need estimates, denominators, follow-up context, and methods to understand those outcomes. Merely listing an endpoint does not show its observed value or the certainty of that value.
Finally, the registry distinguishes an eligible population from the group with sufficient response data. Such distinctions matter because conclusions depend on who was assessed and how missing outcomes were handled. The record says 85 of 102 eligible patients were assessable but does not explain the status of the remaining patients. That gap limits interpretation of the primary endpoint and underscores the importance of transparent participant accounting.
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 main limitation for interpreting efficacy is that the registry record does not report the primary response count or an estimate of its precision. It states that 85 of 102 eligible patients had sufficient data for response assessment, but gives no account of why the remaining eligible patients were not assessable or how their outcomes were handled. The response definition and central review approach are available; the result is not.
The design is single group, with no randomized comparator described. This prevents a direct randomized comparison of the treatment strategy with an alternative and limits attribution of outcomes to any specific treatment component. Although the title refers to chemotherapy with or without second-look surgery and radiotherapy with or without transplantation, the available record does not give complete treatment pathways or a basis for comparing those options.
The treatment description is incomplete in the available record. It describes induction chemotherapy and its planned duration, but ends before all details are given. Actual treatment receipt, deviations, subsequent treatment decisions, and the role of each listed intervention are not reported in the registry record.
Secondary outcomes are listed, but estimates and analysis details are not reported. Follow-up duration, censoring rules, endpoint-specific analysis populations, missing-data methods, and the statistical plan are also not reported in the registry record. The record lists selected adverse-event counts and terms but does not clarify overlap between groupings, attribution, surveillance period, or percentage denominators. These gaps constrain interpretation of both efficacy and safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Neoadjuvant Chemotherapy With or Without Second-Look Surgery Followed by Radiation Therapy With or Without Peripheral Stem Cell Transplantation in Treating Patients With Intracranial Germ Cell Tumors — NCT00047320.
- Registry record last updated 2018-02-14; status last verified 2018-01.
- Results first posted 2014-02-27.
- 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 identifies NCT00047320 as a completed phase II, single-group study sponsored by Children's Oncology Group. Enrollment is listed as 104. The study concerns neoadjuvant chemotherapy for newly diagnosed intracranial germ cell tumors, with possible surgery, radiotherapy, and peripheral stem cell transplantation referenced in the title and treatment descriptions.
The primary endpoint is response after induction chemotherapy, defined as complete or partial response with at least a 65% reduction in tumor size at 18 weeks. Central review is described. The record reports 102 eligible patients and 85 with sufficient data to assess response, but does not report the response count or an estimate of uncertainty. It lists six outcome measures and zero analyses. Secondary outcome results and detailed statistical methods are not reported in the registry record.
The safety summary records selected serious and other adverse-event counts and terms. It does not provide a randomized comparison. The record is consequently more informative about study design and endpoint definitions than about the magnitude or precision of clinical outcomes.