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 Sacral Nerve Stimulation in Treating Low Anterior Resection Syndrome or Fecal Incontinence in Patients With Locally Advanced Rectal Cancer or Other Pelvic Cancer, the RESTORE Study (NCT04066894), a na phase 2 study. The primary outcome is Sacral Nerve Stimulation (SNS) Success.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04066894 |
| Phase | Phase 2 |
| Condition | Low Anterior Resection Syndrome, Malignant Anal Neoplasm, Malignant Bladder Neoplasm |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 3 |
| Arms in the primary outcome | n/a |
| Lead sponsor | M.D. Anderson Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients with low anterior resection syndrome or fecal incontinence following low anterior resection or proctectomy with coloanal anastomosis, or after pelvic chemoradiation. The registry describes eligible cancer settings that include rectal and other pelvic cancers.
Intervention
Sacral nerve stimulation, beginning with placement of a stimulator and external battery pack, with a later decision about internal battery implantation or lead removal.
Comparator
There was no concurrent control group. The study used bowel diary comparisons before lead placement at visit 1 and after lead placement at visit 2 to assess symptom improvement.
Primary question
Whether patients reached the registry-defined SNS success outcome: having the battery implanted at visit 3. The registry also describes physician assessment of bowel diary changes as part of evaluating improvement.
3. Trial Design
RESTORE was registered as a phase II, single-group study of sacral nerve stimulation for low anterior resection syndrome or fecal incontinence in patients with rectal or other pelvic cancer. The registry lists M.D. Anderson Cancer Center as the sponsor. The study began on 2019-04-12, had a primary completion date of 2022-09-01, and is listed as terminated. The reason for termination is not reported in the registry record.
The design has no randomized allocation and no masking. The registry characterizes the model as single group and allocation as not applicable. As a result, there is no control arm for a between-group estimate of intervention effects. The study’s planned symptom comparison was within participants: bowel diary information before SNS lead placement at visit 1 was compared with information after lead placement at visit 2, with a physician determining whether improvement occurred.
The intervention description indicates scheduled, elective surgery for placement of a sacral nerve stimulator with an external battery pack. After 2 weeks, patients were to undergo internal battery implantation or have the leads removed if stimulation was working but symptoms had not improved. The arm description is incomplete in the registry record, so further procedural details are not available there.
Enrollment was 3. Although the registry gives a primary completion date, the primary outcome population field states “No data was collected.” The registry also records 0 analyses. Thus, the design and intended outcome definitions can be described, but the record does not support an estimate of the primary outcome or a comparison of outcomes between groups.
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 | Experimental: Sacral Nerve Stimulation (SNS) |
|---|---|
| STARTED | 3 |
| COMPLETED | 1 |
| NOT COMPLETED | 2 |
Reasons for not completing this period:
| Reason | Experimental: Sacral Nerve Stimulation (SNS) |
|---|---|
| Lack of Efficacy | 1 |
| Screen Failure | 1 |
Analysis population for the primary outcome, as defined in the registry: No data was collected
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 | Experimental: Sacral Nerve Stimulation (SNS) |
|---|---|---|
| Participants analysed | 3 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 3 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 2 |
| Sex: Female, Male: Male | Participants | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 1 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 2 |
| Region of Enrollment: United States | participants | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Sacral Nerve Stimulation (SNS) Success, measured over Up to visit 3.
| 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 SNS success, defined by whether a patient had the battery implanted at visit 3. The registry states that patients who did not have SNS placed, for any reason other than insurance coverage issues, would count as not having success. This is a treatment-pathway outcome: it records progression to battery implantation rather than directly measuring the magnitude of symptom change.
The record separately describes how fecal incontinence and improvement were assessed. Fecal incontinence was to be measured by the physician as the total number of gas, mucus, liquid stool, and solid stool accidental leakage events reported in bowel diaries. Improvement was to be determined by the physician by comparing diaries recorded before lead placement at visit 1 with diaries after lead placement at visit 2.
The endpoint is useful for describing whether the intended device pathway proceeded to internal battery implantation, while the diary assessment addresses bowel symptoms. These are related but distinct pieces of information: implantation status alone does not quantify the amount of symptom change. The planned report was a proportion of patients experiencing SNS success with a 90% credible interval using beta (1,1). No observed proportion or interval is reported because the registry states that no data were collected for the primary outcome.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive limitation is the absence of posted primary outcome data. The registry defines SNS success and describes a planned 90% credible interval, but it does not report how many participants met the success definition or an estimated proportion. Consequently, the record cannot establish the observed frequency of success in this study, nor can it show how precise such an estimate would be.
Enrollment was 3, but enrollment is not a substitute for an analyzed outcome count. The primary outcome population is recorded as “No data was collected,” and the registry lists 0 analyses. No estimate should therefore be inferred from enrollment, the intervention description, or the study status. The termination status also does not explain why the study ended; the reason is not reported in the registry record.
The study was single group and unmasked, with no randomized comparison. Its planned symptom assessment relied on bowel diary comparisons before and after lead placement and physician judgment of improvement. Even if those results had been posted, a within-participant comparison without a concurrent control would describe change over time in the studied participants; it would not by itself separate an intervention-associated change from other influences. That is a general interpretive limitation of uncontrolled comparisons, not a finding about this trial’s outcomes.
The registry’s planned primary measure and its symptom diary assessment answer different questions. Battery implantation records whether participants reached a specified stage of treatment. The diary-based measure concerns leakage events and physician-assessed change. Without results for either measure, there is no basis to characterize the amount, direction, or consistency of symptom change.
The listed adverse-event figures record 3 participants at risk and zero serious adverse events, zero other adverse events, and zero deaths. These are registry counts, not evidence that risk was absent. With such limited recorded exposure and no outcome analyses, the safety information is descriptive and cannot precisely characterize uncommon events or broader safety experience.
Any planning illustration based on an observed effect must be distinguished from observed trial evidence and from the original design. The record describes such illustrations as planning calculations, not observed power. Since no primary outcome result is reported, those illustrations cannot supply missing clinical results or make the trial’s observed effect known.
9. Statistical Methods Explained
The registry identifies the planned primary analysis as a proportion of patients with SNS success, accompanied by a 90% credible interval using beta (1,1). It does not report an estimated proportion, interval limits, or an analysis result. The methods below explain the stated approach in general terms; they do not imply that an estimate was obtained in this study.
What does a proportion describe?
In general, a proportion expresses how many people in an analyzed group meet a defined outcome, relative to the size of that group. Here, the defined outcome is battery implantation at visit 3, with the stated exception for non-placement due to insurance coverage issues. An observed proportion would require outcome classifications for participants. The registry says no primary outcome data were collected, so the proportion cannot be recovered from the recorded enrollment alone.
What is a credible interval?
In general, a Bayesian credible interval describes a range of values for an unknown quantity under a specified statistical model and prior distribution. Its interpretation is conditional on that model and prior: it represents the interval assigned the stated posterior probability after combining the model with the observed data. The registry specifies a 90% credible interval, but does not provide its bounds or a posterior estimate. Without outcome data, there is no interval to interpret for this trial.
What does beta (1,1) contribute?
In general, a beta distribution can be used as a prior distribution for an unknown probability or proportion. The registry specifies beta (1,1) for the planned interval. A prior is part of the statistical framework, not an observed clinical result. Its role is to express assumptions about plausible values before incorporating the study observations. The resulting estimate and interval would depend on the observed outcome data as well as the stated prior. Because the registry reports no primary outcome data, the record does not show how the planned prior and participant outcomes combined.
How should the single-group design be read?
In general, a single-group study can describe outcomes among enrolled participants, but it lacks a concurrent control group for estimating a contrast between assigned treatment groups. RESTORE is listed as single group, with allocation not applicable and no masking. Its diary comparison was before versus after lead placement within participants. Such repeated measurements can describe changes across the recorded timepoints, but they do not on their own establish what would have happened over the same period without the intervention. Other changes over time or measurement circumstances can also affect before-and-after differences. The record does not report results from that comparison.
The primary endpoint also combines a concrete treatment milestone with a separate assessment of symptom improvement. Implantation status is comparatively direct to classify, whereas the diary-based improvement judgment depends on recorded leakage events and physician assessment. The registry gives no scoring details beyond the total number of reported gas, mucus, liquid stool, and solid stool leakage events and the comparison timepoints. Additional operational details are not reported in the registry record.
What can zero analyses tell readers?
The registry lists 0 analyses, and no primary outcome population data were collected. In general, a prespecified statistical method does not become an estimated result unless the relevant observations are available and analyzed. Here, the planned interval communicates how the primary proportion was intended to be summarized; it does not establish a value for that proportion. It is therefore important to distinguish the analysis plan described in the endpoint definition from a completed analysis with an estimate.
The record also identifies secondary outcome measures covering fecal incontinence severity, quality of life, urinary symptoms, bowel function, and the impact of SNS on bowel dysfunction. It lists 11 outcome measures in total. The existence of outcome definitions indicates what the study intended to assess, not that measurements were collected or analyzed. Results for these outcomes are not reported in the registry record.
General methods considerations such as handling incomplete diaries, defining the analysis population, or adjusting for multiple outcomes can affect interpretation in clinical studies. The registry record does not report those procedures. No assumptions about how missing measurements were treated, which participants would be included in each analysis, or whether any interim analyses were planned can be justified from the available record. The stated method is therefore limited to the planned proportion and its 90% credible interval using beta (1,1); the record does not document a completed statistical analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 11 outcome measures, including the primary SNS success endpoint and secondary measures of fecal incontinence severity, quality of life, urinary symptoms, bowel function, and the impact of SNS on bowel dysfunction. Considering multiple outcomes can raise a multiplicity issue: in general, the chance of at least one apparently notable result may change when many outcomes are examined. Whether and how to address that issue depends on the analysis plan. Multiplicity handling is not reported in the registry record.
The record lists 0 analyses and states that no data were collected for the primary outcome. It does not report results for the secondary outcomes. Therefore, no conclusion can be drawn about which measures were analyzed, whether outcomes were selected for emphasis, or whether any adjustment was applied.
Missing-data procedures and analysis populations are also not reported in the registry record. The endpoint definition says that participants who did not have SNS placed for reasons other than insurance coverage issues would count as not having success, but it does not specify how unavailable outcome information would be handled. The registry does not identify a population definition for the primary analysis or explain how incomplete bowel diaries, withdrawals, or other unavailable measurements would be treated. These details should not be inferred from the endpoint description.
In general, missing-data rules and analysis-population definitions matter because they determine which observations contribute to an estimate and what that estimate represents. In this record, the absence of reported outcome data and analysis procedures prevents assessment of those choices.
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 |
|---|---|---|---|
| Experimental: Sacral Nerve Stimulation (SNS) | 0 | 3 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Experimental: Sacral Nerve Stimulation (SNS) | 0 of 3 |
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 |
|---|---|
| Experimental: Sacral Nerve Stimulation (SNS) | 0 of 3 |
The registry lists 3 participants at risk in the experimental SNS group. It records zero serious adverse events, zero other adverse events, and zero deaths. These are counts in the adverse-event record. The registry does not list serious adverse-event terms.
Zero recorded events should be read as a report of the counts in this registry entry, not as proof that the intervention has no risks. The number at risk is limited, and the record provides no event-level descriptions or additional safety analyses. It is not possible to estimate event frequency with precision or to characterize events that might occur less often from these counts alone.
The safety counts also do not substitute for primary or secondary outcome results. They address reported adverse events, whereas the primary endpoint concerns battery implantation and the planned symptom assessment concerns bowel diary changes. No conclusions about symptom benefit follow from the adverse-event counts, and the registry record does not state why the study was terminated.
12. What the Result Does, and Does Not, Mean
The registry record establishes what RESTORE set out to study and how its primary endpoint was defined. It describes a phase II, single-group evaluation of sacral nerve stimulation for low anterior resection syndrome or fecal incontinence in patients following specified rectal or pelvic cancer treatment. SNS success was defined by battery implantation at visit 3, with a planned report of the success proportion and a 90% credible interval using beta (1,1).
The record does not report an observed primary outcome result. It states that no data were collected for the primary outcome and lists 0 analyses. Enrollment of 3 does not reveal how many participants reached battery implantation, how bowel symptoms changed, or how complete the intended assessments were. The listed secondary measures also have no reported results in the registry record.
Accordingly, this record cannot establish whether participants experienced symptom improvement, how often implantation occurred, or how precisely either outcome could be estimated. It also cannot provide a comparison with usual care or another treatment because the design was single group and had no concurrent control. These are limits of what the recorded evidence supports, not evidence for or against treatment efficacy.
The adverse-event entry records zero serious events, zero other events, and zero deaths among 3 participants at risk. Those figures describe the recorded safety counts; they do not establish that there is no safety risk. The trial is listed as terminated, but the reason is not reported in the registry record. Taken together, the record supports a description of the study plan and its limited posted outcome information, rather than a conclusion about clinical effectiveness or safety.
13. Why This Trial Matters Statistically
RESTORE illustrates why trial design and result availability must be considered together. A clearly defined endpoint and a planned statistical summary can make the intended question understandable, but they do not provide evidence of an outcome when observations and analyses are absent. Here, the primary endpoint is specified and the planned uncertainty summary is a 90% credible interval using beta (1,1), yet no primary outcome data or analysis is recorded.
The endpoint also highlights a distinction important in clinical research: a treatment milestone and a patient symptom measure are not interchangeable. Battery implantation at visit 3 defines SNS success, while bowel diaries and physician judgment address leakage and improvement. A study can define both measures, but each requires its own results to answer the corresponding question. Neither can be inferred from enrollment or from the intervention description.
The design provides another statistical lesson. A single-group before-and-after comparison can describe observed changes in participants, but it does not offer the same causal contrast as a concurrent control group. That general limitation is especially relevant when interpreting an intervention intended to affect symptoms that are measured over time. The registry identifies the planned timepoints but reports no comparisons.
Finally, the safety counts show why event totals need context. Zero events in a group of 3 at risk is a descriptive record, not a precise demonstration that events cannot occur. The information available is therefore useful for understanding the planned study question and the limits of its registry record, but it does not support efficacy or comprehensive safety conclusions.
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 most direct limitation is that the registry reports no data for the primary outcome and lists 0 analyses. This leaves the principal endpoint without an observed estimate, interval, or reported participant-level outcome count. Enrollment of 3 does not resolve that gap.
The study is single group, unmasked, and has no randomized allocation. There is no concurrent control group to support a between-group comparison. The planned diary assessment compares observations before and after lead placement, with improvement determined by the physician. In general, such a comparison may describe change over time but cannot by itself distinguish intervention-associated change from other influences.
The primary outcome captures battery implantation at visit 3, while the description of symptom improvement relies on bowel diaries between visit 1 and visit 2. These endpoints reflect different aspects of the treatment pathway and patient experience. The registry does not report results for either assessment or enough information to evaluate whether the symptom assessment was complete and consistently available.
Enrollment was 3, and the study is listed as terminated. The reason for termination, missing-data procedures, analysis populations, and multiplicity handling are not reported in the registry record. The arm description is also incomplete. The adverse-event record lists no events, but the small number at risk and lack of event-level details limit what can be concluded about safety. These limitations restrict interpretation to the study plan and the sparse posted record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Sacral Nerve Stimulation in Treating Low Anterior Resection Syndrome or Fecal Incontinence in Patients With Locally Advanced Rectal Cancer or Other Pelvic Cancer, the RESTORE Study — NCT04066894.
- Registry record last updated 2023-08-14; status last verified 2023-07.
- Results first posted 2023-08-14.
- 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
RESTORE (NCT04066894) is listed as a phase II, single-group study sponsored by M.D. Anderson Cancer Center. It evaluated sacral nerve stimulation for low anterior resection syndrome or fecal incontinence in patients after low anterior resection or proctectomy with coloanal anastomosis, or after pelvic chemoradiation. The study began on 2019-04-12, had a primary completion date of 2022-09-01, and is listed as terminated.
Enrollment was 3. The primary endpoint was SNS success, defined by battery implantation at visit 3, with a planned success proportion and 90% credible interval using beta (1,1). The primary outcome population is recorded as “No data was collected,” and the registry lists 0 analyses. The reason for termination and the approach to missing data, analysis populations, and multiplicity are not reported in the registry record. The adverse-event entry records zero serious adverse events, zero other adverse events, and zero deaths among 3 participants at risk.