Neoadjuvant Study of Sequential Eribulin Followed by FAC Compared to Sequential Paclitaxel Followed by FEC in Early Stage Breast Cancer Not Overexpressing HER-2: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Neoadjuvant Study of Sequential Eribulin Followed by FAC Compared to Sequential Paclitaxel Followed by FEC in Early Stage Breast Cancer Not Overexpressing HER-2 (NCT01593020), a randomized phase 2 study. The primary outcome is Pathologic Complete Response (pCR).

2. Clinical Question

The trial asked whether the proportion of participants with a pathologic complete response differed between two chemotherapy sequences before breast surgery. Both groups received FAC or FEC after their assigned initial chemotherapy; the treating physician selected which of those regimens to use. The registry record describes a randomized, parallel-group phase II study in women with early-stage breast cancer not overexpressing HER-2.

The endpoint was assessed using breast and axillary lymph-node tissue obtained at definitive surgery, scheduled 4–6 weeks after the last FAC or FEC dose. The primary results record 7 participants with a complete response in the paclitaxel group and 1 in the eribulin group. The numbers with primary endpoint results were 26 and 21, respectively. These observed counts describe the registry results; they do not by themselves establish why the groups differed or how the result would apply to patients outside this study.

3. Trial Design

This was a randomized, parallel-group phase II study with no masking recorded. The registry lists 54 participants enrolled and the status as completed. The study concerned women with early-stage breast cancer not overexpressing HER-2. The registry record does not report the original sample-size justification, the allocation ratio, or details of how random assignment was carried out.

Participants in the paclitaxel group received paclitaxel weekly for 12 doses, then FAC or FEC for 4 cycles. Participants in the eribulin group received eribulin on days 1 and 8 every 3 weeks for 4 cycles, then FAC or FEC for 4 cycles. In both groups, the treating physician chose between FAC and FEC. The registry describes the initial treatment and the shared subsequent treatment as sequential regimens.

The primary outcome was pathologic complete response at surgery. Event-free survival and overall survival were also recorded, with follow-up described as from the start of treatment up to 5 years. The record lists 26 participants in the paclitaxel group and 21 in the eribulin group for the primary outcome. The safety results use groups of 28 and 23 participants. The registry does not explain why these outcome and safety group sizes differ, or provide a participant-flow account that would clarify the denominators.

The primary completion date is recorded as 2020-11-04. The registry describes the trial as completed, but does not report the study's original statistical analysis plan or details of any interim monitoring.

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.

Before assignment: 54 patients were accrued. 28 patients were randomized to Paclitaxel and 26 patients to Eribulin group. 2 patients from eribulin were found ineligible and never received treatment and 1 patient withdrew due to physician decision.

Overall Study

Reasons for not completing this period:

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.

6. Primary Endpoint

The registry lists the primary outcome as Pathologic Complete Response (pCR), measured over 4 -6 weeks from last dose of FAC/FEC-regimen..

Pathologic complete response (pCR) was the primary endpoint. It was defined as complete absence of viable invasive cancer cells in both the resected breast and lymph nodes. The assessment was based on pathological examination of breast and axillary lymph-node tissue collected at definitive surgery, which was scheduled 4–6 weeks after the last dose of FAC or FEC. The registry describes surgery by either lumpectomy with axillary dissection or modified radical mastectomy.

This endpoint turns the surgical pathology assessment into a participant-level outcome: each participant either met the stated definition or did not. A count of participants meeting the definition can therefore be compared between the randomized groups. In general, a pathologic response endpoint measures what is found in removed tissue after preoperative treatment; it is distinct from a measure of how long participants live or remain free of an event.

The posted primary outcome records 7 participants with pCR among 26 in the paclitaxel group and 1 among 21 in the eribulin group. The endpoint's stated assessment time is tied to surgery after the final FAC or FEC dose. The registry does not report additional detail about pathology review procedures, whether review was blinded, or how missing surgical assessments were handled.

7. Results Posted in the Registry

• Eribulin on Days 1 and 8 Every 3 Weeks for 4 Cycles (21 Day Cycle) Followed by FAC/FEC: 4.8% (1/21) versus 26.9% (7/26) on control; risk difference -22.2 percentage points (95% CI -41.5 to -2.8), risk ratio 0.18 (0.02–1.33); unadjusted two-proportion z-test p = 0.044.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

5 Year Event Free Survival (EFS)

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Eribulin on Days 1 and 8 Every 3 Weeks for 4 Cycles (21 Day Cycle) Followed by FAC/FEC: 73.9% (17/23) versus 82.1% (23/28) on control; risk difference -8.2 percentage points (95% CI -31.1 to 14.6), risk ratio 0.90 (0.67–1.21); unadjusted two-proportion z-test p = 0.477.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Eribulin on Days 1 and 8 Every 3 Weeks for 4 Cycles (21 Day Cycle) Followed by FAC/FEC and the control. The interval gives the range of effects that remain compatible with the data.

Overall Survival (OS)

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Eribulin on Days 1 and 8 Every 3 Weeks for 4 Cycles (21 Day Cycle) Followed by FAC/FEC: 82.6% (19/23) versus 100.0% (28/28) on control; risk difference -17.4 percentage points (95% CI -32.9 to -1.9), risk ratio 0.83 (0.68–1.00); unadjusted two-proportion z-test p = 0.022.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically lower for Eribulin on Days 1 and 8 Every 3 Weeks for 4 Cycles (21 Day Cycle) Followed by FAC/FEC than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

The registry records event-free survival and overall survival as secondary outcomes, each assessed from the start of treatment up to 5 years. Across these outcomes, the comparison pattern is not fully aligned: the event-free survival estimate is uncertain across both directions, while the overall survival estimate is directional in the same broad direction as the primary comparison. Neither secondary outcome replaces the primary pathological endpoint, which asks whether viable invasive cancer remained in the surgical specimens.

Secondary results can add context, but they usually carry less evidential weight than a prespecified primary outcome. A trial may examine several outcomes, and the more comparisons made, the greater the chance that at least one result appears notable by chance. The registry record does not report a multiplicity adjustment, a hierarchy among secondary outcomes, or a separate confirmatory analysis plan. The unadjusted p-values should therefore be read as descriptive evidence rather than as independent confirmation.

There are also differences in the form and available detail of these results. The registry gives percentages and group denominators but no reported analysis entries. It does not report survival curves, censoring details, or a time-to-event analysis method. Those omissions limit what can be inferred about the timing of events and the handling of participants whose follow-up did not extend to the full stated period.

Taken together, the secondary outcomes provide additional recorded follow-up information, but they do not resolve the uncertainty in the primary comparison. Their relationship to the pCR finding should be considered alongside small groups, unadjusted comparisons, and the absence of reported multiplicity handling. No single secondary result should be interpreted in isolation as a definitive conclusion about the treatment sequences.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• 5 Year Event Free Survival (EFS)
• Overall Survival (OS)

9. Statistical Interpretation

10. Statistical Methods Explained

The primary outcome is binary: a participant either met the pathological definition of pCR or did not. For a binary outcome, the observed count and the number assessed in each group describe how often the event occurred in the recorded participants. The registry reports 7 pCRs among 26 participants in the paclitaxel group and 1 among 21 in the eribulin group. These denominators are the numbers associated with the primary result, not the full enrollment figure.

What does a risk difference describe?

In general, a risk difference compares the event proportions in two groups by subtracting one proportion from the other. The posted contrast is eribulin relative to paclitaxel. A negative value therefore indicates a lower observed pCR proportion in the eribulin group. Unlike a relative measure, a risk difference expresses the contrast on the absolute probability scale. The registry comparison also includes relative measures, but the main interpretation follows the stated risk-difference metric.

What does the p-value tell us?

In general, a p-value describes how compatible the observed data are with a specified null model of no group difference, under the assumptions of the statistical test. A smaller p-value can indicate that the data are less compatible with that null model, but it is not the probability that the null hypothesis is true. It does not quantify clinical importance, and it does not account for every source of uncertainty in the study design. The primary comparison has an unadjusted p-value of 0.044. The registry does not report a multiplicity procedure or a full statistical analysis plan that would establish how this p-value was intended to be interpreted.

How should the confidence interval be read?

In general, a confidence interval gives a range of values compatible with the observed data under a specified method. It communicates uncertainty around an estimate rather than certifying that the true effect lies within the interval with a particular probability after the data have been observed. For a risk difference, an interval that includes zero is compatible with no group difference under that method; an interval entirely on one side of zero indicates that the estimated contrast is consistently directional across the interval. The primary interval is entirely negative. The interval is also wide, so the data remain compatible with a range of magnitudes.

Are these adjusted or reported analyses?

The registry records no reported analysis entries. It does include numerical comparisons and unadjusted p-values. No covariate-adjusted model, stratified analysis, or adjustment for the treating physician's FAC/FEC selection is reported in the registry record. The posted comparison should therefore be read as an unadjusted comparison of the recorded group summaries, rather than as evidence of a model-based adjusted effect.

General statistical interpretation also distinguishes random assignment from the analysis actually reported. Randomization is intended to create comparable groups on average, but it does not make small samples identical on every characteristic, and the record does not provide baseline details with which to assess the groups. Nor does randomization resolve uncertainty caused by outcome information missing from the registry denominators. The record does not report how participants without a recorded primary outcome were treated analytically.

Finally, the study's use of a binary pCR outcome is different from analyzing time until an event. Event-free and overall survival are time-related outcomes, but the registry supplies percentages and binary comparisons for those secondary measures and lists no reported analyses. Details such as censoring methods, survival curves, or a time-to-event model are not reported in the registry record. General statistical methods for time-to-event data should not be assumed to have been used in their absence.

11. Confidence Intervals and Precision

Precision concerns how much uncertainty surrounds an estimated group difference. The primary risk-difference interval is entirely negative, but it is broad. In practical terms, the data indicate a direction in the recorded groups while leaving considerable uncertainty about the magnitude of the difference. The interval's location and width are more informative than a p-value alone: the p-value summarizes compatibility with a null model, while the interval also conveys a range of effect sizes compatible with the data under the stated method.

The small primary outcome groups—26 participants in the paclitaxel arm and 21 in the eribulin arm—limit precision. With few participants, each outcome can have substantial influence on the observed group proportion and on the estimated contrast. The registry does not report the original sample-size justification, so it is not possible to determine from this record what precision the investigators intended to achieve.

The secondary endpoint intervals also convey uncertainty. The event-free survival interval includes no difference, so the estimate is compatible with effects in either direction. The overall survival interval is entirely negative, but the outcome is based on the recorded groups of 28 and 23 and has an unadjusted comparison. Its interval does not remove concerns about limited information or multiple secondary comparisons.

In general, an interval that excludes zero is not automatically precise or conclusive. Its width, the endpoint's role in the study, the group sizes, and the analysis context all matter. No confidence intervals for baseline characteristics or additional adjusted estimates are reported in the registry record.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The planning figures are illustrations based on the observed effect, not the trial's original design calculation. For these binary outcomes, figures refer to participants per arm. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The registry's original sample-size assumptions are not reported in the registry record.

For an effect equal to 100% of the observed effect, the illustration gives 42 participants per arm for 80% power and 55 participants per arm for 90% power. For planning for 75% of the observed effect, the corresponding figures are 85 and 114 participants per arm. For planning for 50% of the observed effect, they are 214 and 286 participants per arm.

In general, power is the chance that a study will detect an effect of a specified size under the assumptions used for planning, if that effect is truly present. The 80% column represents a design targeting an 80% chance of detecting the specified effect; the 90% column represents a higher target. A smaller effect is harder to distinguish from random variation, so detecting it generally requires more participants. The illustrations are not observed power: they do not measure the probability that this completed trial's result is correct or that a treatment effect exists.

The planning calculation uses the observed primary effect as its reference, so its figures depend on a result from a small trial. They are not a substitute for a prospective design calculation based on a clinically chosen effect and the trial's planned analysis. For time-to-event planning, the registry's general note specifies total events using the Schoenfeld method; that convention differs from the participants-per-arm figures for the binary comparisons.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.269; treatment proportion p₁ = 0.048; average p̄ = 0.158.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.5164 = 1.0121.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.4920 = 0.4141.
4. n = (1.0121 + 0.4141)² / (-0.2216)² = 41.4, rounded up to 42 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.269230769230769                          # control proportion
p1 <- 0.0476190476190476                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(1593020)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 42 (80% power), 55 (90% power)
 75% of observed effect: n per arm = 85 (80% power), 114 (90% power)
 50% of observed effect: n per arm = 214 (80% power), 286 (90% power)
power.prop.test: 41.4 
Simulated power at n = 42 per arm: 0.851 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when several outcomes or comparisons are examined. In general, each additional test creates another opportunity for a result to look statistically notable by chance, even if there is no true effect. A study's statistical plan may address this through a prespecified hierarchy, adjustment method, or other strategy. The registry record does not report such a plan or a multiplicity adjustment for the primary and secondary outcomes.

The registry lists one primary endpoint, pCR, and two secondary endpoints, event-free survival and overall survival. It records unadjusted comparisons for these outcomes, but no reported analysis entries. The secondary p-values should therefore be considered in the context of multiple outcomes rather than treated as if each were the sole planned test. Whether the primary p-value was intended as confirmatory under a prespecified testing strategy is not reported in the registry record.

Missing-data handling is also not reported. The registry lists 54 participants enrolled, while the primary outcome groups contain 26 and 21 participants, and the safety groups contain 28 and 23. The record does not explain these differing denominators, state whether any participant lacked an outcome assessment, or describe an approach such as imputation or exclusion. It also does not report whether all randomized participants were analyzed according to their assigned group.

The analysis populations are not defined in the registry record. It is therefore unclear whether the endpoint denominators represent all randomized participants with available data, a per-protocol group, or another population. The record does not give a participant flow diagram or reasons for exclusion from each endpoint.

Interim analyses, stopping rules, and the original sample-size justification are also not reported in the registry record. These details matter because they can affect interpretation of error rates and analysis choices. Without them, the unadjusted estimates and p-values can be described, but the full intended inferential framework cannot be reconstructed.

15. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: neutrophil count decreased (39.1%), fatigue (7.1%), myalgia (4.3%), vomiting (4.3%), alanine aminotransferase increased (4.3%).

The registry reports serious adverse event information for 28 participants in the paclitaxel group and 23 in the eribulin group. Serious adverse events affected 3 participants in the paclitaxel group and 9 in the eribulin group. The record lists 0 deaths for the paclitaxel group and 1 for the eribulin group. Other adverse events affected 0 participants in either group in the reported fields.

These counts should be read alongside their group denominators and the study's small size. They are descriptive counts, not adjusted comparisons, and the registry does not report a statistical analysis of safety differences. The safety denominators also differ from those for the primary outcome; the record does not explain that difference.

The most frequently listed serious adverse event term is decreased neutrophil count, recorded as 39.1%. Other listed terms include fatigue at 7.1%, and myalgia, vomiting, increased alanine aminotransferase, and decreased white blood cell count at 4.3% each. The registry does not clarify in these summaries whether these percentages are pooled across groups or provide a group-specific breakdown.

Serious adverse event counts do not describe every adverse effect, its duration, severity grading, or relationship to treatment. Those details are not reported in the registry record and should not be inferred from the summary fields.

16. What the Result Does, and Does Not, Mean

The results establish what was recorded for this randomized phase II study: the pCR count was 7 among 26 participants in the paclitaxel group and 1 among 21 in the eribulin group. The unadjusted risk-difference comparison is negative for eribulin relative to paclitaxel, and its confidence interval is entirely negative. These are observations from the study groups, accompanied by uncertainty, rather than a guarantee of what would occur in another population.

The result does not establish that one sequence is universally preferable, or that either initial drug alone caused the observed difference. Both groups received subsequent FAC or FEC, and the treating physician selected which regimen each participant received. The record does not report whether that choice was balanced or whether analyses accounted for it. The comparison is between complete treatment sequences as recorded.

The result also does not provide a definitive interpretation of long-term outcomes. Event-free survival and overall survival were recorded up to 5 years, but the registry does not report analysis methods, survival curves, or multiplicity handling. Their unadjusted comparisons need to be understood as secondary findings with limited information, not as independent proof.

In general, statistical significance is not the same as clinical importance. The p-value alone cannot establish the magnitude that matters to patients, and the confidence interval remains broad. The registry does not report a threshold for a clinically important difference. It also does not report enough detail on missing outcomes or analysis populations to determine how those issues may have influenced the estimates.

For these reasons, the findings are best read as a small-study comparison with a directional primary result and substantial uncertainty. They do not demonstrate that a treatment works or does not work, and they should not be extended beyond the population and regimens recorded without additional evidence.

17. Why This Trial Matters Statistically

This trial illustrates why a randomized comparison and a precise estimate are not the same thing. Randomization is an important design feature, but this study enrolled 54 participants and the primary outcome groups were smaller. With limited numbers, the observed results can be strongly influenced by a small number of outcomes, and confidence intervals are essential to understand the uncertainty surrounding a point estimate.

It also illustrates the importance of keeping the endpoint and the estimand clear. The primary question concerns pCR after two sequential treatment components, with FAC or FEC chosen by the treating physician. It is not simply a comparison of eribulin with paclitaxel detached from the rest of the regimen. Describing the treatment sequences accurately helps prevent overstatement about which component accounts for the observed group contrast.

The secondary results show why outcome hierarchy and multiplicity procedures matter. Several endpoints were recorded, but no adjustment or confirmatory testing strategy is reported. Unadjusted secondary p-values can be useful descriptions, yet they do not have the same interpretive weight as a single prespecified primary test within a clearly described analysis plan.

Finally, the different denominators across enrollment, primary outcome, and safety results emphasize the value of participant-flow and missing-data reporting. Without an explanation of who contributed to each analysis, readers cannot fully assess how the observed groups relate to those randomized. These are general principles for interpreting clinical trial evidence, made especially visible by the information recorded for this study.

18. 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 trial-specific limitations affect interpretation. The phase II study enrolled 54 participants, while the primary outcome results list 26 participants in the paclitaxel group and 21 in the eribulin group. Safety results use 28 and 23 participants. The registry record does not explain the different denominators or give reasons for participants not represented in each outcome summary.

The treatment sequences also included a physician-selected component: participants in both groups received FAC or FEC, chosen by the treating physician. The record does not provide counts for each choice by group or an adjusted analysis. This limits interpretation of the comparison as an effect of the initial drug alone.

The study was unmasked, and the registry does not report whether pathological assessment was blinded. It also does not provide the original sample-size justification, allocation details, interim analysis information, or the full statistical analysis plan. Missing-data methods and analysis populations are not defined. These omissions prevent a complete assessment of how the planned and analyzed populations relate.

Finally, the secondary outcome summaries do not include survival curves or reported time-to-event analyses, and no multiplicity handling is described. Follow-up is specified as up to 5 years, but details about censoring and event ascertainment are not reported in the registry record. These limitations do not erase the recorded results, but they narrow the conclusions that can be drawn from them.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Neoadjuvant Study of Sequential Eribulin Followed by FAC Compared to Sequential Paclitaxel Followed by FEC in Early Stage Breast Cancer Not Overexpressing HER-2 — NCT01593020.
• Registry record last updated 2021-09-22; status last verified 2021-08.
• Results first posted 2021-09-22.
• 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.

22. Record Summary

The registry describes a completed randomized, parallel-group phase II study of sequential eribulin followed by FAC or FEC versus sequential paclitaxel followed by FAC or FEC in women with early-stage breast cancer not overexpressing HER-2. No masking was recorded, and the treating physician selected FAC or FEC for participants in both groups. The registry lists 54 participants enrolled.

The primary outcome was pCR in resected breast and lymph-node tissue after treatment. The recorded counts were 7 of 26 in the paclitaxel group and 1 of 21 in the eribulin group; the unadjusted comparison has a p-value of 0.044 and a confidence interval entirely on the negative side for eribulin relative to paclitaxel. Event-free survival and overall survival were also recorded up to 5 years. Their comparisons are secondary and unadjusted. The registry does not report the original design assumptions, analysis populations, missing-data methods, or multiplicity procedures.