Review for 10.1186/s12876-025-04076-7 (2025)

Title: The nomograph predicting the recurrence of Solid Pseudopapillary Neoplasm of the
Pancreas: a study of the SEER database and a Chinese cohort
Version: 1 Date: 27 Jan 2025
Reviewer's report:
Oidong Pei et al. constructed the nomograph for the recurrence of SPN, using the data from
the SEER database as the training cohort and two hospitals in China as the validation cohort.
The manuscript is well-written and novel, identifying previously unclear recurrence factors of
SPN in prior research and constructing a nomogram model based on the largest cohort analysis.
However, several important issues remain that the author needs to address and clarify.
Major comments
1. The most fundamental issue in this study is the lack of a clear definition of recurrence,
which remains ambiguous throughout the analysis. The authors must explicitly describe this
in the Materials and Methods section. The aim of this research is to identify risk factors of
recurrence after pancreatectomy for SPN. However, as shown in Table 1, both the training cohort
and the validation cohort include cases with synchronous metastases and those that did not
undergo surgery. Yet, univariate and multivariate analyses were performed without excluding
these cases. Since this study is intended to investigate risk factors for recurrence after surgical
resection, cases with unresected primary lesions or synchronous distant metastases at the time
of surgery should be excluded. The analysis should focus specifically on factors associated with
recurrence after pancreatic resection
2. Related to Comment No. 1, the definition of "regional nodes positive" in Table 1 must be
clarified—whether it is based on radiological assessment or pathological evaluation. If it is based
on pathological evaluation, the number of cases undergoing surgery and lymph node dissection
would differ from the total number of cases in each cohort, which would consequently affect
the calculated values.
3. The authors included two factors, "age" and "regional nodes positive," which were not
significant in the univariate analysis, in the multivariate analysis based on "clinical necessity."
Furthermore, in the multivariate analysis, the strength of factors that were significant in
the univariate analysis was diminished, and ultimately, the two aforementioned factors were
identified as independent significant factors. This approach and its results are highly subjective
and lack scientific rigor. Factors selected for multivariate analysis should be uniformly limited
to those that demonstrate significance in the univariate analysis (e.g., p < 0.05 or 0.10). A
nomogram constructed from such a multivariate analysis would lose its validity and clinical
utility.
4. A table should be created for the four cases with liver metastases in the validation cohort to
display the scores assigned to each factor in the nomogram.
Minor comments
1. The font of “characteristics” is different.
2. The factors "marital status" and "low income," extracted from the SEER database, are of
limited importance in this study and are not evaluated in the validation cohort. Therefore, they
should be removed from Tables 1 and 2.
3. In Table 2, the author needs to clarify the definition of "chemoradiotherapy" —whether
it refers to adjuvant chemoradiotherapy administered after surgery or chemoradiotherapy
performed as an alternative to surgery.
4. In the schematic diagram in Figure 1, the primary data are indicated to be derived from the
SPN of the pancreas. However, Table 1 includes cases with lesions outside the pancreas in both
cohorts. The authors should clarify this discrepancy and, if necessary, exclude such cases from
the cohorts.
5. The light green text labeled "other" in Figure 2 is barely visible. The color should be adjusted
for better visibility.
6. The font size of “external cohort” in external validation is smaller than others.