The Impact of Resection Margins in Primary Resection of High-Grade Soft Tissue Sarcomas: How Far Is Far Enough?

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files. Major updates include

(a)    A more detailed discussion, including more recent literature and paradigm shifts in treatment

(b)    Revised tables and figures based on the reviewers’ comments

We are convinced that these additions have strengthened our manuscript substantially and we hope that it will now meet the high standards of Biomedicines. Specific comments responding to all questions and suggestions may be found below.

2. Point-by-point response to Reviewer 1 Comments

Comment 1: The introduction section is too brief and fails to provide sufficient background on the current challenges in this field. It would benefit readers if the authors cited more relevant and recent literature to establish the study’s context.

Response 1: We thank the reviewers for this comment. We have added more recent literature and mentioned the paradigm shifts toward more systemic treatments on page 2, introduction, lines 44-47: “accounting for less than 1% of all adult solid tumors. Although treatment regimens have shifted toward a more individualized approach, leveraging advanced molecular profiling and thus including immunotherapy and targeted approaches, surgery remains the cornerstone…” as well as in lines 59-65: Although survival rates have gradually improved over the past two decades, progress has been limited due to a lack of novel therapeutic strategies and the challenges of conducting large, homogeneous studies in this rare and diverse group of cancers. Now, new systemic therapies tailored based on histotype and grading have shown promising data, such as the combination of chemotherapy and immunoinhibitors. Yet, the question of adequate surgical resection remains unanswered.

Additionally, we have added more recent literature such as “A. Yurtbay, Ş. Aydın Şimşek, T. Cengiz, Y. S. Bariş, F. Say, and N. Dabak, “The Impact of Surgical Margin Distance on Local Recurrence and Survival in Patients with Soft Tissue Sarcoma,” Medicina (B Aires), vol. 61, no. 2, p. 289, Feb. 2025, doi: 10.3390/MEDICINA61020289.”

Are there further aspects we should add to the introduction section? Do you have propositions for further studies that should be cited?

Comment 2: Several errors were found in the results section. For instance, in the provided table, the percentages for tumor site and obesity do not sum to 100%.

Response 2: Thank you for pointing this out. We have, accordingly, added the information that due to rounding the numbers do not always sum to 100% as well as due to the untraceableness of exact resection margin in 26 patients, the total does not equal the sum of the depicted subgroups. [page 5, line 135]

Comment 3: Moreover, in Table 3 (“Cox Proportional Hazard Analysis for LR”), the reference value used in the analysis is not indicated, making it difficult for the reader to interpret the results. The same issue is present in Tables 4 and 5.

Response 3: We agree with the reviewer and revised the tables accordingly. Our idea was based on the publication by A. Bilgeri et al., “The effect of resection margin on local recurrence and survival in high grade soft tissue sarcoma of the extremities: How far is far enough?,” Cancers (Basel), vol. 12, no. 9, pp. 1–13, Sep. 2020, doi: 10.3390/cancers12092560. Likewise, the reference value is now indicated through a bold “1” within the tables. Additionally, we added a legend defining the values as Exp(b), hazards ratio; 95% confidence interval for hazards ratio; P, probability P (bold ≤0.05).

Comment 4: Furthermore, Figures 1–4 are of extremely poor quality, making them unreadable. The axes and lines are unclear and impossible to analyze. The placement of Figure 5 in the discussion section is inappropriate. It should be moved to the results section.

Response 4: We revised all figures accordingly and exported them, so that a higher resolution was reached. We submitted all figures separately in TIFF-format to the journal. Moreover, we deleted figure 5 and its discussion and revised the introduction accordingly.

Comment 5: The discussion section is underdeveloped and lacks reference to modern approaches in the field. The authors should expand this section by integrating recent advancements and comparing their findings with existing studies.

Response 5: We agree and have incorporated the reviewer's comment by comparing our study to more recent literature on page 10, line 259-264: “In the most recent study published by Yurtbay et al.[11], the authors proposed that “a negative surgical margins distance greater than 1mm is correlated with a reduced incidence of LR in patients compared to a negative margin distance of less than 1mm. “ While their study design was comparable to ours, the exclusion criteria was not as strict, again including low-grade STS and dividing the subgroups into patients with positive margins, and margins lower and greater than 1mm distance. “

Furthermore, we compared our results to other studies more specifically on page 11, lines 277-280: « The R0-resection rate of 93,5% in our study compares favorably to published reports that range between 80,7% and 89,8%. In contrast, the local recurrence rate of 31% is on the higher end of prior reports that vary from 11 to 40%. This is most likely due to our strict inclusion criteria, excluding low-grade STS.” We added context to our analysis throughout the text by adding statements such as: “Relatively, most DM were found in leiomyosarcoma (71%), followed by synovial sarcoma (60%). However, both subgroups consisted of low numbers (n=7 and 15, respectively.)” on page 12, lines 311-313.

Concerning the change in treatment regimens, we addressed this topic on page 12, paragraph 2, line 327-333: “In recent years, novel treatment regimens have emerged, including immunotherapy, targeted therapies, and alternative chemotherapeutic agents beyond the first-line anthracycline-based treatment for advanced STS, demonstrating promising outcomes. Most of these studies were conducted in patients not eligible for complete resection or in patients with advanced STS, both of which were excluding criteria for this study.“

However, we like to emphasize that this study primarily focusses on the surgical aspects of STS treatment. We hope that we can influence other authors to investigate into both aspects at the same time and deepen our knowledge of adequate treatment as we do not have a satisfying answer to it.

Comments 6: Additionally, the manuscript is difficult to follow, particularly due to the statement: “Supplementary Materials: The following supporting information can be downloaded at www.mdpi.com/xxx/s1, Figure S1: title; Table S1: title; Video S1: title.”

The connection between the main text and the supplementary materials is unclear.

Response 6: We deleted the statement thanks to your information. Raw data material is available upon request.  

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files. Major updates include

(a)    A more detailed discussion, including more recent literature and paradigm shifts in treatment

(b)    Revised tables and figures based on the reviewers’ comments

We are convinced that these additions have strengthened our manuscript substantially and we hope that it will now meet the high standards of Biomedicines. Specific comments responding to all questions and suggestions may be found below.

2. Point-by-point response to Reviewer 2 Comments

Comments 1:
The exclusion of patients undergoing re-resection should be explained more clearly. Please specify whether these patients were excluded due to contaminated margins or other factors.
The total number of patients appears to be 203, but based on the calculations (359 - 108 - 29 - 14 = 208), it should be 208. Please verify this inconsistency and correct it throughout the manuscript.

Response 1: Thank you for pointing this out. The statement on page 3, paragraph 2.2. in line 94 now is: “A follow-up of at least 24 months including MRI and CT scans was required (n = 359) if the study’s main end point (LR) was not reached earlier. The imaging followed a strict scheme of MRIs of the tumor site as well as a low-dose lung-CT every 3 months for the first two years. The intervals were then extended to 6 months and from the 6th year on to 12 months. If patients remained tumor-free for more than 10 years, follow-up was completed. If contaminated margins remained and the patients underwent re-resection (n = 108), they were excluded from this study. Patients presenting with secondary STS, metastasis at presentation (n=29) or those who required amputational surgery (n=14) were also excluded. Tumors of the bone such as Ewing-sarcoma or osteosarcoma, tumors which derived from soft tissue but originated from within the bone (n=5) and gastrointestinal-stroma tumors (GIST) or retroperitoneal STS were not included in this study. In total the number of eligible patients was n=203.”

Comments 2: Statistical Analysis Details
It is mentioned in the statistical methods section that both univariate and multivariate results are presented, but it is not clear in the results section which tables contain the univariate analysis and which contain the multivariate analysis. Please clarify this and label the tables accordingly.

Response 2: We fully agree with the reviewer that the tables had to be revised, and we have, accordingly, added “which obtained significance in univariate analysis were then” in line 118 on page 3, paragraph 2.4. to emphasize this point. Our analysis was conducted by first looking at variables independently in univariate analysis and only then we performed a multivariate analysis on those variables that proved to be significant.

Comments 3: Provide a clearer explanation of how resection margin width was measured. Was it determined by the surgical team or confirmed through histopathological analysis?
Clarify whether the margin width categories (0-1 mm, 1-5 mm, >5 mm) were based on preoperative planning or postoperative assessment.

Response 3: The authors strongly agree that the matter in which resection margin width was measured and subgroups were obtained is of high importance to the statistical analysis. We therefore have added “pathologically” in line 78 on page 2, paragraph 2.1. as well as “Margin width categories were based on postoperative assessment.” In lines 99-100 on page 3, paragraph 2.3.

Comments 3: The discussion on distant metastases lacks depth. Please elaborate on the impact of adjuvant chemotherapy in preventing metastasis and whether certain histological subtypes had a higher tendency to develop distant disease.

Response 3: We strongly agree with your comment. We added the statement “In terms of LR, fibrosarcoma was the most aggressive entity (100%), followed by leiomysarcoma (43%), which also caused the most DM (71%, Table 2).” In line 131-133 on page 4. We further tried to find an explanation about why these subtypes had the highest numbers in LR and DM. [Relatively, most DM were found in leiomyosarcoma (71%), followed by synovial sarcoma (60%). However, both subgroups consisted of low numbers (n=7 and 15, respectively.)] in lines 311-313 on page 12. We also explained why we could not investigate the impact of adjuvant chemotherapy any deeper on the same page in lines 327-334: In recent years, novel treatment regimens have emerged, including immunotherapy, targeted therapies, and alternative chemotherapeutic agents beyond the first-line anthracycline-based treatment for advanced STS, demonstrating promising outcomes. Unfortunately, most of these studies were conducted in patients not eligible for complete resection or in patients with advanced STS, both of which were excluding criteria for this study. Furthermore, since this study primarily focuses on surgical treatment strategies, a detailed investigation of adjuvant therapies is beyond its scope.

We revised Table 2 on page 5 to further describe the occurrence of DM with respect to tumor entity.

We strongly agree with the need for further investigation into how DMFS and OS can be positively impacted and encourage the readers to do so in the following lines (334-336).

Comments 4: The comparison with previous studies needs further elaboration. Specifically, address how your findings align or differ from studies that examined resection margins in STS.
Include a discussion on the role of radiotherapy in cases where achieving a >5 mm margin is not feasible.

Response 4: Table 6 and its correspondent paragraph on pages 9-12, lines 228 – 304 now give an overview of the similarities and differences in the discussed studies in terms of resection margin and adjuvant radiotherapy in which we specifically added the role of radiotherapy in cases where achieving a >5mm is not feasible in lines 282-285 on page 11: “Nevertheless, adjuvant radiotherapy improved the LRFS decisively throughout the subgroups and should be applied even in cases in which a resection margin >5mm is not feasible due to anatomical barriers or other difficulties.” More comparisons to previous literature were made in lines 277-280 on the same page: “The R0-resection rate of 93,5% in our study compares favorably to published reports that range between 80,7% and 89,8%. In contrast, the local recurrence rate of 31% is on the higher end of prior reports that vary from 11 to 40%. This is most likely due to our strict inclusion criteria, excluding low-grade STS.” We included a very recent study on this topic by Yurtbay et al. and compared our findings: “In the most recent study published by Yurtbay et al.[11], the authors proposed that “a negative surgical margins distance greater than 1mm is correlated with a reduced incidence of LR in patients compared to a negative margin distance of less than 1mm. “
While their study design was comparable to ours, the exclusion criteria was not as strict, again including low-grade STS and dividing the subgroups into patients with positive margins, and margins lower and greater than 1mm distance.”

Furthermore, as a result of your suggestion we analyzed adjuvant radiotherapy for every subgroup individually and stated the results on page 6, lines 157 and 158: “Adjuvant radiotherapy itself had a significant impact throughout the subgroups (R1: p = 0.027, >0-1mm: p = <0.001, >1-5mm: p = 0.003, >5mm: p = 0.010).”

Comments 5: The manuscript should include a more explicit discussion of study limitations, such as the retrospective design, single-center nature, and potential selection bias.

Response 5: We agree and included your suggestions in our study limitations (page 13, lines 379-381): “Furthermore, the retrospective design and the single-center nature of this study reduce its significance regarding general validity as well as the data collection during a time before treatment in STS has been shifting toward a more individualized approach.” Furthermore, we addressed the limitations concerning adjuvant treatments such as systemic or chemotherapeutic regimens throughout the text.

Comments 6: It is difficult to distinguish which tables contain univariate results and which contain multivariate results. Please specify this clearly in the table titles.

Response 6: We revised the table titles of table 3-5, adding “multivariate” so that it becomes apparent that these tables contain a multivariate analysis. Please see “Response 2” for further explanation.

Comments 7: The resolution of the figures is too low, making it difficult to interpret them. Please replace them with higher-quality versions.

Response 7: We revised all figures accordingly and exported them, so that a higher resolution was reached. We submitted all figures separately in TIFF-format to the journal; you can see the figures in the revised manuscript.