Spinal Lesions as Clinical Manifestations of Plasma Cell Neoplasia

Round 1

Reviewer 1 Report

This work describes the investigation on surgical outcome for patients with plasma cell neoplasia. Performed studies revealed the need of using multimodal concept including survival treatment and susequent systemic therapy. The Authors revealed that the surgery for patent with plasma cell neoplasia is beneficial in the case of neurological impairment and spinal instability.  In my opinion the introduction section should be developed giving more background for performed experiments.

Author Response

Thank you for pointing this out. We have revised the introduction accordingly and hope to meet your requirements.

Reviewer 2 Report

Good paper. If I can I will suggest to:

1. Introduce the concept of R-ISS (non only ISS) in the introduction

2. The term metastases are not used in the contest of MM. We prefer lesions or involvement

3. The concept of adjuvant therapy is associated to the medical oncologist team. The hematologists do not use that. 

4. Can you explain if the radiotherapy or chemotherapy impacted on OS?

5. Have you some data of neurologic recovery?

6. Can you explain the SIN score?

Author Response

1. Thank you for pointing this out. We have added it. You will find it in lines 70-73.

2. Thank you for pointing this out. We have changed it accordingly.

3. Thank you for the comment. We have tried to emphasize this better. You can find it beginning at line 204.

4. Thank you for the comment. We have analyzed the impact of postoperative radiotherapy and chemotherapy on OS. You will find the results of the multivariate Cox regression analysis in lines 221-225

5. Thank you for the comment. For examination of the neurological status of the patients, we used the ASIA impairment score. This was explained in more detail in the methods (lines 117-122). We have listed the neurological deficits preoperatively and postoperatively in table 1. Relative to the entire cohort, 3 patients improved to ASIA E postoperatively.

6. Thank you for the comment. We have added it to the introduction.

Reviewer 3 Report

The authors analysis 94 myeloma patients and 20 SBP patients with surgical intervention for spinal instability and concluded that surgery is beneficial for patients with spinal instability and myeloma ptients with low number of spinal levels and young patients had better prognosis.

1. The conclusions are not novel for the topic. As surgical intervensi

2. In patients and methods section, it is a retrospective study with many surgical methods, which is difficult for the analysis.

3. The results section, the authors stated that The mean follow-up of the series was 11.1 months (range 0-12.8 months). But the overall survival of SBP is 19.38 months (median?, in table 1). How can a follow up with a range from 0-12.8 months study have a median(?) survival of 19.38 months? The authors should look into the raw data for a explanation.

4. In survival analysis, the authors do not show up the factors use for univariate analysis and multivariate analysis and the analysis results.

5. For survival analysis, the myeloma risks factors, including, age, staging, cytogenetic/molecular status, should be showed up and analysis. In addition, the treatment agents, course, and response are also important for analysis. 

Author Response

1. Thank you for pointing this out. Unfortunately, the rest of the sentence is missing, so we can't improve anything at the moment. We would be happy to do so if you could complete the comment.
2. Thank you for pointing this out. We have, due to the surgical aspect of the paper, listed our surgical care. However, we lack larger patient numbers for a more detailed statistical analysis.
3. Thank you for pointing this out. In the initial version we calculated the OS from surgery date to death or censored at the time of last follow-up. We understand that this has led to confusion and have now improved this. We have now modified the calculation of OS time. In the revised version of the manuscript, OS is calculated from the initial diagnosis of plasma cell neoplasia until death or censored at the time of last follow-up.
4. Thank you for the comment. We have supplemented this accordingly. You can read it from line 154 onwards.

5. Thank you for the suggestion. We have conducted a multivariate Cox regression analysis, including age, sex, KPSS, SIN-Score and number of spinal levels supplied as risk factors for mortality. You can find the analysis in lines 187-191. Of course, the cytogenetic/molecular status is important in disease prognostication and for survival analysis as there are molecular subgroups with different outcomes. We mention this in the introduction. Unfortunately, these data were not available to us.