Rate of reclassification of HER2-equivocal breast cancer cases to HER2-negative per the 2018 ASCO/CAP guidelines and response of HER2-equivocal cases to anti-HER2 therapy

James Crespo; Hongxia Sun; Jimin Wu; Qing-Qing Ding; Guilin Tang; Melissa K. Robinson; Hui Chen; Aysegul A. Sahin; Bora Lim

doi:10.1371/journal.pone.0241775

Peer Review History

Original SubmissionJuly 30, 2020
15 Sep 2020 Decision Letter - Paul J van Diest, Editor PONE-D-20-23814 Rate of reclassification of HER2-equivocal breast cancer cases to HER2-negative per the 2018 ASCO/CAP guidelines and response of HER2-equivocal cases to anti-HER2 therapy PLOS ONE Dear Dr. Lim, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Oct 30 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. 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You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: This is a well written article on category/group 4 of the HER2 dual ISH assessment results as defined by the 2018 ASCO/CAP guidelines. Most of the cases classified as equivocal on the basis of the 2013 recommendations turned out to be negative per definitions of the 2018 recommendations. The limitations of the study are listed, and two of these are the virtual lack of targeted treatment in this subpopulation, and the low frequency of events overall. The references are not uniformly presented (and therefore cannot follow a uniform instruction set for authors); e.g. both capitals and lower case letters for unabbreviated journal names; full confusion with the author names in item 18... Reviewer #2: This is a retrospective single center study investigating the rate of reclassification of so-called HER2-equivocal breast cancers (according to ASCO/CAP guidelines of 2013) to either HER2-negative or HER2-positive breast cancers according to revised ASCO/GAP guidelines of 2018. As the benefit of anti-HER2 therapy is obvious in HER2-positive disease but remains unclear in HER2-equivocal breast cancer, it is important to learn if anti-HER2 therapy is valuable in cases who are to be reclassified as HER2-positive according to new guidelines. The study has been conducted in a well-described manner and FISH analysis and IHC staining are according to international standards. The authors found that only 80.5% of cases were reclassified as HER2-negative. However, in the results it remains unclear why a considerable proportion of cases (n=26 19%) could not be reclassified to either HER2-positive or negative breast cancer. The definition of unknown HER2 status is lacking: was it technically impossible to reclassify or were insufficient tumour cells available for testing? More importantly, only 1 out of 139 cases was reclassified as HER2-positive. The impact of anti-HER2 treatment in patients with equivocal HER2-testing in this series remains unclear, as only 1 patient was reclassified as HER2-positive and 19% was reclassified as HER2-unknown, while none of these patients received anti-HER2 treatment. From the NSABP-42 study it is already known that anti-HER2 therapy of HER21+ or 2+ breast cancer as no additional benefit. This study does therefore not allow to make any conclusions on the impact of anti-HER2 therapy in HER2-equivocal breast cancers, as the number of patients treated with anti-HER2, therapy is too low (n=1 in early breast cancer and n=5 in metastatic breast cancer). Besides, the median follow up (<2 years) is too short to detect any potential benefit both in early breast cancer as well as in metastatic breast cancer as recurrences occur up to 5-10 years after primary diagnosis and median survival in metastatic breast cancer responding to anti-HER2 therapy exceeds 4 years (Cleopatra study). Reference 7 on a phase 1 study with trastuzumab deruxtecan could be replaced by a phase 2 study by Modi S et al, NEJM 2020;382:610-21. In conclusion, the study is well written and well performed, but the conclusion on the impact of anti-HER2 therapy in HER2-equivocal breast cancers can not be made. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: Yes: Gábor CSERNI Reviewer #2: Yes:** Carolina Smorenburg [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. 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Revision 1
6 Oct 2020 Author Response Sep 15, 2020 Dear Dr. Paul J van Diest Academic Editor PLOS ONE Re: PONE-D-20-23814 Rate of reclassification of HER2-equivocal breast cancer cases to HER2-negative per the 2018 ASCO/CAP guidelines and response of HER2-equivocal cases to anti-HER2 therapy We appreciate the kind and thorough review from Drs Cserni, and Smorenburg. Here in this revised version, we tried to address all the concerns from the reviewers. The line by line responses to each concern from the reviewers are listed below. We sincerely hope we have either clarified or fixed the areas of concerns. Reviewer #1: This is a well written article on category/group 4 of the HER2 dual ISH assessment results as defined by the 2018 ASCO/CAP guidelines. Most of the cases classified as equivocal on the basis of the 2013 recommendations turned out to be negative per definitions of the 2018 recommendations. The limitations of the study are listed, and two of these are the virtual lack of targeted treatment in this subpopulation, and the low frequency of events overall. We agree that this is a concern and a limitation. However, we believe that negative findings in such case could still be informative to the field, and therefore our study would further encourage the wider studies to continue to improve our targeted therapeutic strategy towards HER2. We tried to elaborate this limitation further in the discussion section. The references are not uniformly presented (and therefore cannot follow a uniform instruction set for authors); e.g. both capitals and lower case letters for unabbreviated journal names; full confusion with the author names in item 18... Thank you for pointing this out. We realized that the endnote program did not fix all the references into correct format and we overlooked these - that created errors in several references. We made sure to revise all the references to ensure all the references follow the same format in this revised version. Reviewer #2: This is a retrospective single center study investigating the rate of reclassification of so-called HER2-equivocal breast cancers (according to ASCO/CAP guidelines of 2013) to either HER2-negative or HER2-positive breast cancers according to revised ASCO/GAP guidelines of 2018. As the benefit of anti-HER2 therapy is obvious in HER2-positive disease but remains unclear in HER2-equivocal breast cancer, it is important to learn if anti-HER2 therapy is valuable in cases who are to be reclassified as HER2-positive according to new guidelines. The study has been conducted in a well-described manner and FISH analysis and IHC staining are according to international standards.The authors found that only 80.5% of cases were reclassified as HER2-negative. However, in the results it remains unclear why a considerable proportion of cases (n=26 19%) could not be reclassified to either HER2-positive or negative breast cancer. The definition of unknown HER2 status is lacking: was it technically impossible to reclassify or were insufficient tumour cells available for testing? More importantly, only 1 out of 139 cases was reclassified as HER2-positive. In part, our MD Anderson pathology group follows rigorous exercise when the HER2 is reclassified. Many of our reclassified patients in the recurrent/metastatic group, we obtained additional cytology material to confirm the HER2 FISH status (as mentioned in the page 19, section “ In our primary cohort, the proportion of HER2-equivocal cases reclassified as HER2-negative was similar (94.4%) to the proportions in both previous studies. However, in our recurrent/metastatic cohort, we faced the challenge of insufficient cytological material for further analysis, which resulted in a higher rate of HER2-unknown cases on reclassification (44.9% in the recurrent/metastatic cohort vs. 4.4% in the primary cohort). This difference of HER2-unkonw cases between two guidelines might also be due to aggressive re-counting HER2 signals by our dedicated breast pathologists. Indeed, the inter-institutional HER2 FISH discrepancy has been previously reported (18).” Of course, we will not be able to examine the same in the other studies to carefully evaluate the discrepancy among studies, yet we believe this may be the biggest cause of the difference. We hope our explanation that was already included in the previous manuscript is sufficient to rationalize this. The impact of anti-HER2 treatment in patients with equivocal HER2-testing in this series remains unclear, as only 1 patient was reclassified as HER2-positive and 19% was reclassified as HER2-unknown, while none of these patients received anti-HER2 treatment. From the NSABP-42 study it is already known that anti-HER2 therapy of HER21+ or 2+ breast cancer as no additional benefit. We agree. This is one of the major limitations of our study. We believe this was mainly due to reclassification to HER2 negative group at the end of our analysis to re-classify them. As note, one goal of our study was to address the difference between 2013 ASCO/CAP guideline vs 2018 ASCO/CAP guideline about the HER2 status and see how this change could impact the therapeutic efficacy. The fact that most of them are re-classified as HER2 negative, and even small population did not show the HER2 agent therapy benefit supports that new 2018 ASCO/CAP guideline may be more effective in defining the clinically HER2 positive vs negative groups. We added this section to the discussion section as well. This study does therefore not allow to make any conclusions on the impact of anti-HER2 therapy in HER2-equivocal breast cancers, as the number of patients treated with anti-HER2, therapy is too low (n=1 in early breast cancer and n=5 in metastatic breast cancer). Besides, the median follow up (<2 years) is too short to detect any potential benefit both in early breast cancer as well as in metastatic breast cancer as recurrences occur up to 5-10 years after primary diagnosis and median survival in metastatic breast cancer responding to anti-HER2 therapy exceeds 4 years (Cleopatra study). In conclusion, the study is well written and well performed, but the conclusion on the impact of anti-HER2 therapy in HER2-equivocal breast cancers can not be made. I think maybe our statement here gave incorrect message about the anti-HER2 therapy in equivocal cancer – the equivocal group here we mention is based on 2013. To reduce the confusion, we have revised the conclusion sentence that is currently written as “Despite these limitations, our results corroborate the changes in HER2 classification in the 2018 ASCO/CAP guideline and do not support the use of anti-HER2 therapy in the HER2-equivocal group.” -> to “Despite these limitations, our results corroborate the changes in HER2 classification in the 2018 ASCO/CAP guideline and do not support the use of anti-HER2 therapy in the previously classified HER2-equivocal group based on 2013 criteria.” Reference 7 on a phase 1 study with trastuzumab deruxtecan could be replaced by a phase 2 study by Modi S et al, NEJM 2020;382:610-21. Thank you. We have replaced the reference and revised all of our reference to ensure that we follow a correct formatting. Sincerely, Bora Lim, M.D. Attachments Attachment Submitted filename: Response to Reviewers.docx https://doi.org/10.1371/journal.pone.0241775.r002
21 Oct 2020 Decision Letter - Paul J van Diest, Editor Rate of reclassification of HER2-equivocal breast cancer cases to HER2-negative per the 2018 ASCO/CAP guidelines and response of HER2-equivocal cases to anti-HER2 therapy PONE-D-20-23814R1 Dear Dr. Lim, We’re pleased to inform you that your revised manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Paul J van Diest Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0241775.r003
Formally Accepted
4 Nov 2020 Acceptance Letter - Paul J van Diest, Editor PONE-D-20-23814R1 Rate of reclassification of HER2-equivocal breast cancer cases to HER2-negative per the 2018 ASCO/CAP guidelines and response of HER2-equivocal cases to anti-HER2 therapy Dear Dr. Lim: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Paul J van Diest Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0241775.r004

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