Author's response to reviews Title: Gemcitabine in combination with EGF-Receptor antibody (Cetuximab) as a treatment of cholangiocarcinoma - a case report Authors: Martin F Sprinzl (sprinzl@1-me.klinik.uni-mainz.de) Carl C Schimanski (schimanski@1-med.klinik.uni-mainz.de) Markus Moehler (moehler@1-med.klinik.uni-mainz.de) Simin Schadmand-Fischer (schadman@uni-mainz.de) Peter R Galle (galle@mail.uni-mainz.de) Stephan Kanzler (kanzler@mail.uni-mainz.de) Version: 4 Date: 3 May 2006 see over Author's response to reviews:
From Dr. Martin Sprinzl 1 st Department of Internal Medicine University Mainz Langenbeckstr 1 55101 Mainz - Germany To the Editorial Office BioMed Central BMC Cancer Tel: +44 (0)20 7631 9921 Facsimile: +44 (0)20 7631 9923 e-mail: editorial@biomedcentral.com Web: http://www.biomedcentral.com Author s response to reviewers: Manuscript revisions, ID 5560430079214756 Title: Gemcitabine in combination with EGF-Receptor antibody (Cetuximab) as a treatment of cholangiocarcinoma a case report Authors: Martin F. Sprinzl < sprinzl@1-med.klinik.uni-mainz.de> Carl C. Schimanski <schimanski@1-med.klinik.uni-mainz.de > Markus Moehler <moehler@1-med.klinik.uni-mainz.de>, Simin Schadmand-Fischer <schadman@uni-mainz.de>, Peter R. Galle <galle@mail.uni-mainz.de>, Stephan Kanzler <kanzler@mail.uni-mainz.de> Version: 4 Date: 4 May 2006 Author s response to reviewers: see over - 1 -
To the BioMed Central Editorial Team, Dear Ladies and Gentlemen, Regarding to the proposed revisions for the manuscript: Cholangiocellular carcinoma respondiung on Gemcitabine in combination with EGF-Receptor antibody (Cetuximab) A Case Report (ID 5560430079214756), the corrections and annotations corresponding to the peer reviewers comments are listed below: The title has been changed to: Gemcitabine in combination with EGF-Receptor antibody (Cetuximab) as a treatment of cholangiocarcinoma a case report Reviewer: Tushar Patel 1. Acknowledgement should be provided that informed consent was provided by the patient Page 9, line 16ff.: Acknowledgement: The authors are indebted to the patient and his family for providing informed consent and kind permission of this report. 2. Please clarify duration of follow-up - is it 9.7 months after end-of-treatment or from presentation. Page 2, line 9ff.: During the reported follow up (since time of first presentation) 20 cycles of chemotherapy were administered. 3. What was the total duration of treatment? Page 2, line 7ff.: Partial response occurred after 17 weeks of treatment and remained stable during the entire course of chemotherapy for 9.7 months. 4. The conclusion states this is a "safe" way, but the patient experienced treatmentrelated morbidities. Comment: The conclusion that the treatment is save was removed. 5. May be helpful to show a figure of the tissue/cells stained with EGFR if available. The expression of EGFR was marginal (1+) and no representative tissue staining is available. Comment: Level of EGFR expression does not correlate with response to EGFR-directed therapy in colorectal cancer. Therefore we did not expect any relevant impact of EGFR expression levels on chemotherapy response in cholangiocarcinoma. 6. Despite immunological staining for CK7, the clinical presentation raises suspicion of a colonic malignancy. It would be helpful to provide information on colonoscopy or any colonic imaging performed. Page 4, line 8ff.: The tumor was located adjacent to the gallbladder and administration of oral contrast medium before computed tomography did not show any luminal tumor of the intestine. - 2 -
Comment: A immune histochemical study published by Lay and Calaluce (Am J Clin Pathol. 1994 Dec;102(6):764-7.) representing 151 Patients, showed a immunophenotype of cytokeratin 7 positive/cytokeratin 20 negative tissue in 0% of the colonic adenocarcinomas. In contrast, the cytokeratin 7-negative/cytokeratin 20-positive immunophenotype was present in 77% of the colonic carcinomas. Imunophenotyping of hepatic metastasis from patients with colon cancer confirmed by autopsy, showed coherent findings (Tot, T. et al. Cancer 1999; 85: 171 7.). Both citations were added to the revised version of this report. In combination with the results provided by computed tomography, showing no thoracic, pancreatic or intestinal malignancy, the diagnosis seems to be conclusive for a cholangiocarcinoma. 7. Did performance status really improve?- Karnofsky stated as 70% at presentation, 70-80% at end-of treatment. Page 7, line 1ff.: Most importantly, the clinical status (Karnofsky-Index: 70-80%) stabilized during chemotherapy and did not show any worsening until the end of follow up. Reviewer: Vittorio Gebbia 8. However authors must change the conclusion section since non conclusions may be drawn from a single case. Therefore " A combination of cytotoxic chemotherapy with targeted biologicals, like cetuximab, seems to be a safe and efficient way to improve quality of life and survival, as reported in this case of a patient suffering from CCC." should be changed into " this experience may suggest that..." Page 2, Line 22ff.: Our experience from one patient with CC may suggest that a combination of cytotoxic chemotherapy with targeted biologicals, like cetuximab, is an alternative way to affect quality of life and survival. Therefore cetuximab, as a component of palliative chemotherapy against biliary tract cancer, needs further evaluation in prospective randomized trials. Reviewer: Florian Eckel 9. It would be interesting to know, if the clinical course changed after eigth weeks of gemcitabine alone. Any significant changes, e.g. tumor response with cetuximab after progression with gemcitabine alone, would strongly support cetuximab effects. Comment: During the first cycles of chemotherapy the clinical course was dominated by tumorassociated complications like cholangitis and weight loss. Mentioned clinical improvement only occurred after 19 weeks (4.5 months) of therapy, which led to the discontinuation of parenteral nutrition. Therefore the overall performance was not significantly affected during the first three applications of gemcitabine. The Ca 19.9 titres, which were initially quantified at time of diagnosis, have been monitored the first time after the patient has recovered from cholangitis. The first - 3 -
cycles of gemcitabine (45 days of treatment) were limited by interruptions and dose reductions. Further corrections and proof reading revealed that gemcitabine was administered only three times before the combination with cetuximab was initiated. Only 37.5% of the intended cumulative gemcitabine dosage (1000 mg/m² weekly) was achieved initially. Taking tumor-unrelated alterations of Ca 19.9 levels into account, the recovery from cholangitis under antibiotic application might also have contributed to the initial drop of Ca 19.9 titres. Unfortunately no additional radiological follow up was performed to document the effects of gemcitabine as single agent to discriminate them from cetuximab-associated response. Respecting the methodical limitations of this case report, which has no cross over or add on treatment design, only possible synergistic mechanisms of gemcitabine and cetuximab were outlined. Therefore, tumor response to gemcitabine as single agent can not be excluded, but the clinical course indicates an additive effect of cetuximab. We definitely agree that further evaluation of this concept is a domain of controlled clinical trials. In response to the peer reviewer s comments were encouraged to outline the following corrections and annotations: Page 5, line 19: The combination with cetuximab, starting with a loading dose of 400 mg/m² and followed by a weekly maintenance dose of 250 mg/m² bodysurface, was initiated together with the fourth gemcitabine cycle after financial approval for its experimental use. Page 7, line 1 ff.: Most importantly, the clinical status (Karnofsky-Index: 70-80%) stabilized during chemotherapy and did not show any worsening until the end of follow up. Whereas the first three cycles of gemcitabine did not affect overall performance status significantly, tumor-associated anorexia improved after six cycles of combined gemcitabine and cetuximab. Therefore supplemental alimentation was discontinued, which was administered within the first four months after diagnosis. Page 8, line 16ff.: The synergistic effect of cetuximab seems more convincing, if the reduced gemcitabine dosage is taken into account, which was administered every other week in contrast to a standardized weekly schedule (1000mg/m² bodysurface). Even more pronounced dose reductions to only 37.4% of the standard dose were mandatory during the initial administrations of gemcitabine as single agent. Page 9, line 7ff.: Further prospective trials are mandatory to confirm the effects observed in this single case and to discriminate gemcitabine-induced from cetuximabassociated response. Finally, careful proof-reading and corrections were done as recommended by the reviewers. Orthographical corrections are not listed in detail. We now hope that the revised version meets the criteria for publication. Sincerely Yours, Martin Sprinzl (MD) - 4 -