MACQUARIE NEUROSURGERY JOURNAL CLUB

Ahmad M. Badran

10 November 2016

Clinical benefit from resection of recurrent glioblastomas: results of a multicenter study including 503 patients with recurrent glioblastomas undergoing surgical resection

Institution metrics/ Authors/ Journal

20 participating neurosurgical departments in Germany, Switzerland, and Austria.

• Department of Neurosurgery, Klinikum Rechts der Isar, Technische Universita¨ t Mu¨ nchen, Munich, Germany (F.R., H.P., B.M.); Department of Neurosurgery, Heinrich Heine Universita¨ t Du¨ sseldorf, Du¨ sseldorf, Germany (M.S.); Department of Neurosurgery, Universita¨ tsklinikum Carl Gustav Carus, Dresden, Germany (D.K.); Department of Neurosurgery, Universita¨ tsmedizin Go¨ ttingen, Go¨ ttingen, Germany (H.C.B.); Department of Neurosurgery, Charite´ Universita¨ tsmedizin, Berlin, Germany (M.M.); Department of Neurosurgery, Universita¨ tsklinikum Freiburg, Freiburg, Germany (A.W.); Department of Neurosurgery, Universita¨ tsklinikum Wu¨ rzburg, Wu¨ rzburg, Germany (T.W.); Department of Neurosurgery, Goethe Universita¨ t Frankfurt, Frankfurt, Germany (C.S.); Department of Neurosurgery, Inselspital, Universita¨ tsklinikum Bern, Bern, Switzerland (P.S.); Department of Neurosurgery, Universita¨ tskliniken Bonn, Rheinische Friedrich Wilhelms Universita¨ t, Bonn, Germany (M.S.)

Institution metrics/ Authors/ Journal

• Florian Ringel, Haiko Pape, Michael Sabel, Dietmar Krex, Hans Christoph Bock, Martin Misch, Astrid Weyerbrock, Thomas Westermaier, Christian Senft, Philippe Schucht, Bernhard Meyer, Matthias Simon, and the SN1 study group.

• Neuro-Oncology 18(1), 96–104, 2016.

Study Relevance and Originality

• Both relevant and important.

• The role of a surgical resection of recurrent glioblastomas remains largely unclear at present.

• This study aimed to assess the effect of repeated resection of recurrent glioblastomas on patient survival.

Study Relevance and Originality

Research hypothesis

Aggressive surgical resection of recurrent/ progressive glioblastomas, followed by adjuvant therapy, could contribute to increased overall survival.

A beneficial influence of repeat surgery on survival is also suggested by the correlation between the extent of resection and survival.

Study Design

• Retrospective cohort study.

• Database (2006-2010).

• Multicenter study (20 participating neurosurgical departments in Germany, Switzerland, and Austria).

• 503 patients with primary glioblastomas undergoing repeat resections for recurrent tumours were evaluated for factors affecting survival.

• Age, Karnofsky performance status (KPS), extent of resection (EOR), tumour location, and complications were assessed.

Internal Validity

This is a retrospective analysis and is, therefore, inherently subject to bias. Patient’s selection bias may have resulted from the treating surgeons leading a group of patients towards redo surgery.

This is a multi-center analysis and thereby doesn’t reflect the treatment bias of one institution.

The number of patients and longitudinal nature of follow-up was good compared to other reports in the literature.

Statistical analysis was reasonable.

External Validity

• Inclusion criteria:

(i) De novo glioblastoma (WHO IV) upon initial tumour diagnosis.

(ii) Initial diagnosis between January 2006 and June 2010.

(iii) Surgical tumour resection following initial diagnosis.

(iv) Surgical resection of a recurrent tumour or progressive tumour remnant.

External Validity

• Exclusion criteria:

(i) Secondary glioblastomas.

(ii) If the initially diagnosed tumour was not resected (biopsy only).

(iii) If the patient received a nonsurgical treatment for first tumour recurrence.

External Validity

• For each patient, the following parameters were recorded: sex, date of first (second, third, etc.) surgery, age at the respective surgeries, and extent of resection.

• The extent of the surgical resection (EOR) was categorized as (i)complete, (ii) resection above 90% but incomplete, (iii) resection between 50% and 90%, and (iv) resection of less than 50%.

• EOR was assessed at the respective centres, which all used postoperative imaging during the period of patient inclusion as a routine procedure.

Results

Results

Results

Results

Results

Results

Results

Discussion / conclusions

Repeat surgery was believed to be associated with a higher incidence of new neurological deficits, and the oncological benefit of a second resection remained obscure.

When comparing repeat surgery with nonsurgical therapy from retrospective and prospective data, studies so far have failed to reveal a benefit from repeat resection.

Discussion / conclusions

Selection of patients for repeat resections was at the discretion of the respective centres, and not all patients undergoing surgery in the study period might have been reported.

Surprisingly, the duration between initial surgery and re-resection did not influence survival after re-resection. However, this might be due to a selection bias since patients with early progression/recurrence wereprobably not chosen for a re-resection by the contributing centres.

Standardized information on tumour size, location, and extent of resection are not available. This could change the results if onlysmall-sized recurrent tumours would have been included.

Presentation and style

The paper was clear and organized.

The number of words were acceptable.

The tables and figures were good.

Conclusion

Repeat resection of a recurrent/progressive glioblastoma should be considered whenever safely possible, especially in young age group patients, high KPS, and longer time of recurrence.

The surgery should aim at a maximum safe resection and should be followed by adjuvant chemotherapy.

Conclusion

Is the study believable (internally valid)?

Is the study relevant (externally valid)?

Will the study change my practice?

Thank You