Evaluation of the modified Pittsburgh classification for predicting the disease-free survival outcome of squamous cell carcinoma of the external auditory canal

Cindy H Nabuurs; Wietske Kievit; Nilou Labbé; C René Leemans; Conrad F G M Smit; Michiel W M van den Brekel; Robert J Pauw; Bernard F A M van der Laan; Jeroen C Jansen; Martin Lacko; Weibel W Braunius; Shinya Morita; Małgorzata Wierzbicka; Takuma Matoba; Nobuhiro Hanai; Robert P Takes; Henricus P M Kunst

doi:10.1002/hed.26424

Evaluation of the modified Pittsburgh classification for predicting the disease-free survival outcome of squamous cell carcinoma of the external auditory canal

Head Neck. 2020 Dec;42(12):3609-3622. doi: 10.1002/hed.26424. Epub 2020 Aug 13.

Authors

Cindy H Nabuurs^{1

2}, Wietske Kievit^{1

2

3}, Nilou Labbé¹, C René Leemans⁴, Conrad F G M Smit⁴, Michiel W M van den Brekel⁵, Robert J Pauw⁶, Bernard F A M van der Laan⁷, Jeroen C Jansen⁸, Martin Lacko⁹, Weibel W Braunius¹⁰, Shinya Morita¹¹, Małgorzata Wierzbicka¹², Takuma Matoba^{13

14}, Nobuhiro Hanai¹⁴, Robert P Takes^{1

2}, Henricus P M Kunst^{1

2

9}

Affiliations

¹ Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands.
² Rare Cancers, Radboud Institute for Health Sciences, Nijmegen, The Netherlands.
³ Department of Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands.
⁴ Department of Otolaryngology-Head and Neck Surgery, Amsterdam University Medical Centers, VU University, Amsterdam, The Netherlands.
⁵ Department of Head and Neck Surgery, Netherlands Cancer Institute-Antoni van Leeuwenhoek, Amsterdam, The Netherlands.
⁶ Department of Otorhinolaryngology and Head and Neck Surgery, Erasmus Medical Center, Rotterdam, The Netherlands.
⁷ Department of Otorhinolaryngology and Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
⁸ Department of Otorhinolaryngology and Head and Neck Surgery, Leiden University Medical Center, Leiden, The Netherlands.
⁹ Department of Otorhinolaryngology and Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.
¹⁰ Department of Head and Neck Surgical Oncology, University Medical Center Utrecht Cancer Center, Utrecht, The Netherlands.
¹¹ Department of Otolaryngology-Head and Neck Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
¹² ENT Department, Medical University, Pozna'n, Poland.
¹³ Department of Otorhinolaryngology and Head and Neck Surgery, Nagoya City University Hospital, Nagoya, Aichi, Japan.
¹⁴ Department of Head and Neck Surgery, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan.

Abstract

Background: Squamous cell carcinoma (SCC) of the external auditory canal (EAC) is a rare disease, which is commonly classified with the modified Pittsburgh classification. Our aim was to evaluate the predictive performance of this classification in relation to disease-free survival (DFS).

Methods: We examined retrospective data from a nationwide Dutch cohort study including patients with primary EAC SCC. These data were combined with individual patient data from the literature. Using the combined data, the predictive performances were calculated using the c-index.

Results: A total of 381 patients were included, 294 for clinical and 281 for the pathological classification analyses. The c-indices of the clinical and the pathological modified Pittsburgh classification predicting DFS were 0.725 (0.668-0.782) and 0.729 (0.672-0.786), respectively.

Conclusion: The predictive performance of the modified Pittsburgh classification system as such appears to be acceptable to predict the DFS of EAC SCC. Other factors need to be added to a future model to improve the predicted performance.

Keywords: disease-free survival; neoplasm staging; prognosis; squamous cell carcinoma; temporal bone.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Carcinoma, Squamous Cell* / pathology
Carcinoma, Squamous Cell* / therapy
Cohort Studies
Disease-Free Survival
Ear Canal / pathology
Ear Neoplasms* / pathology
Humans
Neoplasm Staging
Prognosis
Retrospective Studies
Treatment Outcome