A change in the study evaluation paradigm reveals that larynx preservation compromises survival in T4 laryngeal cancer patients

Gerhard Dyckhoff, Peter K. Plinkert, Heribert Ramroth

Larynx preservation (LP) is recommended for up to low-volume T4 laryngeal cancer as an evidence-based treatment option that does not compromise survival. However, a reevaluation of the current literature raises questions regarding whether there is indeed reliable evidence to support larynx preservation for T4 tumor patients. In an observational cohort study of 810 laryngeal cancer patients, we evaluated the outcomes of all T4 tumor patients treated with primary chemo-radiotherapy (CRT) or primary radiotherapy alone (RT) compared with upfront total laryngectomy followed by adjuvant (chemo)radiotherapy (TL + a[C]RT). Additionally, we reevaluated the studies that form the evidence base for the recommendation of LP for patients with up to T4 tumors (Pfister et al., J Clin Oncol 24:3693-704, 2006). The evaluation of all 288 stage III and IV patients together did not show a significant difference in overall survival (OS) between CRT-LP and TL + a(C)RT (hazard ratio (HR) 1.23; 95% confidence interval (CI): 0.82-1.86; p = 0.31) using a multivariate proportional hazard model. However, a subgroup analysis of T4 tumor patients alone (N = 107; 13.9%) revealed significantly worse OS after CRT compared with TL + a(C)RT (HR 2.0; 95% CI: 1.04-3.7; p = 0.0369). A reevaluation of the subgroup of T4 patients in the 5 LP studies that led to the ASCO clinical practice guidelines revealed that only 21-45 T4 patients had differential data on survival outcome. These data, however, showed a markedly worse outcome for T4 patients after LP. T4 laryngeal cancer patients who reject TL as a treatment option should be informed that their chance of organ preservation with primary conservative treatment is likely to result in a significantly worse outcome in terms of OS. Significant loss of survival in T4 patients after LP is also confirmed in recent literature.