Extra- Versus Intratumoral Perineural Invasion in Non-Cutaneous Head and Neck Squamous Cell Carcinomas
BA Palla, ME Miller, MA St. John, DA Elashoff, CK Lai. David Geffen School of Medicine, UCLA, Los Angeles
Background: Perineural invasion (PNI) in non-cutaneous head & neck squamous cell carcinoma (HNSCC) is associated with an increased risk of recurrence & decreased survival. It is currently unknown whether extratumoral (ET) PNI imparts a worse prognosis than intratumoral (IT) PNI in HNSCC.
Design: A retrospective review of 60 HNSCC cases from 1/05-5/06 was performed to identify foci of PNI. For each case, PNI density (# PNI foci/# tumor sections), size of largest nerve involved, & distance of each PNI focus to tumor edge (negative value = IT; 0 = at tumor edge; positive value = ET) were measured. PNI was categorized as IT, ET, or peripheral with the latter defined as 0 to -0.2 mm from the tumor edge. A Cox regression model was used to evaluate the effect of tumor (T) stage, nodal (N) stage, lymphovascular invasion (LVI), & PNI on disease-free (DF) survival. Kaplan-Meier survival analyis was performed to evaluate DF survival between IT, ET, & peripheral PNI groups.
Results: Of the 60 patients, 40 were male & 20 were female with a mean age of 61.5 yrs ± 12.8 yrs. There were 34 PNI cases (IT=11, P=7, & ET=16) & 26 cases without PNI. Using the Cox regression model, T-stage, N-stage, LVI, & PNI were not significantly correlated with recurrence or time to recurrence. Among PNI cases, there was a tendency of maximum extent of PNI toward smaller DF intervals (HR=1.24, p=0.15). Addition of T-stage, N-stage, & LVI did not affect this result substantially. Kaplan-Meier survival analysis showed a tendency toward a difference in DF survival between PNI class, i.e., ET+peripheral versus IT PNI groups (p=0.18). No statistically significant relationship between DF survival (p=0.43) & the size of nerve involved as well as the PNI density (p=0.32) was observed.
Conclusions: Preliminary data with a limited number of cases demonstrate a tendency of maximum extent of PNI toward diminished DF survival. Moreover, ET+peripheral PNI tended to have a shorter DF survival than IT PNI. Additional cases need to be analyzed in order to elucidate the statistical significance of this trend. Other clinical and histological parameters will be evaluated.
Category: Head & Neck
Monday, March 22, 2010 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 170, Monday Morning