Impact of Perineural Invasion in the Pathologically N0 Neck in Oral Cavity Squamous Cell Carcinoma

Abstract

OBJECTIVE Patients with oral cavity squamous cell carcinoma (OCSCC) undergo adjuvant radiation for pathologically high risk features including positive nodal disease and extra capsular spread (ECS). In the absence of these high risk features, our objective was to determine if perineural invasion (PNI) is an independent risk factor and if adjuvant radiation (XRT) improves disease control rates. STUDY DESIGN Historical cohort analysis. SETTING Tertiary university hospital. METHODS Eighty-eight OCSCC patients (46 males, 42 females; mean age, 56.7 years; median follow-up, 4.6 years) treated surgically with pN0 necks were studied. Overall 23% (20/88) were pN0/PNI+ and of those with PNI, 70% (14/20) underwent XRT. Survival analysis using Kaplan-Meier followed by multivariable Cox models was performed. RESULTS Multivariate analysis verified PNI to be associated with worse DFI (p=0.012) and LRC (p=0.005) and perivascular invasion (PVI) associated with worse DFI (p=0.05). Amongst pN0/PNI+ patients, those who received XRT demonstrated significantly improved DFI (mean 6.5yrs v. 1.7yrs; p=0.014) and LRC (mean 6.7yrs v. 1.9yrs; p=0.047). There was no improvement in OS (p=0.68) or DSS (p=0.8) in those receiving XRT. CONCLUSIONS PNI is an independent adverse risk factor in the absence of nodal metastasis and extracapsular spread. We observed a statistically significantly longer DFI and LRC when patients were treated with adjuvant radiation.

Patterns of recurrence in oral tongue cancer with perineural invasion

“…Chinn et al identified a worse DSS in patients with early OTSCC with PNI, which was associated with a significantly worse local regional control. (3) Fagan attributed PNI associated disease related mortality to local failure without differences in regional or distant recurrences. (2) Increased nodal metastasis and regional recurrence with local control has also been observed in PNI positive OTSCC.…”

Treatment Factors Associated With Survival in Early-Stage Oral Cavity Cancer

“…Although these factors are inconsistently reported and their prognostic impact is debatable, they could confound the effect of radiation therapy and chemotherapy on survival. [30][31][32] In addition, use of radiation therapy or chemotherapy could be a surrogate marker for less aggressive resection in very localized disease. This could explain our finding that radiation therapy was associated with a greater decrease in survival in stage I disease than in stage II disease.…”

Oral Cavity Carcinoma: Current Management, Controversies, and Future Directions

“…52,53 Despite the poor prognosis associated with these variables, the addition of PORT improved LRC and survival. 6,7,53 No RCTs have been conducted to evaluate the efficacy of PORT compared with surgery alone. However, Lundahl et al 53 performed a retrospective, matched-pair analysis to compare surgery alone versus surgery plus PORT.…”