WPOI-4/5 Correlates With Lymph Node Recurrence and Poor Prognosis in Early-stage Tongue Squamous Cell Carcinoma

Abstract

Background/aim: Neck management in patients with early-stage tongue cancer remains controversial. The worst pattern of invasion (WPOI) of the primary tumor has been associated with the incidence of regional metastasis. We investigated the prognostic role of WPOI, especially in relation to regional lymph node recurrence and disease-specific survival (DSS).

Patients and methods: We retrospectively reviewed medical records and evaluated tumor specimens of 38 patients with early-stage tongue cancer who underwent primary tumor resection without elective neck dissection.

Results: Regional lymph node recurrence rates were significantly higher in patients with WPOI-4/5 compared with WPOI-1 to -3. The 5-year DSS rates were significantly higher for WPOI-1 to -3 than for WPOI-4/5. Notably, patients with WPOI-1 to -3 achieved a 100% 5-year DSS rate with salvage neck dissection and postoperative treatment, even those with cervical lymph node recurrence, whereas patients with WPOI-4/5 had a poorer prognosis.

Conclusion: Patients with WPOI-1 to -3 tumors can be followed up without neck dissection until regional lymph node recurrence is detected, with a good course after salvage treatment. In contrast, patients with WPOI-4/5 tumors who are followed up until the appearance of regional lymph node recurrence have a poor prognosis, even with adequate treatment for recurrent disease.

Keywords: Early-stage tongue cancer; depth of invasion; elective neck dissection; worst pattern of invasion (WPOI).

Figure 1. Kaplan-Meier estimates for regional lymph node recurrence-free survival according to pT stage or worst pattern of invasion (WPOI). (A) Survival rate decreased with pT stage progression, but there was no significant difference (p=0.0753). (B) Survival rate decreased with WPOI progression. (C) The increase in recurrence rates with progression of WPOI was more evident than with pT stage (WPOI 1-3 vs. 4-5, p=0.0065).

Figure 2. Kaplan-Meier estimates for disease-specific survival according to pT stage or worst pattern of invasion (WPOI). (A) Survival rates for pT1 and pT2 were comparable (p=0.9208). (B) Survival rate decreased with WPOI progression. (C) Patients with WPOI-4 or -5 had significantly lower 5-year survival rates compared with those with WOPI-1 to -3 (p=0.0001).