The impact of worst patterns of invasion on survival outcomes in oral cavity cancer: implications for adjuvant therapy and prognostic stratification.

PURPOSE

To examine the impact of the worst patterns of invasion (WPOI) on survival outcomes and possible implications for adjuvant treatment decisions in squamous cell oral cavity cancer patients.

METHODS

The loco-regional progression-free survival (LRPFS) and the distant metastasis-free survival (DMFS) were calculated for 162 patients. Univariate and multivariate analyses were done according to prognostic predictors of stage (early/T1-2 or N0; locally advanced /T3-4 or N +), grade, depth of invasion, WPOI, perineural (PNI), and lymphovascular (LVI) invasion and margin status. WPOI-V, PNI, and LVI were also analyzed for their positive status.

RESULTS

The median follow-up was 46 months (3-77 months). A total of 32 events, as loco-regional (n = 16), systemic progression (n = 14), and second primary lung cancer (n = 2) were observed. The presence of locally advanced disease, PNI or LVI, and WPOI-V were significantly worse prognostic factors for LRFS and DMFS. The 5-year LRPFS (74% vs. 92.8%, p = 0.001) and DMFS (74% vs. 94%, p < 0.0001) were significantly worse in patients with WPOI-V present. In multivariate analysis, WPOI-V patients had a worse prognosis for loco-regional relapse (p = 0.037) in early-stage cancer. There were no triple-positive patients in the early-stage group. LRRFS (90.4% vs. 59.7%, p < 0.0001) and DMFS (97% vs. 42.9%, p = 0.013) were significantly better in triple-negative patients compared to triple-positive patients.

CONCLUSION

WPOI-V indicates a poor prognosis for locoregional progression and distant metastasis. Survival outcomes are significantly worse in triple-positive patients. These results need further evidence for adjuvant radiotherapy for early and systemic therapy for triple-positive locally advanced-stage patients.