Distant treatment failure and prognostic significance of hypercalcemia in patients with oral cavity squamous cell carcinoma

ABSTRACT

Oral cavity squamous cell carcinoma [OCSCC] treatment failure may be locoregional or distant. Unlike locoregional, distant recurrence can not be managed with salvage treatment and signifies a poor prognosis. Paraneoplastic hypercalcemia may result from the production of parathyroid hormone-related protein [PTHrP] by OCSCC. The aim of the study is to assess OCSCC distant treatment failure pattern and to investigate the prognostic role of hypercalcemia. A retrospective review of the medical records of OCSCC patients who completed treatment with curative intent then developed recurrent disease treatment with curative intent then developed recurrent disease was done. From 51 patients, 19 [37%] were eligible for analysis. The main pattern of treatment failure was locoregional. Distant failure occurred in 32% of patients. Hypercalcemia occurred in 53% of patients and was the only variable that correlated significantly with distant failure [p=0.016] by multivariate analysis. The median overall survival of hypercalcemic patients was shorter than normocalcemic patients [16 and 24 months, respectively; p=0.032]. In multivariate analysis, only lymph nodes' involvement was associated with significantly shorter survival [p=0.01]. The median survival from diagnosis of hypercalcemia was only 43 days [95% CI 28-58]. In conclusion, distant failure occurs in about 1/3 of OCSCC treatment failures. Further research is warranted to identify this group of patients at earlier stages and to find an effective treatment. Hypercalcemia is likely to be a terminal event in OCSCC and carries a dismal prognosis. Its diagnosis and management may have a role in end of life care but not in the curative setting. The prognostic significance of PTHrp identification on OCSCC tissue needs further evaluation