Evaluation of prognosis for carcinoma of unknown origin in elderly patients

Purpose: Carcinoma of unknown origin has a poor outcome and usually occurs in elderly patients. In this article, we analyzed the prognostic factors in elderly patients with cancer of unknown primary site (CUP) for treatment considerations. Patients and Methods: Patients >70 years old with histologically proven carcinoma were retrospectively reviewed. The prognostic factors were analyzed with univariate and multivariate Cox regression. Results: We included 63 patients aged 70-79 years and 51 patients ≥80 years old. The results of multivariate Cox regression in the 70-79 years age group revealed white blood cell count ≤10 ⁴/ml [p = 0.033; hazard ratio (HR) 2.51, range 1.079-5.840] and albumin ≥3.5 g/dl (p = 0.007; HR 3.38, range 1.398-8.177) as independent factors. In the group of patients ≥80 years old, Eastern Cooperative Oncology Group performance status <1 (p = 0.020), white blood cell count ≤10 ⁴/ml (p = 0.001), albumin ≥3.5 g/dl (p = 0.006), lactate dehydrogenase (LDH) ≤250 U/l (p = 0.002) and non-chest metastasis (p = 0.043) were significantly better with univariate analysis. Multivariate Cox regression revealed albumin ≥3.5 g/dl (p = 0.007; HR 3.28, range 1.389-7.745) and LDH ≤250 U/l (p = 0.045; HR 3.18, range 1.026-9.848) as independent factors. Conclusions: For elderly patients with CUP, the serum albumin level seems to be a consistently independent prognostic factor. In patients >80 years old, serum LDH plays an important role in prognosis. This study is helpful in predicting the outcome and management for this group of patients.