Aldehyde dehydrogenase-1 predicts favorable prognosis in patients with vulvar squamous cell carcinoma.

BACKGROUNDS: Aldehyde dehydrogenase-1 (ALDH1) has been considered as a potential cancer stem cell marker in different types of cancer. In the present study, we investigated the expression of ALDH1 in vulvar squamous cell carcinoma, and evaluated its correlation with clinicopathological factors in patients suffering from this disease.

MATERIALS AND

METHODS

One hundred and fifty-four patients with vulvar squamous cell carcinoma, together with their verified histopathological and complete clinical data in Norway were included in the study. All paraffin-embedded samples of the primary vulvar carcinoma were recruited. The presence of ALDH1 was detected by immunohistochemistry and compared against commonly recognized prognostic factors.

RESULTS

By immunohistochemical staining, the expression of ALDH1 was observed in 10/154 (6.5%) vulvar squamous cell carcinomas, while being extensively expressed in the suprabasal cells in normal vulvar epithelia from patients with benign gynecological disease and non-malignant epithelia adjacent to the tumor cells. In addition, ALDH1 was highly expressed in stromal fibroblasts, blood vessels and keratinized pearl of the carcinoma in all the samples. Patients with ALDH1-positive tumors had a significantly longer disease-specific survival (p=0.042).

CONCLUSION

Contrary to the characteristics of cancer stem cells shown in other types of cancer with positive expression of ALDH1, the positive expression of ALDH1 in patients with vulvar squamous cell carcinoma indicates a significantly better prognosis. Furthermore, there is a trend that the expression of ALDH1 is associated with better histological differentiation.