Stepwise expression of CDKN2A and RB1 proteins in esophageal mucosa from patients at high risk for squamous cell carcinoma.

Squamous cell carcinoma of the esophagus is a lethal cancer and carries a poor prognosis because of late diagnosis. Identification of molecular markers may aid early diagnosis. We assessed the expression of CDKN2A/RB1 in the esophageal mucosa and its association with the histology. Esophageal biopsies were collected from 38 patients with no esophageal lesion (group 1), from iodine-negative areas of 108 alcoholics/smokers (group 2), and from tumor and nontumor areas in 41 patients with squamous cell carcinoma (group 3). The histologic diagnosis was compared with immunoexpression of CDKN2A/RB1. In group 1, histology showed normal mucosa/mild esophagitis and no expression of CDKN2A/RB1. In groups 2 and 3, the diagnosis was: normal mucosa (38.4%), esophagitis (44.4%), dysplasia and carcinoma in situ (2.8%), and carcinoma (14.3%). The immunoexpression of CDKN2A/RB1 increased in a stepwise manner from the normal mucosa, to esophagitis, dysplasia/carcinoma in situ, and carcinoma (P<0.01). CDKN2A/RB1 was not expressed in the esophageal mucosa of patients without risk factors. p16/pRb expression increased in a stepwise manner, according to the severity of histologic lesions, in biopsies from patients exposed to risk factors or with carcinoma. Esophageal mucosa exposed to risk factors with the expression of those proteins may be at risk for malignant transformation.

Detecting p53 immunoexpression in esophageal mucosa with exfoliative cytology in individuals at risk for squamous cell carcinoma of the esophagus.

OBJECTIVE: To determine the prevalence of p53 expression in cytologic smear collected by the RS Balloon in high-risk individuals, and test its yield in the cytologic screening of squamous cell carcinoma of the esophagus (SCCE). STUDY DESIGN: Asymptomatic individuals at risk for SCCE underwent esophageal exfoliative cytology with the RS Balloon immediately followed by upper gastrointestinal endoscopy with biopsies of unstained areas after iodine mucosal staining of the esophagus. For each patient, cytologic expression of p53 was compared with the worst endoscopic biopsy diagnosis and the histologic expression of p53. RESULTS: One hundred seventy-one individuals were submitted to the study's protocol. There were 8 lost cases (4.7%) due to inadequate cytologic samples. The final sample consisted of 163 individuals where 150 were male (92%), mean age of 52.6 +/- 12.0 years old. There were 3 cases of dysplasia/SCCE. Immunohistochemical expression of p53 protein was positive in 38 patients (23.6%), with basal layer expression in 29 (76.3%), middle layer expression in 8 (21.1%) and superficial layer in 1 (2.6%). All patients with dysplasia/SCCE had positive immunohistochemical expression of p53 protein. Immunocytochemical expression of p53 protein in cytologic smear was negative in all cytology samples. CONCLUSION: The negative results of immunocytochemical expression of p53 protein suggest that its use does not contribute to improving the performance of conventional cytology of the esophagus in the screening for SCCE and its precursor lesions.