Expression of LRIG1 and LRIG3 correlates with human papillomavirus status and patient survival in cervical adenocarcinoma

The incidence of cervical adenocarcinoma, which accounts for 10-20% of all cervical cancers, has increased continuously in developed countries during the last two decades, unlike squamous cell cervical carcinoma. This increasing trend, noted particularly among women under the age of 40 years, has occurred despite extensive cytological Pap smear screening. A deeper understanding of the etiology of cervical adenocarcinoma, better preventive measures and reliable prognostic markers are urgently needed. The human leucine-rich repeats and immunoglobulin-like domains (LRIG) gene family includes: LRIG1, LRIG2 and LRIG3. LRIG expression has proven to be of prognostic value in different types of human cancers, including breast cancer, early stage invasive squamous cervical cancer, cutaneous squamous cell carcinoma, oligodendroglioma and astrocytoma. LRIG1 functions as a tumor suppressor, while less is known about the functions of LRIG2 and LRIG3. This study evaluated the expression of the three LRIG proteins in tumor specimens from 86 women with pure cervical adenocarcinoma by immunohistochemistry. Possible correlations between LRIG expression and known prognostic factors, including human papillomavirus (HPV) status, FIGO stage and histology were investigated. Patient survival data were collected retrospectively and the possible prognostic value of LRIG protein expression was investigated. High staining intensity of LRIG1 and high fraction of LRIG3-positive cells were significantly associated with patient survival, and positive correlations were found between LRIG1 and LRIG3 staining intensity and HPV status. Thus, the LRIG proteins may be important determinants of cervical adenocarcinoma progression and their diagnostic and prognostic potential should be studied further.