Endocrine Abstracts

Introduction: Evidence suggests a relationship between high tumoral Ki-67 LI with persistence of tumor after surgery and lower response rate to medical therapy. Therefore, we aimed to determine the relationship between Ki-67 LI and p53 with age, gender, number of surgeries, cure after surgery and cavernous sinus invasion in pituitary adenomas of patients with acromegaly.

Methods: The paraffin-embedded tissue sections of 30 patiets with acromegaly, operated at our center during 2003–2010 via transsphenoidal route were immunostained for Ki-67 and p53, using avidin–biotin–peroxidase complex method. Clinical and radiological data were obtained through chart review. High Ki-67 LI and diffuse p53 immunoreactivity was defined as immunopositivity for ≥4 and ≥50% of cells respectively.

Results: The current study included 30 patients (17 female, 13 male), ranging in age between 23 and 65 years old. According to MRI, 3 (10%) of the tumors were microadenoma and 27 (90%) were macroadenoma. Cavernous sinus invasion was present in 14 (47%) cases. Seven (23%) of the patient were operated for at least two times and 23 (77%) were operated on once. Six (20%) patients were cured at first surgery and 24 (80%) had active disease. Fourteen tumors (47%) had Ki-LI ≥4% and 2 (6.7%) tumors demonstrated ≥50% p53 immunoreactivity. We could not find a relationship between age, gender, cure at first surgery and number of surgeries with high Ki-67 LI and diffuse p53 immunoreactivity (P>0.05). However, KI-67 LI ≥4% and diffuse p53 immunoreactivity were significantly higher in tumors with cavernouse sinuse invasion (P=0.007 and P=0.03 respectively).

Conclusion: High Ki-67LI and diffuse p53 immunoreactivity are associated with cavernouse sinuse invasion in pituitary adenomas of patients with acromegaly.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.

Figure 1 (A) High Ki-67 LI (11%) in a pituitary adenoma of a petient with acromegaly. (B) Pituitary MRI of the same patient performed after surgery demonstrates right cavernous sinus invasion.