Comparison of Male and Female Prolactinoma Patients Requiring Surgical Intervention

Objectives/Hypotheses: Prolactinomas are the most common pituitary adenoma, comprising up to 50–60% of all functional pituitary tumors. Symptoms of a prolactinoma may stem from hormonal causes, with symptoms such as menstrual irregularities, galactorrhea or reduced libido, or may be the result of tumor mass effect, such as visual changes and chronic headache. Gender differences have been noted in prolactinomas, with males tending to present with larger tumors, and with more neurological sequelae from the mass effect of the tumor. However, no studies have investigated differences in surgical outcomes between males and females. The purpose of this study is to evaluate differences in patient characteristics, disease characteristics, and outcomes between male and female prolactinoma patients refractory to medical therapy.

Study Design: Retrospective chart review

Methods: The medical records of all patients with prolactinomas who underwent endoscopic endonasal skull base surgery at a tertiary medical center between January 1, 2013 and August 30, 2016 were included. Demographic information was collected, along with pathology and immunohistochemistry results, presenting symptoms, prolactin serum level at diagnosis, postoperative prolactin level, length of medical therapeutic trial, response to medical treatment, reason for proceeding to surgery, tumor size at time of surgery, presence of suprasellar extension, invasion of cavernous sinuses, complications, intraoperative and postoperative cerebrospinal fluid leak, type of resection, length of stay, and need for medical therapy postsurgery. Statistical analysis was performed using chi-squared test or student's t-test as applicable.

Results: A total of 42 patients were identified, with 11 male and 31 female. The average age of males was 37.2 years and for females 35.4 years. Male patients were significantly more likely to report decreased libido (p < 0.0001) and visual changes (p = 0.0149) at presentation, whereas females were significantly more likely to report galactorrhea at presentation (p = 0.0029). Prolactin levels were on average higher in males than females, though this was not statistically significant (p = 0.1249). Females tended to have longer trials of medical therapy, though this was not statistically significant (p = 0.0814. Tumor size was on average larger in males, with this difference approaching significance (p = 0.0567). Males were significantly more likely to have suprasellar extension (p = 0.0238). Cavernous sinus invasion was seen more often in males but this difference was not significant (p = 0.0529). In terms of outcomes, males were significantly more likely to have a subtotal resection as opposed to a gross total resection (p = 0.0035) and require continued medical therapy post-operatively (p = 0.0196).

Conclusions: Male prolactinoma patients tend to have larger tumors, with more aggressive symptoms and features. This may have a role in the differences in outcomes noted in this study group. As such, earlier identification and diagnosis in males may lead to improved outcomes.