Long-term response to cabergoline and multi-modal treatment in men with macroprolactinoma: Does size really matter?

Response to cabergoline treatment, gonadal axis recovery, and outcomes of drug withdrawal, in men with microprolactinoma: a retrospective cohort study

PURPOSE

Due to the low incidence of male microprolactinoma, there is a paucity of data in the literature regarding its management. Our aim was to investigate the long-term outcomes of cabergoline treatment in men with microprolactinoma.

METHODS

In this single-center retrospective cohort study, we reviewed patient's records at prolactinoma diagnosis, following cabergoline discontinuation (if occurred), and at the last clinic visit. We collected all available clinical data, laboratory tests, and pituitary magnetic resonance imaging. We report response rates, gonadal axis recovery, and outcomes following cabergoline discontinuation.

RESULTS

The study cohort included 47 men with microprolactinoma [age at diagnosis 45.6 ± 17.6 years; median prolactin 70.0 ng/ml (IQR 51.0-103.4); low testosterone, 34 men (72.3%); adenoma diameter 5.6 ± 2.0 mm; median follow-up 7.1 years (IQR 3.5-10.4)]. Forty-two patients (89.4%) achieved normal prolactin levels within a median treatment time of 4.0 months (IQR 3.0-5.5) and had normal testosterone at last clinic visit. Five men (10.6%) did not achieve prolactin normalization, of whom 3 men remained hypogonadal. Mild side effects occurred in 4.3% of patients and disappeared with dose reduction. Thirteen men that achieved normal prolactin attempted drug discontinuation, but only 5 remained with normoprolactinemia. Men who maintained normal prolactin levels were treated longer with cabergoline [median treatment of 10 years (IQR 4.6-10.3) vs 2.0 years (IQR 1.5-3.2); p < 0.01].

CONCLUSIONS

Ninety percent of men harboring microprolactinoma achieved normoprolactinemia and subsequent testosterone normalization with cabergoline treatment. Men that discontinued cabergoline after prolonged prolactin suppression (>5 years) achieved sustained remission. These findings assist informed decision-making, between medical and surgical treatment.

Good response rates and predictors during the first year of cabergoline treatment in large invasive prolactinomas

PURPOSE

The factors predicting the long-term response to cabergoline are not well known, particularly in more invasive prolactinomas. This study aimed to evaluate the rate of good response (GR) (normoprolactinemia and ≥ 50% tumor shrinkage) at the one-year follow-up and to identify predictors of GR in patients with large invasive prolactinomas.

METHODS

This retrospective single-center study included 38 patients (32 males, 6 females; mean age 41.9 ± 12.8 years) with invasive macroprolactinomas (baseline median prolactin: 2530 (1726-5451) ng/mL, mean longest tumor diameter: 36.4 ± 12.8 mm) who were followed for at least one year under cabergoline therapy. Prolactin levels and tumor volume changes were analyzed at early and late follow-ups. Patients were classified as good responders (GRs) or poor responders (PRs) based on their first-year outcomes.

RESULTS

At the first year, 17 patients (44.7%) achieved a GR. Baseline parameters were comparable between groups, but GRs had significantly higher normoprolactinemia rates (70.6% vs. 23.8%,p = 0.004) and greater tumor shrinkage (57.3 ± 15.6% vs. 41.9 ± 21.9%,p = 0.02) at 3-6 months. An early tumor shrinkage cut-off rate of 44.9% (88% sensitivity, 62% specificity) or an early prolactin cut-off level of 30 ng/mL (75% sensitivity, 77% specificity) were identified as good predictors of GR in the first-year. All GRs maintained normoprolactinemia and ≥ 50% tumor shrinkage, while 33.3% and 42.9% of PRs failed to meet these goals, respectively, at the last visit (p = 0.009, p = 0.002). Three of PRs required surgery during follow-up.

CONCLUSIONS

Approximately half of invasive prolactinoma patients achieved the composite goal within one year of cabergoline therapy. Early follow-up studies, rather than baseline characteristics, are strong predictors of treatment success.

Visual morbidity in macroprolactinoma: A retrospective cohort study

OBJECTIVE

The management of visual field damage in patients with macroprolactinomas is a major therapeutic challenge. We aimed to study the visual morbidity associated with macroprolactinoma and its outcomes following medical and surgical treatment. We aimed to identify predictors of visual recovery.

METHODS

We retrospectively reviewed patient's data including clinical presentation, serial pituitary magnetic resonance imaging, laboratory tests, visual symptoms and neuro-ophthalmologic examination, visual field tests and optical coherence tomography tests. The main outcome was complete visual field recovery. Descriptive analyses were conducted. Predictors of visual recovery were investigated.

PATIENTS

The study cohort included 150 patients with macroprolactinoma [median follow-up, 6.0 years (interquartile range (IQR) 2.9-10.6)].

RESULTS

At diagnosis, visual field defects were evident in 40 patients (26.7%). At the end of follow-up, 24 out of 39 available visual field tests (61.5%) exhibited complete recovery. Patients that achieved complete visual recovery had smaller macroadenomas at diagnosis [30.5 mm (15.0-80.0) vs. 42.0 mm (30.0-85.0), p < .01], lower baseline serum prolactin levels [1414 mcg/L (489-3586) vs. 4119 mcg/L (2715-6315), p < .01], lower rates of central hypogonadism (78.3% vs. 93.3%, p = .05) and central hypothyroidism (20.8% vs. 53.3%, p = .04), lower rates of compressive optic neuropathy (35.3% vs. 87.5%, p = .02) and a better visual acuity (better than 6/8 in both eyes, 93.7% vs. 28.6%, p < .01).

CONCLUSIONS

In our cohort of 150 patients with macroprolactinoma, 40 patients (26.7%) presented with visual field defects, of which 61.5% achieved complete visual recovery with treatment. Patients that achieved complete visual recovery presented with smaller macroadenomas, lower serum prolactin levels, lower rates of central hypogonadism and central hypothyroidism, lower rates of compressive optic neuropathy and better visual acuity.

Experience in the Treatment of Male Prolactinomas: A Single-Center, 10-Year Retrospective Study

INTRODUCTION

Male prolactinomas are uncommon and typically macroadenomas with difficult treatment and management. The purpose of this study was to summarize the treatment and management experiences of 254 male prolactinoma patients at a single center.

METHODS

This was a 10-year retrospective study conducted at a single center. A total of 254 male prolactinoma patients were included. Clinical data for all subjects were collected using an electronic medical record system.

RESULTS

A total of 254 male patients with prolactinoma were studied. Their median age at onset was 28.8 years, and median disease duration was 28.5 months. The median PRL levels were 582.0 ng/mL at diagnosis. Their median maximum tumor diameter was 23.0 mm, with macroadenoma accounting for the majority (76.7%). After treatment, the biochemical remission rate with monotherapy was 36.6%, but significantly increased to 60.6% with multidisciplinary treatment (p < 0.001). Knosp 0-2 patients had significantly higher rates of biochemical remission compared to Knosp 3-4 (all p < 0.05). In addition, the maximum diameter of adenoma (B = -0.110, p = 0.008) and cavernous sinus invasion (B = -1.741, p = 0.023) were negatively correlated with postoperative biochemical remission. The maximum diameter of the adenoma (B = - 0.131, p < 0.001) was a negative correlation factor, while treatment duration (B = 0.034, p = 0.002) was a positive correlation factor for biochemical response to medication.

CONCLUSION

Male prolactinoma has a low biochemical remission rate when treated alone, but multitherapy can improve it even more. Surgery may also be considered for male prolactinoma with a micro, and noninvasive tumor after a thorough evaluation.

INTRODUCTION

Male prolactinomas are uncommon and typically macroadenomas with difficult treatment and management. The purpose of this study was to summarize the treatment and management experiences of 254 male prolactinoma patients at a single center.

METHODS

This was a 10-year retrospective study conducted at a single center. A total of 254 male prolactinoma patients were included. Clinical data for all subjects were collected using an electronic medical record system.

RESULTS

A total of 254 male patients with prolactinoma were studied. Their median age at onset was 28.8 years, and median disease duration was 28.5 months. The median PRL levels were 582.0 ng/mL at diagnosis. Their median maximum tumor diameter was 23.0 mm, with macroadenoma accounting for the majority (76.7%). After treatment, the biochemical remission rate with monotherapy was 36.6%, but significantly increased to 60.6% with multidisciplinary treatment (p < 0.001). Knosp 0-2 patients had significantly higher rates of biochemical remission compared to Knosp 3-4 (all p < 0.05). In addition, the maximum diameter of adenoma (B = -0.110, p = 0.008) and cavernous sinus invasion (B = -1.741, p = 0.023) were negatively correlated with postoperative biochemical remission. The maximum diameter of the adenoma (B = - 0.131, p < 0.001) was a negative correlation factor, while treatment duration (B = 0.034, p = 0.002) was a positive correlation factor for biochemical response to medication.

CONCLUSION

Male prolactinoma has a low biochemical remission rate when treated alone, but multitherapy can improve it even more. Surgery may also be considered for male prolactinoma with a micro, and noninvasive tumor after a thorough evaluation.

Prolactin-secreting pituitary adenomas: male-specific differences in pathogenesis, clinical presentation and treatment

Prolactinomas (PRLomas) constitute approximately half of all pituitary adenomas and approximately one-fifth of them are diagnosed in males. The clinical presentation of PRLomas results from direct prolactin (PRL) action, duration and severity of hyperprolactinemia, and tumor mass effect. Male PRLomas, compared to females, tend to be larger and more invasive, are associated with higher PRL concentration at diagnosis, present higher proliferative potential, are more frequently resistant to standard pharmacotherapy, and thus may require multimodal approach, including surgical resection, radiotherapy, and alternative medical agents. Therefore, the management of PRLomas in men is challenging in many cases. Additionally, hyperprolactinemia is associated with a significant negative impact on men's health, including sexual function and fertility potential, bone health, cardiovascular and metabolic complications, leading to decreased quality of life. In this review, we highlight the differences in pathogenesis, clinical presentation and treatment of PRLomas concerning the male sex.

Predicting hypogonadotropic hypogonadism persistence in male macroprolactinoma

PURPOSE

To study the baseline characteristics predicting hypogonadotropic hypogonadism (HH) persistence in men with macroprolactinoma that achieved prolactin normalization.

DESIGN

Retrospective cohort study.

METHODS

Male patients diagnosed with macroprolactinoma and HH that received cabergoline treatment with subsequent prolactin normalization were included: men that achieved eugonadism, and men that remained hypogonadal. Patient's demographic, clinical and biochemical parameters, sellar imaging, and visual fields tests were obtained. Univariate and multivariate models were used to identify predictors of HH persistence.

RESULTS

Fifty-eight male patients (age 49.2 ± 12.6 years) with a median baseline prolactin of 1154 ng/mL (IQR 478-2763 ng/mL) and adenoma (maximal) diameter of 25.9 ± 14.8 mm were followed for a median of 5.6 years (IQR 3.0-10.7). Twelve men (21%) suffered from HH persistence at the end of follow-up and 46 men achieved eugonadism. Forty-two out of 46 men (91%) accomplished eugonadism within the first year following prolactin normalization. In a multivariate logistic regression model, hypopituitarism (OR 10.1; 95% CI 1.10-101.94), visual field defect (OR 9.9; 95% CI 1.07-92.33), and low baseline testosterone levels (OR 0.5; 95% CI 0.29-0.93) were independent predictors of HH persistence.

CONCLUSION

In our cohort of men with macroprolactinoma that reached prolactin normalization with cabergoline treatment, 21% had HH persistence. Pituitary hormone deficiency, visual field defects, and low baseline testosterone levels were independently associated with HH persistence. 91% of men achieved eugonadism within the first year following prolactin normalization. These findings may support informed clinical decision-making regarding the initiation of testosterone replacement in men with macroprolactinomas.

Prolactinoma: Clinical Characteristics, Management and Outcome

Aim Prolactinoma, a prolactin (PRL) secreting functioning pituitary tumor, is the most common of all pituitary adenomas (PA) accounting for 40-60% and dopamine agonists (DA) are the cornerstone of treatment. The aim of this study was to review the clinical presentation, treatment modalities and therapeutic outcomes of patients with prolactinomas in the South Asia region. Methods This retrospective study was conducted in the Endocrinology Department of Shaukat Khanum Memorial Cancer Hospital and Research Centre from December 2011 till December 2019. Medical records were used to retrieve for patient's demographics, clinical features at diagnosis, PRL levels and size of prolactinoma on MRI at diagnosis and after start of dopamine agonists and outcome of medical management. Results A total of 107 patients were included in this study. Mean age at diagnosis was 35 (22-54) years for men and 32 (18-50) years for women and 66.4% (71) of the patients were females. Our study included 38 (35.5%) microadenoma, 50 (46.7%) macroadenoma and 19 (17.8%) giant adenomas. At presentation, the most common symptom among females was menstrual irregularity/amenorrhea seen in 73.2% of females and among males was visual disturbance (80.6%). A significant reduction in PRL levels was seen within six to 12 months of treatment. Mean PRL levels decreased from 3162.8 ng/ml to 1.52 ng/ml. A notable decrease in tumor size was seen with medical management, mean adenoma size decreased from 2.18 cm to 1.04 cm. With cabergoline (CAB) 83.3% biochemical cure was seen compared to bromocriptine (BRC) which has 60.4%. The radiological response rate in CAB and BRC groups was 65.45% and 60%, respectively. Complete resolution of adenoma was seen in 13 patients (nine were microadenoma, two macro and two giant adenomas). The prolactin level at diagnosis was positively correlated with maximum tumor diameter (r = 0.469, P = 0.001). Two patients developed cerebrospinal fluid (CSF) rhinorrhea and the defect was repaired in both patients. Median follow-up duration was 40 (12-288) months. Conclusion Clinical presentation and demographics of prolactinoma are the same in our region when compared to the rest of the world. Cabergoline is superior to bromocriptine in prolactin normalization and tumor shrinkage but still bromocriptine is being used in a significant number of patients in low-income countries as first-line due to its low cost.

Resistant prolactinomas: a case series of 26 patients

PURPOSE

Prolactin (PRL)-secreting tumors are the most common functional pituitary adenomas. They usually respond to dopamine agonist (DA) treatment, with PRL normalization and adenoma shrinkage. Our aim was to characterize patients with prolactinoma resistant to DA treatment.

METHODS

This retrospective case series included patients diagnosed with DA-resistant prolactinomas between 1993-2017 in three medical centers. Resistance was defined as PRL levels above three times the upper limit of normal (ULN) despite a weekly dose of ≥2 mg cabergoline (CAB). Clinical and biochemical information, and response to treatment, were retrieved from medical records.

RESULTS

Twenty-six patients were identified; 20 males. Of 25 macroadenomas, three were giant tumors (>40 mm) and 15 (57.7%) were invasive. The mean age at diagnosis was 31.8 ± 14.9 years (range: 13-62). The median maximal CAB dose was 3.5 mg/week (IQR, 2.5-5). Half the patients received only CAB in escalating doses, nine received CAB and underwent transsphenoidal surgery, and four underwent surgery and radiotherapy in addition to CAB treatment. PRL levels at baseline between patients treated only with CAB and those operated were (91.6 [51.1-296.7] vs. 73.1 [22.6-170.9] XULN p = 0.355), and under maximal CAB dose PRL levels between patients treated only with CAB and those operated were similar (5.77 [1.27-11.27] vs 5.27 (2.9-26) XULN p = 0.317). At the last visit patients who received combined therapy achieved lower PRL levels than those treated with DA only (5.22 [1.7-21.6] vs 1.1 [0.44-3.99] XULN p = 0.017) PRL normalization was attained in seven patients and levels below 3 × ULN in fourteen patients; the overall response was 56%.

CONCLUSIONS

Resistant prolactinomas usually require a multi-modal treatment strategy. We were able to control 14/25 (56%) of resistant tumors.