Socioeconomic differences between medically and surgically treated prolactinomas: a retrospective review of 598 patients

OBJECTIVE

Socioeconomic status (SES) is known to affect presentations and outcomes in pituitary neuroendocrine tumor resections, but there is a paucity of literature examining its impact specifically on patients with prolactinomas, who may be treated medically or surgically. The authors sought to determine whether SES was associated with differences in treatment choice or outcomes for prolactinoma patients.

METHODS

The authors retrospectively reviewed patient records at a high-volume academic pituitary center for prolactinoma diagnoses. Patients were split into medically and surgically treated cohorts. Race, ethnicity, insurance status, primary care physician (PCP) status, and zip code-based income data were collected and examined as socioeconomic covariates. Outcomes of interest included pretreatment likelihood of surgical cure, medical versus surgical treatment allocation, and posttreatment remission rates.

RESULTS

The authors analyzed 568 prolactinoma patients (351 medically treated and 217 surgically treated). Patients receiving surgery were more likely to have Medicaid or private insurance (p < 0.001) and have lower incomes (p < 0.001) than medically treated patients. Lower-income surgical patients were more likely to require surgical intervention for an indication such as tumor decompression than higher-income patients (p = 0.023). Surgical patients with a PCP had a higher estimated likelihood of surgical cure (p = 0.008), while no SES-based differences in surgical remission likelihood existed in the medical cohort. After surgery, surgical patients who achieved remission had significantly higher income than those who did not (p < 0.001). Other SES factors were not associated with surgical remission, and among medically treated patients, remission rates were not affected by any SES factor. Income was inversely related to prolactinoma size in both cohorts (surgical, p < 0.001; medical, p = 0.005) but was associated more prominently in surgical patients (surgical, -0.65 mm per $10,000; medical, -0.37 mm per $10,000).

CONCLUSIONS

While surgical prolactinoma patients were prone to income and PCP-related disparities, no SES disparities were found among medically treated patients. Income had a more pronounced association with tumor size in the surgical cohort and likely contributed to the increased need for surgical intervention seen in low-income surgical patients. Addressing socioeconomic healthcare disparities is needed among surgical prolactinoma patients to increase rates of early presentation and improve the outcomes of low-SES populations.

Correlation between tumor volume and serum prolactin and its effect on surgical outcomes in a cohort of 219 prolactinoma patients

OBJECTIVE

Prolactinoma is the most common pituitary adenoma and can be managed medically or surgically. The authors assessed the correlation between tumor volume and prolactin level and its effect on surgical outcomes.

METHODS

The authors reviewed 219 patients who underwent transsphenoidal prolactinoma resection at a single institution from 2012 to 2019. Outcomes were compared between patients with and without biochemical remission. Tumor volumes were quantified with BrainLab Smartbrush. Correlation analysis and linear regression were used to examine the association between tumor volume and serum prolactin level. Volume-adjusted prolactin level was defined as serum prolactin level divided by tumor volume. The authors utilized receiver operating characteristic (ROC) curve analysis to determine the thresholds for predicting biochemical remission status.

RESULTS

The mean tumor volume was 5.66 cm3, and the mean preoperative prolactin level was 752.3 µg/L. Men had larger prolactinomas than women (mean volume 11.32 vs 2.54 cm3; p < 0.001), and women had a greater volume-adjusted prolactin level (mean 412.5 vs 175.9 µg/L/cm3, p < 0.001). In total, 66.7% of surgical patients achieved biochemical remission 6 weeks after surgery, whereas a similar cohort of medically treated patients during the same time frame demonstrated a 69.4% remission rate. Pearson correlation and linear regression analysis revealed a strong association between preoperative tumor volume and prolactin levels, with an increase in serum prolactin level of 101.31 µg/L per 1-cm3 increase in tumor volume (p < 0.001). This held true for men (R = 0.601, p < 0.001) and women (R = 0.935, p < 0.001), with women demonstrating a greater increase in prolactin level per 1-cm3 increase in volume (185.70 vs 79.77 µg/L, p < 0.001). Patients who achieved remission exhibited a 66.08-µg/L increase in preoperative prolactin level per 1 cm3 of preoperative tumor volume (p < 0.001), which was less than the 111.46-µg/L increase per 1 cm3 in patients without remission (p < 0.001). Patients who failed to achieve remission had residual tumors with a 77.77-µg/L increase in prolactin per 1 cm3 of remaining tumor volume after resection (p < 0.001). ROC curve analysis revealed significant thresholds that optimally predicted lack of postoperative remission on the basis of preoperative prolactin and tumor volume. These thresholds were rendered nonsignificant in patients with documented Knosp grade ≥ 3.

CONCLUSIONS

Although the authors found a correlation between prolactinoma volume and serum prolactin level, patients without remission had a greater increase in serum prolactin level per increase in preoperative tumor volume than those who achieved remission, suggesting unique tumor composition. The authors also identified prolactin and tumor volume thresholds that optimally predicted biochemical remission status. The authors hope that their results can be used to identify prolactinomas for which surgery could achieve remission as an alternative to medical management.

Identifying risk factors for postoperative diabetes insipidus in more than 2500 patients undergoing transsphenoidal surgery: a single-institution experience

OBJECTIVE

Diabetes insipidus (DI) following transsphenoidal surgery can adversely impact quality of life and be difficult to manage. This study sought to characterize pre- and perioperative risk factors that may predispose patients to DI after pituitary surgery.

METHODS

A retrospective review of patients treated at a single institution from 2007 to 2019 was conducted. DI was defined as postoperative sodium > 145 mEq/L and urine output > 300 ml/hr and/or postoperative desmopressin (ddAVP) use. DI was further characterized as transient or permanent. Uni- and multivariate analyses were performed to determine variables associated with postoperative DI.

RESULTS

The authors identified 2529 patients who underwent transsphenoidal surgery at their institution. Overall, DI was observed in 270 (10.7%) of the 2529 patients, with 114 (4.5%) having permanent DI and 156 (6.2%) with transient symptoms. By pathology type, DI occurred in 31 (46.3%) of 67 craniopharyngiomas, 10 (14.3%) of 70 apoplexies, 46 (14.3%) of 322 Rathke's cleft cysts, 77 (7.7%) of 1004 nonfunctioning pituitary adenomas (NFPAs), and 62 (7.6%) of 811 functioning pituitary adenomas (FPAs). Final lesion pathology significantly affected DI rates (p < 0.001). Multivariate analysis across pathologies showed that younger age (odds ratio [OR] 0.97, p < 0.001), intraoperative CSF encounter (OR 2.74, p < 0.001), craniopharyngioma diagnosis (OR 8.22, p = 0.007), and postoperative hyponatremia (OR 1.50, p = 0.049) increased the risk of DI. Because surgery for each pathology created specific risk factors for DI, the analysis was then limited to the 1815 pituitary adenomas (PAs) in the series, comprising 1004 NFPAs and 811 FPAs. For PAs, younger age (PA: OR 0.97, p < 0.001; NFPA: OR 0.97, p < 0.001; FPA: OR 0.97, p = 0.028) and intraoperative CSF encounter (PA: OR 2.99, p < 0.001; NFPA: OR 2.93, p < 0.001; FPA: OR 3.06, p < 0.001) increased DI rates in multivariate analysis. Among all PAs, patients with DI experienced peak sodium levels later than those without DI (postoperative day 11 vs 2). Increasing tumor diameter increased the risk of DI in FPAs (OR 1.52, p = 0.008), but not in NFPAs (p = 0.564).

CONCLUSIONS

In more than 2500 patients treated at a single institution, intraoperative CSF encounter, craniopharyngioma diagnosis, and young age all increased the risk of postoperative DI. Patients with postoperative hyponatremia exhibited higher rates of DI, suggesting possible bi- or triphasic patterns to DI. Greater vigilance should be maintained in patients meeting these criteria following transsphenoidal surgery to ensure early recognition and treatment of DI.

Clinical characteristics and outcomes of null-cell versus silent gonadotroph adenomas in a series of 1166 pituitary adenomas from a single institution

OBJECTIVE

Nonfunctioning pituitary adenomas present without biochemical or clinical signs of hormone excess and are the second most common type of pituitary adenomas. The 2017 WHO classification scheme of pituitary adenomas differentiates null-cell adenomas (NCAs) and silent gonadotroph adenomas (SGAs). The present study sought to highlight the differences in patient characteristics and clinical outcomes between NCAs and SGAs.

METHODS

The records of 1166 patients who underwent transsphenoidal surgery for pituitary adenoma between 2012 and 2019 at a single institution were retrospectively reviewed. Patient demographics and clinical outcomes were collected.

RESULTS

Of the overall pituitary adenoma cohort, 12.8% (n = 149) were SGAs and 9.2% (n = 107) NCAs. NCAs were significantly more common in female patients than SGAs (61.7% vs 26.8%, p < 0.001). There were no differences in patient demographics, initial tumor size, or perioperative and short-term clinical outcomes. There was no significant difference in the amount of follow-up between patients with NCAs and those with SGAs (33.8 months vs 29.1 months, p = 0.237). Patients with NCAs had significantly higher recurrence (p = 0.021), adjuvant radiation therapy usage (p = 0.002), and postoperative diabetes insipidus (p = 0.028). NCA pathology was independently associated with tumor recurrence (HR 3.64, 95% CI 1.07-12.30; p = 0.038), as were cavernous sinus invasion (HR 3.97, 95% CI 1.04-15.14; p = 0.043) and anteroposterior dimension of the tumor (HR 2.23, 95% CI 1.09-4.59; p = 0.030).

CONCLUSIONS

This study supports the definition of NCAs and SGAs as separate subgroups of nonfunctioning pituitary adenomas, and it highlights significant differences in long-term clinical outcomes, including tumor recurrence and the associated need for adjuvant radiation therapy, as well as postoperative diabetes insipidus. The authors also provide insight into independent risk factors for these outcomes in the adenoma population studied, providing clinicians with additional predictors of patient outcomes. Follow-up studies will hopefully uncover mechanisms of biological aggressiveness in NCAs and associated molecular targets.

Plurihormonal PIT-1-Positive Pituitary Adenomas: A Systematic Review and Single-Center Series

OBJECTIVE

The 2017 World Health Organization classification of pituitary adenomas identified the plurihormonal PIT-1-positive (PP1) adenoma as a distinct subtype. The reported data suggest that PP1 adenomas encompass the former class of silent subtype 3 (SS3) adenomas and might have an aggressive phenotype. In the present study, we summarized the current clinical data on PP1 and SS3 adenomas and compared the reported data with the data from a single institutional cohort.

METHODS

Medline and Google Scholar were searched from 1990 to 2020 for clinical series of PP1 and SS3 adenomas in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. Studies were included if they had reported pituitary pathology as PP1 or SS3 adenomas and had reported the clinical outcomes after surgical intervention. To better define the PP1 phenotype compared with non-PP1 adenomas, we also reviewed the adenomas treated surgically at our institution from 2012 to 2019.

RESULTS

Of all the tumors reported in the studies as PP1 or SS3, 99% were macroadenomas and 18% were giant adenomas (>4 cm). Of the reported patients, 31.8% had received radiotherapy, and 22.9% had undergone multiple surgeries for their pituitary tumor. In our single-center experience, 20 patients had an adenoma that met the criteria for a PP1 adenoma. Compared with the 1146 non-PP1 tumors, the PP1 tumors did not show statistically significant differences in the extent of resection, size, number of previous surgeries, future reoperations, rate of radiotherapy, p53 staining, or MIB-1 labeling index.

CONCLUSIONS

The findings from the present large, single-center study comparing PP1 and non-PP1 adenomas do not suggest that PP1 tumors are more aggressive. Further work is warranted to identify the pathologic subtypes of pituitary adenomas that are consistently more clinically aggressive.

NCOG-51. CORRELATION BETWEEN TUMOR VOLUME AND SERUM PROLACTIN AND IMPACT OF TUMOR CELLULAR DENSITY ON PROLACTINOMA SURGICAL OUTCOMES IN A COHORT OF 181 PATIENTS

INTRODUCTION

Prolactinomas are common pituitary adenomas managed medically or surgically.

METHODS

Reviewed 181 prolactinomas resected transsphenoidally 2012-2019. Tumor volumes were quantified using BrainLab Smartbrush. Pearson correlation analysis and linear regression were used to identify associations between tumor volumes and serum prolactin. Tumor density was defined as serum prolactin divided by tumor volume.

RESULTS

Mean tumor volume was 6.33cm3 and mean pre-op prolactin was 803.4ug/L, with men having larger (12.11 vs 2.93cm3;p&lt; 0.001) and women having denser (173.9 vs 107.6ug/L/cm3;p=0.011) prolactinomas. Pearson correlation (R=0.688;p&lt; 0.001) and linear regression revealed a strong association between pre-op volume and prolactin levels, with 96.9g/L increase in prolactin/cm3 increase in volume (p&lt; 0.001); this holds true for men (R=0.584;p&lt; 0.001) and women (R=0.939;p&lt; 0.001), with women demonstrating greater prolactin/cm3 tumor density (186.5 vs 75.0ug/L;p&lt; 0.001). MiB index did not correlate with pre-op volume (p=0.449) or pre-op prolactin (p=0.452). Logistic regression showed decreased biochemical remission with increasing pre-op volume (OR=0.891;p&lt; 0.001). Increased MiB index (p=0.971) and p53 (p=0.525) staining did not affect remission rates. Positive PIT-1 staining was associated with higher remission rates (OR=2.508;p=0.005). Patients without remission had denser tumors (149.9 vs. 100.6ug/L/cm3;p=0.013), with Pearson correlation yielding R=0.736 between pre-op volume and pre-op prolactin (p&lt; 0.001), and R=0.476 between residual volume and post-op prolactin (p&lt; 0.001). Patients without remission exhibited 142.9ug/L increase in prolactin/cm3 of pre-op volume (p&lt; 0.001), higher than the 58.9ug/L increase in prolactin/cm3 in patients with remission (p&lt; 0.001). Patients without remission had residual tumors with 68.4ug/L increase in prolactin/cm3 of remaining volume after resection (p&lt; 0.001).

CONCLUSION

Our analysis revealed significant correlation between prolactinoma volume and serum prolactin levels. Patients without remission had greater tumor cellular density than those with remission. The volume-prolactin correlation persisted post-operatively, although surgery reduced tumor density. These results could identify prolactinomas for which surgery could achieve biochemical remission.

NCOG-54. SAFETY OF TRANSSPHENOIDAL SURGERY FOR NONFUNCTIONING PITUITARY ADENOMA IN ELDERLY PATIENTS

INTRODUCTION

Life expectancy has increased over the past century, shifting the demographic distribution towards older age groups. Elderly patients comprise up to 14% of patients with pituitary tumors, with most lesions being nonfunctioning adenomas (NFPAs). Here, we compare clinical and surgical outcomes and post-operative complications between non-elderly adult (age ≥ 18 years and ≤ 65 years) and elderly (age &gt; 65 years) NFPA patients.

METHODS

Retrospective review of 908 patients undergoing transsphenoidal surgery for NFPA at a single institution from 2007-2019.

RESULTS

Elderly patients represented 32.4% of patients. Both groups were similar in gender (57.3% vs 60.5% male;P=0.4), tumor size (2.56 vs 2.46 cm;P=0.2), and cavernous sinus invasion (35.8% vs 33.7%;P=0.6). Regarding post-operative outcomes, length of stay (1 vs 2 days; P=0.5), extent of resection (59.8% vs 64.8% GTR;P=0.2), CSF leak requiring surgical revision (4.3% vs 1.4%;P=0.06), 30-day readmission (8.1% vs 7.3%;P=0.7), infection (3.1% vs 2.0%;P=0.5), and new hypopituitarism (13.9% vs 12.0%;P=0.3) were similar between both groups. Elderly patients were less likely to have adjuvant radiation (8.7% vs 16.3%;P=0.009), future re-operation (3.8% vs 9.5%;P=0.003), and post-operative diabetes insipidus (DI) (3.7% vs 9.4%;P=0.002), and more likely to have post-operative hyponatremia (26.7% vs 16.4%;P&lt; 0.001) and new cranial nerve deficit (1.9% vs 0.0%;P=0.01). Elderly patients’ post-operative sodium peaked and troughed on POD3 (mean=138.7 mEq/L) and POD9 (mean=130.8 mEq/L), respectively, compared to non-elderly patients (peak POD2 mean=139.9 mEq/L, trough POD8 mean=131.3 mEq/L).

CONCLUSION

Our analysis revealed that elderly patients experienced more post-operative hyponatremia, while non-elderly patients experienced more post-operative DI. Elderly patients also experience later peak and trough in serum sodium, suggesting age-related differences in stalk-related morbidities of NFPA resection. Overall, our results show that transsphenoidal surgery for NFPA in elderly patients is safe with low complication rates. We hope our results will guide discussions with elderly patients regarding possible risks and outcomes.

Clinical characteristics and outcomes in elderly patients undergoing transsphenoidal surgery for nonfunctioning pituitary adenoma

OBJECTIVE

Life expectancy has increased over the past century, causing a shift in the demographic distribution toward older age groups. Elderly patients comprise up to 14% of all patients with pituitary tumors, with most lesions being nonfunctioning pituitary adenomas (NFPAs). Here, the authors evaluated demographics, outcomes, and postoperative complications between nonelderly adult and elderly NFPA patients.

METHODS

A retrospective review of 908 patients undergoing transsphenoidal surgery (TSS) for NFPA at a single institution from 2007 to 2019 was conducted. Clinical and surgical outcomes and postoperative complications were compared between nonelderly adult (age ≥ 18 and ≤ 65 years) and elderly patients (age > 65 years).

RESULTS

There were 614 and 294 patients in the nonelderly and elderly groups, respectively. Both groups were similar in sex (57.3% vs 60.5% males; p = 0.4), tumor size (2.56 vs 2.46 cm; p = 0.2), and cavernous sinus invasion (35.8% vs 33.7%; p = 0.6). Regarding postoperative outcomes, length of stay (1 vs 2 days; p = 0.5), extent of resection (59.8% vs 64.8% gross-total resection; p = 0.2), CSF leak requiring surgical revision (4.3% vs 1.4%; p = 0.06), 30-day readmission (8.1% vs 7.3%; p = 0.7), infection (3.1% vs 2.0%; p = 0.5), and new hypopituitarism (13.9% vs 12.0%; p = 0.3) were similar between both groups. Elderly patients were less likely to receive adjuvant radiation (8.7% vs 16.3%; p = 0.009), undergo future reoperation (3.8% vs 9.5%; p = 0.003), and experience postoperative diabetes insipidus (DI) (3.7% vs 9.4%; p = 0.002), and more likely to have postoperative hyponatremia (26.7% vs 16.4%; p < 0.001) and new cranial nerve deficit (1.9% vs 0.0%; p = 0.01). Subanalysis of elderly patients showed that patients with higher Charlson Comorbidity Index scores had comparable outcomes other than higher DI rates (8.1% vs 0.0%; p = 0.006). Elderly patients’ postoperative sodium peaked and troughed on postoperative day 3 (POD3) (mean 138.7 mEq/L) and POD9 (mean 130.8 mEq/L), respectively, compared with nonelderly patients (peak POD2: mean 139.9 mEq/L; trough POD8: mean 131.3 mEq/L).

CONCLUSIONS

The authors’ analysis revealed that TSS for NFPA in elderly patients is safe with low complication rates. In this cohort, more elderly patients experienced postoperative hyponatremia, while more nonelderly patients experienced postoperative DI. These findings, combined with the observation of higher DI in patients with more comorbidities and elderly patients experiencing later peaks and troughs in serum sodium, suggest age-related differences in sodium regulation after NFPA resection. The authors hope that their results will help guide discussions with elderly patients regarding risks and outcomes of TSS.