The lateralization accuracy of inferior petrosal sinus sampling in Cushing's disease: experiences of a tertiary center.

BACKGROUND: The purpose of this study is to determine the accuracy of bilateral inferior petrosal sinus sampling (IPSS) in lateralization and to investigate variables associated with accurate IPSS lateralization prediction. METHODS: Initially, data from 55 patients who underwent IPSS in our institution were reviewed retrospectively. IPSS lateralization and pituitary magnetic resonance imaging (MRI) results of these patients were compared with postoperative follow-up and immunohistochemical data to calculate the positive predictive values (PPVs) for IPSS and MRI. Variables likely to be associated with the accurate prediction of IPSS lateralization were analyzed. RESULTS: Twenty-seven patients (85.2% female, mean age of 38.5 ± 13.1 years) were enrolled in the study. With IPSS, interpetrosal ratios were found to be ≥ 1.4 in 26 (96.2%) cases, and this ratio correctly predicted adenoma localization for 18 patients (PPV: 69.2%). For 16 (59.2%) patients, right lateralization was detected, while left lateralization was detected for 10 (37%) patients. Right-sided IPSS lateralization was associated with enhanced accuracy (p = 0.026). No masses were detected in the MRI images of 10 (37%) patients, while microadenoma of ≤ 6 mm was detected for 17 (63%) patients. MRI results (when positive) correctly identified adenoma localization for 14 of the patients with lateralization accuracy higher than that of IPSS (PPV: 82.3% vs. 69.2%). DISCUSSION: IPSS is a valuable procedure in detecting tumor lateralization, especially in patients with Cushing's disease who have negative pituitary MRI results. However, since lateralization has a limited reliability, the pituitary gland should be comprehensively evaluated by taking into account the MRI findings (if positive) as well as data on the side of IPSS lateralization.

Age, GH/IGF-1 levels, tumor volume, T2 hypointensity, and tumor subtype rather than proliferation and invasion are all reliable predictors of biochemical response to somatostatin analogue therapy in patients with acromegaly: A clinicopathological study.

PURPOSE: To determine whether biochemical responses to long-acting forms of first-generation somatostatin analogue (SSA) therapy in patients with acromegaly could be predicted from baseline and postoperative hormone concentrations, and tumor radiological and histopathological characteristics. METHODS: A total of 68 patients with acromegaly for whom postoperative SSA therapy was started were categorized according to their responses to treatment (SSA-responders vs. non-responders). The patients were compared based on their demographic characteristics, hormone levels, magnetic resonance imaging (MRI), and histopathological findings. Receiver-operating-characteristic (ROC) curves were constructed using the predictive factors that were significant in the univariate analysis to determinate the optimal cut-off values. RESULTS: The SSA-responders were significantly older (p = 0.041). Lower GH at diagnosis (p = 0.036), the postoperative 1st-week GH level (p = 0.027), baseline GH, insulin-like growth factor-1 (IGF-1) and IGF-1% upper limit of normal (ULN) (p = 0.001, p = 0.006, p = 0.023, respectively) were associated with biochemical response. T2-hypointensity and lower tumor volume were more common in the SSA-responders (p = 0.018, p = 0.03, respectively). Compared to sparsely granulated somatotroph tumors, densely granulated somatotroph tumors and other PitNETs causing GH excess including mammosomatotroph and mixed somatotroph and lactotroph tumors were more likely to respond to SSA therapy (p = 0.026, p = 0.03, respectively). The cut-off values generated by ROC curve analysis were GH at diagnosis of ≤8.8 ng/mL, GH at baseline of ≤2.69 ng/mL, IGF-1 at baseline ≤461.5 ng/mL, IGF-1% ULN at baseline ≤180.4%, and tumor volume of ≤1.11 cm3 (all p < 0.05). There were no differences between the groups in terms of tumor invasiveness, proliferative activity (mitotic count per 2 mm2 and Ki-67 labeling index) and quantitative analyses of T2-weighted MRI. CONCLUSION: This study underscores that advanced age, low baseline GH and IGF-1 at diagnosis, low tumor volume, densely granulated tumor subtype, and T2 hypointensity may help predict biochemical response to SSA therapy in cases of acromegaly. These variables should be assessed with utmost attention for all patients prior to SSA treatment. In cases of possible resistance to SSA therapy, therapeutic activity should be monitored more closely and other therapies should be administered immediately in the event of poor response.

Cancer prevalence and cancer screening in patients with acromegaly: a single center experience.

PURPOSE: To investigate the prevalence of cancer in patients with acromegaly and the variables associated with malignant and premalignant lesions detected by cancer screening. METHODS: The data of 214 patients diagnosed with acromegaly in our institution were evaluated retrospectively. Prevalence of cancer was compared with national rates to estimate standardized incidence ratios (SIRs). The relationships of malignant and premalignant lesions detected by cancer screening with demographic, clinical, and radiological variables were also analyzed. RESULTS: Cancer was detected in 24 (13.4%) of 179 patients enrolled in the study. Compared to the general population, the incidence of all malignancies was increased in both women and men with acromegaly (SIR: 4.78, 95% CI: 2.43-8.53, p = 0.002 and SIR: 8.97, 95% CI: 5.51-14.7, p < 0.001, respectively). The most common cancers were thyroid, colorectal, breast, kidney, gastric, and testicular cancer, respectively. Duration of disease was the only independent risk factor for the development of cancer (OR: 1.007, 95% CI: 1.002-1.011, p = 0.002). Malignant/premalignant lesions were detected in 21.5% of the patients with a colonoscopy scanning procedure and in 20.8% with an esophagogastroduodenoscopy procedure, and current age was found to be higher among the patients with malignant/premalignant lesions (p = 0.023 and p = 0.003, respectively). Breast cancer was detected in 3.7% of screening tests performed with mammography. CONCLUSION: In this study, it was shown that the prevalence of cancer increases with acromegaly and this increase is associated with disease duration. Considering the increase in the number of premalignant lesions, the scope of cancer screening recommendations in the guidelines should be expanded to ensure early diagnosis.

Efficacy of preoperative therapeutic plasma exchange in patients with hyperthyroidism and factors affecting the number of sessions.

PURPOSE: Achieving preoperative euthyroidism in patients with hyperthyroidism for whom antithyroid drugs (ATDs) cannot be used for treatment is a serious clinical problem. We aimed to evaluate the effectiveness of therapeutic plasma exchange (TPE) in hyperthyroid patients scheduled for surgery and predictive factors for a high number of TPE sessions. METHODS: We retrospectively analyzed the data of 21 patients with hyperthyroidism who were treated with TPE for preoperative euthyroidism in our institution. Pre- and post-TPE thyroid function tests were compared to assess efficacy. Binary logistic regression analysis was applied to determine predictors of patients requiring a high number of TPE sessions. RESULTS: All patients (20 patients with Graves' disease and 1 patient with toxic multinodular goiter; 12 women and 9 men; mean age 35.71 ± 12.38 years) had severe hyperthyroidism before TPE. The changes before and after TPE in fT3, fT4, and TSH levels were statistically significant (p < 0.001, p < 0.001, p = 0.002, respectively). The median number of TPE sessions was 8 (range: 1-24). Levels of fT3 before TPE were significantly higher in patients for whom higher numbers of TPE sessions were required (≥8) (OR: 1.427, 95% CI: 1.038-1.961, p = 0.028). Receiver operating characteristic curve analysis revealed an optimum cut-off value of 12.8 pg/ml for fT3 before TPE (91% sensitivity, 80% specificity, area under the curve: 0.927). CONCLUSION: TPE should be considered as an effective alternative treatment option that can be used to rapidly achieve euthyroidism before surgery when ATDs cannot be used. Pre-TPE fT3 levels of >12.8 pg/ml may be an independent factor predicting the need for higher numbers of TPE sessions (≥8).