Parathyroidectomy for Normocalcemic Primary Hyperparathyroidism is Associated with Improved Bone Mineral Density Regardless of Postoperative Parathyroid Hormone Levels.

BACKGROUND: Biochemical cure in normocalcemic primary hyperparathyroidism (nPHPT) is defined as parathyroid hormone (PTH) level normalization 6 months after parathyroidectomy. However, recent studies show that a significant number of nPHPT patients have persistent PTH elevation postoperatively. We sought to correlate changes in PTH levels with skeletal outcomes after parathyroidectomy in nPHPT patients. METHODS: Adult patients who underwent parathyroidectomy at a tertiary referral center for sporadic PHPT between 2010 and 2020 were reviewed. Pre- and postoperative (6 months, 18 months, and last follow-up) laboratory and bone mineral densities (BMD) were recorded. Primary outcome was 18-month postoperative BMD change in the lumbar spine (LS), total hip (TH) and femoral neck (FN) in normocalcemic and hypercalcemic PHPT (hPHPT) patients. RESULTS: Of 661 patients included, 68 had nPHPT. nPHPT patients frequently had multigland disease (31% vs. 18%, p = 0.014), more bilateral cervical explorations (22% vs. 13%, p = 0.042), and fewer achieved biochemical cure (76% vs. 95%, p < 0.001) than hPHPT patients. Twenty-eight nPHPT patients had BMD data for comparison. Overall, nPHPT patients had improvement in the LS (1.84%, p = 0.002) and TH (1.64%, p = 0.014). When stratified by postoperative PTH levels, nPHPT patients with persistent PTH elevation had more BMD improvement at the TH than those who normalized PTH (3.73% vs. - 0.83%, p = 0.017). There was no difference in improvement at the LS or FN (p = NS). CONCLUSION: Parathyroidectomy is associated with improved BMD in nPHPT patients with bone disease. Although one in four nPHPT patients had elevated postoperative PTH levels persisting throughout the study, BMD improvement was still seen regardless of postoperative PTH level normalization.

Association of Vitamin D Status With Hospital Morbidity and Mortality in Adult Hospitalized Patients With COVID-19.

OBJECTIVE: To determine the association between vitamin D status and morbidity and mortality in adult hospitalized coronavirus disease 2019 (COVID-19) patients METHODS: We performed a retrospective chart review study in COVID-19 patients aged ≥18 year hospitalized at Boston University Medical Center between March 1 and August 4, 2020. All studied patients tested positive for COVID-19 and had serum levels of 25-hydroxyvitamin D (25[OH]D) results measured within 1 year prior to the date of positive tests. Medical information was retrieved from the electronic medical record and was analyzed to determine the association between vitamin D status and hospital morbidity and mortality. RESULTS: Among the 287 patients, 100 (36%) were vitamin D sufficient (25[OH]D >30 ng/mL) and 41 (14%) died during hospitalization. Multivariate analysis in patients aged ≥65 years revealed that vitamin D sufficiency (25[OH]D ≥30 ng/mL) was statistically significantly associated with decreased odds of death (adjusted OR 0.33, 95% CI, 0.12-0.94), acute respiratory distress syndrome (adjusted OR 0.22, 95% CI, 0.05-0.96), and severe sepsis/septic shock (adjusted OR 0.26, 95% CI, 0.08-0.88), after adjustment for potential confounders. Among patients with body mass index <30 kg/m2, vitamin D sufficiency was statistically significantly associated with a decreased odds of death (adjusted OR 0.18, 95% CI, 0.04-0.84). No significant association was found in the subgroups of patients aged <65 years or with body mass index ≥30 kg/m2. CONCLUSION: We revealed an independent association between vitamin D sufficiency defined by serum 25(OH)D ≥30 ng/mL and decreased risk of mortality from COVID-19 in elderly patients and patients without obesity.

Is estrogen exposure a protective factor for pancreatic neuroendocrine tumours in female patients with multiple endocrine neoplasia syndrome type 1?

OBJECTIVE: Pancreatic neuroendocrine tumours (PNETs) are the most common cause of death in patients with multiple endocrine neoplasia type 1 (MEN1). Women have been shown to have improved survival, which may suggest a possible protective effect of female sex hormones. The aim of this study was to evaluate the relationship between estrogen exposure and PNET tumourigenesis, tumour growth and survival in female MEN1 patients with these tumours. DESIGN: We performed a retrospective chart review of the existing MEN1 database in our institution. Detailed information about female patients' menstrual and reproductive history, and PNET clinicopathologic characteristics was collected. Questionnaires regarding estrogen exposure were used to collect information that was missing in the database. PATIENTS: Of 293 confirmed MEN1 cases, 141 women met the inclusion criteria. MEASUREMENTS: We used measures of cumulative estrogen exposure time (CEET), parity, live birth pregnancies and bilateral oophorectomy to estimate estrogen exposure. RESULTS: There was no significant association between CEET and time to PNET diagnosis (hazard ratio = 0·966, P = 0·380). For the correlation between estrogen exposure and PNET type, size, numbers, distant metastasis, lymph node metastasis, lymphovascular invasion, AJCC (American Joint Committee on Cancer) stage and overall survival, only CEET was significantly correlated with PNET size (P = 0·043). CONCLUSIONS: In female patients with MEN1, estrogen exposure may inhibit PNET growth. A demonstrable protective effect against PNET tumourigenesis, tumour growth and survival of patients with these tumours may require a larger cohort.

Is there a role for liquid biopsy in the surveillance of parathyroid carcinoma?

BACKGROUND: Parathyroid carcinoma is a rare malignancy with high recurrence rates. Liquid biopsy is a stratifying tool in disease recurrence/progression in other malignant processes. This study sought to assess the feasibility and application of liquid biopsy in parathyroid carcinoma and its impact on surveillance. METHODS: Retrospective review of a prospectively maintained database of adults treated for parathyroid carcinoma at a tertiary care center (2017-2023). Demographics, clinical characteristics, and laboratory variables were collected. Circulating cell-free deoxyribonucleic acid enrichment and circulating tumor cell enumeration were obtained from serial blood samples. RESULTS: A total of 25 patients were identified-64% were male patients, with a median age of 56 years (interquartile range 45-63). Fifty blood samples were collected postoperatively. At first, circulating tumor cell enumeration, 56% (14/25) of patients had no evidence of disease, and 32% (8/25) had distant metastasis. Median follow-up was 53 months (interquartile range 23-107). At the last follow-up, 40% (10/25) of patients were found to have distant metastasis. Serial circulating tumor cell enumeration was performed in 52% of patients, median highest circulating tumor cell was (interquartile range 1-22). Circulating cell-free deoxyribonucleic acid was assessed in 64% of patients (16/25). There was no difference in circulating tumor cells or circulating cell-free deoxyribonucleic acid between those with distant metastasis and those without distant metastasis. The most common mutation identified was TP53, present in 88% of circulating cell-free deoxyribonucleic acid samples with a mutation. Circulating cell-free deoxyribonucleic acid and parathyroid hormone levels were not found to have any association (r = -0.27, P = .39), but parathyroid hormone and circulating tumor cell had a linear relationship (r = 0.76, P < .001). CONCLUSION: Liquid biopsy appears to be a feasible tool in parathyroid carcinoma surveillance. The relationship between circulating cell-free deoxyribonucleic acid and parathyroid hormone levels remains unclear, and the association between circulating tumor cell enumeration and parathyroid hormone levels may be impactful. The finding that TP53 mutation is more prevalent in patients with distant metastasis may impact further management.

RET kinase inhibitors for RET-altered thyroid cancers.

Precision oncology has opened a new era in cancer treatment focused on targeting specific cellular pathways directly involved in tumorigenesis. The REarrangement during Transfection (RET) proto-oncogene is involved in the pathogenesis of various thyroid cancer subtypes. Mutations in RET give rise to both hereditary and sporadic medullary thyroid cancer (MTC). RET fusions are found in follicular cell-derived thyroid cancers (papillary, poorly differentiated, and anaplastic). Hence, drugs that block the RET tyrosine kinase receptor have been explored in the management of locally advanced or metastatic thyroid cancer. The multikinase inhibitors (MKIs) with nonselective RET inhibition are sorafenib, lenvatinib, vandetanib, cabozantinib, and sunitinib. Although the efficacy of these drugs varies, a major issue is the lack of specificity resulting in a higher rate of drug-related toxicities, leading to dose reduction, interruption, or discontinuation. Moreover, MKIs are subject to drug resistance by RET Val804 residue gatekeeper mutations. In phase I/II clinical studies, the highly selective first-generation RET inhibitors, selpercatinib and pralsetinib, demonstrate high efficacy in controlling disease even in the presence of gatekeeper mutations combined with greater tolerability. However, resistance mechanisms such as RET solvent front mutations (SFMs) have evolved in some patients, giving the need to develop the selective second-generation RET inhibitors. Although the approval of selpercatinib and pralsetinib in 2020 has profoundly benefited patients with RET-altered thyroid cancer, further research into optimal treatment strategies, mechanisms of drug resistance, long-term consequences of potent RET-inhibition, and development of more effective agents against emergent mutations are much needed.

Gender differences in bone mineral density in patients with sporadic primary hyperparathyroidism.

CONTEXT: Primary hyperparathyroidism reduces bone mineral density, which increases the risk of fracture. OBJECTIVE: To investigate differences in bone mineral density and clinical characteristics after parathyroidectomy between men and women (premenopausal and postmenopausal) with sporadic primary hyperparathyroidism. DESIGN: This is a retrospective study of adult patients who underwent parathyroidectomy in a tertiary referral center from 1990 to 2013. PATIENTS: A total of 1529 patients underwent parathyroidectomy during the study period; 80 patients met the inclusion criteria. Of these, 24 were men and 56 were women (10 premenopausal and 46 postmenopausal). MEASUREMENTS: Demographics, preoperative and postoperative biochemical analysis, preoperative and postoperative T-scores, preoperative Z-scores, preoperative and postoperative absolute bone mineral density values, and percentage change in bone mineral density from baseline to 12 ± 6 months after parathyroidectomy in the lumbar spine, femoral neck, total hip and distal one-third of the nondominant radius. RESULTS: Preoperative 24-hour urinary calcium levels were significantly higher in men than in women overall (P = 0.02) and postmenopausal women (P = 0.01). Men had significantly lower preoperative Z-scores than women overall, premenopausal women and postmenopausal women. Men had greater percentage change of increase in bone mineral density in the femoral neck than did women overall (2.77%; P = 0.04) and postmenopausal women (2.98%; P = 0.03) 1 year after parathyroidectomy. CONCLUSIONS: From this study, men demonstrated a greater improvement of bone mineral density in the femoral neck from baseline after parathyroidectomy compared with women.

Pericytes Elicit Resistance to Vemurafenib and Sorafenib Therapy in Thyroid Carcinoma via the TSP-1/TGFß1 Axis.

PURPOSE: The BRAFV600E oncogene modulates the papillary thyroid carcinoma (PTC) microenvironment, in which pericytes are critical regulators of tyrosine-kinase (TK)-dependent signaling pathways. Although BRAFV600E and TK inhibitors are available, their efficacy as bimodal therapeutic agents in BRAFV600E-PTC is still unknown. EXPERIMENTAL DESIGN: We assessed the effects of vemurafenib (BRAFV600E inhibitor) and sorafenib (TKI) as single agents or in combination in BRAFWT/V600E-PTC and BRAFWT/WT cells using cell-autonomous, pericyte coculture, and an orthotopic mouse model. We also used BRAFWT/V600E-PTC and BRAFWT/WT-PTC clinical samples to identify differentially expressed genes fundamental to tumor microenvironment. RESULTS: Combined therapy blocks tumor cell proliferation, increases cell death, and decreases motility via BRAFV600E inhibition in thyroid tumor cells in vitro. Vemurafenib produces cytostatic effects in orthotopic tumors, whereas combined therapy (likely reflecting sorafenib activity) generates biological fluctuations with tumor inhibition alternating with tumor growth. We demonstrate that pericytes secrete TSP-1 and TGFß1, and induce the rebound of pERK1/2, pAKT and pSMAD3 levels to overcome the inhibitory effects of the targeted therapy in PTC cells. This leads to increased BRAFV600E-PTC cell survival and cell death refractoriness. We find that BRAFWT/V600E-PTC clinical samples are enriched in pericytes, and TSP1 and TGFß1 expression evoke gene-regulatory networks and pathways (TGFß signaling, metastasis, tumor growth, tumor microenvironment/ECM remodeling functions, inflammation, VEGF ligand-VEGF receptor interactions, immune modulation, etc.) in the microenvironment essential for BRAFWT/V600E-PTC cell survival. Critically, antagonism of the TSP-1/TGFß1 axis reduces tumor cell growth and overcomes drug resistance. CONCLUSIONS: Pericytes shield BRAFV600E-PTC cells from targeted therapy via TSP-1 and TGFß1, suggesting this axis as a new therapeutic target for overcoming resistance to BRAFV600E and TK inhibitors.