Safety and activity of vandetanib in combination with everolimus in patients with advanced solid tumors: a phase I study

Background

Preclinical studies suggest that combining vandetanib (VAN), a multi-tyrosine kinase inhibitor of rearranged during transfection (RET) proto-oncogene, vascular endothelial growth factor receptor (VEGFR), and epidermal growth factor receptor (EGFR), with everolimus (EV), a mammalian target of rapamycin (mTOR) inhibitor, may improve antitumor activity. We determined the safety, maximum tolerated dose (MTD), recommended phase II dose (RP2D), and dose-limiting toxicities (DLTs) of VAN + EV in patients with advanced solid cancers and the effect of combination therapy on cancer cell proliferation and intracellular pathways.

Patients and methods

Patients with refractory solid tumors were enrolled in a phase I dose-escalation trial testing VAN (100-300 mg orally daily) + EV (2.5-10 mg orally daily). Objective responses were evaluated using RECIST v1.1. RET mutant cancer cell lines were used in cell-based studies.

Results

Among 80 patients enrolled, 72 (90%) patients were evaluable: 7 achieved partial response (PR) (10%) and 37 had stable disease (SD) (51%; duration range: 1-27 cycles). Clinical benefit (SD or PR ≥ 6 months) was observed in 26 evaluable patients [36%, 95% confidence intervals (CI) (25% to 49%)]. In 80 patients, median overall survival (OS) was 10.5 months [95% CI (8.5-16.1)] and median progression-free survival (PFS) 4.1 months [95% CI (3.4-7.3)]. Six patients (7.5%) experienced DLTs and 20 (25%) required dose modifications. VAN + EV was safe, with fatigue, rash, diarrhea, and mucositis being the most common toxicities. In cell-based studies, combination therapy was superior to monotherapy at inhibiting cancer cell proliferation and intracellular signaling.

Conclusions

The MTDs and RP2Ds of VAN + EV are 300 mg and 10 mg, respectively. VAN + EV combination is safe and active in refractory solid tumors. Further investigation is warranted in RET pathway aberrant tumors.

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VAN + EV is safe, active and provides clinical benefit in some patients with refractory solid cancers.

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Dual therapy is superior to monotherapy at inhibiting proliferation and intracellular signaling of RET mutant cancer cells.

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This study highlights the importance of identifying novel combination therapies to overcome therapeutic resistance.

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Next-generation sequencing of advanced solid tumors may inform treatment strategies and guide future drug development.

No calcitonin change in a person taking dulaglutide diagnosed with pre-existing medullary thyroid cancer

BACKGROUND

Glucagon-like peptide-1 receptor agonists, such as dulaglutide, exenatide and liraglutide, are approved to treat Type 2 diabetes mellitus. Although these drugs provide substantial glycaemic control, studies in rodents have prompted concerns about the development of medullary thyroid carcinoma. These data are reflected in the US package insert, with boxed warnings and product labelling noting the occurrence of these tumours after clinically relevant exposures in rodents, and contraindicating glucagon-like peptide-1 receptor agonist use in people with a personal or family history of medullary thyroid carcinoma, or in people with multiple endocrine neoplasia type 2. However, there are substantial differences between rodent and human responses to glucagon-like peptide-1 receptor agonists. This report presents the case of a woman with pre-existing medullary thyroid carcinoma who exhibited no significant changes in serum calcitonin levels despite treatment with dulaglutide 2.0 mg for 6 months in the Assessment of Weekly AdministRation of LY2189265 [dulaglutide] in Diabetes-5 clinical study (NCT00734474).

CASE REPORT

Elevated serum calcitonin was noted in a 56-year-old woman with Type 2 diabetes mellitus at the 6-month discontinuation visit in a study of long-term dulaglutide therapy. Retroactive assessment of serum collected before study treatment yielded an elevated calcitonin level. At 3 months post-study, calcitonin level remained elevated; ultrasonography revealed multiple bilateral thyroid nodules. Eventually, medullary thyroid carcinoma was diagnosed; the woman was heterozygous positive for a germline RET proto-oncogene mutation.

CONCLUSION

The tumour was not considered stimulated by dulaglutide therapy because calcitonin remained stable throughout.

The impact of age and gender on papillary thyroid cancer survival

CONTEXT

Thyroid cancer predominately affects women, carries a worse prognosis in older age, and may have higher mortality in men. Superimposed on these observations is the fact that most women have attained menopause by age 55 yr.

OBJECTIVE

The objective of the study was to determine whether men contribute disproportionately to papillary thyroid cancer (PTC) mortality or whether menopause affects PTC prognosis.

DESIGN

Gender-specific mortality was normalized using age-matched subjects from the U.S. population. Multivariate Cox proportional hazard regression models incorporating gender, age, and National Thyroid Cancer Treatment Cooperative Study Group stage were used to model disease-specific survival (DSS).

PARTICIPANTS AND SETTING

Patients were followed in a prospective registry.

MAIN OUTCOME MEASURE

The relationships between gender, age, and PTC outcomes were analyzed.

RESULTS

The unadjusted hazard ratio (HR) for DSS for women was 0.40 [confidence interval (CI) 0.24-0.65]. This female advantage diminished when DSS was adjusted for age at diagnosis and stage with a HR encompassing unity (HR 0.72, CI 0.44-1.19). Additional multivariate models of DSS considering gender, disease stage, and various age groupings showed that the DSS for women diagnosed at under 55 yr was improved over men (HR 0.33, CI 0.13-0.81). However, the HR for DSS increased to become similar to men for women diagnosed at 55-69 yr (HR 1.01, CI 0.42-2.37) and at 70 yr or greater (HR 1.17, CI 0.48-2.85).

CONCLUSIONS

Although the overall outcome of women with PTC is similar to men, subgroup analysis showed that this composite outcome is composed of two periods with different outcomes. The first period is a period with better outcomes for women than men when the diagnosis occurs at younger than 55 yr; the second is a period with similar outcomes for both women and men diagnosed at ages greater than 55 yr. These data raise the question of whether an older age cutoff would improve current staging systems. We hypothesize that older age modifies the effect of gender on outcomes due to menopause-associated hormonal alterations.

Approach to the patient with advanced differentiated thyroid cancer

Patients with advanced thyroid cancer may benefit from l-thyroxine treatment at doses that suppress serum TSH level, local treatment interventions, and radioiodine therapy. In those patients who are refractory to radioiodine therapy and in whom progressive disease has been documented, the efficacy of cytotoxic chemotherapy is poor. Encouraging results have been obtained with the use of kinase inhibitors that should be offered as first-line treatment, preferably in the context of a prospective trial.

Cytotoxic chemotherapy for differentiated thyroid carcinoma

For patients with metastatic differentiated thyroid carcinoma that progresses despite standard therapies, systemic cytotoxic chemotherapy has traditionally been a limited option. Historically, phase II studies and small retrospective series have failed to identify highly effective drugs or regimens, in part by failing to recruit sufficient numbers of patients. Doxorubicin remains the single most effective cytotoxic chemotherapy for the treatment of metastatic disease, although complete responses are rare, partial responses limited and toxicity considerable. Newer agents, such as pemetrexed, may be of benefit and potentially better tolerated. Newer approaches to treatment as well as trial design and recruitment, emphasising the role of thyroid cancer patients in early drug trials, may yield advances in patient benefit.

Follow-up of low-risk differentiated thyroid cancer patients who underwent radioiodine ablation of postsurgical thyroid remnants after either recombinant human thyrotropin or thyroid hormone withdrawal

BACKGROUND

We previously demonstrated comparable thyroid remnant ablation rates in postoperative low-risk thyroid cancer patients prepared for administration of 3.7GBq (131)I (100 mCi) after recombinant human (rh) TSH during T(4) (L-T4) therapy vs. withholding L-T4 (euthyroid vs. hypothyroid groups). We now compared the outcomes of these patients 3.7 yr later.

PATIENTS AND METHODS

Fifty-one of the 63 original patients (28 euthyroid, 23 hypothyroid) participated. Forty-eight received rhTSH and serum thyroglobulin (Tg) sampling. A (131)I whole-body scan was performed in 43 patients, and successful ablation was defined by criteria from the previous study. Based on the criterion of uptake less than 0.1% in thyroid bed, 100% (43 of 43) remained ablated. When no visible uptake instead was used, five patients (four euthyroid, one hypothyroid) had minimal visible activity. When the TSH-stimulated Tg criterion was used, only two of 45 (one euthyroid, one hypothyroid) had a stimulated Tg level greater than 2 ng/ml.

RESULTS

No patient in either group died, and no patient declared disease free had sustained tumor recurrence. Nine (four euthyroid, five hypothyroid) had received additional (131)I between the original and current studies due to detectable Tg or imaging evidence of disease; with follow-up, all now had a negative rhTSH-stimulated whole-body scan and seven (three euthyroid, four hypothyroid) had a stimulated serum Tg less than 2 ng/ml.

CONCLUSIONS

In conclusion, after a median 3.7 yr, low-risk thyroid cancer patients prepared for postoperative remnant ablation either with rhTSH or after L-T4 withdrawal were confirmed to have had their thyroid remnants ablated and to have comparable rates of tumor recurrence and persistence.

Treatment (tx) with tyrosine kinase inhibitors (TKIs) for patients (pts) with differentiated thyroid cancer (DTC): The M. D. Anderson Cancer Center (MDACC) experience

6060

Background: DTC is a relatively common tumor and about 20% will develop distant metastases (mets) of which at least 50% will not respond to standard tx. Until recently, tx for pts with progressive, RAI negative disease was limited. However, the identification of biologic targets in DTC has led to several trials with TKIs. Objectives: We sought to describe the MDACC experience with off-label use of TKIs to determine which pts benefit the most. Methods: Adult pts with a diagnosis of DTC treated with single agent sorafenib (SOR) or sunitinib (SUN), and who had a baseline and at least 1 follow-up (f/u) scan after 3 months (mos) of therapy, were included. All imaging data, as well as the TSH-suppressed thyroglobulin (TG) levels corresponding to each scan date were collected. RECIST was used to determine response. Results: We identified 33 pts from our clinical database. 15 pts met inclusion criteria: 9 women, 6 men. No pts were excluded due to progression or death before 3 mos. Median age 61 years (range, 38–83). 7 patients had papillary, 6 follicular (including 2 insular subtypes), 2 Hurthle cell. Most patients had RAI negative disease. SOR was used in 13, SUN in 2. Both SUN pts had been on SOR; 1 failed and 1 had intolerable side effects to SOR. Median time on tx was 42 weeks. All pts had evidence of PD prior to start of tx. Best response was 3 (20%) PR, 9 (60%) SD, 3 (20%) PD. Clinical benefit (PR+SD) = 80%. The SUN pt who was refractory to SOR had a 38% reduction in tumor size. The most noticeable activity occurred in lung (median change: -16%), whereas lymph nodes had PD or SD (median change: +3%). The 2 pts with pleural mets had PD. Four pts had bone mets: 2 had XRT and had SD in bone, while the other 2 did not have XRT and had PD in bone. At 12 mos PFS was 65% and OS was 85%. Median f/u time was 16 mos. All histologic types had similar responses. Log (TG) correlated with response (p = 0.0005). Conclusions: SOR and SUN are effective in pts with widely metastatic, progressive DTC, with most pts achieving SD or PR. The most noticeable responses occurred in the lungs in contrast with minimal changes in nodal mets, suggesting a tissue-specific response to tx. Log (TG) significantly correlated with response to tx and therefore may have value as a surrogate marker of response.

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Assessment of the incremental value of recombinant thyrotropin stimulation before 2-[18F]-Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography imaging to localize residual differentiated thyroid cancer

PURPOSE

The purpose of the study was to assess prospectively the impact of recombinant human TSH (rhTSH) administration on positron emission tomography (PET)/computed tomography (CT) imaging in differentiated thyroid cancer patients who, after primary treatment, had a suppressed or stimulated serum thyroglobulin greater than 10 ng/ml and no radioactive iodine uptake consistent with thyroid cancer on a whole body scan.

PATIENTS AND METHODS

PET/CT was performed before (basal PET) and 24-48 h after rhTSH administration (rhTSH-PET) in 63 patients (52 papillary and 11 follicular thyroid cancers). Images were blindly analyzed by two readers. The proposed treatment plan was prospectively assessed before basal PET, after basal PET, and again after rhTSH-PET.

RESULTS

A total of 108 lesions were detected in 48 organs in 30 patients. rhTSH-PET was significantly more sensitive than basal PET for the detection of lesions (95 vs. 81%; P = 0.001) and tended to be more sensitive for the detection of involved organs (94 vs. 79%; P = 0.054). However, basal PET and rhTSH-PET did not have significantly different sensitivity for detecting patients with any lesions (49 vs. 54%; P = 0.42). Changes in treatment management plan occurred in 19% of the patients after basal PET. Lesions found only by rhTSH-PET contributed to an altered therapeutic plan in eight patients, among whom only four were true-positive on pathology (6%).

CONCLUSION

The use of rhTSH for 2-[18F]-fluoro-2-deoxy-D-glucose-PET/CT significantly increased the number of lesions detected, but the numbers of patients in whom any lesion was detected were no different between basal and rhTSH-stimulated PET/CT scans. Treatment changes due to true positive lesions occurred in 6% of cases.

Initial results from a phase II trial of motesanib diphosphate (AMG 706) in patients with differentiated thyroid cancer (DTC)

6017

Background: This phase 2 study evaluated the safety and efficacy of AMG 706, an oral, investigational multikinase (MKI) inhibitor with antiangiogenic and direct antitumor activity achieved by selectively targeting VEGF, PDGF, and Kit receptors and RET, in pts with advanced DTC or medullary thyroid cancer (MTC). Presented here are results from the DTC stratum. Methods: This was a multicenter, phase 2, open-label, single-arm study of pts with advanced thyroid cancer stratified by DTC or MTC (planned n=80 each). The primary endpoint was objective tumor response per modified RECIST by independent central review. Secondary DTC endpoints were duration of response and progression-free survival (PFS). Pts = 18 yrs with progressive, 131I-resistant disease, ECOG 0–2, and no prior treatment with VEGFr MKIs received AMG 706 125mg QD until disease progression or unacceptable toxicity. Assessments included tumor response (q8w), pharmacokinetics (PK), and safety. Results: 93 pts with DTC were enrolled and received at least 1 dose of AMG 706. DTC subtypes were: papillary, 58%; Hürthle cell, 18%; follicular, 16%; other, 8%. Median (range) age was 62 (36–81) yrs. 20% of pts had prior chemotherapy; 96% had prior 131I therapy. With median follow-up of 32 wks, objective tumor response (CR or PR) rate (95% CI) was 12% (6.1, 20.2); SD, n=64 (69%; durable SD =24 wks, 24%); PD, n=7 (8%). Median (95% CI) time to response was 103 (53, 161) days; median PFS was 276 (221, not estimable) days. 85% of pts were alive >8 months after starting therapy. All pts (100%) had some treatment- emergent adverse events (AE): grade 3, 55%; grade 4, 10%; grade 5, 5% (all grade 5 were deemed unrelated to AMG 706). Common AEs included diarrhea (70%; 11% grade 3), fatigue (58%; 5% grade 3), hypertension (49%; 22% grade 3), headache (43%; 4% grade 3), nausea (40%; 2% grade 3), and hypothyroidism and/or increased TSH (17%; no grade 3); none of these were grade 4 or 5. 6% of pts had cholecystitis. PK results showed that AMG 706 PK at 125mg QD was comparable to data obtained in other monotherapy studies at the same dose level. Conclusions: In this study of pts with advanced 131I-resistant DTC, AMG 706 showed encouraging antitumor activity and had tolerable and manageable toxicities. Further investigation is warranted.

No significant financial relationships to disclose.

Phase I/II trial of capecitabine (C), dacarbazine (D) and imatinib (I) (CDI) for patients (pts) metastatic medullary thyroid carcinomas (MTC)

13048

Background: MTC is a rare tumor that responds poorly to conventional chemotherapy. 5-FU and D are frequently used, with an expected response rate of around 15%. MTC is often associated with multiple endocrine neoplasia type 2, an autosomal dominant syndrome caused by a mutation in the RET proto-oncogene which encodes RET, a tyrosine kinase receptor. I is a tyrosine kinase inhibitor with activity against c-Kit, PDGF and possibly RET, and we postulated that its addition to chemotherapy would increase its efficacy against this disease. Methods: We designed a phase I/II trial combining escalating doses of oral C, IV D and oral I. Pts with any advanced solid tumors were eligible for the phase I part of the trial. Results: 13 pts were entered and 12 were eligible (7 MTC, 2 adrenocortical, 1 islet-cell, 1 insular thyroid and 1 small cell). 4 pts did not complete one cycle (1 pt withdrew after 5 days and 2 pts progressed in less than 10 days and were replaced for toxicity analysis, 1 had a DLT and is included). 3 patients were entered in dose level 1, without DLT. 2 out of 6 pts developed DLT at the second dose level (1 G 3 fatigue and 1 G3 hypokalemia). Three additional pts are being entered on dose level 1. The first one had PD after 7 days and is being replaced. For the 11 pts who were evaluable, best response was 3 SD (range 3 to 9 + months) and 8 PD. Conclusions: The combination of CDI is feasible but has resulted in an unexpected pattern of toxicity in this patient population, with fatigue and hypokalemia as the DLT. No significant diarrhea or hand-foot syndrome was seen. Only G1 and 2 fluid retention and neutropenia have been encountered. Only minor reduction in tumor size has been seen among these heavily pretreated pts. Once the phase I is complete, the trial will continue in a phase II setting for untreated MTC pts.

[Table: see text]

[Table: see text]

Thyroid microcarcinoma: prevalence, prognosis, and management

OBJECTIVE

To review the usual course of thyroid microcarcinoma (TMC) and the associated prognosis and treatment of affected patients.

METHODS

We discuss predisposing factors in the formation of TMC and the modulation of its behavior, diagnostic evaluation, and management options.

RESULTS

TMC, generally defined as a well-differentiated thyroid cancer less than or equal to 15 mm in diameter, has an estimated prevalence (based on autopsy studies) of about 5 to 10%. Studies, however, have shown that most of these cancers are smaller than 5 mm in diameter. The high prevalence of TMC in the general population contrasts with the rarity of thyroid cancers of greater size, which constitute less than 1% of malignant neoplasms in the United States. The frequent detection of TMC as a result of routine imaging of the neck for unrelated reasons and as a incidental finding in surgical specimens has raised a question about whether the management of TMC should differ from that for thyroid cancer of appreciable size. The uncertainty about optimal management of TMC is attributable to the small number of long-term follow-up studies as well as the common observation that patients usually have an excellent prognosis. Although in most patients harboring a TMC the cancer remains quiescent and never becomes clinically significant, in some cases TMC can demonstrate an aggressive course. Several variables, such as older age, multifocality, bilateral disease, and extrathyroidal spread at initial assessment, may have some adverse prognostic significance. After a partial surgical removal of the thyroid gland for TMC, the recurrence rate may be as high as 11%. Therefore, a treatment dilemma is caused by the low propensity of TMC for progression to clinically significant disease, yet the potential for recurrence and aggressive behavior in some cases.

CONCLUSION

In general, surgical resection of TMC is based on results of fine-needle aspiration biopsy and the rate of growth of the nodule. Aggressive management seems indicated in high-risk patients, particularly older patients, those with a history of radiation exposure, and those with multifocal disease, bilateral disease, or lymph node involvement.

A consensus report of the role of serum thyroglobulin as a monitoring method for low-risk patients with papillary thyroid carcinoma

Recent studies have provided new information regarding the optimal surveillance protocols for low-risk patients with differentiated thyroid cancer (DTC). This article summarizes the main issues brought out in a consensus conference of thyroid cancer specialists who analyzed and discussed this new data. There is growing recognition of the value of serum thyroglobulin (Tg) as part of routine surveillance. An undetectable serum Tg measured during thyroid hormone suppression of TSH (THST) is often misleading. Eight studies show that 21% of 784 patients who had no clinical evidence of tumor with baseline serum Tg levels usually below 1 micro g/liter during THST had, in response to recombinant human TSH (rhTSH), a rise in serum Tg to more than 2 micro g/liter. When this happened, 36% of the patients were found to have metastases (36% at distant sites) that were identified in 91% by an rhTSH-stimulated Tg above 2 micro g/liter. Diagnostic whole body scanning, after either rhTSH or thyroid hormone withdrawal, identified only 19% of the cases of metastases. Ten studies comprising 1599 patients demonstrate that a TSH-stimulated Tg test using a Tg cutoff of 2 micro g/liter (either after thyroid hormone withdrawal or 72 h after rhTSH) is sufficiently sensitive to be used as the principal test in the follow-up management of low-risk patients with DTC and that the routine use of diagnostic whole body scanning in follow-up should be discouraged. On the basis of the foregoing, we propose a surveillance guideline using TSH-stimulated Tg levels for patients who have undergone total or near-total thyroidectomy and (131)I ablation for DTC and have no clinical evidence of residual tumor with a serum Tg below 1 micro g/liter during THST.

Optimal treatment strategy in patients with papillary thyroid cancer: a decision analysis

BACKGROUND

The management of patients with papillary thyroid carcinoma (PTC) remains controversial. We used decision analysis to identify the optimal treatment strategy for patients with PTC, stratified by risk-group classification.

METHODS

We designed a Markov model to compare thyroid lobectomy and total thyroidectomy (with adjuvant radioiodine therapy) in low- and high-risk patients with PTC. Morbidity, recurrence, and mortality estimates were obtained from the literature. Outcomes were quality-adjusted by using health state preferences.

RESULTS

In low-risk patients, lobectomy and total thyroidectomy resulted in 31.7 and 32.9 quality-adjusted life years (QALYs). Total thyroidectomy was the optimal strategy as long as the relative risk of recurrence after lobectomy was greater than 1.3. Lobectomy became the preferred strategy if subjects were willing to give up 1.5 years of life to avoid thyroid hormone dependency and a remote risk of radioiodine-induced malignancy. In high-risk patients, lobectomy and total thyroidectomy resulted in 11.2 and 16.5 QALYs. Model results were robust to varying the permanent complication rates of initial or completion thyroidectomy, the efficacy of adjuvant radioiodine therapy, and the impact of complications and cancer recurrence on quality of life, irrespective of risk-group classification.

CONCLUSIONS

Total thyroidectomy maximized quality-adjusted life expectancy in low- and high-risk patients with PTC.

Adenocarcinoma of the salivary gland metastatic to the pituitary gland: case report

OBJECTIVE AND IMPORTANCE

A case of metastasis to the pituitary gland from a ductal adenocarcinoma of the salivary gland is presented. Metastasis to this site is rare, and a salivary gland source has never previously been described.

CLINICAL PRESENTATION

This patient presented with hypopituitarism, including diabetes insipidus.

INTERVENTION

A craniotomy was performed to alleviate visual loss. The histological features of the sellar tumor were identical to those of a tumor removed from the parotid gland 18 months earlier.

CONCLUSION

Although intrasellar tumors originating from embryonic rests of salivary gland tissue have been reported, metastasis from a malignant neoplasm arising within a true salivary gland is also possible and should not be excluded from consideration for patients in whom a salivary gland-like tumor is discovered in the sella turcica.

A comparison of recombinant human thyrotropin and thyroid hormone withdrawal for the detection of thyroid remnant or cancer

Recombinant human TSH has been developed to facilitate monitoring for thyroid carcinoma recurrence or persistence without the attendant morbidity of hypothyroidism seen after thyroid hormone withdrawal. The objectives of this study were to compare the effect of administered recombinant human TSH with thyroid hormone withdrawal on the results of radioiodine whole body scanning (WBS) and serum thyroglobulin (Tg) levels. Two hundred and twenty-nine adult patients with differentiated thyroid cancer requiring radioiodine WBS were studied. Radioiodine WBS and serum Tg measurements were performed after administration of recombinant human TSH and again after thyroid hormone withdrawal in each patient. Radioiodine whole body scans were concordant between the recombinant TSH-stimulated and thyroid hormone withdrawal phases in 195 of 220 (89%) patients. Of the discordant scans, 8 (4%) had superior scans after recombinant human TSH administration, and 17 (8%) had superior scans after thyroid hormone withdrawal (P = 0.108). Based on a serum Tg level of 2 ng/mL or more, thyroid tissue or cancer was detected during thyroid hormone therapy in 22%, after recombinant human TSH stimulation in 52%, and after thyroid hormone withdrawal in 56% of patients with disease or tissue limited to the thyroid bed and in 80%, 100%, and 100% of patients, respectively, with metastatic disease. A combination of radioiodine WBS and serum Tg after recombinant human TSH stimulation detected thyroid tissue or cancer in 93% of patients with disease or tissue limited to the thyroid bed and 100% of patients with metastatic disease. In conclusion, recombinant human TSH administration is a safe and effective means of stimulating radioiodine uptake and serum Tg levels in patients undergoing evaluation for thyroid cancer persistence and recurrence.

Surgical strategy for the treatment of medullary thyroid carcinoma

OBJECTIVE

To evaluate surgical complications, patterns of lymph node metastases, and calcitonin response to compartment-oriented lymphadenectomy in patients with primary or recurrent medullary thyroid carcinoma (MTC).

SUMMARY BACKGROUND DATA

The majority of patients with invasive MTC have metastasis to regional lymph nodes at the time of diagnosis, as evidenced by the frequent finding of persistently elevated calcitonin levels after thyroidectomy and the high rates of recurrence in the cervical lymph nodes reported in retrospective studies. These data have provided the rationale for surgeons to perform a more extensive lymphadenectomy at the time of initial thyroidectomy and to consider reoperative cervical lymphadenectomy in patients with persistently elevated calcitonin levels after thyroidectomy.

METHODS

Forty patients underwent surgery for MTC from 1991 to 1997 (23 sporadic cases, 17 familial cases). Patients were divided into three groups based on whether they had undergone previous thyroidectomy and on the results of standardized staging studies performed after referral to the authors' institution. Group 1 (11 patients) had received no previous surgery; group 2 (13) underwent thyroidectomy before referral and had an elevated calcitonin level without radiologic evidence of local regional or distant metastases; and group 3 (16) underwent thyroidectomy before referral and had an elevated calcitonin level with radiologic evidence of local-regional recurrence. The central neck compartment was dissected in all patients; preoperative staging and the extent of previous surgery dictated the need for lateral (modified radical) neck dissection. After primary or reoperative surgery, calcitonin levels were assessed.

RESULTS

All patients had major reductions in postoperative calcitonin levels. Seven (29%) of 24 patients in groups 1 and 2 achieved normal calcitonin values compared with only 1 (6%) of 16 in group 3. Postoperative complications included seven cases (17%) of permanent hypoparathyroidism; five (71%) of these occurred in group 3. There were no iatrogenic recurrent laryngeal nerve injuries; one patient required recurrent nerve resection to achieve complete tumor extirpation. At a median follow up of 35 months, local recurrence was documented in 5 (13%) of 40 patients.

CONCLUSIONS

Compartment-oriented lymphadenectomy performed early in the course of MTC is safe and may return calcitonin levels to normal in up to 25% of carefully selected patients. However, reoperation for bulky cervical disease (group 3) rarely results in normal calcitonin levels and is associated with a high incidence of permanent hypoparathyroidism.

Image analysis of papillary thyroid carcinoma fine-needle aspirates: significant association between aneuploidy and death from disease

BACKGROUND

Papillary thyroid carcinoma is the most common thyroid malignancy in the U.S. As many as half of patients with papillary carcinoma present with cervical lymph node metastases at the time of diagnosis. Metastatic disease involving cervical lymph node tissue has not historically been proven to correlate with a more aggressive course; however, distant metastases worsen prognosis.

METHODS

Diagnostic fine-needle aspiration (FNA) smears from 26 primary and metastatic papillary carcinomas underwent Feulgen reaction and were studied by image analysis to determine DNA pattern, proliferation index, and the percentage of cells with DNA content >5C. The medical records of all the patients were reviewed for metastatic disease pattern and survival data. For metastatic pattern, two groups were defined: 1) confined to thyroid/local lymph node metastases/soft tissues of the neck involved by tumor, and 2) distant metastases.

RESULTS

Among the 26 patients, 16 had "nonaggressive" DNA patterns described as diploid, abnormal diploid, or tetraploid, and 10 had "aggressive" DNA patterns described as aneuploid. Only 2 of the 16 patients in the "nonaggressive" DNA pattern group developed distant metastases, whereas 5 of the 10 patients in the aneuploid group developed distant metastatic disease. In addition, none of the 16 patients with "nonaggressive" DNA patterns died of disease, whereas 3 of the 10 individuals with DNA histograms interpreted as aneuploid did die of metastatic disease complications.

CONCLUSIONS

Aneuploidy identified by image analysis of FNA of papillary thyroid carcinoma is significantly associated with death from papillary carcinoma (log rank test, P=0.027).

Central hypothyroidism associated with retinoid X receptor-selective ligands

BACKGROUND

The occurrence of symptomatic central hypothyroidism (characterized by low serum thyrotropin and thyroxine concentrations) in a patient with cutaneous T-cell lymphoma during therapy with the retinoid X receptor-selective ligand bexarotene led us to hypothesize that such ligands could reversibly suppress thyrotropin production by a thyroid hormone-independent mechanism and thus cause central hypothyroidism.

METHODS

We evaluated thyroid function in 27 patients with cutaneous T-cell lymphoma who were enrolled in trials of high-dose oral bexarotene at one institution. In addition, we evaluated the in vitro effect of triiodothyronine, 9-cis-retinoic acid, and the retinoid X receptor-selective ligand LGD346 on the activity of the thyrotropin beta-subunit gene promoter.

RESULTS

The mean serum thyrotropin concentration declined from 2.2 mU per liter at base line to 0.05 mU per liter during treatment with bexarotene (P<0.001), and the mean serum free thyroxine concentration declined from 1.0 ng per deciliter (12.9 pmol per liter) at base line to 0.45 ng per deciliter (5.8 pmol per liter) (P<0.001) during treatment. The degree of suppression of thyrotropin secretion tended to be greater in patients treated with higher doses of bexarotene (>300 mg per square meter of body-surface area per day) and in those with a history of treatment with interferon alfa. Nineteen patients had symptoms or signs of hypothyroidism, particularly fatigue and cold intolerance. The symptoms improved after the initiation of thyroxine therapy, and all patients became euthyroid after treatment with bexarotene was stopped. In vitro, LGD346 suppressed the activity of the thyrotropin beta-subunit gene promoter in thyrotrophs by as much as 50 percent, an effect similar to that of triiodothyronine and 9-cis-retinoic acid.

CONCLUSIONS

Hypothyroidism may develop in patients with cutaneous T-cell lymphoma who are treated with high-dose bexarotene, most likely because the retinoid X receptor-selective ligand suppresses thyrotropin secretion.

Toward a standard clinicopathologic staging approach for differentiated thyroid carcinoma

Physicians attempting disease staging for differentiated thyroid carcinoma have a broad variety of clinicopathologic classification approaches from which to choose. Unfortunately, no consensus has yet emerged as to the optimal method, and considerable differences of opinion still exist. Eight of the most commonly used classifications are described, along with results of recent comparative analyses of multiple schemes. Recommendations are provided to permit standardized approaches to clinicopathologic staging, and future research directions are identified.

Adjuvant therapy and long-term management of differentiated thyroid carcinoma

As with most therapies for differentiated thyroid carcinoma, there is little consensus about optimal use of postoperative adjuvant therapies or long-term follow-up strategies. However, an increasing body of data indicates that most patients can benefit from postoperative radioiodine ablation followed by thyroid hormone suppression therapy. An approach to long-term monitoring and therapy is provided, including the use of strategies dependent upon the extent of the patient's initial disease.

Unknown primary cancer presenting as an adrenal mass: frequency and implications for diagnostic evaluation of adrenal incidentalomas

BACKGROUND

Fine-needle aspiration biopsy to identify adrenal metastasis from an occult primary malignancy has been recommended as part of the evaluation of the patient who presents with an incidentally discovered adrenal mass. This recommendation was assessed by examining the frequency of adrenal involvement in patients with suspected unknown primary cancer.

METHODS

Data from 1715 patients referred for evaluation of suspected unknown primary cancer were retrospectively reviewed.

RESULTS

Of 1639 patients found to have cancer, the adrenal gland was identified as a site of involvement at presentation in 95 (5.8%). Involvement was limited to the adrenal gland in 4 patients (0.2%). All 4 patients had large (> or = 6 cm) adrenal tumors, 3 of 4 had bilateral involvement, and all had symptoms that otherwise mandated evaluation for an occult malignancy; none had a true adrenal incidentaloma.

CONCLUSIONS

Although cancer of an unknown primary site occasionally involves the adrenal gland, metastatic cancer presenting as a true adrenal incidentaloma is extremely rare. Therefore, in the absence of a history of prior malignancy or symptoms, physical examination findings, radiographic findings, or laboratory findings suggestive of an occult malignancy, we do not recommend fine-needle aspiration biopsy as part of the diagnostic evaluation of the patient who presents with a unilateral adrenal mass.

Thyrotropin suppression and disease progression in patients with differentiated thyroid cancer: results from the National Thyroid Cancer Treatment Cooperative Registry

The ideal therapy for differentiated thyroid cancer is uncertain. Although thyroid hormone treatment is pivotal, the degree of thyrotropin (TSH) suppression that is required to prevent recurrences has not been studied in detail. We have examined the relation of TSH suppression to baseline disease characteristics and to the likelihood of disease progression in a cohort of thyroid cancer patients who have been followed in a multicenter thyroid cancer registry that was established in 1986. The present study describes 617 patients with papillary and 66 patients with follicular thyroid cancer followed annually for a median of 4.5 years (range 1-8.6 years). Cancer staging was assessed using a staging scheme developed and validated by the registry. Cancer status was defined as no residual disease; progressive disease at any follow-up time; or death from thyroid cancer. A mean TSH score was calculated for each patient by averaging all available TSH determinations, where 1 = undetectable TSH; 2 = subnormal TSH; 3 = normal TSH; and 4 = elevated TSH. Patients were also grouped by their TSH scores: group 1: mean TSH score 1.0-1.99; group 2: mean TSH score 2.0-2.99; group 3: mean TSH score 3.0-4.0. The degree of TSH suppression did not differ between papillary and follicular thyroid cancer patients. However, TSH suppression was greater in papillary cancer patients who were initially classified as being at higher risk for recurrence. This was not the case for follicular cancer patients, where TSH suppression was similar for all patients. For all stages of papillary cancer, a Cox proportional hazards model showed that disease stage, patient age, and radioiodine therapy all predicted disease progression, but TSH score category did not. However, TSH score category was an independent predictor of disease progression in high risk patients (p = 0.03), but was no longer significant when radioiodine therapy was included in the model (p = 0.09). There were too few patients with follicular cancer for multivariate analysis. These data suggest that physicians use greater degrees of TSH suppression in higher risk papillary cancer patients. Our data do not support the concept that greater degrees of TSH suppression are required to prevent disease progression in low-risk patients, but this possibility remains in high-risk patients. Additional studies with more patients and longer follow-up may provide the answer to this important question.

Prospective multicenter study of thyroiscarcinoma treatment: initial analysis of staging and outcome. National Thyroid Cancer Treatment Cooperative Study Registry Group

BACKGROUND

A novel prognostic staging classification encompassing all forms of thyroid carcinoma was created for the National Thyroid Cancer Treatment Cooperative Study (NTCTCS) Registry, with the goal of prospective validation and comparison with other available staging classifications.

METHODS

Patient information was recorded prospectively from 14 institutions. Clinicopathologic staging was based on patient age at diagnosis, tumor histology, tumor size, intrathyroidal multifocality, extraglandular invasion, metastases, and tumor differentiation.

RESULTS

Between 1987 and 1995, 1607 patients were registered. Approximately 43% of patients were classified as NTCTCS Stage I, 24% Stage II, 24% Stage III, and 9% Stage IV. Patients with follicular carcinoma were more likely to have "high risk" Stage III or IV disease than those with papillary carcinoma. Of 1562 patients for whom censored follow-up was available (median follow-up, 40 months), 78 died of thyroid carcinoma or complications of its treatment. Five-year product-limit patient disease specific survival was 99.8% for Stage I, 100% for Stage II, 91.9% for Stage III, and 48.9% for Stage IV (P < 0.0001). The frequency of remaining disease free also declined significantly with increasing stage (94.3% for Stage I, 93.1%for Stage II, 77.8% for Stage III, and 24.6% for Stage IV). The same patients also were staged applying six previously published classifications as appropriate for their tumor type. The predictive value of the NTCTCS Registry staging classification consistently was among the highest for disease specific mortality and for remaining disease free, regardless of the tumor type.

CONCLUSIONS

The NTCTCS Registry staging classification provides a prospectively validated scheme for predicting short term prognosis for patients with thyroid carcinoma.

Effects of pharmacological fiber supplements on levothyroxine absorption

To determine the effect of pharmacological fiber supplements, we measured levothyroxine (LT4) absorption without and with simultaneous ingestion of either calcium polycarbophil or psyllium hydrophilic mucilloid. Serum thyroxine (T4) levels in 8 volunteers were measured following ingestion of 600 microg of LT4 on 3 separate occasions at 4-week intervals: (1) LT4 alone; (2) LT4 together with 1000 mg polycarbophil; and (3) LT4 together with 3.4 g psyllium. The amount of absorbed LT4 was calculated as the incremental rise in serum T4 level during the first 6 hours multiplied by the volume of distribution for the hormone, and expressed as a percentage of the dose administered. Absorption of LT4 alone averaged 89% (95% confidence interval [CI]: 75%-104%), occurring at a median of 180 minutes. After simultaneous ingestion of calcium polycarbophil, LT4 absorption was 86% (95% CI: 74%-97%), occurring at 180 minutes. With simultaneous ingestion of psyllium and LT4, the absorption was 80% (95% CI: 64%-95%), occurring at 240 minutes. In summary, neither calcium polycarbophil nor psyllium hydrophilic mucilloid are likely to cause malabsorption of LT4 that could be detected by these methods.

Prognosis and treatment of brain metastases in thyroid carcinoma

We analyzed 47 cases of brain metastases from thyroid cancer seen at 1 institution over 5 decades. Brain metastases were a primary clinical feature at initial presentation in 15% of the cases, were identified during the subsequent course of the disease in 68%, and were only discovered at autopsy in 23%. The primary thyroid tumor was differentiated cancer in 68%, anaplastic cancer in 23%, and medullary cancer in 9%. Patients were typically older, with frequent evidence of aggressive disease and distant metastases at initial cancer diagnosis. Once brain metastases were diagnosed, disease-specific mortality was 78%, with a median product-limit survival of 4.7 months (67% and 12.4 months, respectively, for those with differentiated cancer). Resection of one or more foci of brain metastases significantly improved survival. The median disease-specific survival from diagnosis of brain metastases was 16.7 months for patients who underwent local excision of one or more brain metastases, compared with 3.4 months for those who did not (P < 0.05), independent of the presence of multifocal brain lesions. Recombinant human TSH safely stimulated radioiodine uptake for treatment of brain metastases in 1 patient. However, no evidence of survival benefit was found from radioiodine therapy, external beam radiotherapy, or chemotherapy. In summary, brain metastases from thyroid carcinoma are an extremely poor prognostic sign. Although selection bias and other unidentified factors inherent to retrospective analysis limit this conclusion, surgical resection of brain metastases may be associated with prolonged survival in differentiated carcinoma.

Augmented hepatic and skeletal thyromimetic effects of tiratricol in comparison with levothyroxine

A thyroid hormone analog with organ-selective effects could have therapeutic application for disorders such as hyperlipidemia and osteoporosis. We performed a randomized clinical trial to determine the specific thyromimetic effects of tiratricol. Twenty-four athyreotic patients underwent detailed metabolic and physiological evaluation after a 2-month baseline period, taking TSH-suppressive doses of L-T4. They were then randomized to blinded treatment with either tiratricol (24 micrograms/kg twice daily) or L-T4 (1.9 micrograms/kg daily). The dose of hormone was increased until the TSH level was less than 0.1 mU/L, and the metabolic and physiological testing was repeated. Comparing the change from baseline to the study drug periods, when serum TSH levels were equivalently suppressed, there were no significant differences between the two groups in resting metabolic rate, weight, urea nitrogen excretion, or symptom score. Plasma total and low density lipoprotein cholesterol levels declined 13 +/- 4% and 23 +/- 6% in the tiratricol group compared with 2 +/- 2% and 5 +/- 3% in the L-T4 group (P = 0.015 and P = 0.0066, respectively). Serum sex hormone-binding globulin levels increased 55 +/- 13% with tiratricol compared with a 1.7 +/- 4% decline with L-T4 (P = 0.0006), indicating an augmented hepatic response to tiratricol. Skeletal metabolic activity was enhanced, with increased levels of serum osteocalcin and urinary excretion of calcium and pyridinium cross-links. Tiratricol and L-T4 had comparable effects on cardiovascular function. Tiratricol has distinct augmented hepatic and skeletal thyromimetic actions of potential therapeutic value.

Clinical and socioeconomic predispositions to complicated thyrotoxicosis: a predictable and preventable syndrome?

PURPOSE

To identify the clinical, demographic, and hormonal features that characterize and place patients at greater risk for complicated thyrotoxicosis.

PATIENTS AND METHODS

Fifty-nine patients with documented thyrotoxicosis complicated by cardiovascular, neuropsychiatric, gastrointestinal, or thermoregulatory dysfunction, were retrospectively identified among 498,000 hospital admissions between 1979 and 1992. Clinical, demographic, and hormonal information were obtained from these charts, as well as from the charts of 118 randomly selected thyrotoxic outpatients.

RESULTS

Age distribution of complicated thyrotoxicosis patients was bimodal, with a median of 41 years. Forty-nine percent of patients had been previously diagnosed with thyrotoxicosis, but most had been noncompliant with prescribed medication. Cardiovascular complications were among the primary causes for admission in 46% of patients, followed by neuropsychiatric indications in 42%, fever in 34%, and gastrointestinal dysfunction in 17%. Only 8% had primary involvement of > 2 organ systems. There was high correlation between organ systems with pre-existing dysfunction and those with a complication of thyrotoxicosis (P < 0.0001). Compared to uncomplicated controls, patients with complicated thyrotoxicosis were more likely to be uninsured or covered by Medicaid (OR, 2.64; 95% CI 1.78 to 3.91); to be < 30 or > 50 years old (OR, 1.93; 95% CI 1.23 to 3.03); and to have serum T4 concentrations greater than twice the upper limit of normal (OR, 1.67; 95% CI, 1.15 to 2.44).

CONCLUSIONS

Certain thyrotoxic patients are at greater risk for developing complications. By addressing the medical needs of these patients, it may be possible to reduce the likelihood of complications requiring hospitalization.

Sucralfate causes malabsorption of L-thyroxine

PURPOSE

To determine if sucralfate causes malabsorption of L-thyroxine.

PATIENTS AND METHODS

Five healthy volunteers ingested L-thyroxine, 1,000 micrograms, administered orally (1) without sucralfate, (2) with sucralfate, 1 g, and (3) 8 hours after sucralfate, 2 g. The amount of L-thyroxine absorbed was calculated from the peak increase in serum T4 levels within 6 hours of hormone ingestion multiplied by the volume of distribution for the hormone.

RESULTS

Peak absorption of L-thyroxine in the absence of sucralfate was 796 micrograms (95% confidence interval (CI): 515-1,074 micrograms). Coadministration of sucralfate, 1 g, with L-thyroxine reduced thyroid hormone absorption to 225 micrograms (95% CI: 151-299 micrograms) (P = 0.0029 compared with control). Peak hormone absorption was delayed 2 hours by simultaneous sucralfate ingestion. Separation of administered L-thyroxine and sucralfate doses by 8 hours returned hormone absorption to control values. Maximum T3 levels did not differ, regardless of drug regimen, but suppression of thyroid-stimulating hormone (TSH) by L-thyroxine was reduced by coadministration of sucralfate.

CONCLUSIONS

Sucralfate causes malabsorption of L-thyroxine, presumably by intraluminal binding of hormone.

Clinical utility of posttreatment radioiodine scans in the management of patients with thyroid carcinoma

A retrospective comparison was performed of whole body scans obtained before and after 143 131I treatments in 93 patients with thyroid carcinoma. Pretreatment scans were performed with 74-185 megabecquerel 131I, and posttreatment scans were performed 5-12 days after dosing with 1.1-7.4 GBq. In 38 (27%) treatment cycles, the results of posttreatment and pretreatment scans differed. Only 14 (10%) posttreatment scans detected new locations of metastatic disease. Seventeen posttreatment scans demonstrated metastatic locations that were already known from previous studies but not seen on the pretreatment scan. Among parameters evaluated (including demographic and histological characteristics), only the combination of age at diagnosis less than 45 yr and history of previous 131I therapy contributed to the likelihood of a new finding on posttreatment scan (relative risk, 3.8). Five of the 14 new posttreatment scan findings were subsequently corroborated by other radiographic studies or thyroglobulin elevations, all in patients with extrathyroidal extension of the primary tumor. Seven (5%) posttreatment scans were unable to detect a focus of uptake seen on the corresponding pretreatment scan. In conclusion, posttreatment scans were most likely to reveal clinically important new information in young patients who had previously received 131I therapy. In older patients and those without previous 131I therapy, posttreatment scans rarely yielded new information that would potentially alter the patient's prognosis.

Follicular variant of papillary thyroid carcinoma. A clinicopathologic study

BACKGROUND

A retrospective clinicopathologic study was performed to identify the influence of diagnostic and therapeutic procedures on the outcomes of patients with the follicular variant of papillary thyroid carcinoma (FVPTC).

METHODS

The results of 37 patients with FVPTC were compared with those of 37 randomly selected patients with papillary carcinoma and 22 patients with follicular carcinoma. Diagnostic, therapeutic, and follow-up data were obtained by review of clinical and histologic materials.

RESULTS

Median follow-up was approximately 3 years in all groups. Fine-needle aspiration had a sensitivity of 75% for FVPTC, which was similar to that for papillary carcinoma. Frozen section evaluation had a sensitivity of only 27% for FVPTC but 94% for papillary carcinoma and 44% for follicular carcinoma. All patients for whom the fine-needle aspiration specimen contained cytologic features of papillary carcinoma and frozen section suggested a follicular lesion proved to have FVPTC: Consequently, hemithyroidectomy was performed three times more often among patients with FVPTC than among those with papillary carcinoma. FVPTC tumors were modestly, but significantly, smaller than papillary carcinoma tumors (1.2 versus 1.6 cm). Metastases to cervical lymph nodes occurred least often in patients with FVPTC and usually were detected within 3 months of diagnosis. The frequency of distant metastases within this limited period of follow-up did not differ between FVPTC and papillary carcinoma.

CONCLUSIONS

Fine-needle aspiration appears to be superior to frozen section for identification of FVPTC, although the number of aspirations performed was limited. Greater use of aspiration may permit more appropriate surgical management of this disease. Local and distant metastases of FVPTC do not occur more often than do those of papillary carcinoma.

Organ-specific effects of tiratricol: a thyroid hormone analog with hepatic, not pituitary, superagonist effects

Tiratricol has been used to suppress pituitary TSH secretion, with reported attenuation of extrapituitary thyromimetic effects. A randomized, double-blind trial was performed to define precisely the tissue-specific thyromimetic actions of tiratricol. Ten athyreotic patients, treated for thyroid carcinoma, were randomly assigned to receive L-T4 sodium 0.7 micrograms/kg daily and either tiratricol 10 micrograms/kg or placebo twice daily. The daily dose of L-T4 was increased by 25-50 micrograms increments until the TRH-stimulated TSH level was less than 0.1 mU/L. After measurement of biochemical and physiological parameters of thyroid hormone actions, patients crossed treatment groups. Patients required 46% less L-T4 to achieve equivalent TSH suppression when taking tiratricol. Hepatic effects were enhanced by tiratricol administration, with significant increases in sex hormone binding globulin and ferritin concentrations, 14% and 37%, respectively. Levels of serum cholesterol, LDL cholesterol, and apolipoprotein B were reduced by 7%, 10%, and 13%, respectively, during tiratricol therapy. Triglyceride levels also declined, but there were no changes of high density lipoprotein cholesterol or apolipoproteins AI and AII. Resting metabolic rate, body weight, urea nitrogen excretion, and symptoms did not differ between the two treatment regimens. Cardiovascular function, as reflected by mean arterial pressure and pulse wave arrival time, was not different during tiratricol therapy. Skeletal metabolic activity was affected by tiratricol, with marked elevation of osteocalcin without significant change in serum calcium, PTH, and urinary calcium and hydroxyproline excretion. Tiratricol has increased hepatic and skeletal actions of potential therapeutic value, but does not have enhanced thyromimetic activity specific to the pituitary gland.

Reversible alterations in myocardial gene expression in a young man with dilated cardiomyopathy and hypothyroidism

Thyroid hormone effects on myocardial gene expression have been well defined in animal models, but their relationship to the pathogenesis of cardiac dysfunction in hypothyroid humans has been uncertain. We evaluated a profoundly hypothyroid young man with dilated cardiomyopathy. Before and during 9 months of thyroxine therapy, serial assessment of myocardial performance documented substantial improvements in the left ventricular ejection fraction (16-37%), left ventricular end-diastolic diameter (7.8-5.9 cm), and cardiac index (1.4-2.7 liters.min-1.m-2). Steady-state levels of mRNAs encoding selected cardiac proteins were measured in biopsy samples obtained before and after thyroxine replacement. In comparison with myocardium from nonfailing control hearts, this patient's pretreatment alpha-myosin heavy-chain mRNA level was substantially lower, the atrial natriuretic factor mRNA level was markedly elevated, and the phospholamban mRNA level was decreased. All of these derangements were reversed 9 months after restoration of euthyroidism. These observations in an unusual patient with profound myxedema and cardiac dilatation permit correlation between the reversible changes in myocardial function and steady-state mRNA levels in a cardiomyopathy. They suggest that alterations in gene expression in the dilated myopathic heart may be correctable when a treatable cause is identified.

Octreotide therapy of growth hormone excess in the McCune-Albright syndrome

We report a patient with the McCune-Albright syndrome and growth hormone excess. Biochemical evaluation demonstrated characteristic changes typical of acromegaly, and an unusual pattern of delayed somatotropin response to hGHRH40, not previously described in this syndrome. Therapeutic trial of low-dose octreotide successfully reversed his growth hormone excess, whereas bromocriptine failed to reduce growth hormone levels. Previous reports of acromegaly and McCune-Albright syndrome are reviewed, and the unique features of this case discussed.

Percutaneous transluminal coronary angioplasty in hypothyroidism

PURPOSE

To determine the risks of percutaneous transluminal coronary angioplasty (PTCA) in hypothyroid individuals.

PATIENTS AND METHODS

In a retrospective cohort study, 13 patients with primary hypothyroidism were identified among 382 consecutive PTCA cases in 1987. Twenty-two euthyroid PTCA control subjects and 13 hypothyroid patients who underwent coronary artery bypass surgery (CAB) were identified for comparison.

RESULTS

Hypothyroid and euthyroid PTCA patients had similar mean ages, numbers of prior and recent acute myocardial infarctions, diseased coronary arteries, coronary arteries dilated, and serum cholesterol levels. There were no significant differences in procedure-related mortality (0% versus 0%); coronary artery dissection (23% versus 23%); reocclusion (8% versus 5%); bradycardia (0% versus 0%); heart failure (0% versus 5%); hypotension (31% versus 27%); myocardial infarction (8% versus 0%); gastrointestinal dysfunction (0% versus 0%); neuropsychiatric disturbance (15% versus 9%); hyponatremia (23% versus 23%); hypothermia (0% versus 0%); or fever (15% versus 5%). Hematoma formation tended to be more frequent in the hypothyroid group (38% versus 18%, p = 0.18). Similar results were obtained when the subgroup of more severely hypothyroid patients (thyrotropin level more than 20 mU/L, n = 7) was examined. Compared to hypothyroid CAB patients, hypothyroid PTCA patients had less incidence of heart failure (0% versus 31%, p less than 0.025); neuropsychiatric disturbance (15% versus 54%, p less than 0.025); hyponatremia (23% versus 62%, p less than 0.05); gastrointestinal dysfunction (0% versus 23%, p less than 0.025); and fever (15% versus 62%, p less than 0.001).

CONCLUSION

PTCA can be performed in hypothyroid patients without increased mortality or major morbidity, and when appropriate, may be preferred to bypass surgery for coronary revascularization in patients intolerant of full thyroid hormone replacement.