Advanced RAI-refractory thyroid cancer: an update on treatment perspectives

During the last decades, the knowledge on follicular cell-derived thyroid cancer molecular biology has led to the evolution of a number of novel therapies for these tumors, mainly tyrosine kinase inhibitors. Lenvantinib, sorafenib and recently cabozantinib have been approved for differentiated thyroid cancer (DTC), while larotrectinib and entrectinib for neurotrophic-tropomyosin receptor kinase-fusion thyroid cancer. For radioiodine (RAI) refractory DTCs ongoing research aims to identify agents that may restore RAI-avidity via redifferentiation protocols (vemurafenib or dabrafenib and trametinib) or combination treatments. These treatments are based on the tumor molecular signature. The treatment with targeted therapies has changed the therapeutic strategies and the disease prognosis, however drug resistance remains the main reason for treatment failure. Thus, the understanding of both molecular pathways implicated in tumorigenesis, and tumoral escape mechanisms, are of paramount significance for the development of new therapies for DTC. The present review focuses on the molecular landscape of DTC, the approved targeted therapies as well as the mechanisms of drug resistance. Furthermore, it points to the ongoing research and the future perspectives for the development of more efficient drugs for DTC.

Histology is more ιmportant than persistent anti-Tg antibodies for progression of differentiated thyroid cancer

CONTEXT

Anti-thyroglobulin antibodies (anti-Tg), present in 20%-25% of differentiated thyroid cancer (DTC) patients, interfere with thyroglobulin measurements posing a challenge in the follow-up.

OBJECTIVES

The aim of this study was to identify clinical-histological factors that may affect anti-Tg persistence and disease outcome in DTC with positive anti-Tg.

METHODS

We retrospectively studied 234 DTC patients, with positive anti-Tg at diagnosis (females: 82.1%, age at diagnosis: 46.0 ± 14.4 yrs, median follow-up: 5 yrs (1.5-32 yrs). 221/234 (94.4%) received radioiodine (RAI) ablation. Patients were divided into two subgroups: those whose anti-Tg became undetectable (anti-Tg-NEG) and those whose anti-Tg remained positive (anti-Tg-POS) at the end of the follow-up period.

RESULTS

Anti-Tg-POS patients (n = 80, 34.2%) compared to anti-Tg-NEG (n = 154, 65.8%) had more frequently lymph node infiltration (36.3% vs 20.1%, P = .01), extrathyroidal extension (ETE, 35.0% vs 22.1%, P = .04), poorly differentiated DTC and increased tumour size (P ≤ .004). They received higher total RAI dose (P < .001). In most cases, additional RAI administration and/or additional surgeries did not lead to anti-Tg elimination. These had more frequently structural disease persistence/progression compared to anti-Tg-NEG (remission: 78.8% vs 95.5%, persistence: 13.8% vs 3.9%, progression: 7.5% vs 0.6%, P < .001). In Kaplan-Meier analysis, the probability of disease progression was higher in anti-Tg-POS. In Cox proportional hazard analysis, the predictors of disease progression were size (P = .002) and ETE (P = .006).

CONCLUSIONS

Worse histological features are more frequent in patients with anti-Tg persistence during follow-up. Further additional RAI administration and/or surgeries do not affect anti-Tg elimination in most cases. Anti-Tg persistence correlates with structural persistence although tumour size and extrathyroidal extension are the main predictors of disease progression.

Long-term outcome of differentiated thyroid cancer in children and young adults: risk stratification by ATA criteria and assessment of pre-ablation stimulated thyroglobulin as predictors of disease persistence

PURPOSE

Differentiated thyroid cancer (DTC) has an increasing incidence in childhood and adolescence but long-term outcome data are limited. We aimed to identify possible risk factors associated with disease persistence, with special focus on the usefulness of ATA risk stratification system and pre-ablation stimulated thyroglobulin (Tg) levels.

METHODS

We retrospectively studied 103 patients, 79 females (76.7%), aged 15.6 ± 3.2 years (range 5-21 years) who underwent total thyroidectomy for DTC. Patients were classified by ATA risk stratification criteria as low, intermediate, and high risk for recurrence. All, except five with papillary microcarcinoma, received radioactive iodine (RAI) treatment.

RESULTS

At diagnosis, 44.7% of patients had cervical lymph node and 7.8% pulmonary metastases. Amongst the 72 patients with long-term follow-up data, 31.9% had persistent disease. Lymph node as well as pulmonary metastases and increased pre-ablation stimulated thyroglobulin (Tg) levels were associated with persistent disease. The risk of persistent disease was significantly higher in both the intermediate- (OR 17.95; 95% CI 2.66-120.94, p < 0.01) and high-risk (OR 17.65; 95% CI 4.47-69.74, p < 0.001) groups. ROC curve analysis showed that a pre-ablation Tg level higher than 14 ng/ml had a sensitivity of 94.7% to predict persistence, corresponding to a positive (PPV) and negative predictive values (NPV) of 66.7% and 93.8%, respectively.

CONCLUSIONS

ATA risk stratification was validated in our population of children and young adults with DTC. Moreover, pre-ablation stimulated Tg levels of <14 ng/ml were associated with a low risk of long-term persistence and may therefore serve as a marker to identify patients who may need less intensive surveillance.

DKA cases over the last three years: has anything changed?

BACKGROUND

Diabetic ketoacidosis (DKA) has been related mainly to type 1 diabetes mellitus (T1DM). However, it is not solely related to T1DM. The purpose of this study was to assess the prevalence of DKA among type 1 and type 2 patients with diabetes mellitus, who were hospitalized in our Clinic due to DKA, as well as to determine the etiology beyond DKA.

PATIENTS AND METHODS

A cohort of 109 patients with DKA, 17-86 years of age, who were hospitalized in the Department of Endocrinology, Diabetes and Metabolism of our hospital between 2015 and 2017, were included in the study.

RESULTS

Among the 109 patients, 50 (45.9%) had mild DKA, 48 (44.1%) had moderate DKA, whereas 11 patients (10%) had severe DKA. Sixty-five patients (60%) developed DKA as the first manifestation of T1DM, 30 patients (27%) developed DKA in the context of type 2 diabetes (T2DM), mainly due to the co-existence of serious infections, 11 patients (10%) had T1DM, but had omitted their insulin dosages, and 3 patients (3%) developed DKA due to unknown reasons.

CONCLUSIONS

Most patients with DKA presented with mild and moderate DKA and only a minority presented with the severe form of the disease. The etiology of DKA was mainly T1DM and less frequent uncontrolled T2DM, usually due to the co-existence of severe infections, while only in a tiny minority, the causes remained unidentifiable.

Progression of Albuminuria Among Patients with Type 1 Diabetes Mellitus: A Long Term Observational Follow-up Study

BACKGROUND

The purpose of the present study was to determine whether patients with DM1 have shown improvement, stabilization or deterioration of their urine albumin excretion levels during a close follow-up.

PATIENTS AND METHODS

A cohort of 84 patients, 18-76 years of age, a median duration of diabetes of 24 years (1-50 years) and a median follow-up duration of 12 years (1-37 years) were included in the study.

RESULTS

Among the 84 patients for whom we had UAE levels at the beginning and by the end of the study, mean glycosylated hemoglobin was statistically significantly decreased during the follow-up period, from 8.02±2.04-7.06±1.05% (p=0.036). Normoalbuminuria was present in 66 patients and remained so in 56 patients while 9 patients progressed to microalbuminuria and one patient to macroalbuminuria by the end of the study. Microalbuminuria was present in 15 patients: regression was observed in 8 patients, and progression in one patient. Regression of macroalbuminuria to microalbuminuria was noted in one patient and to normoalbuminuria was noted in one participant, too.

CONCLUSIONS

Improvement of glycemic control with close monitoring of DM1 patients together with the appropriate use ACE or AT2 inhibitors and statins, seems to exert nephron-protective potential and to delay or even reverse the presence of micro/macroalbuminuria. This long term follow-up study has demonstrated a statistically significant increase in serum HDLcholesterol levels. The study also revealed that intensively treated diabetes patients may show reductions in serum ALP levels. Whether this finding is related to diabetic nephropathy, NAFLD, or diabetic hepatosclerosis remains to be assessed in future trials.

Autoimmune thyroiditis in patients with type 1 diabetes mellitus: A long-term follow-up study

AIMS

In type 1 diabetes mellitus and autoimmune thyroiditis, there seems to be common genetic loci. The purpose of the present study was to determine whether patients with type 1 diabetes had increased prevalence of autoimmune thyroiditis, and which factors were influencing the co-existence of these two clinical entities.

PATIENTS AND METHODS

A cohort of 256 patients, 18-79 years of age, a median duration of diabetes of 20 years and a mean follow-up duration of 13 years were included in the study.

RESULTS

Of the 256 patients with type 1 diabetes, 150 participants (58.6%) were women and 106 (41.4%) were men. One hundred and fifty-nine patients (64.6%) did not have autoimmune thyroiditis, whereas 97 (35.4%) had autoimmune thyroiditis, as was documented by the presence of anti-thyroid antibodies (anti-TPO and/or anti-TG). Of the 97 patients with both diabetes type 1 and autoimmune thyroiditis, 64 (66%) were women and 33 (34%) were men. Among the 97 patients who had both diabetes type 1 and autoimmune thyroiditis, 87 had abnormal levels of both anti-TPO and anti-TG, while 7 patients had subnormal levels of solely anti-TPO and only 3 patients had abnormal levels of only anti-TG.

CONCLUSIONS

There was a slightly higher prevalence of autoimmune thyroiditis among our patients with type 1 diabetes mellitus. Also, female sex was predominant, when compared to male sex, among the adult participants of this study. Therefore, regular screening of thyroid function and thyroid autoantibodies may be suggested for all patients with type 1 diabetes.

Thyroid-stimulating hormone is not the primary regulator of thyroid development in euthyroid children and adolescents living in an iodine-replete area

OBJECTIVES

It is known that there are multiple factors which can affect thyroid gland development during childhood and adolescence. Our aim was to investigate this issue by examining the relationships between age, sex, several anthropometric parameters, pubertal status, thyroid function tests, and iodine intake status with thyroid volume (TV) in children and adolescents.

STUDY DESIGN

This was a cross-sectional field study conducted in 11 representative cities and villages of Uzbekistan. Six hundred and ten children and adolescents participated. Anthropometric indices and TV were estimated. In addition, thyroid function tests (TFTs) and urinary iodine excretion (UIE) measures were obtained.

RESULTS

Median UIE was 151 μg/L, thus the studied areas were iodine-sufficient. TFTs fluctuated in both genders during childhood and adolescence and the thyroid growth spurt was observed, in both sexes, at the ages of 12 and 13 years, which coincided with the age of menarche in girls. Thyroid volume was positively correlated with body surface area (BSA) (r = 0.800, p < 0.001), age (r = 0.780, p < 0.001), fat-free mass (FFM) (r = 0.797, p < 0.001) and negatively correlated with serum TSH (r = -0.154, p = 0.05). No association between thyroid volume and UIE was observed.

CONCLUSIONS

In euthyroid children and adolescents living in iodine-replete areas, thyroid gland development appears to follow the pattern of linear growth and displays a growth spurt at the onset of puberty, probably due to the abrupt increase of circulating sex steroids. At this age, TSH does not appear to be the main regulator of thyroid gland development.

Monitoring of patients with type 2 diabetes and nephropathy in a specialized diabetic nephropathy clinic seems to be beneficial

BACKGROUND

The purpose of this study was to evaluate the outcome of DM2 patients with nephropathy when they are under surveillance of a joined clinic run by endocrinologists & nephrologists.

PATIENTS AND METHODS

A cohort of 106 patients with DM2, 42-83 years of age, and eGFR < 60 ml/min/m² were included. Age, sex, duration of diabetes, duration of attending our clinic, smoking habits, BMI, data regarding ischemic heart disease and induction of hemodialysis, urine albumin excretion (UAE) levels, eGFR (MDRD equation) and values of various biochemical parameters were recorded too. Follow-up period ranged from one to 25 years. Paired samples t-test and non-parametrical Kruskal-Wallis test were used for the analyses of the data.

RESULTS

Fifty percent of patients had no further progression, 25.9% improvement, while 24.1% had worsening of the UAE levels. During the follow-up in the joined clinic, there was a smaller than the expected from the medical literature decrease in median eGFR, i.e. 2,3 ml/min/m² and a statistically significant improvement in glycosylated hemoglobin levels from 8.0% to 7.4% (p = 0.016). Time in years of follow-up in the joined clinic of our hospital appeared to be the most significant factor in the improvement or stabilization against deterioration of the UAE levels (p = 0.018).

CONCLUSIONS

Close follow-up of DM2 patients with eGFR < 60 ml/min/m² has resulted in a minor annual eGFR decrease. Monitoring of these patients in a specialized diabetic nephropathy clinic is beneficial for this group of patients for delaying the occurrence of end-stage renal disease.

Differentiated thyroid cancer in childhood: a literature update

Differentiated thyroid cancer in childhood is rare. Apart from family history, radiation exposure is a major risk factor. Although its clinical course is quite aggressive with higher rates of lymph node and pulmonary metastases as compared to adults, the final outcome tends to be favorable with mortality rates less than 2%. We herein review the clinical picture, genetic background response to treatment and recurrence rates of differentiated thyroid cancer in children and young adolescents are thoroughly reviewed and the main differences with adult differentiated thyroid cancer are highlighted.

X-linked adrenoleukodystrophy: are signs of hypogonadism always due to testicular failure?

We present the clinical and hormonal findings of a young male with X-linked adrenoleukodystrophy (X-ALD), with special emphasis on the biochemical and clinical pattern of hypogonadism. A patient, with primary adrenal insufficiency since the age of 5 years, developed progressive neurological symptoms at the age of 29. Diagnosis of X-ALD was established by elevated serum very long chain fatty acids (VLCFAs) and genetic testing. His sexual body hair was sparse. Hormonal investigations revealed normal testosterone and inappropriately elevated LH levels. Androgen receptor gene analysis was negative for mutations or polymorphic variants associated with decreased receptor activity. Signs of hypogonadism in patients with confirmed X-ALD are not exclusively due to primary testicular failure. Tissue specific androgen resistance represents an alternative possibility. Since no loss-of-function mutations were detected in the androgen receptor, it is speculated that the patient's androgen resistance could be part of a functional defect mediated through VLCFA accumulation at the testosterone receptor and/or post-receptor levels.

High prevalence of exon 8 G533C mutation in apparently sporadic medullary thyroid carcinoma in Greece

OBJECTIVE

Genetic screening for ret mutation has become routine practice in the evaluation of medullary thyroid carcinoma (MTC). Approximately 25% of these tumours are familial, and they occur as components of the multiple endocrine neoplasia type 2 syndromes (MEN 2A and 2B) or familial MTC. In familial cases, the majority of mutations are found in exons 10, 11, 13, 14 or 15 of the ret gene. A rare mutation involving exon 8 (G533C) has recently been reported in familial cases of MTC in Brazil and Greece; some of these cases were originally thought to be sporadic. The aim of this study was to re-evaluate a series of sporadic cases of MTC, with negative family history, and screen them for germline mutations in exon 8.

DESIGN AND PATIENTS

Genomic DNA was extracted from peripheral lymphocytes in 129 unrelated individuals who had previously been characterized as 'sporadic' based on the negative family history and negative screening for ret gene mutations. Samples were analysed in Applied Biosystems 7500 real-time PCR and confirmed by sequencing.

MEASUREMENTS AND RESULTS

The G533C exon 8 mutation was identified in 10 of 129 patients with sporadic MTC. Asymptomatic gene carriers were subsequently identified in other family members.

CONCLUSION

In our study, we found that 7·75% patients with apparently sporadic MTC do carry G533C mutation involving exon 8 of ret. We feel that there is now a need to include exon 8 mutation screening in all patients diagnosed as sporadic MTC, in Greece.

Health status of Greek thyroid cancer patients after radioiodine administration compared to a demographically matched general population sample

The impact of radioiodine-131 ((131)I) treatment on thyroid cancer patients' quality of life is controversial. We conducted a cross-sectional study of 60 patients aged 18-73 years old who had recently underwent near total thyroidectomy due to papillary thyroid cancer and were scheduled for (131)I treatment. On admission to our department, prior to (131)I administration patients underwent clinical and laboratory investigation including routine clinical biochemistry, thyroid stimulating hormone (TSH) and thyroglobulin (Tg) measurements. Health-related quality of life (HRQoL) was estimated by the SF-36 Health Survey a generic instrument which consisted from eight scales (four for physical and four for mental health). After (131)I administration patients were discharged and approximately 6 months later they were re-evaluated. Our results showed that HRQoL in thyroid cancer patients receiving (131)I treatment is independent of age/gender and thyroid cancer-related variables. All SF-36 scales significantly improved six months after administration (P<0.05). Compared to Greek general population, before (131)I administration all scales were significantly lower (P<0.05). Six months post (131)I administration, scales were significantly lower for physical functioning (P=0.02), physical role (P=0.01), social functioning (P=0.03) and emotional role limitations (P=0.04), whereas the remaining SF-36 scales were comparable to the general population. In conclusion, hypothyroidism and anxiety for the outcome of their disease before (131)I treatment exert a negative impact on thyroid cancer patients. Quality of life improvement post (131)I is mainly attributed to the resumption of euthyroidism and familiarization with treatment and followup procedures rather than (131)I treatment itself. There was no significant difference between patients receiving lower (2220-3700MBq) and higher (3700-7400MBq) dosage.

Treating iodine deficiency: long-term effects of iodine repletion on growth and pubertal development in school-age children

BACKGROUND

Iodine deficiency (ID) is still a major universal health problem. Iodine deficiency disorders (IDDs) affect people of all ages, among whom the most vulnerable are children and adolescents. The aim of the present study was to assess the long-term effects on growth and pubertal development of correcting severe ID in areas of Azerbaijan between 1999 and 2000.

METHODS

Iodized oil was administered orally to 293,000 children, aged 6-16 years. Among those, 364 children were randomly selected and were examined 1 year before the administration of iodized oil (Group I-neg, iodine negative) and 295 children (Group I-Rx, iodine treated) were examined 4 years (Group I-R x 4, iodine treated 4 years later; n = 173) or 5 years (Group I-R x 5, iodine treated 5 years later; n = 122) after the last dose of iodide.

RESULTS

In Group I-neg the median urine iodine concentration (UIC) (mcg/L) was 36 (mean: 36.272 +/- 11.036) and increased significantly (p < 0.001) in Group I-R x 4: 188 (mean: 230.969 +/- 155.818) and in Group I-R x 5: 175 (mean: 201.176 +/- 130.369). The prevalence of goiter was 99% in Group I-neg and 2% in Group I-R x 4. Children in Group I-Rx had a greater standard deviation score (SDS) for height (-0.1364 +/- 1.279, n = 294) than children in Group I-neg (-0.5019 +/- 1.17, n = 363) (p < 0.001, t = -3.817), which was more significant for boys. SDS for weight was similar in both groups (Group I-neg: -0.17 +/- 0.78, n = 363; Group I-Rx: -0.115 +/- 0.917, n = 294). The rate of puberty development as judged by the development of breast and pubic hair was normalized in both sexes after the correction of ID.

CONCLUSIONS

Our results demonstrate that long-term correction of severe ID leads to sustained improvement of linear growth accompanied by a normalization of the time of onset of pubertal development for both sexes.

Iodine 131 treatment for differentiated thyroid carcinoma in patients with end stage renal failure: dosimetric, radiation safety, and practical considerations

BACKGROUND

Iodine 131 ablation following total thyroidectomy is considered an indispensable element of successful treatment of differentiated thyroid carcinoma (Dtc). because of the essential role of the kidneys in iodine clearance, (131)I therapy of Dtc in patients with end stage renal disease, particularly those maintained on haemodialysis, present a number of special features: the (131)I activity needs to be modified, the haemodialysis sessions need to be adjusted at the time of (131)I therapy, and there are radiation safety considerations during dialysis. there is considerable controversy over these crucial questions in the reports published so far in the literature, which concern a total of fourteen patients.

OBJECTIVE

the aim of our study was to present our experience on (131)I treatment of 5 Dtc patients with end stage renal disease.

DESIGN

the data of 5 Dtc patients with end stage renal disease, treated with (131)I, were retrospectively analysed; four cases were treated for remnant ablation and one for locoregional progression. In order to allow for prolonged plasma clearance of (131)I, we used a lower activity of radioiodine, reduced to roughly 40-50% of the empirically calculated activity used for normal individuals; dialysis sessions were performed immediately before and at 48 hours after (131)I administration. All patients had (131)I retention measurements performed post dialysis; in two of them some additional measurements such as iodine clearances were also performed.

RESULTS

None of the patients experienced any short-term side effects, while they all had undetectable thyroglobulin levels on the first post therapy evaluation off thyroxine. (131)I elimination in the first haemodialysis was about 60%. staff incidental exposure and (131)I contamination were insignificant.

CONCLUSIONS

On the basis of our experience, an empiric activity of 40-50% of that used for normal individuals appears to be effective as well as safe. these encouraging findings are discussed in relation with other reports in the literature.

Long term thyroid function after (131)I treatment for toxic adenoma

Radioactive iodine is a widely used treatment for hyperthyroidism caused by solitary autonomously functioning thyroid nodule (toxic adenoma). The aim of this retrospective analysis is to report the long term effects of this therapy on the thyroid function of patients with toxic adenoma treated in our department. Between 1968 and 1996, 160 patients received a single dose of (131)I (range 25-40 mCi) for hyperthyroidism caused by toxic adenoma. In 126 of these (110 females, 26 males), follow-up was feasible either in our Endocrine Outpatient Clinic or through correspondence. The mean observation period was 5.3 years (range 1-21 years, median 4.0). Post treatment evaluation revealed that: a) 57 patients became euthyroid and remained free of disease up to the last visit (mean observation period 5.76+/-0.52 years, range 1-21 years, median 5 years), b) 69 patients developed hypothyroidism, all within 1 to 12 months (5.9+/-0.49 months), c) persistence or recurrence of the disease (ie. thyrotoxicosis) was not observed, d) the (131)I dose, or the (131)I pretreatment TSH levels were not different between patients who developed hypothyroidism and those who became and remained euthyroid.

CONCLUSION

131I administration in the above-mentioned dose to patients with toxic adenoma: a) was a safe and very effective therapy, and b) led to hypothyroidism which developed within the first year after (131)I administration in 55% of the patients.

Differentiated thyroid cancer: a retrospective analysis of 832 cases from Greece

OBJECTIVE

To analyse the initial manifestations, pathological findings, therapy, outcome and prognostic factors in patients with papillary and follicular carcinoma.

PATIENTS

832 patients with well differentiated thyroid carcinoma managed in our department during a period of 30 years (1965-1995). Follow-up data were available for 609 patients for a mean of 5.5 years (range 1-38 years), the remainder having been lost to follow-up.

RESULTS

The patients were 677 (81%) with papillary and 155 with follicular carcinoma. They were predominantly female (75%), presenting mainly with a single nodule (53%), while at the time of diagnosis 72% had intrathyroidal carcinomas (class I), 17% had nodal metastases (class II), 7% soft tissue invasion (class III) and 4% distant metastases (class IV). Fifty-five percent of the patients had a complete thyroidectomy (36% had a near total or total thyroidectomy and 19% near total or total thyroidectomy plus block dissection), 2.6% received external radiotherapy and 94% had radioactive iodine as part of the treatment of the original disease. Kaplan-Meier survival analysis was used to calculate both cancer related mortality and disease free survival in the patients followed-up. Although mortality (21 cancer-related deaths) was slightly higher for follicular than papillary carcinoma (10% vs. 5% and 16% vs. 10% in 10- and 15-year survival, respectively) the difference was not statistically significant. Extent of disease at diagnosis, male sex, tumour size and age > 60 years affected probability of cancer death. Cox's proportional hazard regression analysis for disease free survival showed that adverse independent prognostic factors were, for papillary carcinoma, male sex, class II or higher, tumour size > 1 cm and age > 60 years, while for follicular, class III or higher, size > 4 cm and age > 40 years.

CONCLUSIONS

We conclude that there is a higher prevalence of follicular carcinoma in our country probably due to a moderate degree of iodine deficiency still existing in Greece. Age and extent of disease at diagnosis were important prognostic factors affecting morbidity and mortality, whereas sex, tumour features and histological type were of minor importance. All these prognostic factors and their relative importance should be taken in consideration in the management of this disease.