Frontiers in thyroid cancer: December 2009

Differentiated Thyroid Cancer: A Health Economic Review

Simple Summary

This review reflects on health economic considerations associated with the increasing diagnosis and treatment of differentiated thyroid cancer. Analysis of different relevant health economic topics, such as overdiagnosis, overtreatment, surgical costs, and costs of follow-up are being addressed. Several unanswered research questions such as optimising molecular markers for diagnosis, active surveillance of primary tumours, and improved risk stratification and survivorship care all influence future healthcare expenditures.

Abstract

The incidence of differentiated thyroid cancer (DTC) is rising, mainly because of an increased detection of asymptomatic thyroid nodularity revealed by the liberal use of thyroid ultrasound. This review aims to reflect on the health economic considerations associated with the increasing diagnosis and treatment of DTC. Overdiagnosis and the resulting overtreatment have led to more surgical procedures, increasing health care and patients’ costs, and a large pool of community-dwelling thyroid cancer follow-up patients. Additionally, the cost of thyroid surgery seems to increase year on year even when inflation is taken into account. The increased healthcare costs and spending have placed significant pressure to identify potential factors associated with these increased costs. Some truly ground-breaking work in health economics has been undertaken, but more cost-effectiveness studies and micro-cost analyses are required to evaluate expenses and guide future solutions.

PREDICTIVE VALUE OF SOMATIC MUTATIONS FOR THE DEVELOPMENT OF MALIGNANCY IN THYROID NODULES BY CYTOPATHOLOGY

OBJECTIVE

The purpose of our prospective longitudinal study was to evaluate the predictive efficacy of genetic testing for malignancies in fine-needle aspiration biopsy samples that are cytologically benign at the time of biopsy.

METHODS

A total of 779 aspirated cytological samples collected from thyroid nodules of 626 patients were included in a 3-year follow-up study. Consecutive patients with cytologically benign thyroid nodules by the Bethesda System for Reporting Thyroid Cytopathology were enrolled in the study. At enrollment, somatic 1-point nucleotide polymorphisms of BRAF and RAS family genes were tested by melting-point analysis, while RET/PTC and PAX8/PPAR-gamma rearrangements were examined by real-time polymerase chain reaction. The genetic test was considered to be positive if a somatic mutation was found. Malignant cytopathologic diagnoses were confirmed by histopathology.

RESULTS

In samples collected from 779 thyroid nodules, there were 39 BRAF, 33 RAS mutations, and 1 RET/PTC rearrangements found at the beginning of the study. No PAX8/PPAR-gamma rearrangement was identified. There were 52 malignant thyroid tumors removed during follow-up, out of which 24 contained a somatic mutation. The specificity of the presence of somatic mutations for malignancies was as high as 93.3%, and sensitivity was 46.2%. The negative predictive value of genetic testing reached 96.0%.

CONCLUSION

Our results show that our set of genetic tests can predict the appearance of malignancy in benign thyroid nodules (at the beginning of follow-up) with high specificity and strong negative predictive value.

ABBREVIATIONS

BRAF = v-raf murine sarcoma viral oncogene homolog B1 FLUS = follicular lesion of undetermined significance FNAB = fine-needle aspiration biopsy FTC = follicular thyroid carcinoma HRAS = homologous to the oncogene from the Harvey rat sarcoma virus KRAS = homologous to the oncogene from the Kirsten rat sarcoma virus NRAS = first isolated from a human neuroblastoma/neuroblastoma RAS = viral oncogene homolog PAX8 = paired box 8 PCR = polymerase chain reaction PPAR-gamma = peroxisome proliferator-activated receptor gamma PTC = papillary thyroid carcinoma RAS = rat sarcoma RET = rearranged during transfection tyrosine-kinase proto-oncogene SM = somatic mutation SNP = single-nucleotide polymorphism.

BRAF(V600E) Is Correlated with Recurrence of Papillary Thyroid Microcarcinoma: A Systematic Review, Multi-Institutional Primary Data Analysis, and Meta-Analysis

BACKGROUND

Given the increasing incidence of papillary thyroid carcinoma despite stable disease-specific mortality rates, the potential for the disease to reoccur is a key outcome to predict. The BRAF(V600E) mutation has been associated with recurrent disease in larger tumors. However, its correlation in papillary thyroid microcarcinoma (PTMC) is not clear in individual series.

METHODS

The MEDLINE, EMBASE, Web of Science, and Cochrane databases were searched for studies including patients with PTMC undergoing initial surgical treatment. Studies with at least two years of follow-up, BRAF genotyping (the comparator), and recurrence as an outcome were included, as were unpublished primary data on 485 patients from two institutions. The metameter analyzed was odds ratio (OR) for recurrence between patients with BRAF(V600E) versus BRAF wild type (BRAFwt).

RESULTS

The initial search identified 431 references. After screening of the abstracts for inclusion, 44 manuscripts were reviewed in full by two independent reviewers. Four published studies and primary data from two institutional cohorts were included in the final analysis. A meta-analysis of 2247 PTMC patients revealed that patients with a BRAF(V600E) mutation had a higher likelihood for recurrence (odds ratio 2.09 [confidence interval 1.31-3.33], p = 0.002).

CONCLUSIONS

This meta-analysis shows that BRAF mutational status correlates with recurrence of PTMCs, highlighting the potential utility of genotyping in preoperative and postoperative planning. BRAF mutation may be helpful in risk-stratifying patients with PTMC for surgical management versus observation.

Annual financial impact of well-differentiated thyroid cancer care in the United States

BACKGROUND

Well-differentiated thyroid cancer (WDTC) is a prevalent disease, which is increasing in incidence faster than any other cancer. Substantial direct medical care costs are related to the diagnosis and treatment of newly diagnosed patients as well as the ongoing surveillance of patients who have a long life expectancy. Prior analyses of the aggregate health care costs attributable to WDTC in the United States have not been reported.

METHODS

A stacked cohort cost analysis was performed on the US population from 1985 to 2013 to estimate the number of WDTC survivors in 2013. Incidence rates, and cancer-specific and overall survival were based on Surveillance, Epidemiology, and End Results (SEER) data. Current and projected direct medical care costs attributable to the care of patients with WDTC were then estimated. Health care-related costs and event probabilities were based on Medicare reimbursement schedules and the literature.

RESULTS

Estimated overall societal cost of WDTC care in 2013 for all US patients diagnosed after 1985 is $1.6 billion. Diagnosis, surgery, and adjuvant therapy for newly diagnosed patients (41%) constitutes the greatest proportion of costs, followed by surveillance of survivors (37%), and nonoperative death costs attributable to thyroid cancer care (22%). Projected 2030 costs (in 2013 US dollars) based on current incidence trends exceed $3.5 billion.

CONCLUSIONS

Health care costs of WDTC are substantial. Unlike other cancers, the majority of the cost is incurred in the initial and continuing phases of care. With the projected increasing incidence, population, and survival trends, costs will continue to escalate.