Sociation with longer time to thyroid cancer diagnosis. doi:10.1371/journal.pone.0127354.tPLOS ONE | DOI:10.1371/journal.pone.0127354 May 28,7 /Thyroid FNA and Thyroid Cancer Diagnosisthe proportion of non-diagnostic specimens increased with greater cystic components of the nodules [30]. When repeated aspiration was performed, up to 38 of the initial non-diagnostic fpsyg.2017.00209 nodules may remain non-diagnostic [29]. Furthermore, the malignancy rates were 11.4 and 11.9 among cases with initial non-diagnostic and indeterminate fine needle aspiration biopsies in one study [31]. In short, a proportion of patients are likely to experience delayed or missed diagnoses if only one aspiration is done. Compared with single FNAB, sequential biopsy was reported to increase the diagnostic sensitivity by 13.8 and specificity by 6.2 , and reduce the false positive/negative results by 14.2 [32]. Hence, repeated aspirations seem necessary to improve the overall diagnostic accuracy. This may be crucial for physicians to consider for possible false-negative results in thyroid aspiration and to highlight the importance of regular follow-up. There is still no consensus on the optimal timetable for repeat aspiration of a thyroid nodule [13, 14, 33]. In initially benign cases, some suggest routine repeat biopsy during subsequent follow-up [13, 34]. Others recommend repeat aspiration only when there is evidence of nodule growth or suspicious sonographic features [14, 33]. Using Kaplan-Meier survival analysis, a higher aspiration frequency is significantly associated to shorter AZD-8835 chemical information median time to thyroid cancer diagnosis. Although such observations may partly be the result of patient and physician selection, the MGCD516 supplement finding may provide a better understanding of the approximate time lag from different aspiration intervals. Using Cox regression model in adjusting for confounders, the same results are revealed. These support the more aggressive approach of routine repeated biopsy mentioned in the American Association of Clinical Endocrinologists (AACE), Associazione Medici Endocrinologi (AME), and European Thyroid Association (ETA) guidelines [13]. Nonetheless, the ideal re-aspiration timeframe warrants further investigation. Older age and male sex are established risk factors for malignant thyroid nodule and worse wcs.1183 thyroid cancer prognoses [9, 13, 35]. Male sex is also associated with larger tumor size and more advanced tumor stages [35?7]. These may presumably affect the physician’s management decisions, thereby leading to the earlier diagnoses in men and in the elderly in this study. In addition, after adjusting for the effects of the frequency of aspiration, an increased frequency of ultrasonography is also an independent prognostic factor for early diagnosis. In other words, high-resolution ultrasonography may provide additional benefits in the diagnosis of thyroid cancer and may serve as a substitute exam if routine repeat biopsy is not desired. The main strength of this research is its long-term nationwide evaluation of the overall diagnosis of thyroid cancer using aspiration biopsy. The longitudinal health insurance database in Taiwan allows researchers to trace persons over time and across hospitals, grounded on a population-based record. Hence, the results possess superior reliability and generalizability than single-center studies. However, the current study also has limitations. First, it is unable to specify the exact thyroid cancer subtype. Taiwan’s thyroid cancer d.Sociation with longer time to thyroid cancer diagnosis. doi:10.1371/journal.pone.0127354.tPLOS ONE | DOI:10.1371/journal.pone.0127354 May 28,7 /Thyroid FNA and Thyroid Cancer Diagnosisthe proportion of non-diagnostic specimens increased with greater cystic components of the nodules [30]. When repeated aspiration was performed, up to 38 of the initial non-diagnostic fpsyg.2017.00209 nodules may remain non-diagnostic [29]. Furthermore, the malignancy rates were 11.4 and 11.9 among cases with initial non-diagnostic and indeterminate fine needle aspiration biopsies in one study [31]. In short, a proportion of patients are likely to experience delayed or missed diagnoses if only one aspiration is done. Compared with single FNAB, sequential biopsy was reported to increase the diagnostic sensitivity by 13.8 and specificity by 6.2 , and reduce the false positive/negative results by 14.2 [32]. Hence, repeated aspirations seem necessary to improve the overall diagnostic accuracy. This may be crucial for physicians to consider for possible false-negative results in thyroid aspiration and to highlight the importance of regular follow-up. There is still no consensus on the optimal timetable for repeat aspiration of a thyroid nodule [13, 14, 33]. In initially benign cases, some suggest routine repeat biopsy during subsequent follow-up [13, 34]. Others recommend repeat aspiration only when there is evidence of nodule growth or suspicious sonographic features [14, 33]. Using Kaplan-Meier survival analysis, a higher aspiration frequency is significantly associated to shorter median time to thyroid cancer diagnosis. Although such observations may partly be the result of patient and physician selection, the finding may provide a better understanding of the approximate time lag from different aspiration intervals. Using Cox regression model in adjusting for confounders, the same results are revealed. These support the more aggressive approach of routine repeated biopsy mentioned in the American Association of Clinical Endocrinologists (AACE), Associazione Medici Endocrinologi (AME), and European Thyroid Association (ETA) guidelines [13]. Nonetheless, the ideal re-aspiration timeframe warrants further investigation. Older age and male sex are established risk factors for malignant thyroid nodule and worse wcs.1183 thyroid cancer prognoses [9, 13, 35]. Male sex is also associated with larger tumor size and more advanced tumor stages [35?7]. These may presumably affect the physician’s management decisions, thereby leading to the earlier diagnoses in men and in the elderly in this study. In addition, after adjusting for the effects of the frequency of aspiration, an increased frequency of ultrasonography is also an independent prognostic factor for early diagnosis. In other words, high-resolution ultrasonography may provide additional benefits in the diagnosis of thyroid cancer and may serve as a substitute exam if routine repeat biopsy is not desired. The main strength of this research is its long-term nationwide evaluation of the overall diagnosis of thyroid cancer using aspiration biopsy. The longitudinal health insurance database in Taiwan allows researchers to trace persons over time and across hospitals, grounded on a population-based record. Hence, the results possess superior reliability and generalizability than single-center studies. However, the current study also has limitations. First, it is unable to specify the exact thyroid cancer subtype. Taiwan’s thyroid cancer d.