Next-generation sequencing in residual liquid-based cytology specimens for cancer genome analysis

Advances in diagnostic liquid-based cytology

Liquid-based cytology (LBC) has changed the landscape of gynaecological cytology. A growing demand exists for LBC in diagnostic cytology, particularly for ancillary testing, such as immunocytochemistry and molecular testing. Ancillary testing solely based on conventional preparation (CP) methods remains challenging. Recently, the increased demand for specialist testing and minimally invasive techniques, such as endoscopic ultrasonography fine-needle aspiration, to obtain cellular samples has led to an increasing demand for ancillary testing on cytology LBC supernatant, slides and cell block (CB). This facilitates the diagnosis and prognosis in cytology samples enabling personalized treatment. An understanding of the history and future prospects of LBC is crucial for its application in routine diagnostics by cytopathologists and cytotechnologists. In this review, we initiated an internet search using the keyword 'liquid-based cytology', and we conducted a literature review to discuss the usefulness of combined diagnosis of LBC and CP, immunocytochemistry and molecular testing and assessed the quality of nucleic acids in diagnostic LBC. High-quality and cell-rich diagnostic LBC surpassed the CP method alone in terms of reliability and versatility of ancillary testing in cytological diagnosis. Conclusively, diagnostic LBC lends itself to various new technologies and is expected to continue evolving with innovations in the future.

Using the DNA Integrity Number to Analyze DNA Quality in Specimens Collected from Liquid-Based Cytology after Fine-Needle Aspiration of Breast Tumors and Lesions

INTRODUCTION

Cancer genome analysis using next-generation sequencing requires adequate and high-quality DNA samples. Genomic analyses were conventionally performed using formalin-fixed paraffin-embedded sections rather than cytology samples such as cell block or smear specimens. Specimens collected from liquid-based cytology (LBC) have the potential to be sources of high-quality DNA suitable for genetic analysis even after long-term storage.

METHODS

We collected breast tumor/lesion fractions from 92 residual LBC specimens using fine-needle aspiration (FNA) biopsy, including breast carcinoma (1 invasive carcinoma and 4 ductal carcinomas in situ), papillomatous lesion (5 intraductal papillomas), and fibroepithelial lesion (19 phyllodes tumors and 53 fibroadenomas) samples, and others (1 ductal adenoma, 1 hamartoma, 1 fibrocystic disease, and 7 unknown). DNA was extracted from all samples and subjected to DNA integrity number (DIN) score analysis.

RESULTS

Average DIN score collected from 92 LBC specimens was significantly higher score. In addition, high-quality DNA with high DIN values (7.39 ± 0.80) was successfully extracted more than 12 months after storage of residual LBC specimens.

CONCLUSION

Residual LBC specimens collected from FNA of the breast were verified to carry high-quality DNA and could serve as an alternate source for genetic analysis.

Aptamer-functionalized MOFs and AI-driven strategies for early cancer diagnosis and therapeutics

Metal-Organic Frameworks (MOFs) have exceptional inherent properties that make them highly suitable for diverse applications, such as catalysis, storage, optics, chemo sensing, and biomedical science and technology. Over the past decades, researchers have utilized various techniques, including solvothermal, hydrothermal, mechanochemical, electrochemical, and ultrasonic, to synthesize MOFs with tailored properties. Post-synthetic modification of linkers, nodal components, and crystallite domain size and morphology can functionalize MOFs to improve their aptamer applications. Advancements in AI and machine learning led to the development of nonporous MOFs and nanoscale MOFs for medical purposes. MOFs have exhibited promise in cancer therapy, with the successful accumulation of a photosensitizer in cancer cells representing a significant breakthrough. This perspective is focused on MOFs' use as advanced materials and systems for cancer therapy, exploring the challenging aspects and promising features of MOF-based cancer diagnosis and treatment. The paper concludes by emphasizing the potential of MOFs as a transformative technology for cancer treatment and diagnosis.

Study of Liquid-Based Cytology Using Next-Generation Sequencing as a Liquid Biopsy Application in Patients with Advanced Oncological Disease

In patients with advanced cancer, it is necessary to detect driver mutations and genetic arrangements. If a mutation is found, targeted therapy may become an option. However, in most patients with advanced cancer, obtaining material can be challenging, and these determinations must be made based on small biopsies or cytologic samples. We analyzed the ability of liquid-based cytology to determine the mutational status in patients with advanced cancer by next-generation sequencing. We studied cytologic samples from 28 patients between 1 January 2018 and 31 December 2022. All samples were processed by next-generation sequencing using the Oncomine^® Precision and Comprehensive Assay Panels for Solid Tumors. Eleven male and 17 female patients with a median age of 63.75 years were included. Clinical stage IV was predominant in 21 patients. Eleven patients died, and 17 survived. The DNA and RNA concentrations were 10.53 ng/µL and 13 ng/µL, respectively. Eleven patients showed actionable mutations, and 17 showed other genomic alterations. Liquid-based cytology can be used as a component of liquid biopsy, as it allows the identification of actionable mutations in patients with advanced oncological disease. Our findings expand the utility of liquid biopsy from different body fluids or cell aspirates.

Next-Generation Sequencing Analysis of Pancreatic Cancer Using Residual Liquid Cytology Specimens from Endoscopic Ultrasound—Guided Fine-Needle Biopsy: A Prospective Comparative Study with Tissue Specimens

This study evaluated the feasibility and clinical utility of liquid-based cytology (LBC) specimens via endoscopic ultrasound–guided fine-needle biopsy (EUS-FNB) for next-generation sequencing (NGS) of pancreatic cancer (PC). We prospectively evaluated the performance of DNA extraction and NGS using EUS-FNB samples obtained from PC. Thirty-three consecutive patients with PC who underwent EUS-FNB at our hospital were enrolled. DNA samples were obtained from 96.8% of the patients. When stratified with a variant allele frequency (VAF) > 10% tumor burden, the NGS success rate was 76.7% (n = 23) in formalin-fixed paraffin-embedded (FFPE), 83.3% (n = 25) in LBC, and 76.7% (n = 23) in frozen samples. The overall NGS success rate was 86.7% (n = 26) using FFPE, LBC, or frozen samples. The detection rates for the main mutated genes were as follows: 86.7% for KRAS, 73.3% for TP53, 66.7% for CDKN2A, 36.7% for SMAD4, and 16.7% for ARID1A. LBC had the highest median value of VAF (23.5%) for KRAS and TP53. PC mutation analysis using NGS was successfully performed using LBC compared with FFPE and frozen samples. This approach provides an alternative and affordable source of molecular testing materials.

A retrospective study of parotid gland tumors at a single institution

The aim of the present study was to analyze the clinical characteristics, surgical treatments and clinical outcome of patients with parotid gland tumors and to compare the results with those cited in the literature. A retrospective study was conducted in 140 patients (male, n=77; female, n=63) with parotid gland tumors who underwent parotidectomy at Hokuto Hospital Department of Otolaryngology-Head and Neck Surgery (Obihiro, Japan) between April 2007 and December 2021. Of the 140 patients enrolled, 118 (84.3%) patients had benign tumors, including 63 (45%) patients with pleomorphic adenomas and 43 (30.7%) patients with Warthin tumors, and 22 patients (15.7%) had parotid carcinoma. Comparison of the three groups of patients with parotid gland tumors indicated that pack years as an indicator of smoking status were significantly higher in patients with Warthin tumors than in those with parotid carcinomas (P=0.011) or pleomorphic adenoma (P<0.001). Fine-needle aspiration cytology (FNAC) was non-diagnostic for only 6 (4.3%) of 140 patients. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of FNAC by both conventional smear and liquid-based cytology (LBC) for parotid carcinomas were 70, 99, 93.3, 94.4 and 82.9%, respectively. Among the 22 patients with parotid carcinoma, extended total/total and superficial parotidectomy were performed in 10 (45%) and 11 (50%) cases, respectively. Total and selective neck dissection of the area from level II to I, II and III were performed in 6 (24%) and 7 (32%) patients, respectively. Postoperative radiotherapy (50 Gy) was performed in 15 (68%) patients. The overall survival (OS) and disease-free survival (DFS) rates at 5 years were 51.5 and 76.4%, respectively. Univariate analysis revealed that age >65 years was significantly associated with poorer 5-year OS (P<0.001) and DFS (P<0.001). Multivariate analysis revealed that an age of more than 65 years combined with high-grade histologic malignancy was associated with worse DFS (P=0.02; hazard ratio, 3.628; 95% confidence interval, 1.283-9.514). In conclusion, the clinical characteristics and treatment outcomes of parotid gland tumors were consistent with the results of previous reports. Smoking may be closely related to the pathogenesis of Warthin tumors. LBC potentially provides improved accuracy in FNAC.

Optimization of pre-analytical and analytical steps for DNA and RNA analysis of fresh cytology samples

BACKGROUND

Different cytology preparations can be used for molecular diagnostics, however the influence of pre-analytical and analytical steps on the results are not yet well defined. We aimed to determine optimal steps for efficient extraction of DNA and RNA from fresh cells for molecular diagnostics.

METHODS

MCF7 and FaDu human cell lines, were used as a model to determine fresh cells storage conditions (temperature: 25°C, 4°C, -20°C, -80°C; duration: 0 h, 4 h, 12 h, 24 h, 48 h) and optimal nucleic acids extraction method. Besides, the minimal number of total cells and minimal percentage of mutated cells needed for successful extraction of nucleic acids and subsequent determination of present mutation were evaluated.

RESULTS

Extraction of nucleic acids using spin columns yielded the highest quantity and quality of nucleic acids. Isolation of nucleic acids was feasible in all storage conditions, however higher temperature and longer duration of fresh cells storage were associated with lower quality of isolated nucleic acids and similar quantification cycle of housekeeping genes. Successful molecular testing was feasible with least 10⁴ cells, while specific mutation was detected in as low as 5% of mutated cells.

CONCLUSIONS

Our cell line model, mimicking fresh cytology samples, showed that quantity of extracted either DNA or RNA declined with higher temperatures and longer duration of storage but regardless of the storage conditions, we successfully detected both housekeeping genes and mutated gene using qPCR.

Evaluation and diagnostic value of next-generation sequencing analysis of residual liquid-based cytology specimens of pancreatic masses

BACKGROUND

Liquid-based cytology (LBC) is a widely used method for processing specimens obtained by endoscopic biopsy. This study evaluated next-generation sequencing (NGS) analysis of LBC specimens to improve the diagnostic accuracy of pancreatic lesions.

METHODS

Upon the diagnosis of a suspected pancreatic mass, LBC residues were used retrospectively. The quantity and quality of DNA extracted from residual LBC samples were evaluated, and an NGS analysis targeting 6 genes (KRAS, GNAS, TP53, CDKN2A, SMAD4, and PIK3CA) was performed.

RESULTS

The library was prepared from LBC specimens taken from 52 cases: 44 were successful, and 8 preparations failed. An analysis of DNA quantity and quality suggested that the success or failure of NGS implementation depended on both properties. The final diagnosis was achieved by a combination of the pathological analysis of the surgical excision or biopsy material with clinical information. Among the 33 cases of pancreatic ductal adenocarcinoma (PDAC), KRAS, TP53, CDKN2A, and SMAD4 mutations were identified in 31 (94%), 16 (48%), 3 (9%), and 2 (6%), respectively. Among the 11 benign cases, only a KRAS mutation was identified in 1 case. On the basis of NGS results, 18 of 33 PDACs (55%) were classified as highly dysplastic or more, and 10 of 11 benign lesions were evaluated as nonmalignant, which was consistent with the final diagnosis.

CONCLUSIONS

NGS analysis using LBC specimens from which DNA of appropriate quantity and quality has been extracted could contribute to improving the assessment of pancreatic tumor malignancies and the application of molecular-targeted drugs.

Evaluating Pancreatic and Biliary Neoplasms with Small Biopsy-Based Next Generation Sequencing (NGS): Doing More with Less

Simple Summary

Pancreatic cancer and cholangiocarcinoma are aggressive diseases mostly diagnosed at an advanced and inoperable stage. This review presents the value of next-generation sequencing (NGS) when performed on small biopsies—including fine-needle aspiration/biopsy samples, brushings, pancreatic juice and bile, and also blood—in the field of pancreatobiliary neoplasia. NGS could guide physicians while evaluating pancreatic solid and cystic lesions or suspicious biliary strictures, performing surveillance in high-risk individuals, or monitoring the disease and assessing prognosis in already diagnosed cancer patients. Evidence suggests that NGS performed on small biopsies is a robust tool for the diagnosis and pre-operative risk stratification of pancreatic and biliary lesions, whereas it also carries significant prognostic and therapeutic value. However, effective standardization of the pre-analytical and analytical assay parameters used for each clinical scenario is needed to fully implement NGS into routine practice and provide more personalized management in patients with suspected or established pancreatobiliary neoplasia.

Abstract

Pancreatic cancer and cholangiocarcinoma are lethal diseases mainly diagnosed at an inoperable stage. As pancreatobiliary surgical specimens are often unavailable for further molecular testing, this review aimed to highlight the diagnostic, prognostic, and therapeutic impact of next-generation sequencing (NGS) performed on distinct small biopsies, including endoscopic ultrasound fine-needle aspirations and biopsies of pancreatic solid and cystic lesions, biliary duct brushings, and also “liquid biopsies” such as the pancreatic juice, bile, and blood. NGS could clarify indeterminate pancreatic lesions or biliary strictures, for instance by identifying TP53 or SMAD4 mutations indicating high-grade dysplasia or cancer. It could also stratify pancreatic cystic lesions, by distinguishing mucinous from non-mucinous cysts and identifying high-risk cysts that should be excised in surgically fit patients, whereas the combination of cytology, elevated cystic CEA levels and NGS could improve the overall diagnostic accuracy. When NGS is performed on the pancreatic juice, it could stratify high-risk patients under surveillance. On the plasma, it could dynamically monitor the disease course and response to therapy. Notably, the circulating tumor DNA (ctDNA) levels have been associated with staging, grading, and survival. Lastly, NGS has shown potential in identifying potentially actionable molecular alterations. In conclusion, NGS applied on small biopsies could carry significant diagnostic, prognostic, and therapeutic value.

Molecular Evaluation of Endometrial Dedifferentiated Carcinoma, Endometrioid Carcinoma, Carcinosarcoma, and Serous Carcinoma Using a Custom-Made Small Cancer Panel

It is often difficult to histologically differentiate among endometrial dedifferentiated carcinoma (DC), endometrioid carcinoma (EC), serous carcinoma (SC), and carcinosarcoma (CS) due to the presence of solid components. In this study, we aimed to categorize these carcinomas according to The Cancer Genome Atlas (TCGA) classification using a small custom-made cancer genome panel (56 genes and 17 microsatellite regions) for integrated molecular diagnosis. A total of 36 endometrial cancer cases with solid components were assessed using IHC, next-generation sequencing (NGS), and the custom-made panel. Among 19 EC cases, six were categorized as MMR-deficient (MMR-d) and eight were classified as having a nonspecific molecular profile. Three EC cases were classified as POLE mutation (POLEmut)-type, which had a very high tumor mutation burden (TMB) and low microsatellite instability (MSI). Increased TMB and MSI were observed in all three DC cases, classified as MMR-d with mutations in MLH1 and POLD1. Except for one case classified as MMR-d, all SC cases exhibited TP53 mutations and were classified as p53 mutation-type. SC cases also exhibited amplification of CCND1, CCNE1, and MYC. CS cases were classified as three TCGA types other than the POLEmut-type. The IHC results for p53 and ARID1A were almost consistent with their mutation status. NGS analysis using a small panel enables categorization of endometrial cancers with solid proliferation according to TCGA classification. As TCGA molecular classification does not consider histological findings, an integrated analytical procedure including IHC and NGS may be a practical diagnostic tool for endometrial cancers.

Differential diagnosis of lipoma and atypical lipomatous tumor/well-differentiated liposarcoma by cytological analysis

BACKGROUND

Adipocytic tumors are the most common soft tissue tumors, with lipomas and atypical lipomatous tumor/well-differentiated liposarcomas (ALT/WDL), which comprise most cases. Preoperative differential diagnosis of lipoma or ALT/WDL can provide important information for decisions regarding treatment. We evaluated the cytological findings of 20 cases of lipoma and ALT/WDL.

METHODS

Fluorescence in situ hybridization (FISH) was performed on formalin-fixed paraffin-embedded specimens (FFPE) to examine mouse double minute 2 homolog (MDM2) amplification in all cases. Tissue samples were collected from the center of the surgical materials, stained with Pap, and evaluated for 12 cytological parameters by six cytotechnologists.

RESULTS

The findings regarding large atypical cells, multinucleated cells, and nuclear pleomorphism were highly concordant among the cytotechnologists and were associated with MDM2 amplification. Large atypical cells, considered a highly specific feature of ALT/WDL, were not observed in lipoma cases. However, the sensitivity of the large atypical cell findings was not high (67%); therefore, comprehensive evaluation of multinucleated cells and pleomorphism is crucial for predicting ALT/WDL diagnosis. FISH of MDM2 on Pap-stained specimens was performed in four cases. In two, the results were similar to those of MDM2 FISH performed on FFPE sections and were reproducible, whereas in the other two, the signal could not be evaluated because of the strong background coloration.

CONCLUSIONS

Cytology specimens may be useful for the preoperative diagnosis of adipocytic tumors, particularly if the FISH conditions for Pap-stained specimens and the detection accuracy of MDM2 amplification can be improved.

Impact of LBC fixative type and fixation time on molecular analysis of pancreatic cancer cells: A comparative study of cell morphology, antigenicity and nucleic acids

Introduction:

Liquid-based cytology (LBC) has been widely used since 2000. Next-Generation Sequencing (NGS) analysis of residual specimens in LBC fixative may also be performed for pancreatic cancer in the near future. We examined cell morphology, antigenicity and nucleic acids in pancreatic cancer cells at different fixation times using two types of LBC fixatives.

Methods:

PANC-1 cells were fixed in 1 ml CytoRich Red (CR), CytoRich Blue (CB), 95% ethanol (95% AL) or 10% neutral buffered formalin (10% NBF) and evaluated for cell area, antigenicity and nucleic acids with fixation times of 1 hour and 1, 3, 9, and 14 days. Antigenicity was evaluated by immunocytochemical staining for p53 and CK20, and nucleic acid fragmentation was assessed by real-time PCR.

Results:

There was no difference in total cell area between 1 hour and 14 day fixation times for the CR group, but the CB group showed cell contraction with 9 days fixation. In immunocytochemical staining, the CR group showed high p53 and CK20 positivity even after 14 days fixation. The CB group had a lower p53 positive rate than the CR group from 1 hour fixation. For nucleic acid fragmentation, Ct values for the CR group increased with fixation time. The CB group had consistently low Ct values.

Conclusion:

Different LBC fixatives and fixation time can have varying effects on cell morphology, antigenicity and nucleic acids in pancreatic cancer cells. Therefore, fixative type and fixation time should be considered for molecular testing on residual samples in LBC fixatives.

Performance of a 50-gene next generation sequencing panel with post-centrifuge supernatant cytology fluid in non-small-cell lung cancer

BACKGROUND

Liquid based cytology (LBC) specimens are increasingly utilized for molecular analysis, as results are comparable to molecular analysis performed on traditional specimens (biopsy or cell block). However, there are few studies demonstrating the long-term viability of DNA in LBC samples.

METHODS

In this study, a 50-gene next generation sequencing (NGS) panel was performed on DNA isolated from post-centrifuged supernatant LBC samples of cases of non-small-cell lung carcinoma. Comparison was made to results of an identical NGS panel performed on a concurrent clinical sample (biopsy or cell block). Quality parameters including DNA concentration, total reads, amplicons with reads under 450 and 350, and variant allele fraction were also compared. For a subset of LBC samples, DNA was isolated after being held for varying extended lengths of time after collection (up to 41 days) at 5°C and results compared.

RESULTS

Results of NGS mutation analysis were concordant between LBC samples and clinical samples. DNA concentration was on average higher in the LBC samples compared to the clinical samples. The remaining metrics were more variable, but illustrated the adequacy of LBC samples for NGS testing. DNA isolated from LBC samples held for longer periods of time was of good concentration. NGS analysis was successfully performed on all samples, with concordance with results of clinical samples.

CONCLUSION

DNA isolated directly from LBC fluid is suitable for NGS analysis. DNA is also stable in LBC preservative for extended periods of time before isolation and NGS analysis can subsequently be successfully performed.

Direct next-generation sequencing analysis using endometrial liquid-based cytology specimens for rapid cancer genomic profiling

BACKGROUND

Genomic examination of cytology specimens is often performed on cell blocks or conventional smears rather than on liquid-based cytology (LBC) specimens. Since LBC specimens preserve high-quality DNA, cancer genome profiling using next-generation sequencing (NGS) is also attainable from residual LBC specimens. One of the advantages of using LBC specimens for NGS is that it allows direct extraction of DNA from residual specimens, avoiding a sacrifice of smear slides and minimizing genomic profiling processing time.

METHODS

Endometrial LBC specimens were subjected to NGS analysis to validate the practicality of rapid cancer genomic profiling in a pathology laboratory. The extracted DNA was subjected to NGS using a customized cancer gene panel comprising 56 genes and 17 microsatellite regions. The workflow strategy was defined, and the processing time estimated for specimen sampling, cell counting, NGS run, and genome profiling.

RESULTS

NGS analysis of most LBC specimens revealed somatic mutations, tumor mutation burden, and microsatellite instability, which were almost identical to those obtained from formalin-fixed paraffin-embedded tissues. The processing time for direct NGS analysis and cancer genomic profiling of the residual LBC specimens was approximately 5 days.

CONCLUSION

The residual LBC specimens collected using endometrial cytology were verified to carry a high tumor fraction for NGS analysis and could serve as an alternate source for rapid molecular classification and diagnosis of endometrial cancers, as a routine process in a pathology laboratory.

How limited molecular testing can also offer diagnostic and prognostic evaluation of thyroid nodules processed with liquid-based cytology: Role of TERT promoter and BRAF V600E mutation analysis

BACKGROUND

Mutational analysis contributes to the diagnosis and prognosis of thyroid nodules analyzed with fine-needle aspiration cytology (FNAC). Although several advanced molecular tests based on multiple molecular markers are available for clinical use and have increased their impact on clinical management of patients, they are not widely available. Among them is BRAF V600E, one of the most studied mutations. Other genetic alterations, such as TERT promoter mutations, may coexist in thyroid carcinomas. Previous studies have demonstrated that this duet might be involved in the aggressiveness of thyroid cancer, although its prognostic value related to mortality remains undefined. The detection of such genetic alterations in thyroid liquid-based cytology (LBC) thus may assist with patient management.

METHODS

From January 2013 to June 2014, 356 thyroid FNAC samples were processed by LBC, including 174 surgical follow-up samples. BRAF V600E and TERT mutation analyses were performed on both LBC and histopathology.

RESULTS

The study included 119 samples categorized as atypia of undetermined significance, 42 categorized as follicular neoplasms, 61 categorized as suspicious for malignancy, and 34 categorized as positive for malignancy. BRAF V600E mutation was detected in 10.4% of all cases, whereas TERT promoter mutations were identified in 1.1%. TERT-mutated cases belonged to the positive for malignancy category, with a histologic diagnosis of tall cell variant of papillary thyroid carcinoma. These genetic alterations correlated with lymph node metastases (P = .0349) and higher disease stage.

CONCLUSIONS

BRAF V600E and TERT analysis can be performed on LBC. TERT mutations are rarely identified in well differentiated thyroid carcinoma but are associated with higher stage. Although a larger molecular panel may offer more information, analyzing these few point mutations is still likely to be useful for managing potentially more aggressive thyroid carcinomas.

Thyroid Lobectomy for Low to Intermediate Risk Differentiated Thyroid Cancer

Simple Summary

Total thyroidectomy used to be recommended for all thyroid cancers. We now know that some thyroid cancers have a relatively low risk of recurrence. Today, for some of these cancers, depending on the type of tumor, its’ size and other tumor characteristics, a thyroid lobectomy (or hemithyroidectomy) can be performed without increasing the patient’s risk of cancer recurrence. Thyroid lobectomy has the advantages of having less risk of surgical complications and a less frequent need for thyroid hormone replacement therapy. This approach is not optimal for all thyroid cancers, however, and careful tumor and patient selection are necessary. This review explains the rationale and criteria for patient selection for thyroid lobectomy for selected thyroid cancers.

Abstract

Many recent publications and guidelines have promoted a “more is less” approach in terms of treatment for low to intermediate risk differentiated thyroid cancer (DTC), which comprise the vast majority of thyroid cancers: less extensive surgery, less radioactive iodine, less or no thyroid hormone suppression, and less frequent or stringent follow-up. Following this approach, thyroid lobectomy has been proposed as a means of decreasing short- and long-term postoperative morbidity while maintaining an excellent prognosis for tumors meeting specific macroscopic and microscopic criteria. This article will examine the pros and cons of thyroid lobectomy for low to intermediate risk cancers and discuss, in detail, criteria for patient selection and oncological outcomes.