Poor Glycemic Control Is Associated with Failure to Complete Neoadjuvant Therapy and Surgery in Patients with Localized Pancreatic Cancer.

BACKGROUND: The impact of glycemic control in patients with pancreatic cancer treated with neoadjuvant therapy is unclear. METHODS: Glycated hemoglobin (HbA1c) values were measured in patients with localized pancreatic cancer prior to any therapy (pretreatment) and after neoadjuvant therapy prior to surgery (preoperative). HbA1c levels greater than 6.5% were classified as abnormal. Patients were categorized based on the change in HbA1c levels from pretreatment to preoperative: GrpA, always normal; Gr B, worsened; GrpC, improved; and GrpD, always abnormal. RESULTS: Pretreatment HbA1c levels were evaluable in 123 patients; there were 67 (55%) patients in GrpA, 8 (6%) in GrpB, 22 (18%) in GrpC, and 26 (21%) in GrpD. Of the 123 patients, 92 (75%) completed all intended therapy to include surgery; 57 (85%) patients in GrpA, 4 (50%) patients in GrpB, 16 (72%) patients in GrpC, and 15 (58%) patients in GrpD (p = 0.01). Elevated preoperative carbohydrate antigen 19-9 (CA19-9) (OR 0.22;[0.07-0.66]), borderline resectable (BLR) disease stage (OR 0.20;[0.01-0.45]) and abnormal preoperative HbA1c (OR 0.30;[0.11-0.90]) were negatively associated with completion of all intended therapy. Abnormal preoperative HbA1c was associated with a 2.74-fold increased odds of metastatic progression during neoadjuvant therapy (p = 0.08). CONCLUSIONS: Elevated preoperative HbA1c is associated with failure to complete neoadjuvant therapy and surgery and a trend for increased risk of metastatic progression.

Neoadjuvant therapy versus upfront surgical strategies in resectable pancreatic cancer: A Markov decision analysis.

BACKGROUND: Neoadjuvant therapy is gaining acceptance as a valid treatment option for borderline resectable pancreatic cancer; however, its value for clearly resectable pancreatic cancer remains controversial. The aim of this study was to use a Markov decision analysis model, in the absence of adequately powered randomized trials, to compare the life expectancy (LE) and quality-adjusted life expectancy (QALE) of neoadjuvant therapy to conventional upfront surgical strategies in resectable pancreatic cancer patients. METHODS: A Markov decision model was created to compare two strategies: attempted pancreatic resection followed by adjuvant chemoradiotherapy and neoadjuvant chemoradiotherapy followed by restaging with, if appropriate, attempted pancreatic resection. Data obtained through a comprehensive systematic search in PUBMED of the literature from 2000 to 2015 were used to estimate the probabilities used in the model. Deterministic and probabilistic sensitivity analyses were performed. RESULTS: Of the 786 potentially eligible studies identified, 22 studies met the inclusion criteria and were used to extract the probabilities used in the model. Base case analyses of the model showed a higher LE (32.2 vs. 26.7 months) and QALE (25.5 vs. 20.8 quality-adjusted life months) for patients in the neoadjuvant therapy arm compared to upfront surgery. Probabilistic sensitivity analyses for LE and QALE revealed that neoadjuvant therapy is favorable in 59% and 60% of the cases respectively. CONCLUSION(S): Although conceptual, these data suggest that neoadjuvant therapy offers substantial benefit in LE and QALE for resectable pancreatic cancer patients. These findings highlight the value of further prospective randomized trials comparing neoadjuvant therapy to conventional upfront surgical strategies.

Patency rates of portal vein/superior mesenteric vein reconstruction after pancreatectomy for pancreatic cancer.

BACKGROUND: Pancreatectomy with venous reconstruction (VR) for pancreatic cancer (PC) is occurring more commonly. Few studies have examined the long-term patency of the superior mesenteric-portal vein confluence following reconstruction. METHODS: From 2007 to 2013, patients who underwent pancreatic resection with VR for PC were classified by type of reconstruction. Patency of VR was assessed using surveillance computed tomographic imaging obtained from date of surgery to last follow-up. RESULTS: VR was performed in 43 patients and included the following: tangential resection with primary repair (7, 16%) or saphenous vein patch (9, 21%); segmental resection with splenic vein division and either primary anastomosis (10, 23%) or internal jugular vein interposition (8, 19%); or segmental resection with splenic vein preservation and either primary anastomosis (3, 7%) or interposition grafting (6, 14%). All patients were instructed to take aspirin after surgery; low molecular weight heparin was not routinely used. An occluded VR was found in four (9%) of the 43 patients at a median follow-up of 13 months; median time to detection of thrombosis in the four patients was 72 days (range 16-238). CONCLUSIONS: Pancreatectomy with VR can be performed with high patency rates. The optimal postoperative pharmacologic therapy to prevent thrombosis requires further investigation.

Sequential changes in gene expression profiles in breast cancers during treatment with the aromatase inhibitor, letrozole.

The study aim was to identify early (within 14 days) and late changes (by 3 months) in breast cancer gene expression profiles associated with neoadjuvant therapy with letrozole. RNA from sequential tumour biopsies in 54 patients was analyzed on microarrays; changes were determined by frequency, magnitude and significance analyses. Substantially more genes were changed at 3 months (1503) than at 14 days (237). Early changed genes were associated with cell cycle (downregulation), blood vessel development and extracellular matrix (upregulation); late changes included 'cellular metabolic process', 'generation of precursor metabolites and energy' (decreased) and 'cell adhesion' 'biological adhesion' (increased). A striking difference between the early and late changes was the general location of downregulated genes-nuclear structures at 14 days and mitochondria after 3 months. These changes in gene expression profiles provide a new and important database by which to understand molecular mechanisms of letrozole in breast cancers.

EGFR/HER2 inhibitor AEE788 increases ER-mediated transcription in HER2/ER-positive breast cancer cells but functions synergistically with endocrine therapy.

BACKGROUND: Cross-talk between receptor tyrosine kinases and the oestrogen receptor (ER) is implicated in resistance to endocrine therapy. We investigated whether AEE788 (a combined inhibitor of EGFR, HER2 and VEGFR) plus tamoxifen or letrozole enhanced the individual anti-tumour effects of these agents. METHODS: Breast cancer cell lines modelling endocrine-resistant and -sensitive disease were engineered to express aromatase (A) and examined using proliferation, western blotting and ER-alpha transcription assays. RESULTS: AEE788 enhanced the anti-proliferative effect of tamoxifen and letrozole in ER(+) cell lines (MCF-7 2A, ZR75.1 A3 and BT474 A3). This associated with an elevated G1 arrest and nuclear accumulation of p27. It is noteworthy that AEE788 alone or in combination with endocrine therapy increased the expression of progesterone receptor (PGR) and TFF1 in BT474 A3 cells. This may indicate a mechanism of resistance to AEE788 in ER(+)/HER2(+) breast cancers. In a ZR75.1 A3 xenograft, AEE788 alone or in combination with tamoxifen provided no further benefit compared with letrozole. However, letrozole plus AEE788 produced a significantly greater inhibition of tumour growth compared with letrozole alone. CONCLUSION: These data suggest that AEE788 plus letrozole in breast cancer overexpressing HER2 may provide superior anti-tumour activity, compared with single agents.

Elevated plasma endoglin (CD105) predicts decreased response and survival in a metastatic breast cancer trial of hormone therapy.

Background Endoglin (CD105) is a co-receptor for TGF-beta, is expressed by human vascular endothelial cells, and plays a major role in angiogenesis. Materials and methods Pretreatment EDTA plasma from 224 metastatic breast cancer patients enrolled in a phase III 2nd-line hormone therapy trial and 50 control subjects were assayed for endoglin using an ELISA. Results The female control group (n = 50) plasma endoglin upper limit of normal was defined as the mean + 2 SD (8.7 ng/ml). The breast cancer patient plasma endoglin was 6.40 +/- 2.23 ng/ml (range 3.00-19.79 ng/ml). Elevated plasma endoglin levels were detected in 26 of 224 patients (11.6%). Patients with elevated plasma endoglin had a reduced clinical benefit rate (CR + PR + Stable) (15 vs. 42%) (P = 0.01) to hormone therapy. TTP was shorter for patients with elevated plasma endoglin, but did not reach statistical significance (P = 0.2). Patients with elevated plasma endoglin had decreased overall survival (median 645 vs. 947 days) (P = 0.005). Conclusion Elevated pretreatment plasma endoglin levels predicted for decreased clinical benefit and a shorter overall survival in metastatic breast cancer patients treated with 2nd-line hormone therapy.

The integration of chemoradiation in the care of patient with localized pancreatic cancer.

The use of chemoradiation for patients with localized pancreatic cancer is controversial. Although some randomized trials have indicated that chemoradiation improves the median survival of patients with locally advanced as well as resected pancreatic cancer, other more recent trials have called into question the role of chemoradiation and have supported the use of chemotherapy. In the adjuvant setting, the high local tumor recurrence/persistence rate in all trials probably reflects the inclusion of patients with incompletely resected tumors, whose prognosis is similar to the prognosis of patients with locally advanced who do not undergo resection, making these trials difficult to interpret. More precise clinical staging and selection of patients appropriate for surgical resection is an important goal. The keys to the successful integration of radiotherapy in the care of patients with localized pancreatic cancer are selection, sequencing and smaller treatment volumes. A strategy of initial chemotherapy followed by consolidation with a well-tolerated chemoradiation regimen both in the adjuvant and locally advanced settings maximizes benefits of both treatment options, which are in fact complementary. Herein, we discuss the rationale for this approach as well as the ongoing investigation of novel radiation approaches designed to enhance outcome through the molecular and physical targeting of disease as well as the investigation of neoadjuvant chemoradiation in radiographically resectable and borderline resectable pancreatic cancer.

A randomised study of the effects of letrozole and anastrozole on oestrogen receptor positive breast cancers in postmenopausal women.

INTRODUCTION: Changes in proliferation as measured by Ki67 occur within 14 days of starting treatment with an aromatase inhibitor and these changes have been shown to be predictors of long term outcome. This study aimed to compare changes in proliferation following 14 days of treatment with anastrozole and letrozole. METHODS: Two hundred and six women with 209 estrogen receptor (ER) positive operable breast cancers (three bilateral) were randomly allocated to receive either 14 days treatment with 2.5 mg of letrozole or 1 mg of anastrozole prior to surgery. Changes in expression of estrogen (ER) and progesterone receptors (PgR) as assessed by ALLRED scores and proliferation as assessed by Ki67 were analysed. The HER2 status of each tumour was also assessed using a combination of the Hercept test and FISH. RESULTS: Both letrozole and anastrozole reduced ER expression (ALLRED score) by a mean of 0.32 (0.20-0.44), P<0.001 and PgR fell by a mean of 2.54 (2.20-2.89) P<0.0001. Letrozole reduced proliferation from a geometric mean of 6.37% to 0.81%, P<0.0001 and anastrozole reduced proliferation from 5.81% to 0.77%, P<0.0001. There was no differences between drugs in the fall in ER, PgR or proliferation. Both letrozole and anastrozole produced significant falls in proliferation in both HER2 positive and HER2 negative cancers, all P<0.001. DISCUSSION: 14 days of both letrozole and anastrozole reduces proliferation, ER and PgR expression. No significant difference between these two drugs was identified.

Impact of preoperative thyroid ultrasonography on the surgical management of primary hyperparathyroidism.

BACKGROUND: Primary hyperparathyroidism (PHPT) with coexisting thyroid disease has been considered a contraindication to minimally invasive parathyroidectomy (MIP). This study assessed the impact of thyroid ultrasonography and guided fine-needle aspiration (FNA) biopsy with cytological review of the aspiration in distinguishing patients eligible for MIP from those requiring open parathyroidectomy with thyroid surgery. METHODS: The records of 194 consecutive patients who had minimally invasive or open parathyroidectomy for sporadic PHPT were reviewed retrospectively. Thyroid ultrasonographic findings and FNA results were compared with surgical and pathology records. RESULTS: A total of 163 patients (84.0 per cent) were eligible for MIP based on ultrasonographic findings with or without FNA results. Ultrasonography detected concurrent thyroid disease in 163 patients (84.0 per cent). Thirty-nine (23.9 per cent) underwent FNA, of whom 16 had benign findings and were eligible for MIP; the remaining 23 had suspicious FNA results and had open parathyroidectomy combined with thyroid surgery. Postoperative thyroid histopathology confirmed malignancy in nine patients, eight of whom had disease detected ultrasonographically. Micronodular thyroid disease (less than 1 cm) accounted for four of nine malignancies. CONCLUSION: Most patients with PHPT are eligible for MIP. Experienced ultrasonographers can diagnose coexisting micronodular and macronodular thyroid disease, and identify patients eligible for MIP.

Intraductal papillary mucinous neoplasms of the pancreas.

The introduction of the exocrine pancreatic classification by the World Health Organization and improvements in pancreatic imaging have led to an improved understanding of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. As a result, IPMNs of the pancreas are increasingly being recognized as a separate disease entity. IPMNs are characterized by the cystic dilatation of the pancreatic duct and its branches, with papillary projections. There are three histological subtypes of IPMNs: main duct, branch duct, and mixed. The degree of atypia ranges from adenoma to frank invasive carcinoma. The lymph nodes are involved considerably less frequently than they are in pancreatic adenocarcinoma. Most patients are symptomatic at diagnosis and require a diagnostic workup similar to that for patients with pancreatic adenocarcinoma. Although some investigators continue to advocate total pancreatectomy, the evidence in support of this is decreasing. Partial pancreatectomy remains the treatment option. Intraoperative assessment of the resection surgical margins is an important component of surgical resection. Additionally, controversy also exists regarding the nature of the follow-up and the need for adjuvant chemoradiation therapy in the patient. Unlike ductal adenocarcinomas, IPMNs follow a relatively indolent course; the 5-year survival rate in patients with invasive IPMNs is 57%. A mural nodule and a main pancreatic duct diameter greater than 5 mm have been found to be predictors of malignancy.

Staging of pancreatic cancer with multidetector CT in the setting of preoperative chemoradiation therapy.

BACKGROUND: Preoperative chemoradiation can potentially improve outcomes in patients with pancreatic cancer. This study addresses its effect on staging pancreatic cancer with multidetector computed tomography (MDCT). METHODS: Fifty-five patients underwent a dual-phase MDCT pancreas protocol for proved pancreatic cancer. Of these, 16 patients underwent preoperative chemoradiation. Three radiologists independently reviewed images to assess for locally advanced disease, liver and peritoneal metastases on baseline studies of all 55 patients, and on follow-up preoperative studies for the 16 patients receiving preoperative therapy. Overall score for resectability was graded on a scale from 1 to 5 (1, definitely resectable; 5. definitely unresectable). Receiver operating characteristic curves and weighted (kappa statistics were determined. RESULTS: The areas under the receiver operating characteristic curves for readers 1, 2, and 3 were 0.98, 0.96, and 0.90, respectively. Weighted kappa values for reader 1 versus reader 2, reader 1 versus reader 3, and reader 2 versus reader 3 were 0.90, 0.57, and 0.54, respectively. Interpreting scores of 1 to 3 for resectability as resectable disease, the mean values for sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were 0.92, 0.91, 0.74, 0.98, and 0.92 respectively. CONCLUSION: The negative predictive value for MDCT for identifying unresectable pancreatic cancer in the setting of preoperative therapy is comparable to that reported in the absence of neoadjuvant therapy.

The validation of new aromatase monoclonal antibodies for immunohistochemistry--a correlation with biochemical activities in 46 cases of breast cancer.

Intratumoral aromatase is a therapeutic target for the treatment of post-menopausal estrogen-dependent breast cancers. Therefore, reliable methods should be developed for routine application for the detection of intratumoral aromatase. Immunohistochemistry (IHC) is considered one of the most suitable methods in this regard. A multi-centre collaborative group has been established to generate and validate new aromatase monoclonal antibodies. We have selected two monoclonal antibodies, #677 against native aromatase protein and F2 against formalin-fixed protein for this purpose. With these two monoclonal antibodies 43 cases of invasive ductal carcinoma, which had been previously assayed for aromatase activity by product isolation methodology, were immunostained in three laboratories in UK, USA and Japan and independently evaluated by three pathologists (H.S., T.A. and S.G.S.). Staining of malignant epithelium, adipose tissue, normal/benign and stromal compartments of the tumors were assessed by estimating the proportion of positive staining cells and the relative intensity of staining in this fashion. Immunoreactivity could be detected in each component of the tissue specimens but a significant positive correlation with biochemical activity was detected only in malignant epithelium stained with 677 not in other components with #677 and not in any of the components. Staining using F2 as a primary antibody did not produce a positive correlation in any components with aromatase activity. These results suggest that we now have a monoclonal antibody against aromatase (#677) which may be used to stain archival materials. A methodology and scoring system is recommended whereby staining significantly correlates with aromatase activity of the resected tissue specimens of breast cancer.

Overexpression of neuropilin-1 promotes constitutive MAPK signalling and chemoresistance in pancreatic cancer cells.

Neuropilin-1 (NRP-1) is a novel co-receptor for vascular endothelial growth factor (VEGF). Neuropilin-1 is expressed in pancreatic cancer, but not in nonmalignant pancreatic tissue. We hypothesised that NRP-1 expression by pancreatic cancer cells contributes to the malignant phenotype. To determine the role of NRP-1 in pancreatic cancer, NRP-1 was stably transfected into the human pancreatic cancer cell line FG. Signal transduction was assessed by Western blot analysis. Susceptibility to anoikis (detachment induced apoptosis) was evaluated by colony formation after growth in suspension. Chemosensitivity to gemcitabine or 5-fluorouracil (5-FU) was assessed by MTT assay in pancreatic cancer cells following NRP-1 overexpression or siRNA-induced downregulation of NRP-1. Differential expression of apoptosis-related genes was determined by gene array and further evaluated by Western blot analysis. Neuropilin-1 overexpression increased constitutive mitogen activated protein kinase (MAPK) signalling, possibly via an autocrine loop. Neuropilin-1 overexpression in FG cells enhanced anoikis resistance and increased survival of cells by > 30% after exposure to clinically relevant levels of gemcitabine and 5-FU. In contrast, downregulation of NRP-1 expression in Panc-1 cells markedly increased chemosensitivity, inducing > 50% more cell death at clinically relevant concentrations of gemcitabine. Neuropilin-1 overexpression also increased expression of the antiapoptotic regulator, MCL-1. Neuropilin-1 overexpression in pancreatic cancer cell lines is associated with (a) increased constitutive MAPK signalling, (b) inhibition of anoikis, and (c) chemoresistance. Targeting NRP-1 in pancreatic cancer cells may downregulate survival signalling pathways and increase sensitivity to chemotherapy.

Surgical and endoscopic palliation for pancreatic cancer.

Patients with pancreatic cancer often present with locally advanced or metastatic disease and are deemed not to be candidates for a curative resection. Palliation in these patients focuses on relief of biliary obstruction, gastroduodenal obstruction and pain. Palliative treatment modalities include both surgical and nonsurgical approaches. Biliary obstruction is often initially treated with endoscopic biliary stenting. Two major types of biliary stents are used, plastic and metallic stents. Both of these provide similar initial relief of biliary obstruction, however, plastic stents have a greater propensity for occlusion and should primarily be used in patients with anticipated short survival duration. Metallic stents have a greater initial cost, but provide an overall cost-saving in patients with expected survival duration of over 6 months. Surgical palliation for biliary obstruction should be primarily considered in patients who fail endoscopic biliary decompression or who develop clinical evidence of gastroduodenal obstruction. In these patients, surgical palliation should consist of biliary decompression with a choledochojejunostomy when ever feasible, a gastroduodenal bypass and a chemical splanchnicectomy for pain relief. An initial prophylactic gastroenterostomy at the time of endoscopic biliary decompression is rarely indicated. The role of palliative pancreaticoduodenectomy remains controversial and to date there are no prospective randomized data to support its role in palliation of locally advanced pancreatic cancer. This review examines the available data from prospective trials for surgical and nonsurgical palliation of locally advanced and metastatic pancreatic cancer.

Validation of new aromatase monoclonal antibodies for immunohistochemistry: progress report.

Intratumoral aromatase is a potential therapeutic target for the treatment of postmenopausal estrogen-dependent breast cancers. Therefore, reliable methods should be developed for routine application for the detection of intratumoral aromatase. A multi-center collaborative group has been established to generate and validate new aromatase monoclonal antibodies (MAbs). A recombinant GST-aromatase fusion protein was expressed in baculovirus and the purified protein was used for immunization of mice either as a native or formalin-fixed antigen. Hybridomas were generated using standard techniques and screened biochemically prior to immunohistochemistry (IHC) evaluation in human placenta, ovary and breast cancer tissues. Twenty-three MAbs selected by biochemical assays were further evaluated by IHC of paraffin-embedded tissue sections including normal ovary, and placenta, and a small series of 10 breast carcinomas. Of the 23 MAbs, 2 (clones 677 and F2) were determined to specifically stain cell types known to express aromatase in normal tissues. In breast carcinomas staining of malignant epithelium, adipose tissue, normal/benign and stromal compartments was detected. IHC was performed and independently evaluated by three pathologists (HS, TJA and SGS), each using the same evaluation criteria for staining intensity and proportion of immunopositive cells. With these two MAbs, interpathologist and intralaboratory variations were minimal in comparison with differences which could be detected between tissue specimens and antibodies.

An integrated view of aromatase and its inhibition.

Aromatase inhibition has become a major treatment strategy for postmenopausal women with oestrogen-dependent breast cancer. Its optimal application is, however, dependent upon (i) the accurate identification of cancers which are ultimately dependent upon the activity of the aromatase enzyme, (ii) the use of the best method/inhibitor by which to blockade aromatase activity. The single best predictor of response to aromatase inhibitors is the presence of tumour oestrogen receptors; receptor-negative cancers rarely respond whereas those with high levels seem particularly likely to benefit. However, there is a need for additional discriminatory markers. The use of microarray technology coupled with neoadjuvant therapy is likely to yield promising candidate genes. The finding that, amongst peripheral tissues, the tumour itself may have high activity has led to the suggestion that the tumour aromatase measurements may be predictive; however, in situ studies and the lack of robust assays for tumour aromatase suggest that tumour aromatase may not be an influential marker. Whilst drugs such as anastrozole, exemestane, formestane and letrozole are all effective and specific inhibitors of aromatase, they differ in structure, potency and mechanism of action. Thus, differential sensitivity of tissues/tumours and non-cross resistance mean inhibitors are not equivalent and individual agents may have differing roles according to the setting in which they will be used. Aromatase inhibitors have evolved as key endocrine agents in the treatment of breast cancer. They offer the promise of rational treatment management based on the accurate identification of individual cohorts of tumours responsive to specific drugs.

Pancreatic leak after left pancreatectomy is reduced following main pancreatic duct ligation.

BACKGROUND: Although much is known about the long-term outcome of patients undergoing left (distal) pancreatectomy for malignancy, comparatively little is known about the optimal management strategy for the residual transected pancreatic parenchyma and the divided pancreatic duct. Clinicopathological and operative factors that may contribute to postoperative pancreatic leak were evaluated. METHODS: A retrospective review of the medical records of 126 patients who underwent left pancreatectomy between June 1990 and December 1999 at the University of Texas M. D. Anderson Cancer Center was performed. RESULTS: Indications for left pancreatectomy included pancreatic neoplasms (n = 42; 33.3 per cent), en bloc resection for management of retroperitoneal sarcoma (n = 21; 16.7 per cent), gastric adenocarcinoma (n = 14; 11.1 per cent), renal cell carcinoma (n = 11; 8.7 per cent) and other tumours or benign conditions (n = 38; 30.2 per cent). Pancreatic parenchymal closure was accomplished by a hand-sewn technique, mechanical stapling, or a combination of the two in 83, 20 and 15 patients respectively. No form of parenchymal closure was used in eight patients. Identification of the pancreatic duct and suture ligation was performed in 73 patients (57.9 per cent). Twenty-five patients (19.8 per cent) developed a pancreatic leak. For subgroups having duct ligation or no duct ligation, pancreatic leak rates were 9.6 per cent (seven of 73 patients) and 34.0 per cent (18 of 53 patients) respectively (P < 0.001). Multivariate analysis including clinicopathological and operative factors indicated that failure to ligate the pancreatic duct was the only feature associated with an increased risk for pancreatic leak (odds ratio 5.0 (95 per cent confidence interval 2.0 to 10.0); P = 0.001). CONCLUSION: Pancreatic leak remains a common complication after left pancreatectomy. The incidence of leak is reduced significantly when the pancreatic duct is identified and directly ligated during left pancreatectomy.

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.