Comparison of methylation profiling in cancerous and their corresponding normal tissues from korean patients with breast cancer.

BACKGROUND: Aberrant DNA hypermethylation plays a pivotal role in carcinogenesis and disease progression; therefore, accurate measurement of differential gene methylation patterns among many genes is likely to reveal biomarkers for improved risk assessment. We evaluated the gene hypermethylation profiles of primary breast tumors and their corresponding normal tissues and investigated the association between major clinicopathological features and gene hypermethylation. METHODS: A single reaction using methylation-specific multiplex ligation-dependent probe amplification was used to analyze the DNA methylation status of 24 tumor suppressor genes in 60 cancerous tissues and their corresponding normal tissues from patients with primary breast cancer. RESULTS: In cancerous breast tissues, 21 of 24 genes displayed promoter methylation in one or more samples. The most frequently methylated genes included RASSF1 (43.3%), APC (31.7%), CDKN2B (25.0%), CDH13 (23.3%), GSTP1 (16.7%), and BRCA1 (10%). APC was associated with lymph node metastasis, and BRCA1 was associated with negative estrogen receptor and negative progesterone receptor expression. In normal breast tissues, 8 of 24 tumor suppressor genes displayed promoter hypermethylation; CDKN2B (28.3%) and RASSF1 (8.3%) hypermethylation were most frequently observed. CONCLUSIONS: RASSF1 and CDKN2B hypermethylation in Korean breast cancer patients were the most frequent in cancerous tissue and corresponding normal tissue, respectively. Our data indicates that methylation of specific genes is a frequent event in morphologically normal breast tissues adjacent to breast tumors as well as the corresponding breast cancers. This study also suggests that gene methylation is linked to various pathological features of breast cancer; however, this requires confirmation in a larger study.

Prognostic value of CAPZA1 overexpression in gastric cancer.

F-actin capping protein α1 subunit (CAPZA1) was previously identified in a proteomic analysis of human gastric cancer clinical specimens and selected for further study. The association between CAPZA1 overexpression, detected by immunohistochemistry, and clinicopathological features including survival were evaluated. In vitro gain-of-function and loss-of-function approaches were utilized to assess the function of CPAZA1 in malignancy. Univariate analysis revealed that poorly differentiated disease, according to the World Health Organization (WHO) classification, advanced T stage, positive lymph nodes, high TNM stage, D2 lymph node dissection, adjuvant chemotherapy and CAPZA1 underexpression were significantly associated with cancer-related death (p<0.05); however, only high TNM stage remained significantly associated by multivariate analysis (p<0.01). CAPZA1 overexpression was associated with well differentiated histology, smaller tumor size, lower T stage, absence of lymph node metastasis, lower TNM stage, lower recurrence rate and longer survival time, compared to CAPZA1 underexpression. In vitro, forced expression of CAPZA1 caused a significant decrease in gastric cancer cell migration and invasion, whereas CAPZA1 depletion had the opposite effect. The present study suggests that CAPZA1 could be a marker of good prognosis in gastric cancer and shows that CAPZA1 is associated with decreased cancer cell migration and invasion.

Laparoscopic left hemihepatectomy for left intrahepatic duct stones.

PURPOSE: The feasibility of laparoscopic left hemihepatectomy for the management of intrahepatic duct (IHD) stones was evaluated. METHODS: The clinical data of 26 consecutive patients who underwent total laparoscopic left hemihepatectomy for IHD stones at Gyeongsang National University Hospital between January 2009 and June 2011 were reviewed retrospectively. RESULTS: The mean operation time was 312.1 ± 63.4 minutes and the mean postoperative hospital stay was 11.8 ± 5.0 days. There were 2 cases of postoperative bile leakage and 3 cases of intra-abdominal fluid collection, which were successfully managed conservatively. Remnant stones were detected in 2 patients. The initial success rate of stone clearance was 92.3% (24 of 26). The remnant stones were located in the common bile duct in both cases and were removed by endoscopic retrograde cholangiopancreatography and endoscopic sphincterotomy. Therefore, the final success rate of stone clearance was 100% (26 of 26). During a mean follow-up of 22 months (range, 7 to 36 months), there was no patient with recurrent stone. CONCLUSION: Laparoscopic surgery could be an effective treatment modality for the management of IHD stones in select patients.

Fatty acid-binding protein 5 promotes cell proliferation and invasion in human intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is a rare primary malignant liver tumor with an extremely poor prognosis. Recently its incidence has increased, however, little attention has been directed to factors related to its molecular carcinogenesis, including oncogenes, tumor suppressor genes and cell cycle-related proteins. ICC is generally characterized by strong proliferation, invasion and early metastasis. These biological behaviors of ICC, with respect to the genetic and molecular aspects, remain to be clarified. In this study, we performed a proteomic analysis to identify the proteomic alterations associated with carcinogenesis of ICC. Protein expression profiles of sixteen cases of ICC were compared with those of adjacent non-involved bile duct tissue. Among the 151 protein spots that showed a statistically significant expression difference (P<0.05), there were 50 spots with significantly increased intensity (3-fold increase) and 17 spots with decreased intensity (3-fold decrease) in cancerous tissues. Of these, increased expression of fatty acid-binding protein 5 (FABP5) was further confirmed by western blot analysis and immunohistochemical analysis. Immunohistochemical analysis of FABP5 expression in tumor specimens obtained from 43 patients with mass-forming (MF) type ICC showed a positive correlation of FABP5 immunoreactivity with tumor size (P=0.047), lymph node metastasis (P=0.013), angioinvasion (P=0.032) and staging (P=0.007). In addition, silencing FABP5 with short hairpin RNA (shRNA) suppressed cell proliferation and invasiveness in HuCCT1 cells, and conversely, overexpression of FABP5 in FABP5-negative Hep3B cells increased cell proliferation and invasiveness. Our study shows that FABP5 is significantly overexpressed in ICC combined lymph node metastasis and is involved in cell proliferation and invasion in vitro. Our data suggest that FABP5 may be associated with tumor progression in ICC.

Clinical features and prognostic factors in papillary thyroid microcarcinoma depends on age.

PURPOSE: Clinical outcomes of papillary thyroid microcarcinoma (PTMC) vary. In general, age at diagnosis is an independent prognostic factor in conventional papillary thyroid carcinoma. However, it is unclear in patients of PTMC. The purpose of this study was to identify clinicopathologic features and prognostic factors of PTMC according to patients' age. METHODS: Five hundred twenty-seven patients who received thyroid surgery and diagnosed as having PTC between January 2001 and December 2009 were included. The clinical data were retrospectively analyzed. RESULTS: We divided the patients into two groups; group I who were younger than 45 years, and group II who were 45 years old or older. The mean tumor size and incidences of neck lymph nodes involvement of group I was larger than group II. In group II, however, there were more patients who had multiple cancer foci and were body mass index ≥ 25 kg/m(2). The overall incidence of recurrent disease was 3.2%. The incidence of recurrence was higher in group II (2.0% vs. 4.0%), without a statistical difference. In multivariate analysis, the significant risk factors of recurrence were male gender and multifocality in group I, and lymph node metastasis and multifocality in group II. In particular, the male gender and multifocality showed the highest odds ratio (OR) on each group (OR, 4.721 and 6.177). CONCLUSION: The patients with PTMCs had different clinical features and prognostic factors according to age. Hence, clinicians should consider a different strategy for therapy and plan for follow-up according to age.

Analysis of risk factors for postoperative morbidity in perforated peptic ulcer.

PURPOSE: Emergency operations for perforated peptic ulcer are associated with a high incidence of postoperative complications. While several studies have investigated the impact of perioperative risk factors and underlying diseases on the postoperative morbidity after abdominal surgery, only a few have analyzed their role in perforated peptic ulcer disease. The purpose of this study was to determine any possible associations between postoperative morbidity and comorbid disease or perioperative risk factors in perforated peptic ulcer. MATERIALS AND METHODS: In total, 142 consecutive patients, who underwent surgery for perforated peptic ulcer, at a single institution, between January 2005 and October 2010 were included in this study. The clinical data concerning the patient characteristics, operative methods, and complications were collected retrospectively. RESULTS: The postoperative morbidity rate associated with perforated peptic ulcer operations was 36.6% (52/142). Univariate analysis revealed that a long operating time, the open surgical method, age (≥60), sex (female), high American Society of Anesthesiologists (ASA) score and presence of preoperative shock were significant perioperative risk factors for postoperative morbidity. Significant comorbid risk factors included hypertension, diabetes mellitus and pulmonary disease. Multivariate analysis revealed a long operating time, the open surgical method, high ASA score and the presence of preoperative shock were all independent risk factors for the postoperative morbidity in perforated peptic ulcer. CONCLUSIONS: A high ASA score, preoperative shock, open surgery and long operating time of more than 150 minutes are high risk factors for morbidity. However, there is no association between postoperative morbidity and comorbid disease in patients with a perforated peptic ulcer.

Plasma microRNA 210 levels correlate with sensitivity to trastuzumab and tumor presence in breast cancer patients.

BACKGROUND: Trastuzumab is part of the standard treatment for patients with human epidermal growth factor receptor 2 (HER-2)-positive breast cancer, but not all patients respond to trastuzumab. Altered microRNA (miR) expression levels in cancer cells have been correlated with prognosis and response to chemotherapy. The authors of this report hypothesized that altered miR expression levels in plasma are associated with sensitivity to trastuzumab in patients with HER-2 positive breast cancer. METHODS: Quantitative reverse transcriptase-polymerase chain reaction was used to analyze plasma samples, including samples from patients with breast cancer who were enrolled in a clinical trial of neoadjuvant trastuzumab-based chemotherapy. Expression levels of miR-210, miR-21, miR-29a, and miR-126 were analyzed according to the type of response (pathologic complete response [n = 18] vs residual disease [n = 11]). MicroRNA expression levels also were compared in trastuzumab-sensitive and trastuzumab-resistant breast cancer cells derived from BT474 cells and in an independent set of preoperative plasma samples (n = 39) and postoperative plasma samples (n = 30) from 43 breast cancer patients who did not receive any treatment. RESULTS: At baseline before patients received neoadjuvant chemotherapy combined with trastuzumab, circulating miR-210 levels were significantly higher in those who had residual disease than in those who achieved a pathologic complete response (P = .0359). The mean expression ratio for miR-210 was significantly higher in trastuzumab-resistant BT474 cells, and miR-210 expression was significantly higher before surgery than after surgery (P = .0297) and in patients whose cancer metastasized to the lymph nodes (P = .0030). CONCLUSIONS: Circulating miR-210 levels were associated with trastuzumab sensitivity, tumor presence, and lymph node metastases. These results suggest that plasma miR-210 may be used to predict and perhaps monitor response to therapies that contain trastuzumab.

Body size and thyroid nodules in healthy Korean population.

PURPOSE: Excess weight and obesity have been associated with numerous diseases including thyroid cancer, but the relationship has been weak. The objective of this study was to evaluate the relationship of body sizes on thyroid nodules in healthy Korean population. METHODS: A total of 7,763 persons who underwent a health examination in our health examination center were included in this study. The epidemiologic factors, body size and thyroid ultrasound results were reviewed. We investigated the effects of body size on the presence of thyroid nodules and malignancy. RESULTS: The incidence of thyroid nodules was 20.6%. In the group who were found to have thyroid nodules, mean height, weight and body surface area (BSA) were significantly smaller compared to the others. Especially, in the women, smaller height (less than 160 cm) and overweight (≥ 60 kg) were identified as independent risk factors for the presence of thyroid nodules. The patients with body mass index (BMI) subgroups of normal or overweight had a tendency to have thyroid nodules more frequently. The detection rate of thyroid cancer was 0.47%. The patients with thyroid cancer tended to be smaller in height and BSA than the others. CONCLUSION: A higher frequency of thyroid nodules was associated with women and, older age. In women, there were significant correlations in height, weight and BMI subgroups to the presence of thyroid nodules.

Comparison of hybrid natural orifice transluminal endoscopic surgery and single-port laparoscopic surgery for sentinel node basin dissection in a porcine model.

BACKGROUND: The aim of the present study was to use a porcine model to compare one- and two-port transvaginal natural orifice transluminal endoscopic surgery (NOTES) with single-port laparoscopic surgery (SPLS) for sentinel node basin dissection. STUDY DESIGN: Three groups (n=3 per group) of healthy female pigs were subjected to lymph node dissection. For hybrid NOTES, an endoscope was inserted via the transvaginal route. For SPLS, a 5-mm 30° telescope with two-port laparoscopic instrument was inserted via the transumbilical port. The three methods were used to dissect the regions of the pig stomach that corresponded to four lymph node areas on the lesser curvature of the anterior wall and greater curvatures in humans. RESULTS: For two-port NOTES, SPLS, and one-port NOTES, the overall rates of complete dissection of the lymph node stations were 91.6 %, 83%, and 50%, respectively (P>.05). The mean resected tissue weights were 49.3, 37.9, and 22.5 g, respectively (P=.03). The mean operation times for two-port NOTES (69.9 minutes) and SPLS (68 minutes) were shorter than that for one-port NOTES (99 min) (P>.05). CONCLUSION: Two-port NOTES and SPLS are more feasible than one-port NOTES for sentinel node basin dissection in a porcine model. One-port NOTES is difficult to perform and requires long operation times; however, we foresee this operation as becoming more common in the future.

Synchronous Adenocarcinoma and Gastrointestinal Stromal Tumor of the Stomach Treated by a Combination of Laparoscopy-assisted Distal Gastrectomy and Wedge Resection.

The simultaneous occurrence of a gastrointestinal stromal tumor (GIST) and a gastric adenocarcinoma is uncommon, and has rarely been reported in the literature. The present report describes the case of a 74-year-old male patient who initially presented with an adenocarcinoma that had invaded the antral mucosa. Computed tomography then revealed the presence of a suspected GIST, in the form of a 2×2 cm mass at the hilum of the spleen. In view of the advanced age of the patient, a surgical approach that would minimize risk and maximize quality of life was preferred. The patient therefore underwent simultaneous laparoscopy-assisted distal gastrectomy for the adenocarcinoma and wedge resection for the GIST. This approach was only chosen after confirming that it would be possible to preserve three or more of the short gastric arteries that supply the area below the wedge resection site. This may be considered a feasible approach to the management of the simultaneous occurrence of a mid-to-low gastric body adenocarcinoma and a high gastric body GIST.

The indices of body size and aggressiveness of papillary thyroid carcinoma.

PURPOSE: The incidence of papillary thyroid carcinoma (PTC) is increasing worldwide. Positive associations between indices of body size and thyroid cancer have been reported. However, the relationships to cancer severities and/or behaviors are uncertain. METHODS: We performed a retrospective analysis of the data of patients who underwent total thyroidectomy due to PTC. The epidemiologic factor and pathologic report after operation were determined based on chart review. The relationships between indices of body size and these parameters were assessed. RESULTS: Positive association between body mass index and T stage was found, but it was not statically significant. In neck lymph node metastasis, the group with metastasis had a tendency for larger mean height and weight, but significant difference was found only in height. However, in the multivariate analysis, the age and size of nodules were only identified as independent risk factors of neck lymph node metastasis (P = 0.000 and 0.019). CONCLUSION: There was no independent association between indices of body size and stages of PTC in patients who underwent total thyroidectomy.

Laparoscopic resection of a appendiceal mucocele.

Laparoscopic resection of appendiceal mucoceles has recently been described, but the safety and efficacy are controversial. We present two cases of laparoscopic mucocelectomies involving 14 and 15 cm cystic masses originating from the appendix. The laparoscopic mucocelectomies were performed using four ports. From the beginning of the procedure, a laparoscopic bag was used to safely contain the mucocele, prevent rupture of the mucocele, and retract the mucocele. An endoscopic stapling device was used to transect the base of the cecum. Minimal handling was achieved by gravity and with the use of laparoscopic instruments. Laparoscopic appendectomies are widely performed for acute appendicitis, but laparoscopic resection is not routinely performed for an appendiceal mucocele because of the risk of perforation and subsequent pseudomyxoma peritonei. We report two cases of laparoscopic appendiceal mucocelectomies, which were performed safely with laparoscopic instruments and minimal manipulation.

Trans-vaginal specimen extraction following totally laparoscopic subtotal gastrectomy in early gastric cancer.

BACKGROUND: Although natural orifice extraction is now widely performed, there have been no reports of this procedure following subtotal gastrectomy for gastric cancer. This report describes trans-vaginal specimen extraction in four patients with early gastric cancer. METHODS: The clinical data of four patients with early gastric cancer were reviewed. Totally laparoscopic subtotal gastrectomy and D1 + ß lymph node dissection was performed using five trocars and a conventional procedure. Posterior colpotomy was performed by an experienced gynecologist, who retrieved the specimens in a retrieval bag via the trans-vaginal route. The colpotomy site was repaired immediately following specimen removal. Reconstruction was performed using the intracorporeal Billroth II method and an endo-GIA 60. RESULTS: Totally laparoscopic subtotal gastrectomy and trans-vaginal specimen extraction was successfully accomplished in all patients without intraoperative complications. CONCLUSIONS: The present technique may be a safe and feasible operative procedure for some limited groups of elderly female patients with early gastric cancer.

Pancreatic Diabetes after Distal Pancreatectomy: Incidence Rate and Risk Factors.

PURPOSE: Pancreatectomy can impair production of endocrine and exocrine hormones. In this study, we evaluated: 1) the incidence rate of diabetes in patients undergoing distal pancreatectomy; 2) the correlation between the occurrence of pancreatic diabetes and the extent of the resected pancreas; and 3) factors associated with the development of pancreatic diabetes. METHODS: We retrospectively reviewed the cases of 26 patients who could be compared in abdominal computed tomography before and after distal pancreatectomy for benign or malignant lesions between January, 1999 to June, 2010. RESULTS: The incidence of pancreatic diabetes was 19.2%. Obese patients (BMI>25.0 kg/m(2)) had a higher incidence (p=0.029) of pancreatic diabetes after distal pancreatectomy than non-obese patients. The diabetes group had larger volumes of resected pancreas, but the difference was not statistically significant (p=0.105). CONCLUSION: Several factors may be associated with the development of pancreatic diabetes after distal pancreatectomy. It is necessary to closely follow-up development of pancreatic diabetes regardless of the extent of resection.

Risk of recurrence after laparoscopy-assisted radical gastrectomy for gastric cancer performed by a single surgeon.

BACKGROUND: The risk of recurrence after laparoscopy-assisted radical gastrectomy (LAG) was investigated. MATERIALS AND METHODS: Clinical data of 398 consecutive patients who underwent radical gastrectomy with R0 resection for gastric cancer at Gyeongsang National University Hospital between January 2005 and December 2007 were reviewed retrospectively. RESULTS: Of the patients, 65.4% (n = 261) and 34.6% (n = 138) underwent LAG and open radical gastrectomy (OG), respectively. Of the LAG cases, 73.2% (n = 192), 10.7% (n = 28), 12.6% (n = 33), and 3.1% (n = 8) had stage I, II, III, and IV gastric cancer, respectively. All patients were followed up for a mean of 36.8 ± 13.7 months, and 14.6% (n = 58) had recurrence during the follow-up period. Univariate analysis revealed that tumor size, tumor-node-metastasis (TNM) stage, method of approach (LAG versus OG), and operation type were associated significantly with recurrence. Multivariate analysis revealed that only high TNM stage was significantly associated with recurrence (P = 0.00). While patients who underwent OG had higher incidence of recurrence than patients who underwent LAG, OG was not significantly associated with recurrence on multivariate analysis (P = 0.06). CONCLUSIONS: LAG and OG did not differ significantly in terms of recurrence, even when used in advanced gastric cancer cases. Multivariate analysis revealed that high TNM stage was significantly associated with recurrence. Thus, LAG appears to be a safe and feasible procedure that has the potential to be an alternative to open surgery, even for advanced gastric cancer.

Decreased annexin A3 expression correlates with tumor progression in papillary thyroid cancer.

PURPOSE: The aim of this study is to identify the potential tumor markers that function in carcinogenesis and tumor progression, thus providing important diagnostic and prognostic information. EXPERIMENTAL DESIGN: We performed 2-D gel electrophoresis and MALDI-TOF MS to investigate the differentially expressed proteins in 25 papillary thyroid carcinoma tissues. For validation of candidate proteins and investigation of clinical significance, we performed Western, Northern blot analysis and immunohistochemical staining. RESULTS: Our proteomic analyses revealed significantly decreased annexin A3 expression in papillary thyroid carcinoma at both the protein and mRNA levels, compared with normal thyroid tissue. ANXA3 immunoreactivity was not significantly correlated with lymph node metastasis, multifocality, capsular invasion or perithyroidal extension in thyroid cancer. However, the tumor subgroup with a lymph node metastasis score of >3 displayed significantly lower ANXA3 expression than did subgroups with negative and ≤3 scores (p=0.001). Moreover, ANXA3 expression was markedly lower in large tumors (>1 cm in diameter) than in microcarcinomas (p=0.001). CONCLUSION AND CLINICAL RELEVANCE: Decreased expression of ANXA3 in papillary thyroid cancer supports the idea that ANXA3 may be an effective marker of microcarcinoma, and a negative predictor of papillary thyroid cancer progression.

Up-regulation of RhoGDI2 in human breast cancer and its prognostic implications.

PURPOSE: Recent research has identified many genes and proteins that play specific roles in the process of systemic metastasis in various types of cancer. Rho GDP dissociation inhibitor 2 (RhoGDI2) has been shown to inhibit metastasis in human bladder cancer, but its role in breast cancer is controversial. MATERIALS AND METHODS: We examined the regulation and clinical significance of RhoGDI2 in Korean breast cancer patients by using proteomic approaches. RESULTS: By using a proteomic approach, we observed an increased expression of RhoGDI2 in human breast cancer tissues when compared to that of the normal breast tissues, and we validated its up-regulation in an independent cohort of 8 breast cancer patients. The clinical implication of a RhoGDI2 expression was investigated in 57 breast cancer patients by performing immunohistochemistry. RhoGDI2 did not show a significant association with the tumor size, lymph node metastasis, the histologic grade or the hormone receptor status. However, the patients with RhoGDI2-expressing tumors had significantly shorter disease-free survival (p=0.043; hazard ratio, 3.87) and distant metastasis-free survival (p=0.039; hazard ratio, 5.15). CONCLUSION: Our results demonstrated a potential role of RhoGDI2 as a poor prognostic marker as well as a potential therapeutic target. The pro-metastatic nature of RhoGDI2 shown in our study may indicate its organ-specific role in cancer metastasis.

Gastric lymphatic basin dissection for sentinel node biopsy using hybrid natural orifice transluminal endoscopic surgery (NOTES).

The aim of the present study was to describe a method of gastric lymphatic basin dissection for sentinel node biopsy using natural orifice transluminal endoscopic surgery with laparoscopic assistance (hybrid NOTES) in a porcine model. Lymph node dissection was performed in three healthy female domestic farm pigs (each around 40 kg) between October, 2007, and December, 2007. The pigs were administered a general anesthetic and laparoscopy-guided transvaginal colpotomy was performed. A two-channel endoscope was then inserted through the incision into the peritoneal cavity via the transvaginal route. An endoscope was inserted simultaneously into the mouth and indocyanine green solution was injected into the submucosal layer of the gastric wall at four sites. Dyed omentum and lymphatics were dissected using a laparoscopic dissector and the grasping forceps of a transvaginal endoscope. Lymphatics and omentum (mean 13.3 cm, range 8-20 cm) were removed transvaginally. The mean number of detected and resected sentinel nodes was 2.6 (range 1-4, diameter 2~12 mm). Sentinel lymphatic basin dissection was performed successfully and without intraoperative complications in all three cases. Hybrid NOTES is technically feasible, and this procedure may represent an alternative to laparoscopic sentinel lymph node dissection of the stomach.

Clinical factors affecting the length of minilaparotomy incision in laparoscopy-assisted distal gastrectomy.

This study investigated the factors affecting the length of the minilaparotomy incision (LOMI) in laparoscopy-assisted distal gastrectomy with Billroth I reconstruction. By using abdominal computed tomography scans, we measured the thickness of the rectus muscle (TRM), the thickness of the abdominal wall (TAW), and the distance from the gastroduodenal artery to the skin (GDAS) in 80 patients with early gastric cancer who had undergone surgery. There were positive correlations between the LOMI and body mass index (BMI), TRM, and TAW, and the LOMI increased significantly in patients with BMI > or =25 kg/m2, TAW > or =2.1 cm, and TRM > or =1.0 cm. These observations suggest that patients with two or more of the following clinical factors, BMI > or =25 kg/m2, TAW > or =2.1 cm, and TRM > or =1.0 cm, may require surgical procedures other than laparoscopy-assisted Billroth I, such as total laparoscopic intracorporeal Billroth I, Billroth II, or uncut Roux-en-Y reconstruction.

Thyrotropin level and thyroid volume for prediction of hypothyroidism following hemithyroidectomy in an Asian patient cohort.

BACKGROUND: As more patients undergo diagnostic thyroid surgery, the development of posthemithyroidectomy hypothyroidism is becoming a major concern. We hypothesized that the preoperative thyrotropin (thyroid-stimulating hormone, TSH) level and ultrasonographically measured thyroid volume, both commonly available in thyroid nodule patients, may predict the development of posthemithyroidectomy hypothyroidism. METHOD: Among the 132 patients who underwent hemithyroidectomy from January 2004 to January 2006, a total of 101 patients who were followed for more than a year were included in the analysis. RESULTS: Biochemical hypothyroidism developed in 37 patients (36.6%). Patients who developed postoperative hypothyroidism showed higher TSH levels (P < 0.001) and smaller remnant thyroid volumes (P = 0.014). Logistic regression analysis showed that the TSH level and remnant thyroid volume were independent predictors of posthemithyroidectomy hypothyroidism (P < 0.001 and P = 0.04, respectively). A risk scoring system using these two factors was created based on the results of logistic regression analyses. The incidences of hypothyroidism were 5.3%, 12.1%, 51.7%, and 85.0% according to the risk scores of 0, 1, 2, and 3, respectively. CONCLUSIONS: Patients with a high preoperative TSH level and small thyroid volume are at high risk of developing hypothyroidism following hemithyroidectomy. Potential risk of postoperative hypothyroidism should be discussed with these patients when thyroid surgery is being considered for a diagnostic purpose.