Initial experience of focal therapy for prostate cancer using I-125 seed implantation: Unilateral ablation for patients selected by extended biopsy and MRI findings

99

Background: Focal therapy for prostate cancer could be a minimally invasive therapeutic option with the preservation of genitourinary function to reduce treatment associated complication under the appropriate selection of patients. We have reported the good predict ability to unilateral prostate cancer by extended prostate biopsy combined with transperineal and transrectal approaches (Eur Urol supple, 2009). Among the candidate ablative, brachytherapy which has been proved as a definitive therapy and applied worldwide has been thought to have potential for focal ablation due to its ability of dose and location adjustment by seed implantation under real-time monitoring. Based on the findings, focal therapy with hemiablation using I-125 seed implantation has been started in our instituion. The aim of study is to describe the initial experience of focal therapy for patients selected by extended biopsy and MRI findings.

Methods: The eligible criteria for focal therapy to prostate cancer are as follows. Clinical stage is T2a or less. The positive cores of cancer are proven within unilateral lobe by extended prostate biopsy. There was no cancerous lesion in contralateral lobe by MRI. Gleason score in positive cores was 3 + 4 or less. Maximum cancer length was less than 5 mm. PSA value is less than 10 ng/mL. On the treatment, I-125 seeds were implanted to ablate the unilateral lobe with 160 Gy of the prescription dose. The protocol has been approved by the institutional ethics commit.

Results: At present, 3 patients were enrolled in this study and underwent focal therapy with written informed consents. In all three cases, I-125 seeds implanted (number od seeds: 43, 39, and 37) to unilateral lobe without severe acute complication such as acute urinary retention. In one case that has been followed over 3months among the initial three cases, PSA values decreased to 2.07 mg/ml at 3 months after the seed implantation.

Conclusions: To our knowledge, this is the first report about focal therapy by brachytherapy with hemiablative technique. In our initail experience, severe treatment associated complication has not been observed.

No significant financial relationships to disclose.

C-reactive protein kinetics superior to radiographic response as a surrogate endpoint for survival in patients with advanced renal cell carcinoma

333

Background: As cytokines and targeted agents against advanced renal cell carcinoma (aRCC) are considered to achieve high stable disease (SD) rate rather than objective response (OR) by radiographic measurement, we often face the therapeutic dilemma in deciding whether to continue the ongoing treatment and when to change it. Therefore, other valid surrogate endpoints have been desired. We have previously demonstrated C-reactive protein (CRP) kinetics could predict prognosis of pts with aRCC (Eur Urol. 2009:1145-53).

Methods: This study was performed on 56 pts with aRCC (metastatic: 54, unresectable: 2) enrolled in a phase II trial of interferon-alpha, cimetidine, COX-2 inhibitor and renin-angiotensin-system inhibitor (I-CCA; Cancer Sci. in press). CRP levels were measured at pretreatment, thereafter almost every visit. Pts were divided into 3 groups according to CRP kinetics. Pts whose pretreatment CRP levels were < 5 mg/l were assigned to nonelevated group. Pts whose pretreatment CRP levels were > 5 mg/l but normalized (< 5 mg/l) at least one time during I-CCA were assigned to normalized group. Pts whose CRP level never decreased to normal level were assigned to non-normalized group. Radiographic response was assessed by WHO criteria; survivals were estimated by Kaplan–Meier method and prognostic factors were assessed by Cox's proportional hazard model.

Results: Median follow-up was 26 mo. An OR and clinical benefit rate to I-CCA were 20 and 64%, respectively. The median progression-free and overall survival (OS) was 12 and 45 mo, respectively. The median OS was 74, 83 and 13 mo in in non-elevated (n=26), normalized (n=16) and non-normalized (n=14) group, respectively (p<0.0001). Of the 25 pts achieving SD, CRP kinetics was independent prognostic factor for OS (p<0.0001). Of the pts whose pretreatment CRP was elevated, all pts achieving OR had CRP normalization and multivariate analysis revealed CRP normalization was independent prognostic factor for OS (p=0.0008), whereas achieving OR was not (p=0.19).

Conclusions: CRP kinetics compares favorably with objective response to systemic therapy as a valid surrogate endpoint for survival.

No significant financial relationships to disclose.

Does induction chemoradiotherapy compromise subsequent radical cystectomy? A single-institutional comparative study on perioperative complications according to the Clavien-Dindo classification

284

Background: Recently, bladder-sparing protocols incorporating TUR + chemoradiotherapy (CRT) have been developed. Patients who achieve CR after CRT are subjects for bladder preservation treatment and those who with non-CR undergo radical cystectomy (RC). However, early studies suggest that RC following pelvic irradiation associates with a higher mortality. To validate the impact of induction CRT on perioperative morbidity of RC, we compared complications of RC in patients treated with or without induction CRT at a single university hospital.

Methods: Records of consecutive 193 patients who underwent RC for bladder cancer between April 1989 and May 2010 were reviewed. Induction CRT consists of radiation at 40 Gy to the small pelvis and 2 cycles of concurrent cisplatin at 20 mg/d for 5 days. Any complications occurred within 30 days after RC were graded according to the Clavien-Dindo classification system. Complications of grade I or II were classified as minor and complications of grade III or greater were classified as major.

Results: Eighty-seven patients underwent induction CRT (CRT group) while 106 did not (control group). Patients of CRT group had significantly more advanced disease. No patient died within 90 days. Twenty one (11%) patients experienced at least one major complications; there was no significant difference in the incidence of major complications between CRT and control group (14% vs. 8%, p = 0.26). The details were as follows; infectious (3.5% vs. 3.8%, p = 1.0), gastrointestinal (4.6% vs. 0.9%, p = 0.18), surgical (6.9% vs. 3.8%, p = 0.35), cardiovascular (1.2% vs. 0.9%, p = 1.0). There was no significant difference between the incidence of minor complications (61% vs. 51%, p = 0.19).

Conclusions: Induction CRT at 40 Gy is unlikely to compromise subsequent RC.

No significant financial relationships to disclose.

Incidence of benign pathologic lesions at nephrectomy for renal masses presumed to be stage I renal cell carcinoma in Japanese patients: Impact of sex, age, and tumor size

374

Background: The widespread use of modern imaging techniques has resulted in the increased detection of small, asymptomatic renal tumors. Some recent studies from Western countries have reported that the incidence of benign lesions is approximately 15% in patients undergoing definitive surgery for renal masses presumed to be clinical stage I renal cell carcinoma (RCC). The high level of noncancerous lesions is, to some extent, due to the fact that no imaging feature can accurately distinguish either oncocytoma or lipid-poor angiomyolipma (AML) from RCC. This study attempts to determine the incidence of benign pathologic findings for such renal masses in Asian patients.

Methods: Between 1991 and 2009, 711 consecutive patients (218 women and 493 men) underwent partial (n=206) or radical (n=505) nephrectomy for renal masses presumed to be stage T1N0M0 (T1a/T1b= 503/208) sporadic RCC on preoperative imaging in two Japanese centers. The mean size of the lesions was 3.3 cm (range 0.3-7.0). The pathologic features were reviewed by an experienced pathologist.

Results: Of the 711 masses, 53 (7.5%) revealed benign pathologic findings. Twenty-two (3.1%) were AMLs, 13 (1.8%) were oncocytomas, 8 (1.1%) were complicated cysts, and 10 were others. Twenty-eight (12.8%) of the 218 females and 25 (5.1%) of the 493 males had benign lesions (p=0.0005). Of the 357 patients aged 60 years or younger, 37 (10.4%) had benign lesions while only 16 (4.5%) of the 354 patients over 60 years did (p=0.024). Forty six (9.2%) of the 503 T1a and 7 (3.4%) of the 203 T1b masses were benign (p=0.0071). A multivariate logistic regression model showed that sex, age and tumor size were all independently predictive of benign histology, particularly of AML.

Conclusions: The present incidence (7.5%) of benign lesions in presumed clinical stage T1N0M0 RCC masses at nephrectomy was lower than the incidence of approximately 15% previously reported from Western countries, probably because of the low incidence of oncocytomas in Japanese patients. Female gender, young age and small tumor size are all independently predictive of benign lesions, particularly of AML in Japanese patients.

No significant financial relationships to disclose.

Abstract P5-14-20: Clinical Features of Surgical Resection for Solitary Pulmonary Metastasis and the Discrepancy in Immunopathological Features between Primary and Metastatic Breast Cancer Lesions

Background: The treatment for metastatic breast cancer (MBC) is usually systemic therapy decided by the hormone and HER2 status of primary breast cancer lesion. There are some reports about the discrepancy in hormone and HER2 status between primary and metastatic lesion in these days. We have reported previously that the expression of ALDH-1 which considered the pathological markers of breast cancer stem cell in axillary lymph node matastases is a significant predictor of poor outcome in primary breast cancer patients (Figure 1). We evaluated the role of surgery in the diagnosis and treatment of a solitary pulmonary nodule (SPN) in breast cancer patients and demonstrated the significance of analyzing the immunopathological features in metastatic breast cancer lesion.

Methods: Between 1990 and 2006, 17 patients (PM) with SPN which were diagnosed breast cancer metastases underwent complete pulmonary resection and 36 MBC patients (AP) underwent autopsy after breast cancer related death in our hospitals. We retrospectively analyzed clinicopathological features and the expression of ER, HER2, Ki-67 and ALDH-1 in both primary and metastatic breast cancer lesions.

Results: The median age of PM patients was 53 (range 30-80). All PM patients had not other metastases and had undergone curative breast cancer operation. The pulmonary operation were partial pulmonary resection in 15(88%) and lobectomy in 2 (12%) patients. The median disease free survival (DFS) was 63 months (range 9-175). Median overall survival (OS) was 181 months and the median OS after pulmonary operation was 48 months. The median DFS and OS of AP patients were 21 and 43 months. All AP patients had multiple visceral metastases. We compared the immunohistlogical status between primary and metastatic lesion and evaluated the colletation with these status in metastatic lesion and prognosis in all patients. Conclusion: Pulmonary resection was effective to diagnose and the OS after resection was relatively long in PM patients. We report the value of the expression of ER, HER2, Ki67 and ALDH-1 in distant metastatic lesions.

Prophylactic pancreatic stent placement and post-ERCP pancreatitis: a systematic review and meta-analysis

BACKGROUND AND STUDY AIMS

Pancreatitis is one of the most frequent complications of endoscopic retrograde cholangiopancreatography (ERCP). The placement of a prophylactic pancreatic stent after ERCP can help prevent post-ERCP pancreatitis (PEP). We aimed to provide an up-to-date meta-analysis regarding pancreatic stent placement for prevention of PEP and review the immediate adverse events associated with pancreatic stent placement.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) considering pancreatic stent placement and the subsequent incidence of PEP. The primary outcome measure was the incidence of PEP. We also did a meta-analysis of RCTs and observational studies that reported on immediate adverse events, in order to estimate their incidence.

RESULTS

Eight studies, involving 680 patients, were included in the meta-analysis; 336 patients had pancreatic stent placement, and 344 patients formed the control group. Pancreatic stent placement was associated with a statistically significant reduction in PEP (relative risk [RR] 0.32, 95 % confidence interval [CI] 0.19 - 0.52; P<0.001). Subgroup analysis with stratification according to PEP severity showed that pancreatic stenting was beneficial in patients with mild to moderate PEP (RR 0.36, 95 %CI 0.22 -0.60; P<0.001) and in patients with severe PEP (RR 0.23, 95 %CI 0.06 - 0.91; P=0.04). Subgroup analysis according to patient selection demonstrated that pancreatic stenting was effective for both high risk and mixed-case groups. Weighted pooled estimates from between one and 17 studies for incidences of immediate adverse events were: overall complications 4.4 %; any infection 3.0 %; bleeding 2.5 %; cholangitis or cholecystitis 3.1 %; necrosis 0.4 %; pancreatic stent migration 4.9 % and occlusion 7.9 %; perforation 0.8 %; pseudocysts 3.0 %; and retroperitoneal perforation 1.2 %.

CONCLUSIONS

The meta-analysis shows that pancreatic stent placement after ERCP reduces the risk of PEP.

Synthesis and biological activity of artificial mRNA prepared with novel phosphorylating reagents

Though medicines that target mRNA are under active investigation, there has been little or no effort to develop mRNA itself as a medicine. Here, we report the synthesis of a 130-nt mRNA sequence encoding a 33-amino-acid peptide that includes the sequence of glucagon-like peptide-1, a peptide that stimulates glucose-dependent insulin secretion from the pancreas. The synthesis method used, which had previously been developed in our laboratory, was based on the use of 2-cyanoethoxymethyl as the 2′-hydroxy protecting group. We also developed novel, highly reactive phosphotriester pyrophosphorylating reagents to pyrophosphorylate the 5′-end of the 130-mer RNA in preparation for capping. We completed the synthesis of the artificial mRNA by the enzymatic addition of a 5′-cap and a 3′-poly(A) tail to the pyrophosphorylated 130-mer and showed that the resulting mRNA supported protein synthesis in a cell-free system and in whole cells. As far as we know, this is the first time that mRNA has been prepared from a chemically synthesized RNA sequence. As well as providing a research tool for the intracellular expression of peptides, the technology described here may be used for the production of mRNA for medical applications.

Minimum incision endoscopic surgery (MIES) in Japanese urology: results of adrenalectomy, radical nephrectomy and radical prostatectomy

AIM

The aim of this study was to evaluate the feasibility of our minimum incision endoscopic surgeries (MIES), adrenalectomy, radical nephrectomy and radical prostatectomy, which are operated via a single minimum incision which narrowly permits extraction of the specimen, using an endoscope, without gas insufflation, without any trocar ports and without injury to the peritoneum. These operations have been developed in our department in the late 1990 s and have since been performed in more than 1000 patients and certified as advanced surgery by the Japanese government in 2006.

METHODS

Adrenalectomy, radical nephrectomy and radical prostatectomy were carried out via a single minimum incision under the conditions of gasless, portless (without trocar ports), intact peritoneum and at low cost with reusable devices. The anatomic plane was separated through the incision and a wide working space was made extraperitoneally. New devices were made especially for this operation in our department, which are now commercially available. The results of the most recent consecutive cases (2005-2007) are evaluated. The results of adrenalectomy and radical nephrectomy performed by 12 operators including inexperienced doctors were compared with the initial results performed by 2 operators, mostly by one operator.

RESULTS

In the recent 60 cases of adrenalectomy, the average length of incision, operative time, estimated blood loss were 5.7 cm (5.6 cm in the initial 30 cases), 156 min (147 min) and 174 ml (139 ml), respectively. A complication was observed in one case, injury to the renal artery. Blood transfusion was not performed. Average days to oral feeding, to long walking (more than 100 m) and to possible minimal hospital stay were 1.3 days (2 days), 1.1 days (1.1 days) and 1.9 days (4.6 days), respectively. In the recent 80 cases of radical nephrectomy, the average length of incision, operative time, estimated blood loss were 6.6 cm (6.6 cm in the initial 80 cases), 192 min (186 min) and 315 ml (324 ml), respectively. Complications were not observed in any of the cases (2) and blood transfusion was performed in 1 case (3). Average days to oral feeding, to long walking (more than 100 m) and to possible minimal hospital stay were 1.1 days (1.4 days), 1.2 days (1.4 days) and 1.9 days (4.8 days), respectively. In the recent 50 cases of radical prostatectomy, the average length of incision and operative time were 5.9 cm and 261 min, respectively. Two complications (small rectal injuries) were observed and one blood transfusion was performed. Average days to oral feeding, to long walking (more than 100 m) and possible minimal hospital stay were 1.0 days, 1.0 days and 2.4 days, respectively. Wound pain was minimal and analgesics were generally not required on the second postoperative day in the above 3 operations. Although prophylactic antibiotics were not used in the recent cases of adrenalectomy and radical nephrectomy, surgical site infection was not observed.

CONCLUSION

Minimum incision endoscopic surgery (MIES) in Japanese urology is a safe, reproducible, cost-effective and minimally invasive treatment option for adrenal tumor, renal cell carcinoma and prostate carcinoma.

Effect of GSM-900 and -1800 signals on the skin of hairless rats. I: 2-hour acute exposures

PURPOSE

The acute influence on the skin of non-ionizing electromagnetic fields in the radiofrequency (RF) range used in mobile telephony has not been widely studied to date. The purpose of this work was to determine whether the cells of hairless rat skin are affected by acute local exposure to Global System for Mobile Communication: GSM-900 or -1800 RadioFrequency Radiation (RFR).

MATERIALS AND METHODS

Hairless female rats were exposed or sham-exposed for 2 h to GSM-900 or -1800 signals, using a loop-antenna located on the right part of the rats' back. The local Specific Absorption rate (SAR) at skin level was ca. 5 W/kg (5.8+/-0.4 and 4.8+/-0.4 W/kg at 900 and 1800 MHz, respectively). A skin biopsy was done at the end of the experiment not only at the location of exposure, but also on the symmetrical part of the back.

RESULTS

Analysis of skin sections using Hematoxylin Eosin Saffron (HES) coloration showed no difference in skin thickness or apparent cell toxicity (with no sign of cellular necrosis) among the animal groups. Histological analysis of the epidermis showed that the ratio between cells expressing the antigen Ki-67 (cellular proliferation marker) and the total number of cells remained within the range of normal proliferation ratio for the exposed side of the animal. No Ki-67 labelling was observed at the dermis level. Results on filaggrin, collagen and elastin levels also showed an insignificant influence of RFR.

CONCLUSIONS

These results do not demonstrate any major physical and histological variations at skin level induced by RFR used in mobile telephony.

Effect of GSM-900 and -1800 signals on the skin of hairless rats. II: 12-week chronic exposures

PURPOSE

The purpose of this work was to determine whether the cellular components of Hairless-rat skin are affected by a chronic local exposure to non-ionizing radiations of Global Mobile Phone System: GSM-900 or -1800 radiations at specific absorption rate (SAR) 2.5 and 5 W/kg.

MATERIALS AND METHODS

A selected part of the right back of five-week old female hairless rats was exposed or sham exposed (n = 8) for 2 h per day, 5 days a week, for 12 weeks to GSM-900 or -1800 signals using a loop-antenna. At the end of the experiment, skin biopsies were taken.

RESULTS

Analyses of skin sections using hematoxylin eosin saffron (HES) coloration showed no significant difference in skin thickness among the groups. Immunohistochemical analysis of basal lamella cells in radiofrequency radiation (RFR)-exposed epidermis showed that the ratio of the antigen Ki-67 (cellular proliferation marker) positive cells to total lamella cells remained within the range of the normal proliferation ratio. No significant differences in the level of filaggrin, collagen, and elastin were observed among the different groups.

CONCLUSIONS

The results of this 12-week chronic study do not demonstrate major histological variations in the skin of hairless rats exposed to RFR used in mobile telephony (GSM-900 or -1800).

Multicenter phase II study of a frozen glove to prevent docetaxel-induced onycholysis and cutaneous toxicity for the breast cancer patients (Kinki Multidisciplinary Breast Oncology Group: KMBOG-0605)

Abstract #4093

Background: We have learned from the questionnaire survey of description and hearing type that the onycholysis and skin toxicity occur in approximately 90% of patients(pts) treated with docetaxel (DTX) on hands and 65% on feet. Besides neurotoxicity and edema, these adverse events cause the worse quality of life (QOL) assessment because of the exposure, public noticed site. According to the report that the Elasto-Gel frozen glove (FG) was effective for the prevention of DTX-induced onycholysis and skin toxicity (Scotte F, JCO 23, 4424-29, 2005), we have planned to reanalyze the efficacy and safety of FG for Japanese breast cancer pts by the multicenter, prospective phase II study.&#x2028; Patients and Methods: Patients receiving DTX 75 mg/m2 alone or in combination chemotherapy more than 4 cycles were eligible for this case-control study. Each patient on case group wore an FG for a total of 90 minutes on the both hands. Her feet were not protected. The control data was obtained by the questionnaire survey from the pts who had not used FG during the chemotherapy. Onycholysis and skin toxicity were assessed at each cycle by National Cancer Institute Common Toxicity Criteria and documented by photography. This study had accomplished by multidisciplinary approach by nurses, pharmacists, and doctors. Wilcoxon matched-pairs rank test was used.&#x2028; Results: Between March 2006 and May 2007, 70 pts on case and 52 pts on control were evaluated. Median age were similar for each group, 52 [29-74 years] on case and 51 [25-73 years] on control. Onycholysis and skin toxicity were significantly lower in the FG-protected hands compared with the control hands (P = .0001). Onycholysis was grade (G) 0 in 41% v 8%, G1 in 54% v 74%, and G2 to 3 in 4.3% v 18% for the FG-protected hands and the control hands, respectively. For the feet, there was no difference in frequency between pts on case and on control. Skin toxicity was G0 in 76.6% v 44%, G1 in 13.6% v 42%, and G2 to 3 in 4.4% v 14% for the FG-protected hands and the control, respectively. 32 pts (46%) had experienced the deterioration of pigmentation on hands and/or feet, the FG had seemed not to be able to prevent these unfavorable events. Median time to nail and skin toxicity occurrence was not significantly different between the FG-protected and the control hands of feet, respectively. Although one pt (1.4%) experienced discomfort due to cold intolerance, there were no serious adverse events caused by FG.&#x2028; Conclusion: FG significantly reduces the nail and skin toxicity associated with DTX and is a safety tool on supportive care management. This should be provided in general practice widely to improve a patient's QOL.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4093.

Comparison of twice-daily injections of biphasic insulin lispro and basal-bolus therapy: glycaemic control and quality-of-life of insulin-naïve type 2 diabetic patients

OBJECTIVE

The aim of this study was to evaluate twice-daily injections of biphasic insulin lispro vs. basal-bolus (BB) therapy with regard to quality-of-life (QOL) and glycaemic control in insulin-naïve type 2 diabetic patients.

METHODS

Twenty-eight patients with type 2 diabetes were randomized to receive either twice-daily 50/50 premixed insulin lispro (Mix50 group) or BB (NPH insulin at bedtime and preprandial insulin lispro) therapy (BB group) for 12 weeks. Glycated haemoglobin (HbA1C), 1,5-anhydroglucitol (1,5-AG), blood plasma glucose level, body mass index (BMI), daily total insulin dosage and insulin therapy-related QOL (ITR-QOL) were studied.

RESULTS

ITR-QOL was significantly better in the Mix50 than in the BB group (103.1 +/- 9.8 vs. 90.6 +/- 19.4; p < 0.05). HbA(1c) improved in both groups (from 11.1 +/- 2.1 to 6.9 +/- 1.0% with Mix50 vs. from 11.0 +/- 2.3 to 6.6 +/- 0.8% with BB therapy).

CONCLUSION

These results might suggest that twice-daily injections of premixed rapid-acting insulin analogue therapy could achieve good glycaemic control and better QOL compared with BB therapy in insulin-naïve type 2 diabetes.

Magnetic behavior in an ordered Co nanorod array

The magnetization reversal process of an ordered Co nanorod array is shown using the images obtained from successive in-field magnetic force microscope (MFM) measurements. The magnetization reversal model is discussed according to local and whole magnetization reversal properties measured by the polar magneto-optical Kerr effect (PMOKE) and an alternating gradient magnetometer (AGM), respectively. Additionally, the dipolar field was probed using in-field MFM measurements. By removing the effect of the dipolar field, an intrinsic switching field distribution (SFD) is shown in a map with a hexagonal array. A detailed study of the dipolar field in ordered nanorod arrays with various diameters and pitches was carried out by numerical calculations.

Chemical synthesis of a very long RNA oligomer, a 110mer precursor-miRNA candidate, with 2-cyanoethoxymethyl (CEM) as the 2'-O-protecting group

A long RNA oligomer, a 110mer with the sequence of a precursor-miRNA candidate, has been chemically synthesized in a single synthesizer run by means of standard automated phosphoramidite chemistry. The synthetic method involved the use of 2-cyanoethoxymethyl (CEM), a 2'-hydroxyl protecting group recently developed in our laboratory. We confirmed the identity of the synthetic 110mer by MALDI-TOF mass spectrometry, as well as HPLC, electrophoretic methods, RNase-digestion experiments, and its in vitro gene-silencing activity. The chemical synthesis of RNA oligomers of more than 100 nucleotides, which has until now been extremely difficult, can be practically realized by the CEM method.

Changes in biochemical markers and prediction of effectiveness of intra-articular hyaluronan in patients with knee osteoarthritis

OBJECTIVE

Intra-articular injection of hyaluronan (HA) is frequently used to treat knee osteoarthritis (OA). We studied whether HA injections induced significant changes in levels of biochemical markers in synovial fluid (SF). In addition, we investigated the possibility of predicting the effectiveness of HA based on these biochemical markers.

METHODS

Twenty-eight patients with knee OA underwent five weekly intra-articular injections of HA. Knee pain was measured on visual analog scale (VAS) before and after the five injections. Levels of biochemical markers, including chondroitin 6-sulfate (C6S), chondroitin 4-sulfate (C4S), keratan sulfate (KS), and tenascin-C (TN-C), were determined before and after the five injections. Correlations between the biochemical markers before HA injection and the improvement of VAS after the five injections were evaluated.

RESULTS

After HA injections, levels of C6S, C4S, and KS decreased significantly. Inverse correlations were observed between the levels of TN-C and C4S before HA injection and improvement of VAS after the five injections. In contrast, no significant correlation was seen between levels of C6S and KS before injections and improvement of VAS after the five injections.

CONCLUSION

The reduction in C6S, C4S, and KS levels after HA injections reflects that HA could help maintain normal cartilage metabolism. Our findings suggest that HA injections are effective in patients whose knees contain low levels of TN-C and C4S, reflecting an early stage of OA and limited synovitis.