Treatment of peritoneal carcinomatosis from ovarian cancer. Present, future directions and proposals

Radical cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal sarcomatosis: Results from a reference center and considerations based on current evidence

INTRODUCTION

Peritoneal sarcomatosis is a rare disease, with multiple histological origins and poor overall prognosis. The option of radical cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is controversial. The results of a surgical team experienced in these procedures are analyzed and discussed based on the available evidence.

METHODS

Study on a prospective database of patients with peritoneal sarcomatosis who underwent CRS and HIPEC, from 2016 to 2022, in a national reference center for sarcomas and peritoneal oncological surgery, who met the established inclusion/exclusion criteria.

RESULTS

23 patients were included in the study, with a median age of 53 years (6-68). Recurrent/persistent clinical presentation predominated (78.3%). Visceral origin (including GIST and non-GIST peritoneal) accounted for 47.8% of patients, compared to 43.5% uterine and 8.7% retroperitoneal. The median PCI was 17 (3-36), with CC0 cytoreduction of 87%. Postoperative morbidity (Dindo Clavien III-IV) of 13%, with no postoperative mortality in the series. Overall survival and disease-free survival at 5 years were 64% and 34%, respectively. Histological grade was the most influential prognostic factor for survival.

CONCLUSIONS

The results of the series, with low morbidity, support the benefit of radical peritoneal oncological surgery in patients with peritoneal sarcomatosis after adequate selection, as long as it is performed in high-volume centers, experienced surgeons and expert multidisciplinary teams. However, the role of HIPEC remains to be demonstrated and pending future studies.

Can a morphological description of the peritoneal carcinomatosis in advanced ovarian cancer add prognostic information? Analysis of 1686 patients of the tumor bank ovarian cancer

Background

Peritoneal carcinomatosis in ovarian cancer is frequent and generally associated with higher stage and poorer outcome. The clinical features of peritoneal carcinomatosis are diverse and their relevance for surgical and long-term outcome remains unclear. We conducted this prospective study to describe intraoperatively the different features of peritoneal carcinomatosis(PC) and correlate them with clinicopathological features, progression-free(PFS) and overall survival (OS),.

Methods

We performed a systematic analysis of all patients with documented intraoperative PC and a primary diagnosis of epithelial ovarian, tubal, or peritoneal cancer from January 2001 to September 2018. All data were evaluated by using the systematic tumor bank tool. Specific PC features included texture(soft-hard), consistency(coarse-fine or both), wet vs dry(PC with ascites vs. PC without ascites), and localization(diffuse-local). PC characteristics were then evaluated for correlation with age, FIGO-stage, histology, lymph-node involvement, grade, and presence of residual tumor at primary surgery. Moreover, the influence of PC characteristics on OS and PFS was analyzed.

Results

A total of 1686 patients with PC and primary epithelial ovarian cancer were included. Majority of the patients were characterized by diffuse PC(73.9%). The majority of peritoneal nodules were fine in texture (55.3%) and hard in consistency (87.4%). Moreover, 27.6% of patients had dry PC. Diffuse PC localization was significantly associated with higher FIGO-stage (p<0.001), high-grade (p=0.003) and serous tumors (p=0.006) as well as residual tumor as compared to local PC (p<0.001). Wet PC also significantly correlated with diffuse localization (p <0.001) and residual tumor as compared to dry PC (p<0.001). Coarse PC was significantly associated with residual tumor as compared to fine PC (p=0.044). All other PC features didn´t correlate with clinicopathological features. As for survival outcomes, diffuse peritoneal localization (p<0.001), wet PC (p<0.001), and additional lymph node involvement (p<0.001) were associated with lower OS and PFS rates. Other PC features did not significantly impact survival.

Conclusion

Diffuse localization of peritoneal carcinomatosis was significant predictor of recurrence. Lower OS and PFS were associated with diffuse peritoneal localization, wet PC, and additional lymph node involvement. Further prospective trials are warranted with the inclusion of translational research aspects to better understand the different peritoneal carcinomatosis patterns.

Ascites do not affect the rate of complete cytoreductive surgery and prognosis in patients with primary ovarian cancer with ascites treated with hyperthermic intraperitoneal chemotherapy

Cytoreductive surgery (CRS) is the current standard therapy procedure for patients with advanced ovarian cancer (OC), but numerous patients with OC are complicated with ascites. The aim of the present study was to assess whether massive ascites affect the rate of complete CRS and prognosis for patients with primary OC treated with hyperthermic intraperitoneal chemotherapy (HIPEC). Between December 2006 and December 2015, 1,293 patients with primary OC from the Intracelom Hyperthermic Perfusion Therapy Center of the Cancer Hospital of Guangzhou Medical University prospective database were treated with CRS combined with HIPEC. A total of 1,225 patients were without malignant ascites or small amounts of ascites and 68 had massive malignant ascites. The rate of complete CRS, overall survival (OS), disease-free survival (DFS) and resolution of ascites for patients with massive ascites were analyzed between patients without/small ascites, and with massive ascites. Complete CRS was successful in 86.8% (1,063/1,225) of patients without/small ascites, and 85.3% (58/68) of patients with massive ascites. No statistical differences were identified in complete CRS success between patients with ascites and patients without/small ascites (P=0.080). For patients with massive ascites, all symptoms exhibited regression; the total objective remission rate was 100% (68/68), even for patients with incomplete CRS (10/68) (P=0.100). The mean OS was 58 months and the mean DFS was 26 months in patients without/small ascite, vs. 57 months and 28 months in patients with massive ascites. No significant differences were noted in median DFS and median OS between patients with ascites, and patients without/small ascites (All P>0.05). In conclusion, the results of the present study suggest that ascites does not affect the rate of complete CRS and the prognosis of patients with massive ascites following HIPEC. CRS is suitable for the majority of patients with primary OC and massive ascites.

Reversing platinum resistance in ovarian cancer multicellular spheroids by targeting Bcl-2

Purpose

Peritoneal metastasis is the most common pathway for the spread of ovarian cancer. Ovarian cancer cells in ascites prefer to aggregate into the more chemoresistant multicellular spheroids (MCSs), leading to treatment failure and disease recurrence. We previously established a suspension MCS model of ovarian cancer cells in vitro and found that the MCS cells acquired drug resistance to cisplatin. In the present study, we aimed to uncover the underlying mechanism of the platinum resistance of MCS and the potential targets to reverse the drug resistance.

Materials and methods

MCS models were established for the phenotypic studies, including proliferation, invasion, migration, drug resistance, apoptosis assays, and signaling pathway analysis. The key molecule, Bcl-2, was screened by profile analysis and validated by Western blotting. siRNA was used to verify the anti-cisplatin-induced apoptosis effect of Bcl-2. The Bcl-2 inhibitor, ABT-737, was used for improving the sensitivity of MCS to cisplatin. The 50% inhibitory concentrations (IC50) were measured by viability assays treated with different concentrations of cisplatin. Flow cytometry and Western blotting were used for quantification of drug-induced apoptosis.

Results

The ovarian cancer MCS showed a proliferation-stagnant but invasive phenotype when resuspended. When treated with cisplatin, MCS cells showed much higher viability, with significantly fewer apoptotic cells than the adherent cells. Levels of Bcl-2 were upregulated in ovarian cancer ascitic cells and MCS cells. Bcl-2 knockdown by siRNA or blockage by ABT-737 enhanced the cisplatin-induced apoptosis and reduced the 50% inhibitory concentrations of cisplatin for MCS by 58.5% and 88.2%, respectively.

Conclusion

The upregulated Bcl-2 contributes to cisplatin resistance in our MCS model and targeting it sensitizes the MCS to cisplatin treatment. This provides us a preliminary treatment method for ovarian cancer peritoneal metastasis.

Residual tumour less than 0.25 centimetres and positive lymph nodes are risk factors for early relapse in recurrent ovarian peritoneal carcinomatosis treated with cytoreductive surgery, HIPEC and systemic chemotherapy

AIM

The cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has showed promising results for the survival in patients with recurrent ovarian carcinomatosis, however, some of them will recur within the first year. The aim of this study is focussed on identifying the risk factors to develop the recurrence within the first year after an optimal CRS-HIPEC in patients with recurrent ovarian carcinomatosis.

METHODS

A total of 100 patients with peritoneal carcinomatosis from recurrent ovarian cancer treated by CRS + HIPEC were selected for analysis. Multivariate logistic regression analysis was performed to evaluate the relationship between the variables and the early recurrence.

RESULTS

The mean follow-up was 42.5 months. The mean age was 56.2 years. Early recurrence was observed in the 36%. The group early recurrence presented a higher rate of optimal cytoreductions CC1 (16.2% vs. 3.5%), lymph nodes (32.5% vs. 15%) and the use of hemoderivates (40.5% vs. 33%). Others parameters as Peritoneal Cancer Index, major morbidity? 3, re-operations rate and time to adjuvant chemotherapy were similar in both groups. The five years OS was 58%, for the non-early recurrence was higher than the early recurrence group (64% vs. 41%). In the multivariate analysis, CC-1 (OR 5.73; 1.16-32.04) and positive lymph nodes (OR 2.26; 1.01-4.32) proved to be independent factors for the early recurrence.

CONCLUSION

The combination of both (CC1 and positive lymph nodes) makes that the indication of CRS and HIPEC should be individualised. However, the major morbidity, stage IV and the time to the adjuvant treatment were not associated with an early recurrence, so that, a major aggressiveness is recommended to achieve a CC0.

The role of hyperthermic intraperitoneal chemotherapy using paclitaxel in platinum-sensitive recurrent epithelial ovarian cancer patients with microscopic residual disease after cytoreduction

BACKGROUND

We analyzed the role of hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) on the microscopic component of the disease in patients with a first recurrence of platinum-sensitive ovarian cancer after complete cytoreduction (CCR).

PATIENTS AND METHODS

We analyzed the data of 54 patients who were operated on between January 2001 and July 2012 with the diagnosis of platinum-sensitive recurrent ovarian cancer. In all patients, it was possible to achieve a CCR. Patients were divided into two groups: group I (cytoreduction alone) consisted of 22 surgical patients and group II (cytoreduction and HIPEC) consisted of 32 patients.

RESULTS

There were no significant differences in any of the preoperative variables studied. After a multivariate analysis of factors identified in the univariate analysis, only the presence of tumors with undifferentiated histology (hazard ratio 2.57; 95% CI 1.21-5.46; p < 0.05) was an independent factor associated with a reduced disease-free survival. The 1- and 3-year disease-free survival was 77 and 23% in patients from group I and 77 and 45% in patients from group II, respectively, with a tendency, but no significant differences (p = 0.078). There was no significant difference in postoperative morbidity between the two groups.

CONCLUSIONS

The administration of HIPEC in patients in whom it is possible to achieve a CCR of the disease has not increased postoperative morbidity and mortality rates in our center. HIPEC with paclitaxel is effective in the treatment of microscopic disease in platinum-sensitive recurrent epithelial ovarian cancer patients with microscopic residual disease after cytoreduction, although with no statistically significant difference.

Treatment of microscopic disease with hyperthermic intraoperative intraperitoneal chemotherapy after complete cytoreduction improves disease-free survival in patients with stage IIIC/IV ovarian cancer

BACKGROUND

We analyze the efficacy of hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) for microscopic residual disease in patients with stage IIIC/IV ovarian cancer after a complete cytoreduction of their disease.

PATIENTS AND METHODS

We analyzed the data of 87 consecutive patients diagnosed with stage IIIC/IV ovarian cancer operated between December 1998 and July 2011. In every patient it was possible to achieve a complete cytoreduction of their disease. (Since January 2008, our center has incorporated the use of HIPEC in patients with peritoneal surface malignancies, including patients with peritoneal dissemination of primary ovarian cancer.)

RESULTS

Of 87 patients, 52 were treated with HIPEC (paclitaxel 60 mg/m(2), 60 min, 42 °C). After a univariate analysis, factors associated with lower disease-free interval were: performing a gastrointestinal anastomosis, operative time greater than 270 min, poorly differentiated histology, and not being treated with HIPEC. After multivariate analysis, independent prognostic factors included not being treated with HIPEC [hazard ratio (HR) 8.77, 95 % CI 2.76-14.42, p < 0.01] and the presence of poorly differentiated tumors (HR 1.98, 95 % CI 1.45-8.56, p < 0.05). Disease-free survival at 1 and 3 years was 66 and 18 %, respectively, in patients without HIPEC and 81 and 63 %, respectively, in patients treated with HIPEC (p < 0.01). HIPEC administration did not alter the results obtained for disease-free survival in patients with undifferentiated tumors.

CONCLUSIONS

The treatment of the microscopic disease following complete cytoreduction with HIPEC in patients with advanced ovarian cancer is effective and can prolong disease-free survival. This survival benefit was not seen in undifferentiated tumors.

Outcome of patients with aggressive pseudomyxoma peritonei treated by cytoreductive surgery and intraperitoneal chemotherapy

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare disease with an incidence rate of approximately 1 per million a year. During the past few years, there has been a survival benefit for these patients treated by complete cytoreduction and perioperative chemotherapy. Better survival rates were found in the adenomucinosis group than the carcinomatosis group. The purpose of our study was to analyze the outcome and the prognosis factors of only high-grade PMP.

METHODS

We selected 38 patients from a prospective database of 59 with high-grade PMP from appendiceal origin who were treated by cytoreduction surgery and HIPEC at the Hospital University Reina Sofia (Cordoba, Spain) between 1998 and July 2012. Clinical, surgical, analytical, radiological, and histological data were obtained prospectively. Survival curves were calculated using the Kaplan-Meier method, a univariate analysis was performed and the log rank-test was used to analyze the effects of several clinical and pathologic factors on overall survival (OS) and disease-free survival (DFS).

RESULTS

Median follow-up time was 32 months (range, 2-170). Median age at diagnosis was 57 years (range, 32-77). In 89.5 % of patients, optimal cytoreduction CC-0 (57.9 %) and CC-1 (31.6 %) was achieved. In the remaining 10.5 %, cytoreduction was classified as CC-2. The median PCI score was 21 (range, 4-38). Morbidity complications ≥ Grade 3 in the CTCAE v 3.0 classification was 18.4 %. One patient died 45 days postsurgery. Median OS at the end of follow-up was 36 months (range, 9-83); overall 5-year survival rate was 58.7 %. In the univariate analysis for OS, significant values were obtained for lymph-node involvement and suboptimal cytoreduction. The 5-year OS was 64.5 % when an optimal cytoreduction was achieved. Median DFS was 36 months (17-54); 3-year DFS rate was 49.1 %. Neoadjuvant therapy did not affect the survival of these patients; there was no difference in the 5-year OS (43 % vs. 75 %, p = 0.068).

CONCLUSIONS

In aggressive PMP, cytoreduction with peritonectomy procedure plus HIPEC is a safe procedure that suggests an improvement to the survival rates. Because optimal cytoreduction is a primary prognostic factor for survival rates, this procedure would have to be performed in an experienced center with a low morbidity. Neoadjuvant chemotherapy has not demonstrated benefits in these patients and further research will be required.

[Urinary tract surgery in patients with ovarian peritoneal carcinomatosis treated with cytoreduction and hyperthermic intraoperative intraperitoneal chemotherapy]

INTRODUCTION

The objective of the present work is to describe our experience in the surgery of the ureter and bladder in patients with primary and recurrent ovarian cancer subjected to peritonectomy procedures and the administration of hyperthermic intraoperative intraperitoneal chemotherapy (HIIC).

PATIENTS AND METHOD

Those patients who required surgical procedures on the distal ureter or bladder, were selected from a prospective data base constructed at the beginning of the peritoneal carcinomatosis program in our centre. Seven patients fulfilled this requirement and were included in the study. A total of 81 patients diagnosed with primary or recurrent ovarian cancer from December 2007 to April 2011 were included for maximum effort cytoreduction and HIIC.

RESULTS

It was necessary to perform some surgical manoeuvre on the ureter or bladder in seven patients, with a median age of 46 years (40-71). Four patients were operated on due to recurrence of the ovarian disease and in the other 3 patients the indication was surgical rescue after non-optimal surgery in another centre. There was direct tumour involvement of the lower urinary tract in 4 of them. Three patients (42%) in the series developed at least one postoperative complication.

CONCLUSION

The performing of peritonectomy procedures that include the eventual resection of the ureter or bladder, and the subsequent application of HIIC in a selected group of patients with peritoneal dissemination due to an ovarian carcinoma can be done with reasonable rates of postoperative morbidity. These surgical procedures may be necessary to achieve optimal surgery.

Pseudomyxoma peritonei treated by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: results from a single centre

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare, slowly progressive disease whose prognosis depends primarily on the completeness of cytoreduction. The value of intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) and of additional factors predicting long-term outcome and disease-free survival (DFS) remains poorly understood. This study aims to analyse survival rates and prognostic factors in patients undergoing maximal cytoreduction and HIPEC.

METHODS

Thirty patients were selected from a prospective database of records for patients undergoing cytoreduction and HIPEC with mitomycin C or paclitaxel. Overall survival (OS), DFS, and the prognostic factors influencing them, were examined using multivariate analysis.

RESULTS

Median follow-up was 44 months (range, 8-144). Histological classification of PMPs was DPAM in 6/30 of cases, PMCA-I in 10/30 and PMCA in 14/30. Complete cytoreduction (CC-0 and CC-1) was achieved in 28/30 of patients and CC-2 in 2/30. Median OS was 111 months (range 0-230) and five-year OS rate was 67%. Median DFS was 53.5 months (range 0-120) and 5-year DFS rate was 44%. Incomplete cytoreduction, lymph node involvement and PCI>20 were associated with poor prognosis for OS, while lymph node involvement, elevated CA-125 levels, unfavourable histology and previous chemotherapy were associated with poor outcomes for DFS. There was morbidity of Grade 3 or higher in 9/30. Post-operative mortality occurred in 1 case.

CONCLUSION

Cytoreduction plus peritonectomy procedures combined with HIPEC is a safe treatment and could improve survival rates. Since the optimal cytoreduction is the primary prognostic factor, patients should be centralised under the care of experienced teams.

[Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy associated toxicity in treatment of peritoneal carcinomatosis]

INTRODUCTION

Peritoneal carcinomatosis is a form of intra-abdominal dissemination of several tumours, which is associated with a poor prognosis. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is an alternative treatment. The aim of this study is to describe the toxicity associated with this procedure in patients with peritoneal carcinomatosis.

METHOD

We conducted a descriptive, retrospective, single-centre study, including all patients undergoing this procedure between December 2007 and January 2010. The following data were recorded: anthropometric data, personal and surgical events, indication, previous treatments, extent of carcinomatosis, intervention duration, hospital stay, and type of complications and/or adverse events following application of the multidisciplinary treatment.

RESULTS

We performed 46 interventions on 45 patients diagnosed with peritoneal carcinomatosis from different causes, mainly ovarian cancer (83%). Paclitaxel was the most-used drug (35 interventions). There was no associated mortality, the average intervention time was 6.4 hours and the average hospital stay 7 days. We recorded adverse effects for 42 procedures, being grade 3-4 in 28.3% of the patients. The severe adverse events were: 10.9% gastrointestinal, 10.9% infectious, 6.5% haemorrhage or bleeding, 6.5% medullary toxicity, 4.4% respiratory, 2.2% coagulation and 2.2% hepatobiliary disorders. One patient developed grade III neutropaenia, probably associated with cisplatin.

CONCLUSION

The morbidity and mortality is in line with the average of published studies, and has mainly been attributed to surgical complications. Toxicity data lower than other studies can be due to using more tolerable chemotherapy regimens, not including drug combinations and given that paclitaxel was the main drug.

Neoadjuvant intraperitoneal chemotherapy with paclitaxel for the radical surgical treatment of peritoneal carcinomatosis in ovarian cancer: a prospective pilot study

PURPOSE

The admitted benefits of intraperitoneal chemotherapy during postoperative administration for the treatment of peritoneal carcinomatosis from ovarian origin are limited by their associated morbidity and restricted diffusion by the presence of multiple intra-abdominal adherences. The purpose of the study was to evaluate the security, effectiveness, and cytoreduction optimization of intraperitoneal paclitaxel administration previously to radical surgery/peritonectomy/HIPEC (hyperthermic intraoperative intraperitoneal chemotherapy) either in monotherapy or combined with intravenous carboplatin.

METHODS

Prospective pilot study of 10 patients with ovarian peritoneal carcinomatosis in stage IIIc-FIGO without previous treatment. After staging of the diseases by laparoscopy, five patients received paclitaxel by weekly intraperitoneal administration (60 mg/m(2), 10 cycles), and other five patients additionally received intravenous carboplatin every 21 days (AUC 6, 4 cycles). Subsequently radical surgery/peritonectomy with HIPEC was performed.

RESULTS

The presence of moderate abdominal pain was the most common (70%) side effect associated with neoadjuvant paclitaxel intraperitoneal administration. The intravenous carboplatin administration was not associated with significant increase in adverse effects. It boosted intraperitoneal paclitaxel-associated antitumoral activity with a high average decrease in Index Cancer Peritoneal (21.2 vs. 14.4, P = 0.066) and CA 125(1,053 vs. 346, P = 0.043). All the patients who received combined neoadjuvant chemotherapy obtained R0 cytoreduction. Five-year overall survival was 62%.

CONCLUSIONS

The intraperitoneal paclitaxel weekly administration combined with intravenous carboplatin administration prior to radical surgery/peritonectomy with HIPEC is a safe and effective option in the treatment of ovarian peritoneal carcinomatosis. This study shows the possibility to investigate other forms of intraperitoneal chemotherapy and their combinations thoroughly.

Imaging of 186Re-liposome therapy in ovarian cancer xenograft model of peritoneal carcinomatosis

This study determined the biodistribution of rhenium-186 ((186)Re) encapsulated in biotin-liposomes containing patent blue dye, injected intraperitoneally (IP) with avidin in an OVCAR-3 ovarian cancer xenograft model and evaluated tumor response of this therapy with fluorine-18-fluorodeoxyglucose ((18)F-FDG) microPET imaging. Treated rats (n = 8) received an IP injection of (186)Re-blue-biotin-liposomes (1000 MBq/kg) 30 min before an IP injection of avidin (5 mg), whereas control rats (n = 4) received a sham IP injection of saline. Scintigraphic images showed that (186)Re-blue-biotin liposomes/avidin were retained in the peritoneal cavity with 18% of the original activity remaining after 5 days. From 1 to 4 weeks post-treatment, peritoneal (18)F-FDG standard uptake values decreased 30% in treatment group, yet increased 44% in control group. Total number of cells in ascites was significantly higher in control versus treatment group. Omental fat in control rats had numerous tumor cells compared with treated rats. Results show the potential for (186)Re-blue-biotin-liposome/avidin system in treating advanced ovarian cancer involving peritoneal carcinomatosis.

SPARC ameliorates ovarian cancer-associated inflammation

We have recently identified that the role of secreted protein acidic and rich in cysteine (SPARC) in amelioration of peritoneal ovarian carcinomatosis is mediated, at least in part, through mesothelial cell/lysophosphatidic acid-induced inflammatory response in ovarian cancer cells. The aim of this study was to elucidate the molecular mechanisms of the interactions between tumor cells and the cellular components of the ovarian cancer peritoneal microenvironment, specifically, mesothelial cells and macrophages. We found that SPARC not only significantly reduced macrophage chemoattractant protein-1 production and its macrophage chemotactic effect, but also attenuated the response of ovarian cancer cells to the mitogenic and proinvasive effects of macrophage chemo-attractant protein-1 and decreased macrophage-induced cancer cell invasiveness. Overexpression of SPARC in ovarian cancer cells significantly attenuated macrophage- and mesothelial cell-induced production and activity of interleukin-6, prostanoids (prostaglandins E2 and 8-isoprostanes) as well as matrix metalloproteinases and urokinase plasminogen activator. Moreover, the effects of SPARC overexpression in ovarian cancer cells were mediated, in part, through inhibition of nuclear factor-kappaB promoter activation. These results indicate, for the first time, that the effects of tumor SPARC as a negative regulator of ovarian cancer are mediated through decreased recruitment of macrophages and downregulation of the associated inflammation.