Perioperative morbidity and outcome of secondary cytoreduction for recurrent epithelial ovarian cancer

Secondary Cytoreductive Surgery in Platinum-Sensitive Recurrent Ovarian Cancer: A Meta-Analysis

PURPOSE

The survival impact of secondary cytoreductive surgery in patients with platinum-sensitive recurrent ovarian cancer was studied.

METHODS

We identified published studies from 1983 to 2021 following our inclusion criteria from MEDLINE, EMBASE, and Cochrane library. To integrate the effect size of single-arm studies, meta-analysis was performed using death rate as a primary outcome. The effect of complete cytoreduction and optimal cytoreduction on survival was evaluated using meta-regression. The pooled death rate was presented with a 95% CI. The publication bias was evaluated with the funnel plot and Egger's test, and sensitivity analysis was performed. To overcome missing death rates, the linear regression model was performed on log-transformed median overall survival (OS) time using study size as a weight.

RESULTS

Thirty-six studies with 2,805 patients reporting death rates were used for this meta-analysis of the 80 eligible studies. There was strong heterogeneity, with the P value of the Cochrane Q test of < 0.0001 and Higgins's I² statistics of 86%; thus, we considered a random effect model. The pooled death rate was 44.2% (95% CI, 39.0 to 49.5), and both the complete and optimal cytoreductions were associated with better survival outcomes as significant moderators in the meta-regression model (P < .001 and P = .005, respectively). Although 14 studies were located outside the funnel plot, Egger's test indicated no publication bias (P = .327). A sensitivity analysis excluding 14 studies showed similar results. In the linear regression model on the basis of 57 studies, the median OS time increased by 8.97% and 7.04% when the complete and optimal cytoreduction proportion increased by 10%, respectively, after adjusting other variables.

CONCLUSION

Secondary cytoreductive surgery, resulting in maximal tumor resection, significantly prolongs OS in platinum-sensitive recurrent ovarian cancer.

Enhancing delivery of small molecule and cell-based therapies for ovarian cancer using advanced delivery strategies

Ovarian cancer is the most lethal gynecological malignancy with a global five-year survival rate of 30-50%. First-line treatment involves cytoreductive surgery and administration of platinum-based small molecules and paclitaxel. These therapies were traditionally administered via intravenous infusion, although intraperitoneal delivery has also been investigated. Initial clinical trials of intraperitoneal administration for ovarian cancer indicated significant improvements in overall survival compared to intravenous delivery, but this result is not consistent across all studies performed. Recently cell-based immunotherapy has been of interest for ovarian cancer. Direct intraperitoneal delivery of cell-based immunotherapies might prompt local immunoregulatory mechanisms to act synergistically with the delivered immunotherapy. Based on this theory, pre-clinical in vivo studies have delivered these cell-based immunotherapies via the intraperitoneal route, with promising results. However, successful intraperitoneal delivery of cell-based immunotherapy and clinical adoption of this technique will depend on overcoming challenges of intraperitoneal delivery and finding the optimal combinations of dose, therapeutic and delivery route. We review the potential advantages and disadvantages of intraperitoneal delivery of cell-based immunotherapy for ovarian cancer and the pre-clinical and clinical work performed so far. Potential advanced delivery strategies, which might improve the efficacy and adoption of intraperitoneal delivery of therapy for ovarian cancer, are also outlined.

Extended Pelvic Resections as Part of Secondary Cytoreduction for Relapsed Ovarian Adenocarcinoma

BACKGROUND/AIM

Ovarian cancer presents an aggressive tumor biology, a significant number of patients experiencing recurrent disease. The aim of this study was to examine the feasibility and effectiveness of secondary debulking surgery for relapsed ovarian cancer.

PATIENTS AND METHODS

Between 2014 and 2018, debulking surgery for relapsed ovarian cancer was performed in 40 cases.

RESULTS

Debulking surgery to no residual disease was achieved in 31 cases; among the remaining cases, an R1 resection was feasible in six cases, while in the remaining three cases an R2 resection was performed. The most commonly performed visceral resections were represented by rectosigmoidian resection, right colon resection, total or partial cystectomy and unilateral or bilateral ureteral resection. The early postoperative morbidity rate was 32.5% while the postoperative mortality rate was 2.5%.

CONCLUSION

Extended pelvic resections are feasible in patients with relapsed ovarian cancer and might be performed with acceptable rates of postoperative complications.

TRUST: Trial of Radical Upfront Surgical Therapy in advanced ovarian cancer (ENGOT ov33/AGO-OVAR OP7)

BACKGROUND

Primary cytoreductive surgery followed by chemotherapy has been considered standard management for patients with advanced ovarian cancer over decades. An alternative approach of interval debulking surgery following neoadjuvant chemotherapy was subsequently reported by two randomized phase III trials (EORTC-GCG, CHORUS), which were criticized owing to important limitations, especially regarding the rate of complete resection.

PRIMARY OBJECTIVE

To clarify the optimal timing of surgical therapy in advanced ovarian cancer.

STUDY HYPOTHESIS

Primary cytoreductive surgery is superior to interval cytoreductive surgery following neoadjuvant chemotherapy for overall survival in patients with advanced ovarian cancer.

TRIAL DESIGN

TRUST is an international open, randomized, controlled multi-center trial investigating overall survival after primary cytoreductive surgery versus neoadjuvant chemotherapy and subsequent interval cytoreductive surgery in patients with FIGO stage IIIB-IVB ovarian, tubal, and peritoneal carcinoma. To guarantee adequate surgical quality, participating centers need to fulfill specific quality assurance criteria (eg, ≥50% complete resection rate in upfront surgery for FIGO IIIB-IVB patients, ≥36 debulking-surgeries/year) and agree to independent audits by TRUST quality committee delegates. Patients in the primary cytoreductive surgery arm undergo surgery followed by 6 cycles of platinum-based chemotherapy, whereas patients in the interval cytoreductive surgery arm undergo 3 cycles of neoadjuvant chemotherapy after histologic confirmation of the disease, followed by interval cytoreductive surgery and subsequently, 3 cycles of platinum-based chemotherapy. The intention of surgery for both groups is complete tumor resection according to guideline recommendations.

MAJOR INCLUSION/EXCLUSION CRITERIA

Major inclusion criteria are suspected or histologically confirmed, newly diagnosed invasive epithelial ovarian cancer, fallopian tube carcinoma, or primary peritoneal carcinoma FIGO stage IIIB-IVB (IV only if resectable metastasis). Major exclusion criteria are non-epithelial ovarian malignancies and borderline tumors; prior chemotherapy for ovarian cancer; or abdominal/pelvic radiotherapy.

PRIMARY ENDPOINT

Overall survival.

SAMPLE SIZE

772 patients.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

Accrual completion approximately mid-2019, results are expected after 5 years' follow-up in 2024.

TRIAL REGISTRATION

NCT02828618.

Morbidity and mortality in women with advanced ovarian cancer who underwent primary cytoreductive surgery compared to cytoreductive surgery for recurrent disease: a meta-analysis

Background

The primary treatment for advanced ovarian cancer is aggressive cytoreductive surgery (CRS), which is associated with considerable morbidity. The aim of this meta-analysis is to compare morbidity associated with primary CRS and secondary CRS for recurrent disease.

Methods

A literature search was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for publications reporting morbidity and mortality in patients undergoing CRS in primary and recurrent ovarian malignancy. Embase, Medline, Pubmed, Pubmed Central, clinicaltrials. gov and Cochrane databases were searched. Two independent reviewers applied inclusion and exclusion criteria to select included papers. A total of 215 citations were reviewed; 6 studies comprising 641 patients were selected for the analysis.

Results

Results were reported as mean differences or pooled odds ratios (OR) with 95 % confidence intervals (95 % CI). The overall morbidity rate was 38.4 %, and this did not differ between the two groups (p=0.97). This did not change when only Clavien-Dindo grade 3 and 4 morbidities were accounted for (14 % primary CRS, 15 % recurrent, p=0.83). Compared to primary CRS, secondary CRS was associated with a similar operative time (mean 400 min, I2=79 %, p=0.45), rate of bowel resection (I2=75 %, p=0.37) and transfusion requirements (MD – 0.7 L, I2=76 %, p=0.45). The mortality rate in both groups was too low to allow for meaningful meta-analysis, with four deaths in the group undergoing primary cytoreductive surgery (1.0 %) and two deaths in the group with recurrent disease (0.9 %).

Conclusions

In conclusion, secondary CRS for recurrent ovarian cancer is a safe and feasible option in carefully pre-selected patients with comparable morbidity to primary CRS.

Secondary cytoreductive surgery - viable treatment option in the management of platinum-sensitive recurrent ovarian cancer

OBJECTIVE

This study aimed to evaluate the impact of the secondary cytoreductive surgery on survival parameters in women with platinum-sensitive recurrent ovarian cancer who undergone secondary cytoreduction following chemotherapy compared to women who recieved chemotherapy alone.

STUDY DESIGN

In a retrospective study, data were rewieved from women who were diagnosed and treated with ovarian cancer and its primary platinum-sensitive recurrence at the University Hospital Brno in the Czech Republic between November 2009 and March 2016. Out of the total number of 62 patients with recurrence, 30 women underwent cytoreductive surgery plus chemotherapy and 32 were treated with chemotherapy alone. The good performance status expressed by ECOG score 0-1, the single site of recurrence regardless of platinum-free interval or multiple sites of recurrence but no carcinomatosis and platinum-free interval >12 months, and no or small-volume ascites (<500 ml) were considered inclusion criteria for cytoreductive surgery. Women not meeting these criteria were treated by chemotherapy alone. Descriptive statistics, Kaplan-Meier survival curves and Log-Rank test were used for statistical estimations.

RESULTS

The analysis confirmed more favorable prognosis in patient group treated with a combination secondary cytoreduction and chemotherapy. Mean disease-free survival (DFS) was 49.8 months (95% CI; 33.2-66.3) and mean overall survival (OS) stood at 54.0 months (95% CI; 39.4-68.6) in this patient cohort, while in patient group treated with chemotherapy alone it was found that mean DFS was 16.6 months (95% CI; 7.4-25.8) and mean OS stood at 26.2 months (95% CI; 16.6-35.8). When testing the difference between survival curves, statistically significant differences were observed in both DFS (p = 0.010) and OS (p = 0.007) rates between two treatment groups. Age < 60 years at the time of recurrence and zero macroscopic residual disease after secondary cytoreduction were identified as favorable prognostic factors for both DFS and OS in a multivariate analysis.

CONCLUSION

Secondary cytoreductive surgery is acceptable as a viable treatment option for highly selected women with ovarian cancer recurrence. Complete resection is considered ultimate goal of secondary cytoreduction on condition that the balance between maximal survival gain and minimal operative morbidity will be kept.

Surgery for Recurrent Epithelial Ovarian Cancer in the Netherlands: A Population-Based Cohort Study

OBJECTIVE

The value of secondary cytoreductive surgery (SCS) in patients with recurrent epithelial ovarian cancer is controversial. The aim of this population-based study was to investigate the role of SCS in the Netherlands.

METHODS

Data of 408 patients who underwent SCS between 2000 and 2013 were retrospectively collected from 38 Dutch hospitals. Survival after complete and incomplete SCS was estimated by Kaplan-Meier curves. Factors associated with overall survival (OS) were explored with Cox regression.

RESULTS

Median OS after SCS was 51 months (95% confidence interval [95% CI], 44.8-57.2). Complete SCS was achieved in 295 (72.3%) patients, with an OS of 57 months (95% CI, 49.0-65.0) compared with 28 months (95% CI, 20.8-35.2) in patients with incomplete SCS (log-rank test; P < 0.001). Nonserous histology (HR 0.65; 95% CI 0.45-0.95), a long progression free interval (hazard ratio [HR], 0.29; 95% CI, 0.07-1.18), a good performance status (HR, 0.68; 95% CI, 0.49-0.94), SCS without preoperative chemotherapy (HR, 0.72; 95% CI, 0.51-1.01), and complete SCS (HR, 0.46; 95% CI, 0.33-0.64) were prognostic factors for survival.

CONCLUSIONS

This population-based retrospective study showed that there might be a role for SCS in recurrent epithelial ovarian cancer especially when complete SCS can be accomplished. However, before adopting SCS as a standard treatment modality for recurrent epithelial ovarian cancer, results of 3 ongoing prospectively randomized trials are needed.

Survival Impact of Secondary Cytoreductive Surgery for Recurrent Ovarian Cancer in an Asian Population

OBJECTIVE

The aim of this study was to evaluate the role of secondary cytoreductive surgery in Asian patients with recurrent ovarian cancer and to assess prognostic variables on overall post-recurrence survival time.

METHODS

We conducted a retrospective review of patients with recurrent ovarian cancer who underwent secondary cytoreduction at the Gynaecological Cancer Center at the KK Women's and Children's Hospital, Singapore, between 1999 and 2009. Eligible patients included those who had been firstly treated by primary cytoreductive surgery and followed by adjuvant chemotherapy and had a period of clinical remission of at least six months and subsequently underwent secondary cytoreductive surgery for recurrence. Univariate analysis was performed to evaluate various variables influencing the overall survival.

RESULTS

Twenty-five patients met our eligibility criteria. The median age was 52 years (range=31-78 years). The median time from completion of primary treatment to recurrence was 25.1 months (range=6.4-83.4). Secondary cytoreduction was optimal in 20 of 25 patients (80%). The median follow-up duration was 38.9 months (range=17.8-72.4) and median overall survival time was 33.1 months (95% confidence interval, 15.3-undefined.). Ten (40.0%) patients required bowel resection, but no end colostomy was performed. One (4.0%) patient had wedge resection of the liver, one (4.0%) had a distal pancreatectomy, one (4.0%) had a unilateral nephrectomy, and one (4.0%) had adrenalectomy. There were no operative deaths. The overall survival of patients who responded to secondary cytoreductive surgery and adjuvant chemotherapy was significantly longer than those patients who did not respond to the treatment. Of those patients who responded to the surgical management, patients with clear cell carcinoma fared well compared to those with the endometrioid, mucinous adenocarcinoma, and papillary serous type (p<0.001). Complete secondary cytoreductive surgery appeared to have some relationship to overall survival but was not statistically significant.

CONCLUSION

In carefully selected patients with recurrent ovarian cancer, optimal cytoreductive surgery is possible and in a subgroup of patients who respond to surgery and chemotherapy survival is significantly longer.

A systematic model specification procedure for an illness-death model without recovery

Multi-state models are a flexible tool for analyzing complex time-to-event problems with multiple endpoints. Compared to the Cox regression model with a single endpoint or a summarizing composite endpoint, they can provide a more detailed insight into the disease process. Furthermore, prognosis can be improved by including information from intermediate events occurring during the course of the disease. Different model variants, options and additional assumptions provide many possibilities, but at the same time complicate the implementation of multi-state techniques. So far, no guiding literature is available to specify a multi-state model systematically. The objective of this work was to set up a general specification procedure for an illness-death model that optimizes the model fit and predictive accuracy by stepwise reduction of the model. As an application example, we reanalyzed data from an observational study of 434 ovarian cancer patients with progression as intermediate and death as absorbing state. The technique is described in general terms and can be applied to other illness-death models without recovery. The clock-reset approach was used, implicating that the time was reset to zero after progression. The non-homogeneous semi-Markov characteristic stated that the present time as well as the time between surgery and progression influenced survival after progression. Covariate effects on transitions were estimated and proportionality of transition baseline hazards was tested. The finally developed model optimized the accuracy of predictions for two simulated patients. This stepwise procedure yields parsimonious but targeted multi-state models with well interpretable coefficients and optimized predictive ability, even for smaller data sets.

External validation of two prediction models of complete secondary cytoreductive surgery in patients with recurrent epithelial ovarian cancer

OBJECTIVE

The purpose of this study was to validate the performance of two prediction models, the AGO score and the Tian model, of complete secondary cytoreductive surgery (SCS) in patients with recurrent epithelial ovarian cancer. The predictive value of both models for survival controlled for the outcome of SCS was analyzed and known predictive factors for complete SCS were tested.

METHODS

A population-based database with 408 patients, who underwent SCS between 2000 and 2013 in 38 Dutch hospitals, was used. The validation cohorts for the AGO score and the model of Tian contained 273 (66.9%) and 257 (63.0%) patients, respectively.

RESULTS

The AGO score and Tian model showed a positive predictive value for complete SCS of 82.0% and 80.3% respectively, and a false negative rate of 68.5% and 55.6% respectively. A positive AGO score had no significant association with overall survival (HR 0.73; 95% CI 0.51-1.06) whereas the low risk score of the Tian model did (HR 0.62; 95% CI 0.41-0.93). A good performance status (OR 0.60; 95% CI 0.33-1.10) and the absence of ascites (OR 0.18; 95% CI 0.08-0.41) were prognostic factors for complete SCS.

CONCLUSIONS

Both the AGO score and the model of Tian showed a high positive predictive value for complete SCS but also relatively high false negative rates. However, before the two prediction models can be applied in daily clinical practice the usefulness of SCS itself has to be proven first by the three ongoing randomized controlled trials: DESKTOP III trial, the GOG 213 trial and the Dutch SOCceR trial.

Surgical staging and prognosis in serous borderline ovarian tumours (BOT): a subanalysis of the AGO ROBOT study

BACKGROUND

Incomplete surgical staging is a negative prognostic factor for patients with borderline ovarian tumours (BOT). However, little is known about the prognostic impact of each individual staging procedure.

METHODS

Clinical parameters of 950 patients with BOT (confirmed by central reference pathology) treated between 1998 and 2008 at 24 German AGO centres were analysed. In 559 patients with serous BOT and adequate ovarian surgery, further recommended staging procedures (omentectomy, peritoneal biopsies, cytology) were evaluated applying Cox regression models with respect to progression-free survival (PFS).

RESULTS

For patients with one missing staging procedure, the hazard ratio (HR) for recurrence was 1.25 (95%-CI 0.66-2.39; P=0.497). This risk increased with each additional procedure skipped reaching statistical significance in case of two (HR 1.95; 95%-CI 1.06-3.58; P=0.031) and three missing steps (HR 2.37; 95%-CI 1.22-4.64; P=0.011). The most crucial procedure was omentectomy which retained a statistically significant impact on PFS in multiple analysis (HR 1.91; 95%-CI 1.15-3.19; P=0.013) adjusting for previously established prognostic factors as FIGO stage, tumour residuals, and fertility preservation.

CONCLUSION

Individual surgical staging procedures contribute to the prognosis for patients with serous BOT. In this analysis, recurrence risk increased with each skipped surgical step. This should be considered when re-staging procedures following incomplete primary surgery are discussed.

Cytoreductive surgery followed by chemotherapy versus chemotherapy alone for recurrent platinum-sensitive epithelial ovarian cancer (SOCceR trial): a multicenter randomised controlled study

Background

Improvement in treatment for patients with recurrent ovarian cancer is needed. Standard therapy in patients with platinum-sensitive recurrent ovarian cancer consists of platinum-based chemotherapy. Median overall survival is reported between 18 and 35 months. Currently, the role of surgery in recurrent ovarian cancer is not clear. In selective patients a survival benefit up to 62 months is reported for patients undergoing complete secondary cytoreductive surgery. Whether cytoreductive surgery in recurrent platinum-sensitive ovarian cancer is beneficial remains questionable due to the lack of level I-II evidence.

Methods/Design

Multicentre randomized controlled trial, including all nine gynecologic oncologic centres in the Netherlands and their affiliated hospitals. Eligible patients are women, with first recurrence of FIGO stage Ic-IV platinum-sensitive epithelial ovarian cancer, primary peritoneal cancer or fallopian tube cancer, who meet the inclusion criteria. Participants are randomized between the standard treatment consisting of at least six cycles of intravenous platinum based chemotherapy and the experimental treatment which consists of secondary cytoreductive surgery followed by at least six cycles of intravenous platinum based chemotherapy. Primary outcome measure is progression free survival. In total 230 patients will be randomized. Data will be analysed according to intention to treat.

Discussion

Where the role of cytoreductive surgery is widely accepted in the initial treatment of ovarian cancer, its value in recurrent platinum-sensitive epithelial ovarian cancer has not been established so far. A better understanding of the benefits and patients selection criteria for secondary cytoreductive surgery has to be obtained. Therefore the 4^th ovarian cancer consensus conference in 2010 stated that randomized controlled phase 3 trials evaluating the role of surgery in platinum-sensitive recurrent epithelial ovarian cancer are urgently needed. We present a recently started multicentre randomized controlled trial that will investigate the role of secondary cytoreductive surgery followed by chemotherapy will improve progression free survival in selected patients with first recurrence of platinum-sensitive epithelial ovarian cancer.

Trial registration

Netherlands Trial Register number: NTR3337.

Surgical management and perioperative morbidity of patients with primary borderline ovarian tumor (BOT)

BACKGROUND

Surgery is the cornerstone for clinical management of patients with borderline ovarian tumors (BOT). As these patients have an excellent overall prognosis, perioperative morbidity is the critical point for decision making when the treatment strategy is developed and the primary surgical approach is defined.

METHODS

Clinical and surgical parameters of patients undergoing surgery for primary BOT at our institutions between 1993 and 2008 were analyzed with regard to perioperative morbidity depending on the surgical approach (laparotomy vs. laparoscopy).

RESULTS

A total of 105 patients were analyzed (44 with primary laparoscopy [42%], 61 with primary laparotomy [58%]). Complete surgical staging was achieved in 33 patients at primary surgical approach (31.4%) frequently leading to formal indication of re-staging procedures. Tumor rupture was significantly more frequent during laparoscopy compared to laparotomy (29.5% vs. 13.1%, p = 0.038) but no other intraoperative complications were seen in laparoscopic surgery in contrast to 7 of 61 laparotomies (0% vs. 11.5%, p = 0.020). Postoperative complication rates were similar in both groups (19.7% vs. 18.2%, p = 0.848).

CONCLUSIONS

Irrespective of the surgical approach, surgical management of BOT has acceptable rates of perioperative complications and morbidity. Choice of initial surgical approach can therefore be made independent of complication-concerns. As the recently published large retrospective AGO ROBOT study observed similar oncologic outcome for both approaches, laparoscopy can be considered for staging of patients with BOT if this appears feasible. An algorithm for the surgical management of BOT patients has been developed.

Treatment reality in elderly patients with advanced ovarian cancer: a prospective analysis of the OVCAD consortium

Background

Approximately one third of women diagnosed with ovarian cancer is 70 years or older. Information on the treatment reality of these elderly patients is limited.

Methods

275 patients with primary epithelial ovarian cancer FIGO stage II-IV undergoing cytoreductive surgery and platinum-based chemotherapy were prospectively included in this European multicenter study. Patients <70 and ≥70 years were compared regarding clinicopathological variables and prognosis.

Results

Median age was 58 years (18–85); 47 patients (17.1%) were 70 years or older. The postoperative 60-day-mortality rate was 2.1% for elderly and 0.4% for younger patients (p < 0.001). Elderly patients were less likely to receive optimal therapy (no residual disease after surgery and platinum combination chemotherapy) compared to patients <70 years (40.4% vs. 70.1%, p < 0.001) and their outcome was less favorable regarding median PFS (12 vs. 20 months, p = 0.022) and OS (30 vs. 64 months, p < 0.001). However, in multivariate analysis age itself was not a prognostic factor for PFS while the ECOG performance status had prognostic significance in elderly patients.

Conclusions

Elderly patients with ovarian cancer are often treated less radically. Their outcome is impaired despite no consistent prognostic effect of age itself. Biological age and functional status should be considered before individualized treatment plans are defined.

Diagnosis and management of peritoneal metastases from ovarian cancer

The management and the outcome of peritoneal metastases or recurrence from epithelial ovarian cancer are presented. The biology and the diagnostic tools of EOC peritoneal metastasis with a comprehensive approach and the most recent literatures data are discussed. The definition and the role of surgery and chemotherapy are presented in order to focuse on the controversial points. Finally, the paper discusses the new data about the introduction of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of advanced epithelial ovarian cancer.

The role of secondary cytoreductive surgery in patients with recurrent epithelial ovarian, tubal, and peritoneal cancers: a comparative effectiveness analysis

Background. All published reports concerning secondary cytoreductive surgery for relapsed ovarian cancer have essentially been observational studies. However, the validity of observational studies is usually threatened from confounding by indication. We sought to address this issue by using comparative effectiveness methods to adjust for confounding. Methods. Using a prospectively collected administrative health care database in a single institution, we identified 1,124 patients diagnosed with recurrent epithelial, tubal, and peritoneal cancers between 1990 and 2009. Effectiveness of secondary cytoreductive surgery using the conventional Cox proportional hazard model, propensity score, and instrumental variable were compared. Sensitivity analyses for residual confounding were explored using an array approach. Results. Secondary cytoreductive surgery prolonged overall survival with a hazard ratio (95% confidence interval) of 0.76 (range 0.66-0.87), using the Cox proportional hazard model. Propensity score methods produced comparable results: 0.75 (range 0.64-0.86) by nearest matching, 0.73 (0.65-0.82) by quintile stratification, 0.71 (0.65-0.77) by weighting, and 0.72 (0.63-0.83) by covariate adjustment. The instrumental variable method also produced a comparable estimate: 0.75 (range 0.65-0.86). Sensitivity analyses revealed that the true treatment effects may approach the null hypothesis if the association between unmeasured confounders and disease outcome is high. Conclusions. This comparative effectiveness study provides supportive evidence for previous reports that secondary cytoreductive surgery may increase overall survival for patients with recurrent epithelial, tubal, and peritoneal cancers.

Potential survival benefit of secondary cytoreductive surgery for recurrent epithelial ovarian, tubal, and peritoneal cancers

OBJECTIVE

Although treatment for recurrent epithelial ovarian, tubal, and peritoneal cancers is usually not curative and intends to be palliative, a certain significance of secondary cytoreductive surgery (SCS) for recurrent tumor has been reported; still, there are limitations in this strategy including difficulty in predicting successful complete resection and selecting good candidates. The purpose of this study was to explore the potential survival benefit of SCS in patients with recurrent epithelial ovarian, tubal, and peritoneal cancers.

METHODS

Among all patients who underwent primary therapy for epithelial ovarian, tubal, and peritoneal cancers between 1994 and 2006 at our institute, medical records of patients who were submitted to SCS for recurrence following complete remission after primary therapy were retrospectively investigated. Kaplan-Meier method and log-rank test were used for survival analysis, and Cox proportional hazard regression model was used for quantifying the relations between survival and covariates.

RESULTS

Thirty-four patients met the inclusion criteria. Complete resection of all visible tumors at SCS was achieved in 24 of patients (75%). Median postrecurrence survival was 60 months. On univariate analysis, solitary recurrence, disease-free interval, CA125 value at recurrence, and complete resection were significant prognostic factors on postrecurrence survival; whereas on multivariate analysis, CA125 value at recurrence and complete resection were independent prognostic factors. In addition, a comparison according to the initial method that detected recurrence revealed that patients whose recurrence was detected with CA125 elevations had significantly worse postrecurrence survival than those detected with routine examinations including image scans (P = 0.021).

CONCLUSIONS

In the present study, the impact of SCS on the significant survival benefit was identified for patients with low CA125 value at recurrence as well as with complete resection. Although further analyses are needed, patients whose recurrence was diagnosed by routine examinations without CA125 elevation might be better candidates for SCS.