Microscopic diseases remain in initial disseminated sites after neoadjuvant chemotherapy for stage III/IV ovarian, tubal, and primary peritoneal cancer

Current peritonectomy practice during debulking surgery in patients with newly diagnosed advanced ovarian cancer: a Korean Gynecologic Oncology Group Study (KGOG 4004)

OBJECTIVE

Because of the possible therapeutic benefit of removing occult tumor cells, a source of recurrence and chemoresistance, total parietal peritonectomy (TPP) is an alternative treatment for advanced epithelial ovarian/fallopian tube/primary peritoneal cancer. Interventional studies comparing TPP with selective parietal peritonectomy (SPP) are in progress. Since surgeons skilled in TPP are essential for such trials to be conducted, this nationwide survey aimed to examine current peritonectomy practice among gynecologic oncologists in Korea.

METHODS

A 17-item questionnaire, developed by a surgery committee and reviewed by the scientific review board of the Korean Gynecology Oncology Group (KGOG), was distributed to 144 KGOG members. The questionnaire was divided into 3 categories: respondent demographics, peritonectomy practice during primary debulking surgery (PDS), and peritonectomy practice during interval debulking surgery (IDS).

RESULTS

We received 88 (61.1%) valid responses. Of the valid respondents, 98.9% and 93.8% performed SPP during PDS and IDS, respectively. Only 4.9% of the respondents performed TPP during IDS. Most respondents performed peritonectomy in cases where optimal postoperative outcomes were expected. Approximately 50.6% of the respondents had performed peritonectomy independently, while the others did so in cooperation with non-gynecologic surgeons. The primary reasons for not performing TPP were concerns about morbidity and uncertainty about the clinical benefits of the procedure.

CONCLUSION

SPP is the predominant technique used in both PDS and IDS in Korea. A small percentage (4.9%) of gynecologic oncologists have performed TPP during IDS. Accordingly, a study regarding the feasibility of TPP should be conducted before proceeding with a prospective clinical trial.

3-4 Cycles versus 6 Cycles Neoadjuvant Chemotherapy in Advanced-Stage Epithelial Ovarian Cancer: Survival Is Not Determined by the Number of Neoadjuvant Chemotherapy Cycles

INTRODUCTION

The aim of this study was to compare the disease-free survival (DFS) and overall survival (OS) of patients who underwent interval cytoreductive surgery after 3-4 cycles or 6 cycles of neoadjuvant chemotherapy (NACT) in advanced epithelial ovarian cancer patients.

METHODS

Out of 219 patients with advanced epithelial ovarian cancer, 123 patients received 3-4 cycles and 96 patients received 6 cycles of platinum-based NACT. Afterward, laparotomy was performed for interval cytoreductive surgery.

RESULTS

No statistically significant difference was found for DFS and OS of the patients who received 3-4 cycles and those who received 6 cycles of NACT (HR: 1.047, 95.0% CI [0.779-1.407]; p: 0.746 for DFS, and HR: 1.181, 95.0% CI [0.818-1.707]; p: 0.368 for OS). Evaluating 123 patients who received 3-4 cycles of NACT, 87 patients (70.7%) without macroscopic residual tumor after interval cytoreductive surgery had significantly longer DFS and OS compared to 36 patients (29.3%) with any residual tumor (HR: 1.830, 95.0% CI [1.194-2.806]; p: 0.003 for DFS, and HR: 1.946, 95.0% CI [1.166-3.250]; p: 0.009 for OS). 96 patients who received 6 courses of NACT were evaluated; 63 patients (65.6%) without macroscopic residual tumor after interval cytoreductive surgery had significantly longer DFS and OS than 33 patients (34.4%) with any residual tumor (HR: 1.716, 9 5.0% CI [1.092-2.697]; p: 0.010 for DFS, and HR: 1.921, 95.0% CI [1.125-3.282]; p: 0.013 for OS).

CONCLUSION

In patients with advanced ovarian cancer, there is no significant difference in DFS and OS between 3 and 4 cycles or 6 cycles of NACT. The most important factor determining survival is whether macroscopic residual tumor tissue remains after interval cytoreductive surgery following NACT.

Fluorescence-guided photoimmunotherapy using targeted nanotechnology and ML7710 to manage peritoneal carcinomatosis

Fluorescence-guided intervention can bolster standard therapies by detecting and treating microscopic tumors before lethal recurrence. Tremendous progress in photoimmunotherapy and nanotechnology has been made to treat metastasis. However, many are lost in translation due to heterogeneous treatment effects. Here, we integrate three technological advances in targeted photo-activable multi-agent liposome (TPMAL), fluorescence-guided intervention, and laser endoscopy (ML7710) to improve photoimmunotherapy. TPMAL consists of a nanoliposome chemotherapy labeled with fluorophores for tracking and photosensitizer immunoconjugates for photoimmunotherapy. ML7710 is connected to Modulight Cloud to capture and analyze multispectral emission from TPMAL for fluorescence-guided drug delivery (FGDD) and fluorescence-guided light dosimetry (FGLD) in peritoneal carcinomatosis mouse models. FGDD revealed that TPMAL enhances drug delivery to metastases by 14-fold. ML7710 captured interpatient variability in TPMAL uptake and prompted FGLD in >50% of animals. By combining TPMAL, ML7710, and fluorescence-guided intervention, variation in treatment response was substantially reduced and tumor control improved without side effects.

Do surgeons overestimate diaphragmatic peritoneal disease in interval debulking surgery of ovarian cancer?

INTRODUCTION

Cytoreductive surgery is a key point in ovarian cancer treatment. Substantial morbidity may be consecutive to this major radical surgery. However, the objective of no residual tumor (CC-0) had demonstrated its clear improvement of prognosis. Could macroscopically-driven interval debulking surgery (IDS) overestimate active cancer cells and be unnecessarily morbid?

MATERIALS AND METHODS

This retrospective cohort study was conducted in Center Leon Berard Cancer Center between 2000 and 2018. We included women with advanced epithelial ovarian cancer who received neoadjuvant chemotherapy and underwent an IDS including resection of peritoneal metastases on the diaphragmatic domes. The primary endpoint was the pathological outcome of peritoneal resections of diaphragmatic domes.

RESULTS

Peritoneal resections of diaphragmatic domes consisted of 117 patients. 75 patients required resection of nodules from the right cupola only, 2 patients from the left cupola only, and 40 patients bilaterally. Pathological analysis of the diaphragmatic domes found that 84.6% of samples demonstrated the presence of malignant cells, and only 12.8% found no tumor involvement. Pathology analysis could not be performed for 3 patients (2.6%) (vaporization).

CONCLUSION

Surgical evaluation after neoadjuvant chemotherapy in ovarian cancer does not often overestimate peritoneal involvement by active carcinomatosis. Potential surgical morbidity due to peritoneal resection in IDS is admissible.

Neoadjuvant Chemotherapy plus Interval Cytoreductive Surgery with or without Hyperthermic Intraperitoneal Chemotherapy (NIHIPEC) in the Treatment of Advanced Ovarian Cancer: A Multicentric Propensity Score Study

INTRODUCTION

Epithelial ovarian cancer (EOC) is primarily confined to the peritoneal cavity. When primary complete surgery is not possible, neoadjuvant chemotherapy (NACT) is provided; however, the peritoneum-plasma barrier hinders the drug effect. The intraperitoneal administration of chemotherapy could eliminate residual microscopic peritoneal tumor cells and increase this effect by hyperthermia. Intraperitoneal hyperthermic chemotherapy (HIPEC) after interval cytoreductive surgery could improve outcomes in terms of disease-free survival (DFS) and overall survival (OS).

MATERIALS AND METHODS

A multicenter, retrospective observational study of advanced EOC patients who underwent interval cytoreductive surgery alone (CRSnoH) or interval cytoreductive surgery plus HIPEC (CRSH) was carried out in Spain between 07/2012 and 12/2021. A total of 515 patients were selected. Progression-free survival (PFS) and OS analyses were performed. The series of patients who underwent CRSH or CRSnoH was balanced regarding the risk factors using a statistical analysis technique called propensity score matching.

RESULTS

A total of 170 patients were included in each subgroup. The complete surgery rate was similar in both groups (79.4% vs. 84.7%). The median PFS times were 16 and 13 months in the CRSH and CRSnoH groups, respectively (Hazard ratio (HR) 0.74; 95% CI, 0.58-0.94; p = 0.031). The median OS times were 56 and 50 months in the CRSH and CRSnoH groups, respectively (HR, 0.88; 95% CI, 0.64-1.20; p = 0.44). There was no increase in complications in the CRSH group.

CONCLUSION

The addition of HIPEC after interval cytoreductive surgery is safe and increases DFS in advanced EOC patients.

Significance of cholecystectomy in cytoreductive surgery for advanced ovarian cancer

BACKGROUND

There have been no studies concerning the complications or benefits of cholecystectomy in ovarian cancer. In this study, we aimed to evaluate the outcomes of cholecystectomy performed during various time periods of the disease course and suggest a management strategy for cholecystectomy in ovarian cancer.

METHODS

We retrospectively reviewed the medical records of patients with advanced ovarian cancer who underwent cholecystectomy during the cytoreductive surgery from 2009 to 2020. Cholecystectomy was primarily indicated when the gallbladder and surrounding structures were considered to have metastatic tumor invasion. If the final pathologic results showed free of malignant tumor, patients were placed into the no-infiltration group. Clinical outcomes including the recurrence rate and complications were analyzed.

RESULTS

A total of 62 patients underwent cholecystectomy, 48 of whom (77.4%) underwent cholecystectomy during primary or interval debulking surgery, whereas 14 (22.6%) underwent cholecystectomy during the follow-up period (five with benign disease and 9 with disease recurrence). Among the patients, 32 (51.6%) patients were included in the no-infiltration group in the final pathology. There were no complications observed in the no-infiltration group (n = 32). Seven (78%) of the nine patients who received cholecystectomy for disease recurrence had metastatic disease in the porta-hepatis or lesser sac at the time of primary surgery. However, no recurrent lesions were observed around the porta-hepatis in patients who received cholecystectomy during primary treatment.

CONCLUSION

Considering the safety of the procedure, as well as the risk of disease recurrence or cholecystitis, a cholecystectomy can be offered to patients with ovarian cancer who have metastatic lesions around the gallbladder and porta-hepatis at the time of primary surgery.

Prolonged Exposition with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) May Provide Survival Benefit after Cytoreductive Surgery (CRS) in Advanced Primary Epithelial Ovarian, Fallopian Tube, and Primary Peritoneal Cancer

Background: The usage of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for advanced gynecological cancers is increasing. Methods: Prospectively collected data of 85 advanced primary ovarian/fallopian tube cancer and peritoneal carcinoma patients of a single center were investigated. Results: A total 48, 37, 62, and 25 patients were enrolled into the HIPEC with/without neoadjuvant chemotherapy (upfront vs. interval) and into the 60 min and 90 min long HIPEC groups, respectively. Better overall survival (OS) was observed in the 90 min HIPEC group (p = 0.0330), compared to the 60 min HIPEC group. Neither OS (p = 0. 2410), disease-specific (p = 0. 3670), nor recurrence-free survival (p = 0.8240) differed between upfront and interval HIPEC. Higher peritoneal carcinomatosis index (PCI) values were associated with worse disease-specific survival (p = 0.0724). Age (p = 0.0416), body mass index (p = 0.0044), PCI (p < 0.0001), the type (p = 0.0016) and duration (p = 0.0012) of HIPEC, and increased perioperative morbidity (p < 0.0041) had the greatest impact on OS. Conclusions: Increasing data support the value of HIPEC in the treatment of advanced ovarian cancer. Ongoing prospective studies will definitively clarify the role and timing of this additional therapeutic approach.

The Granger Causal Effects of Canady Helios Cold Plasma on the Inhibition of Breast Cancer Cell Proliferation

Cold atmospheric plasma (CAP) has become a promising tool for modern medicine. With its recent applications in oncology, regenerative medicine, and immunotherapy, CAP can be used for a myriad of different clinical treatments. When using CAP specifically for the treatment of tumors, it is known to elicit an oxidative response within malignant cancer cells, inducing cell cycle arrest and apoptosis. In this study, data of intracellular reactive oxygen species (ROS), caspase activity, Ki-67 expression, and cell cycle activity in the G1 phase were acquired to determine the causal relationships these intermediates have with cell proliferation and death after Canady Helios Cold Plasma (CHCP) treatment. The data were derived from four different subtypes of breast cancer cell lines: BT-474, MCF-7, MDA-MB-231, and SK-BR-3. Data transformation techniques were conducted on the time-series data for the input into the causal model code. The models were created on the basis of Granger causality principles. Our results demonstrated that there was a Granger causal relationship among all potentially causal variables (ROS, caspase, Ki-67, and G1 activity) and cell proliferation after 5 min CHCP treatment; however, not all variables were causal for the 3 min models. This same pattern did not exist for cell death models, which tested all potentially causal variables (ROS, Ki-67, and G1 activity) vs. caspase activity. All models were validated through a variety of statistical tests and forecasting accuracy metrics. A pseudo data set with defined causal links was also created to test R’s ability in picking up known causal relationships. These models, while nonexhaustive, elucidated the effects cold plasma has on cell activity regulators. Research in causal modeling is needed to help verify the exact mechanism of cold plasma for the ultimate optimization of its application in the treatment of cancers.

Survival After Hyperthermic Intraperitoneal Chemotherapy and Primary or Interval Cytoreductive Surgery in Ovarian Cancer: A Randomized Clinical Trial

Question

Does hyperthermic intraperitoneal chemotherapy (HIPEC) after primary or interval cytoreductive surgery increase survival in patients with ovarian cancer?

Findings

In this randomized clinical trial of 184 women with ovarian cancer, among those who underwent interval cytoreductive surgery after neoadjuvant chemotherapy, the addition of HIPEC decreased recurrence and increased overall survival; however, in patients undergoing primary cytoreductive surgery, progression-free survival and overall survival were not improved. No unresolved serious HIPEC-related adverse events were found in either group.

Meaning

These results suggest that HIPEC after interval cytoreductive surgery may increase progression-free and overall survival in patients with ovarian cancer who receive neoadjuvant chemotherapy.

Importance

Ovarian cancer has the highest mortality rate among gynecologic malignant tumors. Data are lacking on the survival benefit of hyperthermic intraperitoneal chemotherapy (HIPEC) in women with ovarian cancer who underwent primary or interval cytoreductive surgery.

Objective

To assess the clinical benefit of HIPEC after primary or interval maximal cytoreductive surgery in women with stage III or IV primary advanced ovarian cancer.

Design, Setting, and Participants

In this single-blind randomized clinical trial performed at 2 institutions in South Korea from March 2, 2010, to January 22, 2016, a total of 184 patients with stage III or IV ovarian cancer with residual tumor size less than 1 cm were randomized (1:1) to a HIPEC (41.5 °C, 75 mg/m² of cisplatin, 90 minutes) or control group. The primary end point was progression-free survival. Overall survival and adverse events were key secondary end points. The date of the last follow-up was January 10, 2020, and the data were locked on February 17, 2020.

Exposures

Hyperthermic intraperitoneal chemotherapy after cytoreductive surgery.

Main Outcomes and Measures

Progression-free and overall survival.

Results

Of the 184 Korean women who underwent randomization, 92 were randomized to the HIPEC group (median age, 52.0 years; IQR, 46.0-59.5 years) and 92 to the control group (median age, 53.5 years; IQR, 47.5-61.0 years). After a median follow-up of 69.4 months (IQR, 54.4-86.3 months), median progression-free survival was 18.8 months (IQR, 13.0-43.2 months) in the control group and 19.8 months (IQR, 13.7-55.4 months) in the HIPEC group (P = .43), and median overall survival was 61.3 months (IQR, 34.3 months to not reported) in the control group and 69.5 months (IQR, 45.6 months to not reported) in the HIPEC group (P = .52). In the subgroup of interval cytoreductive surgery after neoadjuvant chemotherapy, the median progression-free survival was 15.4 months (IQR, 10.6-21.1 months) in the control group and 17.4 months (IQR, 13.8-31.5 months) in the HIPEC group (hazard ratio for disease progression or death, 0.60; 95% CI, 0.37-0.99; P = .04), and the median overall survival was 48.2 months (IQR, 33.8-61.3 months) in the control group and 61.8 months (IQR, 46.7 months to not reported) in the HIPEC group (hazard ratio, 0.53; 95% CI, 0.29-0.96; P = .04). In the subgroup of primary cytoreductive surgery, median progression-free survival was 29.7 (IQR, 17.2-90.1 months) in the control group and 23.9 months (IQR, 12.3-71.5 months) in the HIPEC group, and the median overall survival was not reached in the control group and 71.3 months (IQR, 45.6 months to not reported) in the HIPEC group.

Conclusions and Relevance

The addition of HIPEC to cytoreductive surgery did not improve progression-free and overall survival in patients with advanced epithelial ovarian cancer. Although the results are from a subgroup analysis, the addition of HIPEC to interval cytoreductive surgery provided an improvement of progression-free and overall survival.

Trial Registration

ClinicalTrials.gov Identifier: NCT01091636

A phase 2 trial of short-course Hyperthermic IntraPeritoneal Chemotherapy (HIPEC) at interval cytoreductive surgery (iCRS) for advanced ovarian cancer

OBJECTIVE

to report the final analysis of a phase 2 trial assessing the efficacy and safety of short-course hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with advanced epithelial ovarian cancer (EOC).

METHODS

this was an open-label, multicenter, single-arm trial of HIPEC in patients with advanced EOC who underwent interval cytoreductive surgery (iCRS) after neoadjuvant chemotherapy (NACT). HIPEC was performed as a concentration-based regimen of platinum-based chemotherapy for 30 minutes. Primary endpoint was the rate of disease progression occurring at nine months following iCRS plus HIPEC (PD9). Secondary endpoints were postoperative complications, time to start adjuvant chemotherapy, length of hospital and ICU stay, quality of life (QoL) over treatment, and ultimately 2-year progression-free survival (PFS) and overall survival (OS). Analysis was by intention-to-treat with final database lock for survival outcomes on February 23, 2021.

RESULTS

fifteen patients with stage III EOC were enrolled between February 2015 and July 2019, in four centers. The intention to treat PD9 was 6.7%. With a median follow-up of 33 months (IQR, 24.3-46.5), the median PFS was 18.1 months and corresponding 2-year rates of PFS and OS was 33.3% and 93.3%, respectively. Three patients (20%) experienced graded III complications. Median length of hospital and ICU stay was 5 (IQR, 4-6.5) and 1 (IQR, 1-1) days, respectively. Time to restart systemic chemotherapy was 39 (IQR, 35-49.3) days and no significant difference over time in QoL was observed.

CONCLUSIONS

we demonstrate preliminary efficacy and safety of short-course HIPEC in patient with advanced EOC.

Surgical Techniques and Outcomes of Colorectal Anastomosis after Left Hemicolectomy with Low Anterior Rectal Resection for Advanced Ovarian Cancer

Extended colon resection is often performed in advanced ovarian cancer. Restoring intestinal continuity and avoiding stoma creation improve patients' quality of life postoperatively. We tried to minimize the number of anastomoses, restore intestinal continuity, and avoid stoma creation for 295 patients with stage III/IV ovarian cancer who underwent low anterior rectal resection (LAR) with or without colon resection during cytoreductive surgery. When the remaining colon could not reach the rectal stump after left hemicolectomy with LAR, we used the following techniques for tension-free anastomosis: right colonic transposition, retro-ileal anastomosis through an ileal mesenteric defect, or an additional colic artery division. Rates of stoma creation and rectal anastomotic were 3% (9/295) and 6.6% (19/286), respectively. Among 21 patients in whom the remaining colon did not reach the rectal stump after left hemicolectomy with LAR, 20 underwent tension-free anastomosis, including eight, six, and six patients undergoing right colonic transposition, retro-ileal anastomosis through an ileal mesenteric defect, and an additional colic artery division, respectively. Colorectal anastomosis is feasible for patients with extended colonic resection. Low anastomotic leakage and stoma rates can be achieved with careful attention to colonic mobilization and tension-free anastomosis.

Introduction of rectosigmoid colectomy improves survival outcomes in early-stage ovarian cancer patients

BACKGROUND

To investigate whether rectosigmoid colectomy can improve the prognosis of patients with early-stage ovarian cancer when the ovarian tumor adheres to the rectum.

METHODS

We retrospectively studied 210 consecutive patients with stage I/II ovarian cancer treated between 2000 and 2016. The surgical strategy differed between the periods 2000-2007 and 2008-2016 with respect to adhesion between the ovarian tumor and rectum. In the former period, ovarian tumor was exfoliated from the rectum. Only when the residual tumor was apparently observed on the rectal surface after salpingo-oophorectomy with hysterectomy, it was subsequently removed by colorectal surgeons performing rectosigmoid colectomy. In the latter period, the ovarian tumor was resected en bloc with the rectum by performing rectosigmoid colectomy. We compared the progression-free survival (PFS) between the two treatment periods.

RESULTS

Rectosigmoid colectomy was performed more frequently in the latter period than in the former period (43 patients, 31% vs. 6 patients, 8%, p < 0.001). There was no significant difference in complete resection rate between the two periods (97% in the former period, 99% in the latter period, p = 0.278). However, the 5-year PFS rate was significantly higher in the latter period than in the former period (86.0% vs. 74.4%, log-rank test, p = 0.034). Multivariate Cox proportional-hazards regression analysis indicated that disease stage (hazard ratio [HR], 2.87, 95% confidence interval [CI] 1.14-7.34) and treatment period (HR 0.32, 95% CI 0.14-0.73) were independent risk factors for recurrence.

CONCLUSIONS

Rectosigmoid colectomy could improve the prognosis of patients with early-stage ovarian cancer when the ovarian tumor adheres to the rectum.

Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Carcinomatosis from Epithelial Ovarian Cancer: A 20-Year Single-Center Experience

Despite improvement in treatments, the peritoneum remains the primary site of relapse in most ovarian cancer cases. Patients who underwent cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for peritoneal carcinomatosis from epithelial ovarian cancer were reviewed. Kaplan-Meier curves and multivariate Cox analyses were used to identify survival rates and prognostic factors. This study included 158 patients. The procedure was mostly performed for recurrent disease (46.8%) and high-grade serous carcinoma (58.2%). The median peritoneal cancer index was 14, and complete cytoreduction was obtained in 87.9% of cases. Grade IV morbidity occurred in 15.2% of patients, mostly requiring surgical reoperation, and one patient (0.6%) died within 90 days. The median follow-up was 63.5 months. The Kaplan-Meier 5-year overall survival (OS) and disease-free survival (DFS) rates were 42.1% and 24.3%, respectively. Multiple regression logistic analyses demonstrated that the completeness of cytoreduction (CC) score (p ≤ 0.0001), pancreatic resection (p ≤ 0.0001) and number of resections (p = 0.001) were significant factors influencing OS; whereas the CC score (p ≤ 0.0001) and diaphragmatic procedures (p = 0.01) were significant for DFS. The addition of hyperthermic intraperitoneal chemotherapy to standard multimodality therapy may improve outcomes in both primary and recurrent epithelial ovarian cancer without impairing early postoperative results, but the exact timing has not yet been established. Prospective randomized studies will clarify the role and indications of this approach.

Microscopic Peritoneal Residual Disease after Complete Macroscopic Cytoreductive Surgery for Advanced High Grade Serous Ovarian Cancer

BACKGROUND

Epithelial ovarian cancers (EOC) are usually diagnosed at an advanced stage and managed by complete macroscopic cytoreductive surgery (CRS) and systemic chemotherapy. Peritoneal recurrence occurs in 60% of patients and may be due to microscopic peritoneal metastases (mPM) which are neither eradicated by surgery nor controlled by systemic chemotherapy. The aim of this study was to assess and quantify the prevalence of residual mPM after complete macroscopic CRS in patients with advanced high-grade serous ovarian cancer (HGSOC).

METHODS

A prospective study conducted between 1 June 2018 and 10 July 2019 in a single referent center accredited by the European Society of Gynecological Oncology for advanced EOC management. Consecutive patients presenting with advanced HGSOC and eligible for complete macroscopic CRS were included. Up to 13 peritoneal biopsies were taken from macroscopically healthy peritoneum at the end of CRS and examined for the presence of mPM. A mathematical model was designed to determine the probability of presenting at least one mPM after CRS.

RESULTS

26 patients were included and 26.9% presented mPM. There were no differences in characteristics between patients with or without identified mPM. After mathematical analysis, the probability that mPM remained after complete macroscopic CRS in patients with EOC was 98.14%.

CONCLUSION

Microscopic PM is systematically present after complete macroscopic CRS for EOC and could be a relevant therapeutic target. Adjuvant locoregional strategies to conventional surgery may improve survival by achieving microscopic CRS.

Are There Survival Differences Between Women with Equivalent Residual Disease After Interval Cytoreductive Surgery Compared with Primary Cytoreductive Surgery for Advanced Ovarian and Peritoneal Cancer?

OBJECTIVE

The aim of this study was to investigate survival differences between equivalent residual disease [complete gross resection (CGR), minimal residual disease (MRD), suboptimal] at the time of primary debulking surgery (PDS) and interval debulking surgery (IDS).

METHODS

The National Cancer Database was used to identify patients from 2010 to 2015 with stage IIIC/IV primary peritoneal or ovarian cancer who had residual disease recorded. Propensity score matching (PSM) was used to correct for differences in characteristics between the PDS and IDS groups.

RESULTS

Of 8683 patients with advanced ovarian cancer, 4493 (52%), 2546 (29%), and 1644 (19%) had CGR, MRD, or suboptimal resection, respectively. From 2010 to 2015, the number of patients undergoing IDS increased 27% (p_trend < 0.001), and there was an 18% increase in CGRs (p_trend = 0.005). The increased use of IDS from 2010 to 2015 was associated with increased CGRs (p_trend = 0.02) and decreased MRD (p_trend = 0.001), but not with decreased suboptimal resections (p_trend = 0.18). IDS, even after PSM, was associated with inferior overall survival [OS; hazard ratio (HR) 1.12, 95% confidence interval (CI) 1.03-1.22, p = 0.008]. A CGR at PDS had prolonged median OS compared with a CGR at IDS (51 vs. 44 months, p < 0.001). Additionally, MRD at PDS had worse median OS compared with a CGR at IDS (41 vs. 44 months, p = 0.03), but improved median OS compared with MRD at IDS (median OS 35 months, p = 0.05).

CONCLUSION

The use of IDS continues to rise in the US, and is associated with improved surgical outcomes but not necessarily similar oncologic outcomes. There should be continued efforts to improve cytoreductive outcomes in women with advanced ovarian and peritoneal malignancies.