Peritoneal metastases from rare ovarian cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC).

Objectives: There are limited treatment options and no consensus on the management of advanced rare ovarian malignancies. Rare ovarian malignancies can present with peritoneal metastases (PM), featuring a similar presentation to more common ovarian subtypes. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is an effective treatment for PM of non-gynecologic origin and, recently, epithelial ovarian cancer. We evaluated the feasibility of CRS/HIPEC in the management of PM from rare ovarian malignancies and report postoperative outcomes on these patients. Methods: A retrospective review of a single center, prospective database (1994-2021) was performed to identify patients with rare ovarian malignancies treated with CRS/HIPEC. Clavien-Dindo 90-day morbidity/mortality and Kaplan-Meier overall (OS) and progression-free survival (PFS) were analyzed. Results: Of 44 patients identified, 28 underwent CRS/HIPEC. Six were aborted due to extensive disease. Histologic subtypes included: clear cell (5/28, 17.9 %), endometrioid (5/28, 17.9 %), granulosa cell (3/28, 10.7 %), low-grade serous (6/28, 21.4 %), mesonephric (1/28, 3.6 %), mucinous (6/28, 21.4 %), and small cell (2/28, 7.1 %) carcinomas. Eight (28.6 %) patients had primary and 20 (71.4 %) had recurrent disease. Median peritoneal cancer index (PCI) was 21 (IQR: 6-29). Complete cytoreduction (<2.5 mm residual disease) was achieved in 27/28 (96.4 %). Grade III/IV complications occurred in 9/28 (32.1 %) with one (3.6 %) mortality. After a median follow-up of 65.8 months, 20 patients were alive. Five-year OS and PFS were 68.5 and 52.6 %, respectively. Conclusions: In patients with PM from rare ovarian malignancies, CRS/HIPEC is feasible and has an acceptable safety profile. Longer follow-up and multicenter trials are needed.

Collaborative expertise of gynecological and surgical oncologists in managing advanced epithelial ovarian cancer.

BACKGROUND: Most patients with epithelial ovarian cancer (EOC) present with significant peritoneal spread. We assessed collaborative efforts of surgical and gynecological oncologists with expertise in cytoreductive surgery (CRS) in the management of advanced EOC. METHODS: Using a prospective single-center database (2014-2022), we described the operative and oncologic outcomes of stage IIIC-IVA primary and recurrent EOC perioperatively managed jointly by gynecological and surgical oncologists both specializing in CRS and presented components of this collaboration. RESULTS: Of 199 identified patients, 132 (66 %) had primary and 53 (27 %) had recurrent EOC. Due to inoperable disease, 14 (7 %) cases were aborted and excluded from analysis. Median peritoneal cancer index (PCI) in primary and recurrent patients was 21 (IQR: 11-28) and 21 (IQR: 6-31). Upper abdominal surgery was required in 95 % (n = 125) of primary and 89 % (n = 47) of recurrent patients. Bowel resections were performed in 83 % (n = 110) and 72 % (n = 38), respectively. Complete cytoreduction (CC-0/1) with no disease or residual lesions <2.5 mm was achieved in 95 % (n = 125) of primary and 91 % (n = 48) of recurrent patients. Ninety-day Clavien-Dindo grade III-IV morbidity was 12 % (n = 16) and 21 % (n = 11), respectively. Median follow-up was 44 (95%CI: 33-55) months. Median overall survival in primary and recurrent EOC was 68 (95%CI: 45-91) and 50 (95%CI: 16-84) months. Median progression-free survival was 26 (95%CI: 22-30) and 14 (95%CI: 7-21) months, respectively. CONCLUSIONS: Perioperative collaboration between surgical and gynecological oncologists specializing in CRS allows safe performance of complete cytoreduction in the majority of patients with primary and recurrent EOC, despite high tumor burden.

Sufficient Regional Lymph Node Examination for Staging Adenocarcinoma of the Appendix.

BACKGROUND: The presence of lymph node (LN) metastasis is a known negative prognostic factor in appendix cancer (AC) patients. However, currently the minimum number of LNs required to adequately determine LN negativity is extrapolated from colorectal studies and data specific to AC is lacking. We aimed to define the lowest number of LNs required to adequately stage AC and assess its impact on oncologic outcomes. METHODS: Patients with stage II-III AC from the National Cancer Database (NCDB 2004-2019) undergoing surgical resection with complete information about LN examination were included. Multivariable logistic regression assessed the odds of LN positive (LNP) disease for different numbers of LNs examined. Multivariable Cox regressions were performed by LN status subgroups, adjusted by prognostic factors, including grade, histologic subtype, surgical approach, and documented adjuvant systemic chemotherapy. RESULTS: Overall, 3,602 patients were included, from which 1,026 (28.5%) were LNP. Harvesting ten LNs was the minimum number required without decreased odds of LNP compared with the reference category (≥ 20 LNs). Total LNs examined were < 10 in 466 (12.9%) patients. Median follow-up from diagnosis was 75.4 months. Failing to evaluate at least ten LNs was an independent negative prognostic factor for overall survival (adjusted hazard ratio 1.39, p < 0.01). CONCLUSIONS: In appendix adenocarcinoma, examining a minimum of ten LNs was necessary to minimize the risk of missing LNP disease and was associated with improved overall survival rates. To mitigate the risk of misclassification, an adequate number of regional LNs must be assessed to determine LN status.

Patterns of Recurrence in Appendix Cancer After Complete Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: It is thought that low-grade (LG) appendiceal cancer (AC) demonstrates predominantly intraperitoneal recurrence (IPR) after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), whereas high-grade (HG) tumors progress both intra- and extraperitoneally (EPR). However, evidence supporting this conception is lacking; therefore, we assessed recurrence in various AC histologies. METHODS: A retrospective, cohort study was conducted by using a single-center database (1998-2022). Recurrence patterns (IPR, EPR, combined) were identified for LG, HG, high-grade with signet ring cells (SRC), and goblet cell carcinoma (GCC). RESULTS: We included 432 complete (CC-0/1) CRS/HIPECs: 200 LG, 114 HG, 72 SRC, and 46 GCC. Median follow-up was 78 (95% confidence interval [CI] 70-86) months. Overall, 34% (n = 148) of patients recurred. IPR was the most common (LG 16%, HG 27%, SRC 36%, GCC 26%) with median time to recurrence (MTR) of 21 (IQR: 12-40) months. EPR (liver, lung, pleura, lymph nodes, or bones) occurred in LG 3%, HG 9%, SRC 22%, and GCC 7%. MTR was 11 (IQR: 4-16) months. Combined pattern occurred in LG 0%, HG 8%, SRC 7%, and GCC 0%. MTR was 13 (IQR: 7-18) months. Iterative surgery was performed in 53% IPR, 18% EPR, and 51% combined. Median post-recurrence survival was longer after IPR compared with EPR and combined recurrence: 36 (95% CI 25-47) versus 13 (95% CI 7-19) and 18 (95% CI 6-30) months (p < 0.01). CONCLUSIONS: After complete CRS/HIPEC, IPR was the predominant pattern in all AC histologies and occurred later. Post-recurrence survival after IPR was longer. Knowing AC recurrence patterns can help to understand its biology and plan follow-up and post-relapse management.

Outcomes after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal dissemination from ovarian carcinosarcoma.

BACKGROUND: Ovarian carcinosarcoma (OCS) is an uncommon and aggressive malignancy, with poor response to current treatment approaches and no clear guidelines. Our aim is to evaluate the outcomes of an OCS cohort after cytoreduction with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). METHODS: A descriptive cohort study was performed. Patients who underwent CRS/HIPEC for peritoneal dissemination from tubo-ovarian malignancies (1999-2021) were retrospectively reviewed. Patients with confirmed histopathologic diagnosis of FIGO stage III/IV OCS were included. Overall (OS) and progression-free survival (PFS) were determined with the Kaplan-Meier method. RESULTS: Of 267 patients with tubo-ovarian malignancies reviewed, 7.5% (20/267) had OCS. Of these, 16 underwent CRS/HIPEC, including 9 for a new diagnosis and 7 for disease recurrence. Median age at surgery was 66.5 (IQR: 54.5-74.5) years. Nine (56.2%) patients were FIGO stage IV. Median peritoneal cancer index was 22 (IQR: 14-28). Complete cytoreduction was achieved in 15/16 (93.7%) cases. HIPEC agents included carboplatin (n = 7), cisplatin+doxorubicin (n = 4), and melphalan (n = 5). Major complications occurred in 4/16 (25%), with no 90-day mortality. Median follow-up was 41.8 months. Median PFS was 11.7 (95%CI: 10.5-17.1) months. Malignant bowel obstruction occurred in 3/16 (18.7%). Median OS from CRS/HIPEC was 21.3 (95%CI: 16.3-31.6) months, not reached for newly diagnosed vs 19.7 months for recurrent patients (p = 0.23). CONCLUSIONS: CRS/HIPEC showed promising survival and abdominal disease control with low rates of malignant obstruction in patients with advanced stage OCS. Collaborative studies with larger cohorts and longer follow-up may further elucidate the role of CRS/HIPEC in OCS.

Safety of Nephrectomy Performed During CRS/HIPEC: A Propensity Score-Matched Study.

BACKGROUND: Surgeons may hesitate to perform nephrectomy (NE) during cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) due to a potential increase in morbidity. However, no data are available regarding the impact of NE on outcomes, so the authors decided to assess its safety during CRS/HIPEC. METHODS: A single-center propensity score-matched study was conducted using a prospective database (1994-2021). The study included patients who underwent NE during CRS/HIPEC with completeness of cytoreduction (CC) of 0, 1, or 2. Control subjects (no-NE) were selected in a 1:3 ratio using propensity score-matching weighted by age, histology, peritoneal cancer index (PCI), CC-0 or CC-1 rate, and length of surgery. RESULTS: Among 828 patients, 13 NE and 39 no-NE control subjects were identified. The indications for NE included tumor involvement of the ureter, hilum, and/or kidney with preserved (n = 8), decreased (n = 2), or absent (n = 3) function. NE patients received more intraoperative intravenous (IV) fluids (16,000 vs 11,500 mL; p = 0.045) and had a greater urine output (3200 vs 1913 mL; p = 0.008). NE patients received mitomycin C (40 mg for 90 min) or melphalan (50 mg/m2 for 90 min) without reduction of dose or time. Major morbidity (p = 0.435) and mortality (p = 1.000) were comparable between the two groups. No postoperative acute kidney injury was seen in either group. Adjuvant chemotherapy was administered to 46.2% of the NE and 35.9% of the no-NE patients (p = 0.553), with similar starting times (p = 0.903) between the groups. CONCLUSIONS: Nephrectomy performed during CRS/HIPEC does not seem to increase postoperative morbidity or to delay adjuvant chemotherapy, and NE can be performed if required for complete cytoreduction. The NE patients in our cohort did not have a reduction of mitomycin C or melphalan dose or perfusion time.

Adjuvant chemotherapy for high-grade appendiceal cancer after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy.

INTRODUCTION: There are no available data on the efficacy of adjuvant chemotherapy (ACT) in stage IVA/B high-grade mucinous appendiceal cancer treated with CRS/HIPEC. We evaluated the association between ACT and survival in this cohort. MATERIALS AND METHODS: A single-institution retrospective cohort study using a prospective database was conducted. Stage IVA/B high-grade mucinous appendiceal cancer patients who underwent CRS/HIPEC with CC-0/1 were included. Survival was compared between ACT and no chemotherapy (NoCT) patients. Subgroup analysis was performed with adjustment for confounding variables. RESULTS: We identified 180 patients: 77 ACT and 103 NoCT. ACT regimens included 5-FU/capecitabine (13%), oxaliplatin-based (63%), and irinotecan-based (21%), combined with bevacizumab in 27% of cases. Median number of cycles was 9 (IQR: 6-12). Median overall survival (OS) did not significantly differ between ACT and NoCT (53 vs 75 months, p = 0.566). Multivariable Cox regression showed no OS benefit for ACT vs NoCT in patients with neoadjuvant chemotherapy (HR 1.14; 95%CI: 0.38-3.39) or without it (HR 1.33; 95%CI: 0.69-2.57), with signet ring cell (HR 0.89; 95%CI: 0.38-2.06) or other histologies (HR 1.11; 95%CI: 0.50-2.46), positive lymph nodes (HR 1.60; 95%CI: 0.74-3.49), or peritoneal cancer index ≥20 (HR 1.08; 95%CI: 0.55-2.11) after adjusting for other factors. CONCLUSIONS: In our cohort, colon-type ACT was not associated with better OS in stage IVA/B mucinous appendiceal cancer after CRS/HIPEC, even after adjusting for confounders. This may be due to different tumor biology than colon cancer or small sample size. Prospective collaborative studies are needed.

Systemic Chemotherapy for High-Grade Mucinous Appendiceal Cancer with Peritoneal Spread After Unsuccessful CRS/HIPEC.

BACKGROUND: The best management of patients who have unresectable mucinous appendiceal cancer (MAC) with peritoneal spread after a failed attempt at cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is unclear. This study aimed to assess outcomes after systemic chemotherapy (SCT) for patients with unresectable peritoneal metastases from high-grade MAC. METHODS: A single-center retrospective cohort study was conducted using a prospective CRS/HIPEC database. The study included high-grade MAC patients with peritoneal carcinomatosis who were deemed surgical candidates, but had an aborted CRS/HIPEC or only palliative HIPEC due to unresectable disease. Overall survival (OS) was compared. RESULTS: Of 72 identified patients, 20 received SCT and 52 did not (NoCT). The groups were balanced by age (p = 0.299), sex (p = 0.930), histopathologic subtype (p = 0.096), preoperative chemotherapy (p = 0.981), and postoperative major complication rates (p = 0.338). Both groups had extensive disease (median peritoneal cancer index at exploration, 39 vs 39). The median number of cycles was 12 (interquartile range [IQR], 6-15), and the median time between the procedure and SCT was 7 weeks (IQR, 5-10 weeks). The median follow-up period was 65 months. The median OS was significantly higher for the SCT group (26 months; 95 % confidence interval [CI], 10.8-41.5 months) than for the NoCT group (12 months; 95 % CI, 9.6-14.4 months) (p < 0.001), with hazard ratio (HR) of 0.22 (95 % CI, 0.08-0.66; p = 0.007) after adjustment for other factors. CONCLUSION: Systemic chemotherapy is associated with improved OS for high-grade MAC patients with unresectable peritoneal metastases who are deemed surgical candidates but underwent an unsuccessful CRS/HIPEC attempt. Further prospective studies with a larger sample are required to identify patient subgroups who benefit the most from SCT.

The Role of Microorganisms in Appendiceal Pseudomyxoma Peritonei: A Review.

Pseudomyxoma peritonei (PMP) is a rare clinical syndrome. It originates from neoplasms of the appendix and leads to the formation of peritoneal implants and the accumulation of mucinous ascites. PMP represents a spectrum of low to high-grade disease. Despite aggressive management, many PMP patients recur, leading to debilitating symptoms and few treatment options. Therefore, scientists have continued to look for ways to improve treatment and further understand disease pathogenesis. Microorganisms were previously hypothesized to play a role in PMP progression and development. Hence, antibacterial treatment was suggested by some authors, but the data were limited. In this paper, we review the current data on the role of bacteria in PMP, discuss the significance, and suggest possible solutions to the inherent challenges in these studies. Given the limitations of the discussed studies, we remain skeptical about introducing novel antibacterial treatment into clinical practice at this time; however, the available data are valuable and indicate that more research into the molecular mechanisms of PMP is needed.

Iterative Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Recurrent Mucinous Adenocarcinoma of the Appendix.

BACKGROUND: Recurrence after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for appendiceal tumors (AT) with mucinous carcinomatosis peritonei (MCP) is common. The evidence favoring iterative procedures (iCRS/HIPEC) is limited, and its benefit is not clear for all patients. METHODS: Retrospective (1998-2020) cohorts of AT patients with MCP recurrence after the first CRS/HIPEC were analyzed. Outcomes were compared within tumor grades between iCRS/HIPEC patients and matched control patients without iCRS/HIPEC using propensity score matching (1:1). Post-recurrence survival (PRS) was measured from the date of recurrence after the first CRS/HIPEC to death or last contact. RESULTS: Overall, 55 iCRS/HIPEC patients were identified: 36 low-grade (LGMCP) patients, 13 high-grade (HGMCP) patients, and 6 HGMCP patients with signet-ring features (HGMCP-S). Nine patients had a third CRS/HIPEC. The median peritoneal cancer index (PCI) scores were 33, 19 and 10, with CC-0/1 achieved for 94.4%, 78.2% and 88.9% of the patients after the first, second, and third CRS/HIPEC, respectively. No 90-day postoperative mortality occurred. The median progression-free survival from the first CRS/HIPEC was 19.7 months for the iCRS/HIPEC patients versus 14.2 months for the matched control patients (p = 0.43). The median PRS was 80.2 months for iCRS/HIPEC versus 36.2 for the control patients (p < 0.001). For the iCRS/HIPEC versus the matched control patients, the median PRS by tumor grade was 174.1 versus 51.9 (p < 0.001) for the LGMCP, 42.0 versus 12.4 (p = 0.02) for the HGMCP, and 15.4 versus 8.1 months (p = 0.61) for the HGMCP-S patients, respectively. CONCLUSIONS: Selected low- and high-grade appendiceal cancer patients with MCP recurrence able to undergo iterative CRS/HIPEC procedures showed favorable outcomes and such patients should be considered for surgery when feasible. This survival benefit with iCRS/HIPEC is not evidenced in recurrent MCP with signet ring cell morphology.

Outcomes Following Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy with and without Diaphragmatic Resection in Patients with Peritoneal Metastases.

BACKGROUND: Diaphragmatic resection (DR) is often required during cytoreductive surgery/hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) to achieve complete cytoreduction (CC). While CC provides the best survival, requiring a DR may indicate unfavorable tumor biology. We assessed how DR during CRS/HIPEC affects outcomes. METHODS: A retrospective cohort study was conducted using a prospective single-center database from October 1994-May 2020. Peritoneal surface malignancy patients who underwent CRS/HIPEC with CC-0/1/2 were assigned to DR and NoDR groups. Survival was measured using the Kaplan-Meier method. Subgroup analysis was performed for patients with peritoneal cancer index (PCI) ≥ 20 to eliminate confounding of more extensive disease in DR. RESULTS: Of 824 CRS/HIPECs, 774 were included: 134 DR and 640 NoDR. PCI was significantly higher in DR: 29 versus 21, p < 0.001. CC-0/1 rate was 89% in DR and 95% in NoDR (p = 0.003). Neither 100-day morbidity nor mortality differed between the groups (p = 0.355 and p = 1.000). Median follow-up was 64 months. Median overall survival (OS) was significantly lower in DR (32 vs. 96 months, p < 0.001). Subgroup analysis by tumor type in patients with PCI ≥ 20 showed significantly shorter OS in DR than NoDR in appendiceal (40 vs. 196 months, p < 0.001) and colorectal (14 vs. 23 months, p = 0.003), but not in ovarian tumors (32 vs. 42 months, p = 0.893), whereas median PCI did not differ among subgroups. CONCLUSIONS: DR during CRS/HIPEC does not increase morbidity and mortality. It is associated with worse survival in appendiceal and colorectal tumors, even after adjusting for tumor burden but does not appear to impact ovarian cancer survival.

Surgical and oncological outcomes after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy at a nonacademic center: 25-year experience.

BACKGROUND: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is predominantly performed and studied in academic centers. While developing CRS/HIPEC programs in nonacademic hospitals can increase accessibility, its safety and oncological efficacy remains unclear. We evaluated CRS/HIPEC outcomes in a nonacademic setting. METHODS: A single-center descriptive study was conducted using a prospective database. Data of all CRS/HIPEC attempts in peritoneal surface malignancies (PSM) patients from October 1994 to November 2019 were extracted. Surgical and survival outcomes were measured. Center experience was assessed by quartiles of cases. RESULTS: Overall, 856 patients underwent 948 CRS/HIPEC attempts: 788 (83%) completed CRS/HIPECs, 144 (15%) aborted HIPECs, and 16 (2%) complete cytoreductions (CC-0/1) without chemoperfusion. For completed CRS/HIPECs, median peritoneal cancer index was 24 (interquartile range: 10-33) and CC-0/1 rate was 88%. Major complications occurred in 23.5% with 30- and 100-day mortality of 1.0% and 2.3%, respectively. Median overall survival was 68 months (95% confidence interval [CI]: 50-86). Median progression-free survival was 37 months (95%CI: 28-46). Incomplete cytoreduction and major complication rates decreased over time, while mortality remained low and constant. CONCLUSIONS: CRS/HIPEC at a nonacademic center with advanced surgical and auxiliary services is a safe option to treat PSM with favorable surgical and oncological outcomes.

Outcomes for Elderly Ovarian Cancer Patients Treated with Cytoreductive Surgery Plus Hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC).

BACKGROUND: Women 65 years of age or older with epithelial ovarian cancer (EOC) are thought to have a worse prognosis than younger patients. However, no consensus exists concerning the best treatment for ovarian cancer in this age group. This report presents outcomes for patients treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: A prospective database of EOC patients treated with CRS/HIPEC (1998-2019) was analyzed. Perioperative variables were compared by treatment including upfront CRS/HIPEC, neoadjuvant chemotherapy plus CRS/HIPEC (NACT + CRS/HIPEC), and salvage CRS/HIPEC, and by age at surgery (< 65 and ≥ 65 years). Survival analysis was performed, and outcomes were compared. RESULTS: Of the 148 patients identified, 42 received upfront CRS/HIPEC, 48 received NACT + CRS/HIPEC, and 58 received salvage CRS/HIPEC. Each group was subdivided by age groups (< 65 and ≥ 65 years). The median overall survival (OS) after the upfront CRS/HIPEC was 69.2 months for the patients < 65 years of age versus 69.3 months for those ≥ 65 years of age. The OS after NACT + CRS/HIPEC was 26.9 months for the patients < 65 years of age versus 32.9 months for those ≥ 65 years of age, and the OS after salvage CRS/HIPEC was 45.6 months for the patients < 65 years of age versus 23.9 months for those ≥ 65 years of age. The median progression-free survival (PFS) after upfront CRS/HIPEC was 41.3 months for the patients < 65 years of age versus 45.4 months for those ≥ 65 years of age. The PFS after NACT + CRS/HIPEC was 16.2 months for the patients < 65 years of age versus 11.2 months for those ≥ 65 years of age, and the PFS after salvage CRS/HIPEC was 18.7 months for the patients < 65 years of age versus 10 months for those ≥ 65 years of age. The median follow-up period for the entire cohort was 44.6 months [95% confidence interval (CI) 34.7-60.6 months]. CONCLUSION: Age and feasibility of complete cytoreduction should be considered when treatment methods are selected for elderly patients. A carefully selected elderly population can benefit significantly from aggressive treatment methods.

Critical Analysis of Stage IV Epithelial Ovarian Cancer Patients after Treatment with Neoadjuvant Chemotherapy followed by Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC).

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) after neoadjuvant chemotherapy (NACT) showed promise as initial treatment for stage IIIC (SIII) epithelial ovarian cancer (EOC); however, stage IV (SIV) outcomes are rarely reported. We assessed our experience and outcomes treating newly diagnosed SIV EOC with NACT plus CRS/HIPEC compared to SIII patients. METHODS: Advanced EOC from 2015-2018 managed with NACT (carboplatin/paclitaxel) due to unresectable disease or poor performance status followed by interval CRS/HIPEC were reviewed. Perioperative factors were assessed. Overall survival (OS) and progression-free survival (PFS) were analyzed by stage. RESULTS: Twenty-seven FIGO stage IIIC (n = 12) and IV (n = 15) patients were reviewed. Median NACT cycles were 3 and 4, respectively. Post-NACT omental caking, ascites, and pleural effusions decreased/resolved in 91%, 91%, and 100% of SIII and 85%, 92%, and 71% of SIV. SIII/SIV median PCI was 21 and 20 obtaining 92% and 100% complete cytoreduction (≤0.25 cm), respectively. Median organ resections were 6 and 7, respectively. Grade III/IV surgical complications were 0% SIII and 23% SIV, without hospital mortality. Median time to adjuvant chemotherapy was 53 and 74 days, respectively (p=0.007). SIII OS at 1 and 2 years was 100% and 83% and 87% and 76% in SIV (p=0.269). SIII 1-year PFS was 54%; median PFS: 12 months. SIV 1- and 2- year PFS was 47% and 23%; median PFS: 12 months (p=0.944). CONCLUSION: Outcomes in select initially diagnosed and unresectable SIV EOC are similar to SIII after NACT plus CRS/HIPEC. SIV EOC may benefit from CRS/HIPEC, and further studies should explore this treatment approach.

Defining "Complete Cytoreduction" After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC) for the Histopathologic Spectrum of Appendiceal Carcinomatosis.

BACKGROUND: The completeness of cytoreduction (CC) score, which quantifies residual tumor, is a major prognostic factor when treating appendiceal carcinomatosis with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). Both CC-0 and CC-1 are considered complete cytoreductions (CC-0/1) and associated with the best outcomes. We analyzed if the CC-0/1 definition is reliable across appendiceal histopathologic subtypes. METHODS: A prospective database of CRS/HIPEC patients with appendiceal carcinomatosis from 1998 to 2019 was reviewed to identify patients with CC-0/1. Kaplan-Meier overall survival (OS) and progression-free survival (PFS) by CC-score for each histopathology were calculated. RESULTS: Overall, 297 patients had CC-0/1. Mean age was 54 ± 12 years with 67% females. Histopathologic subtypes were 45% low-grade mucinous carcinoma peritonei (LGMCP), 27% high-grade MCP (HGMCP), 20% HGMCP with signet ring cells (HGMCP-S), and 8% goblet cell adenocarcinoma (GCAC). CC-0 and CC-1 occurred in 57% and 43% of LGMCP, 65% and 35% of HGMCP, 68% and 32% of HGMCP-S, and 79% and 21% of GCAC, respectively. OS and PFS were statistically longer for CC-0 versus CC-1 in HGMCP-S (p = 0.001 and p = 0.005, respectively) and GCAC (p < 0.001 and p < 0.001), but not in LGMCP (p = 0.098 and p = 0.398) or HGMCP (p = 0.167 and p = 0.356). CONCLUSIONS: Survival outcomes for CC-0 and CC-1 after CRS/HIPEC are different for HGMCP-S and GCAC but not for LGMCP and HGMCP. In HGCMP-S and GCAC, only CC-0 should be considered a complete cytoreduction and analyzed separately from CC-1. This distinction is key to understand disease behavior, accurately address patient prognosis, and explore new treatment strategies.

Impact of Mucin Cellularity and Distribution on Survival in Newly Diagnosed Patients with Low-Grade Appendiceal Mucinous Neoplasm Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Low-grade appendiceal mucinous neoplasms (LAMN) are tumors that frequently present with peritoneal spread of either acellular mucin (AM) or cellular mucin (CM). We aim to determine how mucin types and distribution affect survival. PATIENTS AND METHODS: A retrospective cohort study was conducted using a prospective database. Newly diagnosed LAMN patients with AM versus CM treated with cytoreductive surgery/hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) were compared. Postoperative pathology reports were reviewed to assess each involved abdominal zone. Survival was analyzed using the Kaplan-Meier method. RESULTS: Of 121 identified patients, 50 (41%) had peritoneal lesions with AM and 71 (59%) with CM. Peritoneal cancer index was lower in AM versus CM (mean: 19 ± 13 vs 28 ± 10, p = 0.004), but complete cytoreduction (CC) rates were similar (98% vs 96%, p = 0.642). The 5-year progression-free survival (PFS) was higher in AM versus CM (96% vs 69.8%, p = 0.002). CM patients had zones with both types of lesions: with and without cells. The CM subgroup analysis showed significant differences in 5-year progression-free survival (PFS) among patients with 1-3, 4-7, and 8-10 zones with cells (95.2%, 68.4%, and 35.7%, respectively, p < 0.001), but PFS was not affected by the number of zones with any lesion type. There was no difference in overall survival (OS) between groups. CONCLUSIONS: Despite comparable CC rates after CRS/HIPEC, CM patients have shorter PFS than AM patients. In CM patients, more zones with cells, but not the total number of involved zones, negatively impact PFS. Mucin type does not impact OS. It is important to assess and report mucin cellularity in LAMN specimens.

Outcomes in Peritoneal Carcinomatosis from Appendiceal Goblet Cell Carcinoma Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC).

BACKGROUND: Appendiceal goblet cell adenocarcinoma (GCA) is often misclassified and mistreated due to mixed histologic features. In general, cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is standard of care for peritoneal carcinomatosis (PC) from mucinous appendiceal tumors; however, in PC from GCA, data are limited and the role of CRS/HIPEC is controversial. We report outcomes in PC from appendiceal GCA treated with CRS/HIPEC. PATIENTS AND METHODS: A prospective institutional database of 391 CRS/HIPEC patients with appendiceal carcinomatosis from 1998 to 2018 was reviewed. Twenty-seven patients with GCA were identified. Perioperative variables were described. Survival was estimated using the Kaplan-Meier method. RESULTS: GCA occurred in 7% (27/391) of appendiceal CRS/HIPEC patients. Seven (26%) cases were aborted. Two patients underwent a second CRS/HIPEC for peritoneal recurrence. Median age at diagnosis was 53 years (range 39-72 years), and 12 (60%) were female. All underwent previous surgery. Seven (35%) had prior chemotherapy and received a median of 5 cycles (range 3-8). Median PCI was 6 (range 1-39). Complete cytoreduction was achieved in 95% (19/20). Grade III complications occurred in three (15%) patients, and no perioperative deaths occurred. Median follow-up was 97 months. Overall survival at 1, 3 and 5 years was 100%, 74% and 67%, respectively. Progression-free survival at 1, 3, and 5 years was 94%, 67% and 59%, respectively. CONCLUSION: CRS/HIPEC should be considered as the main treatment option for patients with PC from appendiceal GCA. When performed at a CRS/HIPEC specialty center, 5-year OS of 67% can be achieved.