Patterns of pathological response to neoadjuvant chemotherapy and its clinical implications in patients undergoing interval cytoreductive surgery for advanced serous epithelial ovarian cancer- A study by the Indian Network for Development of Peritoneal Surface Oncology (INDEPSO)

Perioperative outcomes and platinum resistant recurrence in patients undergoing systematic, protocol-based, total parietal peritonectomy during interval cytoreductive surgery for advanced ovarian cancer: results of the TORPEDO study

OBJECTIVE

The TORPEDO (CTRI/2018/12/016789) is the single-arm, prospective, interventional study evaluating the role of a total parietal peritonectomy (TPP) in patients undergoing interval cytoreductive surgery (iCRS). In this manuscript, we report the perioperative outcomes and platinum resistant recurrence (PRR) in 218 patients enrolled in the study.

METHODS

A TPP was performed in all patients undergoing iCRS irrespective of the residual disease extent. hyperthermic intraperitoneal chemotherapy (HIPEC) was performed as per the clinician's discretion with 75 mg/m² of cisplatin. Maintenance therapy was also used at the discretion of the treating clinicians.

RESULTS

From 9th December 2018 to 31st July 2022 (recruitment complete), 218 patients were enrolled at 4 medical centers in India. The median surgical peritoneal cancer index was 14 and a complete gross resection was achieved in 95.8%. HIPEC was performed in 130 (59.6%) patients. The 90-day major morbidity was 17.4% and 2.7% patients died within 90 days of surgery. Adjuvant chemotherapy was delayed beyond 6 weeks in 7.3%. At a median follow-up of 19 months (95% confidence interval [CI]=15.9-35 months), 101 (46.3%) recurrences and 19 (8.7%) deaths had occurred. The median progression-free survival was 22 months (95% CI=17-35 months) and the median overall survival (OS) not reached. Platinum resistant recurrence was observed in 6.4%. The projected 3-year OS was 81.5% and in 80 patients treated before may 2020, it was 77.5%.

CONCLUSION

The morbidity and mortality of TPP with or without HIPEC performed during iCRS is acceptable. The incidence was of PRR is low. Early survival results are encouraging and warrant conduction of a randomized controlled trial comparing TPP with conventional surgery.

Visual Peritoneal Evaluation of Residual Disease After Neoadjuvant Chemotherapy in Advanced Ovarian Cancer Patients: The VIPER Study

BACKGROUND

Chemotherapy induces histopathological tumor necrosis and fibrosis which results in macroscopic tissue changes, making surgeons' intraoperative visual evaluation of the disease distribution more difficult to interpret. The aim of the study was to assess the sensitivity, specificity, and accuracy of intraoperative laparoscopic visual evaluation of the diaphragmatic peritoneum and compare it with histopathological examination.

METHODS

Patients receiving diaphragmatic peritonectomy at time of IDS were retrospectively included. The population was grouped based on the surgeon's assessment of the diaphragmatic peritoneum during diagnostic laparoscopy. Group 1 included patients with a "visually pathologic" diaphragmatic peritoneum, and group 2 included patients with a "visually dubious" diaphragmatic peritoneum. Sensitivity, specificity, predictive values, and accuracy were calculated considering the final formalin-fixed pathology as the reference standard.

RESULTS

155 patients were included (92 in group 1 and 63 in group 2). The accuracy rate of visual examination was 67.1%, the negative predictive value was 19%, specificity was 100%, and sensitivity was 64.3%.

CONCLUSION

NACT strongly affects the ability of the surgeon to discern between peritoneal scars and truly pathologic peritoneum. The diaphragmatic laparoscopic visual examination showed a low overall accuracy. We propose an algorithm that can guide the surgeon towards a more tailored approach to diaphragmatic peritonectomy during IDS.

Platinum resistant recurrence and early recurrence in a multi-centre cohort of patients undergoing interval cytoreductive surgery for advanced epithelial ovarian cancer

Background

Aggressive locoregional therapies like hyperthemic intraperitoneal chemotherapy(HIPEC) and total parietal peritonectomy(TPP) have been used to delay recurrence in patients with advanced ovarian cancer undergoing interval cytoreductive surgery(CRS). The aim of this retrospective study was to evaluate the incidence of platinum resistant recurrence (PRR) and early recurrence (ER)(recurrence within 6 months and 1 year of the last dose of platinum based therapy, respectively) in patients undergoing interval CRS. The secondary goal was to study impact of each of these therapies on PRR and ER.

Methods

One-hundred and fifty-three patients undergoing interval CRS from July 2018 to June 2020 were included. The surgical strategy was to perform a TPP in which the entire parietal peritoneum is resected irrespective of the disease extent or a selective parietal peritonectomy (SPP) in which only the peritoneum bearing visible residual disease is resected. The use of HIPEC was at the discretion of the treating oncologists.

Results

The median surgical PCI was 15 [range, 0-37]. A CC-0 resection was obtained in 119 (77.7%) and CC-1 in 29 (18.9%) patients. Eighty-one (53%) patients had a TPP and 72 (47%) had SPP. HIPEC was performed in 98(64%) patients. Bevacizumab maintenance was administered to 31(19.6%) patients. No patients received PARP inhibitors during first-line therapy. PRR was observed in 8(5.2%) patients and ER in 30(19.6%). The respective incidences of PRR and ER were 4.9% and 16% in the TPP group, 4.1% and 23.6% in the SPP group, 9% and 20% in the no-HIPEC group and 3% and 19.3% in the HIPEC groups. On multivariate analysis, CC-0(p=0.014) resection and HIPEC(p=0.030) were independent predictors of a low ER. All patients with PR and 70% with ER had peritoneal recurrence with or without extra-peritoneal sites of recurrence.

Conclusions

The incidence of PRR and ER in this cohort was low as compared to historical data. This low incidence could be attributed to the use of aggressive locoregional therapies like TPP and HIPEC. In future, studies should be conducted to confirm these findings and evaluate the potential additive benefit of TPP and HIPEC coupled together as well as their combination with maintenance therapies.

Greater-omentum lesion-score (GOLS) as a predictor of residual disease in different regions of the peritoneal cavity in patients undergoing interval cytoreductive surgery for advanced ovarian cancer and its potential clinical utility

BACKGROUND AND AIM

The greater omentum(GO) is a common site of residual disease in patients receiving neoadjuvant chemotherapy for advanced epithelial ovarian cancer. The presence of tumor in the GO could predict presence of disease in other peritoneal regions. The goal of this study was to perform a correlation between the greater-omentum lesion-score(GOLS) and presence of disease in different peritoneal regions and determine its potential utility in guiding interval cytoreductive surgery(CRS).

METHODS

This prospective study included 134 patients undergoing interval CRS from July 1, 2018 to June 30, 2020. Each region of Sugarbaker's Peritobneal Cancer Index(PCI) was given a lesion score(LS) from 0 to 3 according to the diameter of the largest tumor in the region. The GOLS was recorded separately from other structures in the region. Correlation between the GOLS and surgical and pathological LS in each region was performed.

RESULTS

As the GOLS increased, the incidence of disease(surgical LS) in other regions of the peritoneal cavity increased. Receiver operating characteristic(ROC) curves showed area under curve more than 80% for regions 1-2 and 7-8 indicating a high probability of disease in these regions in patients with GOLS 1-3. The positive predictive value(PPV) of preoperative imaging for GOLS was 95.7%. No cut-off of the GOLS could predict presence of disease on pathology with more than 70% accuracy.

CONCLUSIONS

Presence of disease in the GO warrants performing upper abdominal exploration and/or cytoreduction and interval CRS should be planned accordingly in these patients. Imaging has a high PPV in detecting disease in the GO.

Total parietal peritonectomy performed during interval cytoreductive surgery for advanced epithelial serous ovarian cancer results in a low incidence of platinum resistant recurrence- results of a prospective multi-centre study

BACKGROUND

The reported incidence of platinum resistant recurrence (PRR) (recurrence within 6 months of the last dose of platinum therapy) after interval debulking/cytoreductive surgery (CRS) is high compared to that after primary CRS. The goal was to study PRR following a total parietal peritonectomy (TPP), that addresses occult disease more completely.

METHODS

This is a prospective multi-center study (CTRI/2018/08/015350). A TPP was performed during interval CRS following a fixed surgical protocol. Patients with a follow-up of 6 months(M) or more were included in this analysis. The incidence and patterns of PRR and factors affecting recurrence were analyzed.

RESULTS

From July 2018 to October 2019, 70 patients with serous carcinoma were included. The median surgical PCI was 15 [range 5-37]. A CC-0 resection was obtained in 55 (78.5%); CC-1 in 10 (14.2%). Occult residual disease was seen in 40%. At a median follow-up of 13 months, 17 (24.2%) had developed recurrence/progression. PRR was seen in 5 (7.1%) patients. The sites of progression (>1 in 2 patients) were pleura (n = 1), visceral peritoneum (n = 2), retroperitoneal nodes (n = 2), mediastinal nodes (n = 1) and small bowel mesentery (n = 2). Overall, though the most common site of recurrence was the visceral peritoneum (N = 9), seven (>40%) patients did not develop recurrence in the visceral peritoneum. Patients with high PCI and grade 3-4 complications had a higher probability of developing recurrence.

CONCLUSIONS

TPP performed during interval CRS resulted in a very low incidence of PRR. These findings need confirmation in a larger series. The benefit of TPP over conventional surgery should be evaluated in a randomized trial.

Distribution of residual disease in the peritoneum following neoadjuvant chemotherapy in advanced epithelial ovarian cancer and its potential therapeutic implications

INTRODUCTION

Residual disease in 'normal appearing' peritoneum is seen in nearly 30% of the patients following neoadjuvant chemotherapy (NACT) for advanced ovarian cancer. The goal was to study the sequence of response in different regions, the commonest sites of occult residual disease, its incidence in different peritoneal regions and the potential therapeutic implications of these.

METHODS

This was a prospective multi-centre study (July 2018-June 2019). Pathological evaluation of cytoreductive surgery specimens was performed according to a fixed protocol. Prevalence of residual disease in different regions was used to study patterns of response and distribution of residual disease.

RESULT

In 85 patients treated between July 2018 to June 2019, microscopic disease in 'normal appearing' peritoneal regions was seen in 22 (25.2%) and in normal peritoneum around tumor nodules in 30 (35.2%) patients. Regions 4 and 8 of Sugarbaker's PCI had the highest incidence of occult disease and regions 9 and 10 the lowest. The response to chemotherapy occurred in a similar manner in over 95%- the least common site of residual disease was the small bowel mesentery, followed by upper regions (regions 1-3), omentum and middle regions (regions 0, 4, 8), lower regions (regions 5-7) and lastly the ovaries.

CONCLUSIONS

During interval CRS, based on the disease mapping provided in this manuscript, regions that have a high probability of residual disease should be explored and dissected. Complete resection of involved the peritoneal region can completely address the occult disease. The role of resection of the entire region as well as 'normal appearing' parietal peritoneal regions should be prospectively evaluated.

Photodynamic Diagnosis and Therapy for Peritoneal Carcinomatosis: Emerging Perspectives

Simple Summary

Peritoneal carcinomatosis, the formation of wide-spread metastases throughout the abdominal cavity, remains challenging to diagnose and treat. Photodynamic diagnosis and photodynamic therapy are promising approaches for the diagnosis and treatment of peritoneal carcinomatosis, which use photosensitizers for fluorescence detection or photochemical treatment of (micro) metastases. With the aim of highlighting the potential of this theranostic approach, this review outlines the clinical state of the art in the use of photodynamic diagnosis and therapy for peritoneal carcinomatosis, identifies the major challenges, and provides emerging perspectives from preclinical studies to address these challenges. We conclude that the development of novel illumination strategies and targeted photonanomedicines may aid in achieving more efficient cytoreductive surgery. In addition to combination treatments with chemo-, and radiotherapy, such approaches hold significant promise to improve the outlook of patients with peritoneal carcinomatosis.

Abstract

Peritoneal carcinomatosis occurs frequently in patients with advanced stage gastrointestinal and gynecological cancers. The wide-spread peritoneal micrometastases indicate a poor outlook, as the tumors are difficult to diagnose and challenging to completely eradicate with cytoreductive surgery and chemotherapeutics. Photodynamic diagnosis (PDD) and therapy (PDT), modalities that use photosensitizers for fluorescence detection or photochemical treatment of cancer, are promising theranostic approaches for peritoneal carcinomatosis. This review discusses the leading clinical trials, identifies the major challenges, and presents potential solutions to advance the use of PDD and PDT for the treatment of peritoneal carcinomatosis. While PDD for fluorescence-guided surgery is practically feasible and has achieved clinical success, large randomized trials are required to better evaluate the survival benefits. Although PDT is feasible and combines well with clinically used chemotherapeutics, poor tumor specificity has been associated with severe morbidity. The major challenges for both modalities are to increase the tumor specificity of the photosensitizers, to efficiently treat peritoneal microtumors regardless of their phenotypes, and to improve the ability of the excitation light to reach the cancer tissues. Substantial progress has been achieved in (1) the development of targeted photosensitizers and nanocarriers to improve tumor selectivity, (2) the design of biomodulation strategies to reduce treatment heterogeneity, and (3) the development of novel light application strategies. The use of X-ray-activated PDT during whole abdomen radiotherapy may also be considered to overcome the limited tissue penetration of light. Integrated approaches that take advantage of PDD, cytoreductive surgery, chemotherapies, PDT, and potentially radiotherapy, are likely to achieve the most effective improvement in the management of peritoneal carcinomatosis.

Total Parietal Peritonectomy Can Be Performed with Acceptable Morbidity for Patients with Advanced Ovarian Cancer After Neoadjuvant Chemotherapy: Results From a Prospective Multi-centric Study

BACKGROUND

Total parietal peritonectomy (TPP) removes areas of "normal-appearing" parietal peritoneum bearing microscopic residual disease and has the potential to improve survival of patients undergoing interval cytoreductive surgery (CRS) for advanced serous epithelial ovarian cancer. This report presents the morbidity outcomes for the first 50 patients enrolled in TORPEDO (CTRI/2018/12/016789), a prospective study.

METHODS

All the patients underwent a TPP during interval CRS. A surgical protocol that includes a description of the boundaries for each of the five peritonectomies was followed. The common toxicology criteria for adverse events (CTCAE) classification was used to record 90-day morbidity and mortality.

RESULTS

The median Peritoneal Cancer Index (PCI) for 50 patients was 15 (range, 5-37). A complete cytoreduction (CC-0 resection) was obtained in 80%, a CC-1 resection in 16%. A bowel resection was performed in 70% of the patients. Grade 3 or 4 complications were seen in 11 patients (22%), and one patient died within 90 days after surgery due to intraperitoneal hemorrhage. The most common complications were postoperative fluid collection requiring aspiration (n = 5), intraperitoneal hemorrhage (n = 2), abdominal wound dehiscence (n = 2), pseudo-obstruction (n = 1), urinary sepsis (n = 2), and ileostomy-related complications (n = 2). No bowel fistulas or anastomotic leaks occurred. Microscopic disease in 'normal appearing' peritoneum adjacent to tumor nodules was observed in 46% of the patients, and in regions given a lesion score of 0 in 34%. The parietal peritoneal regions (0-8) had a higher incidence of residual disease (p < 0.001) and occult disease (p < 0.001).

CONCLUSIONS

During interval CRS, TPP can be performed with acceptable morbidity and mortality. The pathologic findings further support this therapeutic rationale. Survival outcomes should determine the future role of such a procedure in routine clinical practice.

Extent of Peritoneal Resection for Peritoneal Metastases: Looking Beyond a Complete Cytoreduction

Completeness of cytoreduction is one of the most important prognostic factors impacting outcomes of cytoreductive surgery (CRS). To what extent the surrounding normal peritoneum needs to be removed is not known. We hypothesized that the extent of peritoneal resection should be different for different tumors and performed this study to find evidence to support this rationale. To determine the extent of resection of surrounding tissue for any tumor, the mechanisms of tumor development and spread, tumor morphology, the possibility of finding disease in the surrounding normal tissue, and the pattern of lymph node metastases should be known. Surgical resections also depend on patterns of recurrence and the impact of varying extent of resection on survival. We performed a review of literature pertaining to pathways and patterns of peritoneal cancer spread to determine the scientific basis for the extent of peritonectomy. We also reviewed studies comparing less and more extensive peritoneal resection. There is no consensus on the extent of lymphadenectomy required for most PM. Based on this review, we provide recommendations for the extent of peritoneal resection and the extent of lymph node dissection that should be performed for some common peritoneal tumors and identify areas that require further research. We propose that a systematic method of synoptic reporting of pathological specimens of CRS should be developed to capture information regarding the disease distribution within the peritoneal cavity and morphology of PM from different tumors. This can in future be used to establish standard guidelines for such resections.

Target region resection in patients undergoing cytoreductive surgery for peritoneal metastases-is it necessary in absence of visible disease?

BACKGROUND

The aim was to study the patterns of target region (greater omentum, lesser omentum, falciform and umbilical round ligament) involvement in patients undergoing cytoreductive surgery (CRS) from various primary tumors, factors affecting involvement and implications on surgical practice.

METHODS

All patients undergoing CRS from July 2018 to December 2018 were included in this prospective study. The incidence of target region involvement in presence and absence of visible disease and the impact of primary tumor site, PCI and other variables on target region involvement was evaluated.

RESULTS

In 191 patients, greater omentum was involved in over 15% of patients irrespective of the primary tumor type and in 15.7% in absence of visible disease. 75% of these had PCI <20. The involvement of the other three target regions was higher than 20% in ovarian cancer, appendiceal tumors and peritoneal mesothelioma. Involvement of these 3 regions was associated with a higher PCI (p < 0.001 for all) and omental involvement (p < 0.001for all). 2.1% of colorectal cancer patients had umbilical round ligament involvement, 4.2% had falciform ligament involvement and none had lesser omentum involvement.

CONCLUSIONS

Target region involvement varies according to primary tumour site and disease extent. Resection of the greater omentum should be performed during CRS for PM arising from all primary sites. Resection of other target organs may be performed for selected patients with ovarian cancer, peritoneal mesothelioma and mucinous appendiceal tumors in absence of visible disease. For other patients, it should be done only in presence of visible disease.

Pathological assessment of cytoreductive surgery specimens and its unexplored prognostic potential-a prospective multi-centric study

BACKGROUND AND AIM

The grade/histological subtype is one of the most important prognostic markers in patients undergoing cytoreductive surgery (CRS). Our aim was to study other potential prognostic information that can be derived from the pathological evaluation of CRS specimens and provide a broad outline for evaluation of these.

METHODS

This prospective study (July to December 2018) included all patients undergoing cytoreductive surgery (CRS). A protocol for pathological evaluation was laid down which was based on existing practices at the participating centers and included evaluation of the pathological PCI, regional node involvement, response to chemotherapy, morphology of peritoneal metastases (PM) and distribution in the peritoneal cavity.

RESULTS

In 191 patients undergoing CRS at 4 centers, the pathological and surgical PCI differed in over 75%. Nodes in relation to peritoneal disease were positive in 13.6%. Disease in normal peritoneum adjacent to tumor nodules was seen in >50% patients with ovarian cancer and mucinous apppendiceal tumors. 23.8% of evaluated colorectal PM patients had a complete response and 25.0% ovarian cancer patients had a near complete pathological response to chemotherapy.

CONCLUSIONS

Pathological evaluation of extent and distribution of peritoneal disease differs from the surgical evaluation in majority of the patients. Lymph node involvement in relation of peritoneal disease is common. The morphological presentation of PM in ovarian cancer and mucinous appendiceal tumors merits evaluation of more extensive resections in these patients. Standardized methods of synoptic reporting of CRS specimens could help capture vital prognostic information that may in future influence how these patients are treated.