Role of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy in the Management of Colorectal Peritoneal Metastases.

Peritoneal metastases from colon cancer are a particularly challenging disease process given the limited response to systemic chemotherapy. In patients with isolated peritoneal metastases, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy offers a potential treatment option to these patients with limited peritoneal metastases as long as a complete cytoreduction is achieved. Decision about a patient's candidacy for this treatment modality should be undertaken by a multidisciplinary group at expert centers.

Enhancing Lymph Node Yield in Gastric Cancer Resection: Impact of Back Table Dissection on Number of Lymph Node Examined.

INTRODUCTION: During gastric cancer resection, back table dissection (BTD) involves examination and separation of lymph node (LN) packets from the surgical specimen based on LN stations, which are sent to pathology as separately labeled specimens. With potential impact on clinical outcomes, we aimed to explore how BTD affects number of LNs examined. METHODS: A retrospective review of a gastric cancer database was performed, including all cases of gastrectomy with D2 lymphadenectomy from January 2009 to March 2022. Back table dissection and conventional groups were compared using Mann-Whitney U and Fisher's exact tests. Multiple linear regression modeling was used to identify potential predictors of number of LN examined. RESULTS: A total of 174 patients were identified: 39 (22%) BTD and 135 (78%) conventional. More patients in the BTD group underwent neoadjuvant chemotherapy (62% vs 29%, P < .05). Compared to the conventional group, the BTD group had a greater number of LNs examined (42 [26-59] vs 21[15-33], median [IQR], P < .001), lower LN positivity ratio (.01 vs .07, P = .013), and greater number of LNs in patients with BMI >35 (32.5[27.5-39] vs 22[13-27], P = .041). A multiple linear regression model controlling for age, BMI, preoperative N stage, neoadjuvant chemotherapy, surgeon experience, and operative approach identified BTD as a significant positive predictor of number of LN examined (ß = 19.7, P = .001). CONCLUSION: Back table dissection resulted in improved LN yield during gastric cancer resection. As a simple technical addition, BTD helps enhance pathology examination and improve surgeon awareness, which may ultimately translate to improve oncologic outcomes.

Impact of primary tumor resection in the management of metastatic well-differentiated neuroendocrine tumors of the small bowel and pancreas.

Patients with gastroenteropancreatic (GEP) neuroendocrine tumors (NET) often present with advanced disease. Primary tumor resection (PTR) in the setting of unresectable metastatic disease is controversial. Most studies evaluating the impact of PTR on overall survival (OS) have been performed using large population-based databases, with limited treatment related data. This study aims to determine whether PTR improves OS and progression-free survival (PFS) in patients with metastatic well-differentiated GEP-NET. This is a retrospective single-institution study of patients with metastatic well-differentiated GEP-NET between 1978 and 2021. The primary outcome was OS. The secondary outcome was PFS. Chi-squared tests and Cox regression were used to perform univariate and multivariate analyses (MVA). OS and PFS were estimated using the Kaplan-Meier method and log-rank test. Between 1978 and 2021, 505 patients presented with metastatic NET, 151 of whom had well-differentiated GEP-NET. PTR was performed in 31 PNET and 77 SBNET patients. PTR was associated with improved median OS for PNET (136 vs. 61 months, p = .003) and SBNET (not reached vs. 79 months, p<.001). On MVA, only higher grade (HR 3.70, 95%CI 1.49-9.17) and PTR (HR 0.21, 95%CI 0.08-0.53) influenced OS. PTR resulted in longer median PFS for patients with SBNET (46 vs. 28 months, p = .03) and a trend toward longer median PFS for patients with PNET (20 vs. 13 months, p = .07). In patients with metastatic well-differentiated GEP-NET, PTR is associated with improved OS and may be associated with improved PFS and should be considered in a multidisciplinary setting. Future prospective studies are needed to validate these findings.

Patterns of Failure in Patients With Borderline Resectable/Locally Advanced Pancreatic Cancer After Preoperative Chemotherapy and Stereotactic Body Radiation Therapy.

Purpose: The role of preoperative stereotactic body radiation therapy (SBRT) in pancreatic cancer is controversial, and questions regarding the optimal dose and radiation treatment field remain. To better inform future investigations of SBRT dose and radiation fields, we evaluated the patterns of failure in patients with borderline resectable/locally advanced pancreatic cancer (BR/LAPC) after preoperative chemotherapy and SBRT in patients who underwent surgical resection. Methods and Materials: We performed a single-institution retrospective review of consecutive patients treated from September 2017 to January 2022 with BR/LAPC. Patients who underwent preoperative chemotherapy and SBRT followed by surgical resection were reviewed. SBRT was delivered to a dose of 33 Gy in 5 fractions. Kaplan-Meier overall survival and progression-free survival estimates were calculated. Results: In total, 18 patients (12 BRPC, 6 LAPC) were included. Median age was 69 years (range 41-84 years). Median follow-up was 30 months (range 13-59 months). Seventeen patients (94%) had a R0 resection and 13 (72%) underwent vascular reconstruction. Median overall survival and progression-free survival was 42 months (range 13-59 months) and 23 months (range 1-45 months), respectively. In total, 61% (11/18) patients experienced progression at any point during follow-up. Of the patients who experienced recurrence, 27% (3/11) experienced local progression as component of their first recurrence, whereas 100% (11/11) experienced distant progression as a component of their first recurrence. When examining all recurrences that occurred at any point in follow-up, 28% (5/18) of patients experienced local or locoregional recurrence and 61% (11/18) experienced distant progression. Conclusions: Local control and margin negative resection rates were excellent with preoperative chemotherapy and nondose-escalated SBRT in surgically resected patients with BR/LAPC. Distant recurrence was the predominant site of failure with lower incidences of isolated locoregional recurrences. Additional research is needed to determine the ideal treatment volume and patients who may benefit from dose escalation.

Hyperthermic intraperitoneal chemotherapy for gastric cancer: a narrative review.

BACKGROUND AND OBJECTIVE: Gastric cancer (GC) is the 5th most common malignancy globally, and although there have been modest gains in improving survival rates, it remains a leading cause of death. A component contributing to the poor survival rates includes advanced disease stage at presentation. Approximately 30-40% of GC patients present with metastases at diagnosis, with poorer outcomes when peritoneal metastases are present. However, recent studies have demonstrated potential utility of hyperthermic intraperitoneal chemotherapy (HIPEC) for GC with peritoneal carcinomatosis (GCPC) and for prevention of peritoneal carcinomatosis in high-risk patients. HIPEC for GC is highly debated. It is currently not recommended as part of standard of care for GC. The objective of this study is to discuss the various factors influencing the success of HIPEC, current intraperitoneal (IP) chemotherapy treatment regimens, timing of HIPEC administration, major randomized controlled trials (RCTs) and non-RCTs (NRCTs), and meta-analyses in GC patients. METHODS: A review of the Library of Congress, the Cochrane Review, Google Scholar, PubMed, and ClinicalTrials.gov was performed. All articles and trials with available data in English with full text were considered. Necessary keywords used to search included "gastric cancer" and/or "HIPEC". Included articles were independently reviewed by authors. KEY CONTENT AND FINDINGS: Optimal HIPEC administration timing is unclear, but many utilize it in a neoadjuvant or prophylactic setting. Signet ring pathology and epithelial mesenchymal transition (EMT) cell histologic subtypes may have more aggressive pathology, limiting HIPEC success rates. Patients who receive complete cytoreduction and have low peritoneal carcinomatosis index (PCI) burden have been shown to have improved median overall survival (OS) after HIPEC. The data suggests in GCPC, HIPEC can modestly improve recurrence-free and OS. The data regarding benefits of prophylactic HIPEC in advanced GC (AGC) remains mixed. CONCLUSIONS: HIPEC for GC is controversial. Much of the literature is exploratory in nature or difficult to compare, as many outcomes are novel/not cross validated against substantial preceding data, with highly variable patient populations and study designs. However, in certain clinical scenarios in high volume centers, some patients with non-metastatic or low burden disease who undergo prophylactic or intraoperative HIPEC may benefit with improved overall and recurrence free survival (RFS).