Factors correlated with peritoneal carcinomatosis and survival in patients with gastric cancer treated at a single institution in Brazil

Clinical Features of Gastric Signet Ring Cell Cancer: Results from a Systematic Review and Meta-Analysis

BACKGROUND

Conflicting results about the prognostic relevance of signet ring cell histology in gastric cancer have been reported. We aimed to perform a meta-analysis focusing on the clinicopathological features and prognosis of this subgroup of cancer compared with other histologies.

METHODS

A systematic literature search in the PubMed database was conducted, including all publications up to 1 October 2021. A meta-analysis comparing the results of the studies was performed.

RESULTS

A total of 2062 studies referring to gastric cancer with signet ring cell histology were identified, of which 262 studies reported on its relationship with clinical information. Of these, 74 were suitable to be included in the meta-analysis. A slightly lower risk of developing nodal metastases in signet ring cell tumours compared to other histotypes was found (especially to undifferentiated/poorly differentiated/mucinous and mixed histotypes); the lower risk was more evident in early and slightly increased in advanced gastric cancer. Survival tended to be better in early stage signet ring cell cancer compared to other histotypes; no differences were shown in advanced stages, and survival was poorer in metastatic patients. In the subgroup analysis, survival in signet ring cell cancer was slightly worse compared to non-signet ring cell cancer and differentiated/well-to-moderately differentiated adenocarcinoma.

CONCLUSIONS

Most of the conflicting results in signet ring cell gastric cancer literature could be derived from the lack of standardisation in their classification and the comparison with the different subtypes of gastric cancer. There is a critical need to strive for a standardised classification system for gastric cancer, fostering clarity and coherence in the forthcoming research and clinical applications.

Systematic review of diagnostic tools for peritoneal metastasis in gastric cancer-staging laparoscopy and its alternatives

BACKGROUND

Gastric cancer is one of the leading causes of cancer burden and mortality, often resulting in peritoneal metastasis in advanced stages with negative survival outcomes. Staging laparoscopy has become standard practice for suspected cases before a definitive gastrectomy or palliation. This systematic review aims to compare the efficacy of other diagnostic modalities instead of staging laparoscopy as the alternatives are able to reduce cost and invasive staging procedures. Recently, a radiomic model based on computed tomography and positron emission tomography (PET) has also emerged as another method to predict peritoneal metastasis.

AIM

To determine if the efficacy of computed tomography, magnetic resonance imaging and PET is comparable with staging laparoscopy.

METHODS

Articles comparing computed tomography, PET, magnetic resonance imaging, and radiomic models based on computed tomography and PET to staging laparoscopies were filtered out from the Cochrane Library, EMBASE, PubMed, Web of Science, and Reference Citations Analysis (https://www.referencecitationanalysis.com/). In the search for studies comparing computed tomography (CT) to staging laparoscopy, five retrospective studies and three prospective studies were found. Similarly, five retrospective studies and two prospective studies were also included for papers comparing CT to PET scans. Only one retrospective study and one prospective study were found to be suitable for papers comparing CT to magnetic resonance imaging scans.

RESULTS

Staging laparoscopy outperformed computed tomography in all measured aspects, namely sensitivity, specificity, positive predictive value and negative predictive value. Magnetic resonance imaging and PET produced mixed results, with the former shown to be only marginally better than computed tomography. CT performed slightly better than PET in most measured domains, except in specificity and true negative rates. We speculate that this may be due to the limited F-fluorodeoxyglucose uptake in small peritoneal metastases and in linitis plastica. Radiomic modelling, in its current state, shows promise as an alternative for predicting peritoneal metastases. With further research, deep learning and radiomic modelling can be refined and potentially applied as a preoperative diagnostic tool to reduce the need for invasive staging laparoscopy.

CONCLUSION

Staging laparoscopy was superior in all measured aspects. However, associated risks and costs must be considered. Refinements in radiomic modelling are necessary to establish it as a reliable screening technique.

Integration of Genomic Biology Into Therapeutic Strategies of Gastric Cancer Peritoneal Metastasis

The peritoneum is a common site of metastasis in advanced gastric cancer (GC). Diagnostic laparoscopy is now routinely performed as part of disease staging, leading to an earlier diagnosis of synchronous peritoneal metastasis (PM). The biology of GCPM is unique and aggressive, leading to a dismal prognosis. These tumors tend to be resistant to traditional systemic therapy, and yet, this remains the current standard-of-care recommended by most international clinical guidelines. As this is an area of unmet clinical need, several translational studies and clinical trials have focused on addressing this specific disease state. Advances in genomic sequencing and molecular profiling have revealed several promising therapeutic targets and elucidated novel biology, particularly on the role of the surrounding tumor microenvironment in GCPM. Peritoneal-specific clinical trials are being designed with a combination of locoregional therapeutic strategies with systemic therapy. In this review, we summarize the new knowledge of cancer biology, advances in surgical techniques, and emergence of novel therapies as an integrated strategy emerges to address GCPM as a distinct clinical entity.

Shikonin inhibits the cell viability, adhesion, invasion and migration of the human gastric cancer cell line MGC-803 via the Toll-like receptor 2/nuclear factor-kappa B pathway

OBJECTIVES

Shikonin is an active naphthoquinone pigment isolated from the root of Lithospermum erythrorhizon. This study was designed to explore the inhibition of Shikonin on cell viability, adhesion, migration and invasion ability of gastric cancer (GC) and its possible mechanism.

METHODS

3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed for cell viability and adhesion ability of MGC-803 cells. Cell scratch repair experiments were conducted for the determination of migration ability while transwell assay for cell invasion ability. Western blot analysis and real-time polymerase chain reaction assay were used for the detection of protein and mRNA expressions.

KEY FINDINGS

Fifty per cent inhibitory concentration of Shikonin on MGC-803 cells was 1.854 μm. Shikonin (1 μm) inhibited significantly the adhesion, invasion and migratory ability of MGC-803 cells. Interestingly, Shikonin in the presence or absence of anti-Toll-like receptor 2 (TLR2) antibody (2 μg) and nuclear factor-kappa B (NF-κB) inhibitor MG-132 (10 μm) could decrease these ability of MGC-803 cells markedly, as well as the expression levels of matrix metalloproteinases (MMP)-2, MMP-7, TLR2 and p65 NF-κB. In addition, the co-incubation of Shikonin and anti-TLR2/MG-132 has a significant stronger activity than anti-TLR2 or MG-132 alone.

CONCLUSIONS

The results indicated that Shikonin could suppress the cell viability, adhesion, invasion and migratory ability of MGC-803 cells through TLR2- or NF-κB-mediated pathway. Our findings provide novel information for the treatment of Shikonin on GC.

Phase II study of patients with peritoneal carcinomatosis from gastric cancer treated with preoperative systemic chemotherapy followed by peritonectomy and intraperitoneal chemotherapy

BACKGROUND

The aim was to evaluate the feasibility and the effectiveness of neoadjuvant systemic chemotherapy followed by cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC) and early postoperative intraperitoneal chemotherapy (EPIC) in patients with peritoneal carcinomatosis (PC) from gastric cancer.

MATERIAL AND METHODS

Eighteen patients (median age 57 years, range 38-74) were scheduled for three months' neoadjuvant systemic chemotherapy followed by CRS + HIPEC + EPIC.

RESULTS

At the time of surgery, the peritoneal tumor burden was extensive with tumor growth on the entire peritoneal cavity. Only eight patients received the entire treatment and OS was 14.3 months (range 6.1-34.3, 95% CI 6.6-20.3). Six patients had macroscopically radical (CC0) surgery and for this subgroup OS was 19.1 months (range 6.1-34.3, 95% CI 6.9-27.1). Postoperative 90-day mortality was 10% (one patient) and the perioperative grades II-IV adverse events (AE) rate was 62.5%.

DISCUSSION

Neoadjuvant chemotherapy followed by CRS + HIPEC + EPIC does not seem to be associated with prolonged OS in patients with extensive PC growth from gastric cancer unless macroscopically radical surgery is achieved. However, morbidity from this treatment is considerable and it cannot be recommended for routine care until a prospective randomized trial has been performed.

Risk factors of peritoneal recurrence in eso-gastric signet ring cell adenocarcinoma: results of a multicentre retrospective study

INTRODUCTION

The poor prognosis of signet ring cell (SRC) eso-gastric adenocarcinoma (EGA) might be explained by its great affinity for the peritoneum. The aim of this study was to identify predictors of peritoneal carcinomatosis recurrence (PCR) after curative surgery and hence identify high risk patients.

METHODS

A retrospective national survey was conducted over 19 French surgical centers between 1997 and 2010. Patients with non-metastatic disease who benefited from curative surgery without postoperative death were included. Event-free patients who did not reach the time point of 24 months were excluded.

RESULTS

In a cohort of 3010 patients, 1050 were SRC EGA and 424 patients met the selection criteria. The tumor location was mainly gastric (68.9%) and a total gastrectomy was performed in 218 patients (51.4%). Chemoradiotherapy or chemotherapy alone was given preoperatively to 71 (16.7%) and postoperatively to 150 (35.4%) patients. After a median follow-up of 54 months, recurrence was diagnosed in 214 patients (50.5%) within a mean delay of 17 ± 10.7 months. PCR was diagnosed in 81 patients (19.1%). In multivariable analysis, four factors were identified as predictors of PCR: linitis plastica (p < 0.001; OR = 4.83), tumor invasion of/or through the peritoneal serosa (p = 0.022; OR = 1.58), lymph node involvement (p = 0.005; OR = 1.7) and tumors of gastric origin (p = 0.026; OR = 2.36), with PCR rates of 55%, 26%, 23% and 22%, respectively.

CONCLUSION

Identification of strong predictors for PCR among this large series of SRC EGA patients helps to identify subgroups of patients that may benefit from specific therapeutic strategies such as prophylactic hyperthermic intraperitoneal chemotherapy.