Signet-ring cell carcinoma of the stomach: Impact on prognosis and specific therapeutic challenge

Epidemiology of Signet Ring Cell Adenocarcinomas

Signet ring cell adenocarcinomas (SRCCs) are a rare histological subtype of adenocarcinomas with a poor prognosis, typically due to advanced disease at diagnosis. A signet ring cell, mimicking its moniker, contains abundant intracytoplasmic mucin that pushes the nucleus to the periphery. In these cancers, this cell feature comprises more than 50% of the tumor. Despite predilection for the gastrointestinal tract, and in particular the stomach, primary SRCCs are also described in other sites, typically in case reports. This literature, however, lacks a standardized overview of the SRCC disease entity. Using a retrospective cohort approach, we summarize the clinicodemographic and mortality outcomes of SRCCs in thirteen primary sites, comprising 95% of all SRCCs in the Surveillance, Epidemiology, and End Results Program (SEER), a population-level cancer database covering nearly one-third of the United States population. SRCCs general trends compared to matching nonvariant adenocarcinomas are earlier age of onset, with initial presentation favoring higher rates of regional or distant disease presentation and poor tumor differentiation. After multivariable analysis, SRCCs typically have worse overall survivals, but substantial variances exist depending on tumor location. Identifying SRCCs at earlier disease stages is likely the single most important intervention to improving outcomes for these patients.

Should Signet Ring Cell Histology Alter the Treatment Approach for Clinical Stage I Gastric Cancer?

BACKGROUND

Surgery alone is standard-of-care for stage I gastric adenocarcinoma; however, clinicians can offer preoperative therapy for clinical stage I disease with signet ring cell histology, given its presumed aggressive biology. We aimed to assess the validity of this practice.

METHODS

The National Cancer Database (2004-2015) was reviewed for patients with clinical stage I signet ring cell gastric adenocarcinoma who underwent treatment with surgery alone, perioperative chemotherapy, neoadjuvant therapy, or adjuvant therapy. Analysis was stratified by preoperative clinical/pathologic stage. Primary outcome was overall survival (OS).

RESULTS

Of 1018 patients, median age was 60 years (±14); 53% received surgery alone (n = 542), 5% received perioperative chemotherapy (n = 47), 12% received neoadjuvant therapy (n = 125), and 30% received adjuvant therapy (n = 304). For clinical stage I disease, surgery alone was associated with an improved 5-year OS rate (71%) versus perioperative chemotherapy (58%), neoadjuvant therapy (38%), or adjuvant therapy (52%) [overall p < 0.01]. For pathologic stage I, surgery alone had equivalent or improved survival compared with perioperative, neoadjuvant, and adjuvant therapy (5-year OS: 78% vs. 89% [p = 0.77] vs. 64% [p = 0.04] vs. 84% [p = 0.99]). Adjuvant therapy was associated with improved 5-year OS compared with pretreatment for those patients upstaged (37%) to pathologic stage II/III (55% vs. 36% and 34% vs. 7%; all p < 0.01).

CONCLUSIONS

This stage-specific study demonstrates improved survival with surgery alone for clinical stage I signet ring cell gastric adenocarcinoma. Despite 37% of clinical stage I patients being upstaged to pathologic stage II/III, adjuvant therapy offers a favorable rescue strategy, with improved outcomes compared with those treated preoperatively. Surgery alone also affords similar or improved survival for pathologic stage I disease versus multimodality therapy. This study challenges the bias to overtreat stage I signet ring cell gastric adenocarcinoma.

Metastasis From Gastric Signet Ring Cell Adenocarcinoma Presenting as a Rectosigmoid Stricture: A Rare Case

We present the case of a 55-year-old man who was admitted with new abdominal ascites and change in stool caliber. The colonoscopy examination revealed a severe stricture with inflamed friable mucosa measuring 8 cm in length in the rectosigmoid colon. Histologically, poorly differentiated adenocarcinoma with signet ring cells was seen. The patient underwent esophagogastroduodenoscopy (EGD), which was suggestive of linitis plastica of the stomach. On microscopic examination, biopsy reported poorly differentiated adenocarcinoma with occasional signet ring cells as the primary source.

Gastric Cancer: Epidemiology, Risk Factors, Classification, Genomic Characteristics and Treatment Strategies

Gastric cancer (GC) is one of the most common malignancies worldwide and it is the fourth leading cause of cancer-related death. GC is a multifactorial disease, where both environmental and genetic factors can have an impact on its occurrence and development. The incidence rate of GC rises progressively with age; the median age at diagnosis is 70 years. However, approximately 10% of gastric carcinomas are detected at the age of 45 or younger. Early-onset gastric cancer is a good model to study genetic alterations related to the carcinogenesis process, as young patients are less exposed to environmental carcinogens. Carcinogenesis is a multistage disease process specified by the progressive development of mutations and epigenetic alterations in the expression of various genes, which are responsible for the occurrence of the disease.

The rare case of elevated signet ring cell gastric carcinoma with Helicobacter pylori-naïve mucosa

Patients with Helicobacter pylori-naive mucosa may develop a pale, depressed signet ring cell gastric carcinoma or elevated gastric phenotype carcinoma. Almost all signet ring cell carcinomas are of the flat or depressed type, and elevated lesions are rare. We experienced a case of elevated signet ring cell carcinoma with Helicobacter pylori-naïve mucosa. Although the lesion needed to be differentiated from nonepithelial tumor, we diagnosed early and treated with endoscopic submucosal dissection. We report our case along with the relevant literature review.

An application of ERBB2 receptor inhibitors in a rare case of S310F somatic ERBB2 mutation of primary signet-ring cell adenocarcinoma of vagina: A case report and review literature of S310F somatic ERBB2 mutation in breast and gynecologic cancers

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The extremely uncommon subtype of epithelial vaginal cancer.

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Comprehensive genomic sequencing of the rare subtype vaginal cancer.

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Incorporated of the actionable targeted drugs in the treatment of uncommon cancer based on the comprehensive genomic profile.

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A promising response of uncommon disease after the actionable targeted therapy.

Deconvolution of diffuse gastric cancer and the suppression of CD34 on the BALB/c nude mice model

Background

Gastric cancer is a considerable burden for worldwide patients. And diffuse gastric cancer is the most insidious subgroup with poor survival. The phenotypic characterization of the diffuse gastric cancer cell line can be useful for gastric cancer researchers. In this article, we aimed to characterize the diffuse gastric cancer cells with MRI and transcriptomic data. We hypothesized that gene expression pattern is associated with the phenotype of the cells and that the heterogeneous enhancement pattern and the high tumorigenicity of SNU484 can be modulated by the perturbation of the highly expressed gene.

Methods

We evaluated the 9.4 T magnetic resonance imaging and transcriptomic data of the orthotopic mice models from diffuse gastric cancer cells such as SNU484, Hs746T, SNU668, and KATO III. We included MKN74 as an intestinal cancer control cell. After comprehensive analysis integrating MRI and transcriptomic data, we selected CD34 and validated the effect by shRNA in the BALB/c nude mice models.

Results

SNU484, SNU668, Hs746T, and MKN74 formed orthotopic tumors by the 5 weeks after cell injection. The diffuse phenotype was found in the SNU484 and Hs746T. SNU484 was the only tumor showing the heterogeneous enhancement pattern on T2 images with a high level of CD34 expression. Knockdown of CD34 decreased the round-void shape in the H&E staining (P = 0.028), the heterogeneous T2 enhancement, and orthotopic tumorigenicity (100% vs 66.7%). The RNAseq showed that the suppressed CD34 is associated with the downregulated gene-sets of the extracellular matrix remodeling.

Conclusion

Suppression of CD34 in the human-originated gastric cancer cell suggests that it is important for the round-void histologic shape, heterogeneous enhancement pattern on MRI, and the growth of gastric cancer cell line.

From biology to surgery: One step beyond histology for tailored surgical treatments of gastric cancer

Gastric cancer is the third most common cause of cancer related death. Although its incidence is globally declined, prognosis remains dismal in the Western hemisphere, while better outcomes are evidenced in Asian countries. Endoscopic or surgical resection with or without lymphadenectomy represents the only chance of cure, with limited improvements of the prognosis in case of associated chemotherapy in a neoadjuvant or adjuvant setting. This could be mainly attributed to the uniform fashion of treatment of gastric cancer, mainly based on the histological features, that usually do not reflect the complexity of the disease. With the recent introduction of genomic technologies and new generation sequencing techniques, gastric cancer biology is now investigated in great details. This has brought to the publication of three main molecular classifications, based on the underlying molecular biology of gastric cancer. Although only few clinical reports are currently present in literature, the identification of gastric cancer molecular subtypes has shown interesting findings that may pave the way to a tailored clinical and surgical management. The aim of this review is, thus, to give a comprehensive overview of the current molecular classifications as compared to the available histopathological ones, also focusing on the potential clinical and surgical benefits and the future perspectives for a more personalized treatment of gastric cancer.

Predictors of outcomes in patients with gastric cancer treated with contemporary multimodality strategies-a single institution experience

Background

While gastric cancer is a leading cause of cancer-related mortality in Eastern Europe and Asia, it is less common in the United States. Recommendations regarding optimal treatment of non-metastatic gastric cancer with regard to type and extent of surgery, choice and sequence of chemotherapeutic agents, and use of radiation therapy vary somewhat depending on geographic location. There is paucity in the literature for direct comparison of various practices. To determine how variability in treatment practices affects patient outcomes, we conducted a retrospective study in patients with gastric cancer who had multimodality treatment for non-metastatic gastric cancer.

Methods

We gathered clinical data (patient demographics, pathology reports, type of surgical intervention, chemotherapy, and radiation therapy) for patients diagnosed with gastric adenocarcinoma who underwent gastrectomy at five sites from 2010-2017 using Electronic Health Records and California Cancer Registry databases. Medical chart reviews were conducted to validate patient outcomes. We performed multivariate Cox regression analyses to determine predictors for cancer recurrence and survival. We also performed logistic regression analyses to determine predictors of positive resection margins and hospitalization.

Results

One hundred and sixteen patients met eligibility criteria to be included. Mean age was 65.7±11.6 years. About 65.5% were male. The most common ethnicities were Asian (44.0%) and Caucasian (37.9%). About 58.6% of the patients had localized disease (defined as pT1-3, pN0) and the remaining 41.4% had loco-regional disease (i.e., pT4 or pN+). About 41.4% of the tumors were diffuse, 27.6% intestinal, 12.0% mixed, and 19.0% unknown histology. Surgery included laparoscopic (94.8%) and open gastrectomy (5.2%). Chemotherapy and radiation therapy were given in 51.7% and 19.0% of the patients, respectively. After a median follow-up time of 19 months after gastrectomy, 16.4% of patients had recurrence and 19.8% had died. Patients who had loco-regional tumors were more likely to have recurrence and death than those who had localized tumors (hazard ratios =7.0, P=0.0228 for recurrence and hazard ratios =3.3, P=0.0160 for death). Positive resection margins were seen in 9% of the patients and were associated with diffuse histology (odds ratio =6.6, P=0.0207). Hospitalization within six months of gastrectomy was seen in 22% of the patients. Peri-operative chemotherapy was the only significant predictor for re-hospitalization (odds ratio =3.5, P=0.0415).

Conclusions

In this contemporary cohort of patients with localized gastric cancer, only the pathological stage was significantly associated with survival while positive resection margins were associated with diffuse histology. Closer monitoring of patients undergoing perioperative chemotherapy within 6 months of surgery is warranted based on our observation of higher rate of re-hospitalization.

Local and Central Evaluation of HER2 Positivity and Clinical Outcome in Advanced Gastric and Gastroesophageal Cancer-Results from the AGMT GASTRIC-5 Registry

Trastuzumab in combination with a platinum and fluorouracil is the treatment of choice for patients with advanced human epidermal growth factor receptor 2 (HER2) positive gastric cancer and gastroesophageal junction (GEJ) cancer. Pathological assessment of the HER2 status in gastric/GEJ cancer, however, still remains difficult. However, it is a crucial prerequisite for optimal treatment. The GASTRIC-5 registry was designed as an observational, multi-center research initiative comparing local and central HER2 testing. HER2 status was assessed by immunohistochemistry (IHC) and in equivocal cases (IHC score 2+) by additional in-situ hybridization. Between May 2011 and August 2018, tumor samples of 183 patients were tested in local and central pathology laboratories, respectively. Central testing revealed HER2 positivity in 38 samples (21%). Discordant HER2 results were found in 12% (22 out of 183) with locally HER2 positive/centrally HER2 negative results (9%, 17 out of 183), exceeding locally HER2 negative/centrally HER2 positive results (3%, 5 out of 183). Centrally confirmed HER2 positive patients receiving trastuzumab-based palliative first-line therapy showed a longer median overall survival compared to centrally HER2 positive patients not receiving trastuzumab (17.7 months (95% CI: 10,870–24,530) vs. 6.9 months (95% CI: 3.980–9.820), p = 0.016). The findings of the GASTRIC-5 registry corroborate the challenge of HER2 testing in gastric/GEJ cancer and highlight the necessity for central quality control to optimize individual treatment options. Centrally HER2 positive patients not receiving trastuzumab had the worst outcome in a Western real-world gastric/GEJ cancer cohort.

Neoadjuvant chemotherapy vs upfront surgery for gastric signet ring cell carcinoma: A retrospective, propensity score-matched study

BACKGROUND

The benefit of neoadjuvant chemotherapy for patients with signet-ring cell carcinoma of the stomach is controversial.

AIM

To evaluate the perioperative and long-term outcomes of neoadjuvant chemotherapy for locally advanced gastric signet-ring cell carcinoma.

METHODS

This retrospective study identified patients with locally advanced signet-ring cell carcinomas of the stomach (cT3/4 and cN any) diagnosed from January 2012 to December 2017 by using the clinical Tumor-Node-Metastasis (cTNM) staging system. We performed 1:1 propensity score matching (PSM) to reduce bias in patient selection. The histologic and prognostic effects of neoadjuvant chemotherapy were assessed. The overall survival rates were used as the outcome measure to compare the efficacy of neoadjuvant chemotherapy vs surgery-first treatment in the selected patients.

RESULTS

Of the 144 patients eligible for this study, 36 received neoadjuvant chemotherapy, and 108 received initial surgery after diagnosis. After adjustment by PSM, 36 pairs of patients were generated, and baseline characteristics, including age, sex, American Society of Anesthesiologists score, tumor location, and cTNM stage, were similar between the two groups. The R0 resection rates were 88.9% and 86.1% in the surgery-first and neoadjuvant chemotherapy groups after PSM, respectively (P = 1.000). The median follow-up period was 46.4 mo. The 5-year overall survival rates of the neoadjuvant chemotherapy group and surgery-first group were 50.0% and 65.0% (P = 0.235), respectively, before PSM and 50% and 64.7% (P = 0.192), respectively, after PSM. Multivariate analyses conducted before and after PSM showed that NAC was not a prognostic factor.

CONCLUSION

Neoadjuvant chemotherapy provides no survival benefit in patients with locally advanced gastric signet-ring cell carcinoma. For resectable gastric signet-ring cell carcinoma, upfront surgery should be the primary therapy.

Identification of key genes and pathways in gastric signet ring cell carcinoma based on transcriptome analysis

BACKGROUND

Gastric signet ring cell carcinoma (GSRCC) is one of the most malignant tumors. It has the features of high invasiveness, rapid progression, and resistance to chemotherapy. However, systematic analyses of mRNAs have not yet been performed for GSRCC.

AIM

To identify key mRNAs and signaling pathways in GSRCC.

METHODS

A transcriptome analysis of two GSRCC and two non-GSRCC samples was performed in this study. Differentially expressed mRNAs and pathways were identified based on the KEGG and PANTHER pathway annotations. The interactive relationships among the differential genes were mapped with the STRING database. Quantitative real-time polymerase chain reaction was used to validate the key gene expression in GSRCC.

RESULTS

About 1162 differential genes (using a 2-fold cutoff, P < 0.05) were identified in GSRCC compared with non-GSRCC. The enriched KEGG and PANTHER pathways for the differential genes included immune response pathways, metabolic pathways, and metastasis-associated pathways. Ten genes (MAGEA2, MAGEA2B, MAGEA3, MAGEA4, MAGEA6, MUC13, GUCA2A, FFAR4, REG1A, and REG1B) were identified as hub genes in the protein-protein interaction network. The expression levels of five genes (MAGEA2, MAGEA3, MAGEA4, MAGEA6, and REG1B) showed potential clinical value.

CONCLUSION

We have identified the potential key genes and pathways in GSRCC, and these hub genes and pathways could be diagnostic markers and therapeutic targets for GSRCC.

Gene mutations distinguishing gastric from colorectal and esophageal adenocarcinomas

BACKGROUND

Genetic analysis of gastrointestinal malignancies shows a great number of mutations. Most mutations found in gastric tumors are also found in colorectal and esophageal tumors. The challenge remains to identify mutations that distinguish gastric from colorectal and esophageal cancers. Using open-access cancer genomics data, we sought to identify mutations that accounted for the unique phenotypic features of gastric tumors.

METHODS

Thirteen cancer genomics datasets with demographic, clinical, and genetic variables were analyzed. Pathologic stage and histology were compared between subjects with and without a specific mutated gene using two-sample t-tests, adjusted for multiple gene testing. Sequence convergence and functional impact of genetic mutations were analyzed using permutation test and PolyPhen-2 score.

RESULTS

Analysis included 1,915 subjects with valid pathologic stage and histology. Mean age was 68 years (SD =10). About 54% were female. The most common race was Caucasian (37%) while minorities were rare with high rates of missing data (44%). Pathologic stage: 20% stage I, 35% stage II, 31% stage III, and 14% stage IV. Anatomical location: 30% gastric, 59% colorectal, and 11% esophageal. Histology of gastric cancer: 61% intestinal, 23% diffuse, 15% mixed, and 1% missing. Two mutated genes-CDH1, RHOA-distinguished gastric from colorectal and esophageal tumors. These mutations were highly specific to diffuse histology and advanced stages of gastric tumors and recurrent in transcribed regions known to impact protein functions.

CONCLUSIONS

CDH1 and RHOA regulate cell-cell adhesion which is vital to cell growth and proliferation. Identification of these potential driver mutations is critical to better define therapeutic vulnerabilities for the rational design of gastric cancer therapies.

Signet-ring cell carcinoma of the ampulla of Vater: a case diagnosed via repeated biopsies

Signet-ring cell carcinoma of the ampulla of Vater is a rare tumor. A 74-year-old woman presented with epigastric pain and was diagnosed with cholangitis. Her liver enzyme levels were elevated. Computed tomography showed an enhanced area in the periampullary region and marked common bile duct dilatation. On endoscopic retrograde cholangiopancreatography (ERCP), the ampulla exhibited a normal appearance without ulcer or mass. Histological biopsy confirmed the absence of malignancy. During follow-up, the patient again presented with acute cholangitis multiple times and underwent ERCP each time. The ampulla had the appearance of a reddish and erosive mucosa. Although biopsy was repeated, histological examination did not show any malignancy. After a total of 13 biopsies, the patient was diagnosed with ampullary carcinoma of non-exposed protruded type following the third ERC-guided biopsy. Careful follow-up and frequent endoscopic biopsies are important in cases of papillary carcinoma of non-exposed protruded type with normal ampullary mucosa on initial endoscopy because this condition is challenging to diagnose with a single biopsy.

Adenosquamous carcinoma may have an inferior prognosis to signet ring cell carcinoma in patients with stages I and II gastric cancer

BACKGROUND

Primary gastric adenosquamous carcinoma (ASC) is an exceedingly rare histological subtype. Gastric signet ring cell carcinoma (SRC) is a unique subtype with distinct tumor biology and clinical features. The prognosis of gastric ASC vs SRC has not been well established to date. We hypothesized that further knowledge about these distinct cancers would improve the clinical management of such patients.

AIM

To investigate the clinicopathological characteristics and prognosis of gastric ASC vs SRC.

METHODS

A cohort of gastric cancer patients was retrospectively collected from the Surveillance, epidemiology, and end results program database. The 1:4 propensity score matching was performed among this cohort. The clinicopathological features and prognosis of gastric ASC were compared with gastric SRC by descriptive statistics. Kaplan-Meier method was utilized to calculate the median survival of the two groups of patients. Cox proportional hazard regression models were used to identify prognostic factors.

RESULTS

Totally 6063 patients with gastric ASC or SRC were identified. A cohort of 465 patients was recruited to the matched population, including 370 patients with SRC and 95 patients with ASC. Gastric ASC showed an inferior prognosis to SRC after propensity score matching. In the post-matching cohort, the median cancer specific survival was 13.0 (9.7-16.3) mo in the ASC group vs 20.0 (15.7-24.3) mo in the SRC group, and the median overall survival had a similar trend (P < 0.05). ASC and higher tumor-node-metastasis stage were independently associated with a poor survival, while radiotherapy and surgery were independent protective factors for improved prognosis. Subgroup survival analysis revealed that the prognosis of ASC was inferior to SRC only in stages I and II patients.

CONCLUSION

ASC may have an inferior prognosis to SRC in patients with stages I and II gastric cancer. Our study supports radiotherapy and surgery for the future management of this clinically rare entity.

Infiltrating and peripheral immune cell analysis in advanced gastric cancer according to the Lauren classification and its prognostic significance

BACKGROUND

The correlation between immune cells and the Lauren classification subtypes and their prognostic impact in advanced gastric cancer (AGC) are unknown.

METHODS

Circulating natural killer (NK) cells, CD4⁺ and CD8⁺ T cells, regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) were quantified in peripheral blood mononuclear cells (PBMCs) from 67 patients with untreated AGC enrolled in the PRODIGE 17-ACCORD 20 trial. CD56⁺ cells (NK), CD8⁺, and FoxP3⁺ (Treg) tumor-infiltrating lymphocytes (TILs) were assessed in tumor samples.

RESULTS

Circulating NK and Treg proportions were significantly lower in patients with diffuse/mixed-type AGC (n = 27) than those with intestinal type (n = 40; median 6.3% vs 11.5%; p = 0.02 and median 3.3% vs 5.2%; p = 0.03, respectively). Proportions of circulating MDSC, CD4⁺ and CD8⁺ T cells were not associated with one pathological type. Among tumor-infiltrating cells, CD8⁺ T cells, but not NK or FoxP3⁺ cells, were significantly lower in diffuse/mixed-type AGC (median 21 vs 59 cells/field; p = 0.009). Patients with high circulating NK cell counts (> 17%) had a better overall survival than those with < 17% (HR 0.40; 95% CI [0.15-1.06]; p = 0.04). Patients with high CD8⁺ TIL counts (> 31 cells/field) had significantly longer overall survival (HR 0.44; 95% CI [0.21-0.92]; p = 0.02). The prognostic value of CD8⁺ TILs was maintained after adjustment for confounding factors, including the Lauren classification (HR = 0.42; 95% CI [0.18-0.96]; p = 0.039).

CONCLUSION

Diffuse/mixed-type AGC has lower rates of CD8⁺ TILs and circulating NK cells and Tregs than the intestinal type. This "cold tumor" phenotype may be associated with a worse outcome.

Cutaneous Metastasis of Signet Cell Gastric Carcinoma

Gastric cancer is the fourth most commonly diagnosed cancer and the second most common cause of cancer-related death worldwide. Cutaneous metastases of signet-ring cell gastric carcinoma are uncommon. Here, we report a metastatic gastric adenocarcinoma, which manifested itself as an asymptomatic scar-like lesion on the epigastric area and histopathological features of the cutaneous lesion showing signet-ring cell.

A Case of Advanced Gastric Cancer with Folfiri as a Preoperative Chemotherapy

Introduction

In advanced gastric cancer, preoperative chemotherapy is associated with survival benefit. FOLFIRI has demonstrated promising results in terms of survival and tolerance, especially in patients with poor performance status.

Case Presentation

A 59-year-old male, diagnosed with pT4bN2M0 gastric cancer, underwent gastrointestinal anastomosis and three cycles of EOX chemotherapy. Due to disease progression, he was switched to FOLFIRI regimen. After 12 cycles, the patient received a subtotal gastrectomy and D2 lymphadenectomy. Microscopic examination achieved pCR, and the patient has been surviving 34 months without recurrence. No severe toxicities of chemotherapy were recorded.

Conclusions

FOLFIRI might be a safe and effective option in neoadjuvant treatment for advanced gastric cancer among patients with poor performance status or progression after first-line chemotherapy.

Rapidly declining trend of signet ring cell cancer of the stomach may parallel the infection rate of Helicobacter pylori

Background

Studies indicate that gastric cancer (GC) incidence has decreased, whereas signet ring cell carcinoma (SRC) incidence has increased. However, recent trends in GC incidence are unclear. We used our hospital cancer registry to evaluate the changes in the incidence of GC, SRC, and non-SRC (NSRC) over time in comparison to changes in the H. pylori infection rates over time.

Methods

We identified 2532 patients with GC enrolled in our registry between January 2007 and December 2018 and statistically analyzed SRC and NSRC incidence. The H. pylori infection rate in patients with SRC was determined by serum anti-H. pylori antibody testing, urea breath test, biopsy specimen culture, and immunohistochemical analysis (IHC) of gastric tissue. Additionally, genomic detection of H. pylori was performed in SRCs by extracting DNA from formalin-fixed paraffin-embedded gastric tissue and targeting 16S ribosomal RNA of H. pylori.

Results

Overall, 211 patients had SRC (8.3%). Compared with patients with NSRC, those with SRC were younger (P <  0.001) and more likely to be female (P <  0.001). Time series analysis using an autoregressive integrated moving average model revealed a significant decrease in SRC (P <  0.001) incidence; NSRC incidence showed no decline. There was no difference in H. pylori infection prevalence between the SRC and NSRC groups. IHC and genomic methods detected H. pylori in 30 of 37 (81.1%) SRCs.

Conclusions

Reduction in H. pylori infection prevalence may be associated with the decrease in the incidence of SRC, which was higher than that of NSRC.

Signet ring cell variant of follicular thyroid carcinoma: Report of two cases with focus on morphological, expressional and genetic characteristics

Background

Follicular thyroid carcinoma (FTC) is a neoplasm that presents with a micro-follicular growth pattern and a neutrally stained cytoplasm. Seldom, FTCs display unusual morphological characteristics – but given the rarity of these histological subtypes, little is known regarding the underlying genetics and the coupling to patient outcome.

Case presentation

We present two extremely rare cases of minimally invasive FTC with signet ring cell morphology (SRC-FTC) and describe the cytological, microscopic, immunohistochemical and molecular features for both tumors. Both were male patients, age 71 and 51 respectively. The preoperative cytology for both cases could not pinpoint a clear-cut signet ring cell morphology, but a tendency towards nuclear marginalization was seen. The tumors were 38 mm and 22 mm respectively and displayed evident signet ring cell features in subsets of tumor cells as well as degenerative stromal changes. The tumor cells were positive for TTF1, PAX8 and thyroglobulin, and the proliferation indexes were 4% and 1,9% respectively. Both tumors displayed capsular invasion, but not lymphovascular invasion. The tumors were sequenced for mutations in the TERT promoter and 22 additional cancer-related genes, interestingly; one patient was shown to carry a deleterious intronic variant in PTEN, a tumor suppressor gene coupled to thyroid tumorigenesis and Cowden syndrome. Both patients are alive and well awaiting postoperative radioiodine treatment.

Conclusions

The SRC-FTCs described herein were small, TERT promoter wildtype tumors exhibiting low proliferation, thereby suggesting that these exceedingly rare lesions probably carry a favorable prognosis – although the scarce availability regarding descriptions of this tumor entity nevertheless might justify careful clinical monitoring and mandate investigations in larger case series.

Primary signet ring cell carcinoma of the pancreatic head: A case report

Pancreatic SRCC is a rare, aggressive tumor. Given limited evidence and the risk of side effects, physicians may elect to withhold chemotherapy in select patients, with the exception of neoadjuvant chemotherapy use to facilitate resectability.

Immunohistochemical and genetic features of mucinous and signet-ring cell carcinomas of the stomach, colon and rectum: a comparative study

Gastric and colorectal cancers are prevalent and fatal cancers worldwide. Although mucinous adenocarcinoma (MAC) and signet-ring cell carcinoma (SRCC) are relatively uncommon, they are of critical importance because of poor prognosis. In Turkey, studies on MSI and other molecular characteristics in mucinous adenocarcinoma (MAC) and signet-ring cell carcinoma (SRCC) of stomach and colon have not been conducted. The present study aimed to investigate the similarities and differences between gastric/colorectal MACs and SRCCs. A total of 590 patients with gastric carcinoma and 1075 patients with colorectal carcinoma, in whom pathologic diagnosis was made within a period of 8 years in our hospital, were retrospectively evaluated. Tissue blocks and slides obtained from the pathology archive were used for immunohistochemical and genetic studies and for microscopic re-evaluation according to the WHO criteria. Data from a total of 135 patients, of whom 78 had been diagnosed with MAC and 57 had been diagnosed with SRCC, were analyzed. MAC patients were significantly older than those with SRCCs. While colorectal localization was more common among MACs, SRCC patients mostly showed gastric localization. Macroscopically, ulceroinfiltrative type was the most prevalent in both groups followed by fungating type in MAC and infiltrative type in SRCC. When compared with SRCC group, MAC group was associated with higher tumor invasion stage, lower rate of patients with infiltrative growth pattern and perineural invasion, and less frequent lymph node invasion. More effective approaches will be developed in the treatment and prevention of cancer along with more data about the incidence, pathogenesis, prognostic factors, and clinical course of cancers.

Selective targeting of signet ring cell adenocarcinomas

Many epithelial tumors, especially signet-ring cell adenocarcinomas, produce huge amounts of mucin glycoproteins that fill cytoplasm and push nucleus to the periphery, giving a signet ring like structure to the cell. Mucin proteins are very rich of l-threonine which is essential in humans. L-threonine content can reach up to 35% of total amino acid composition of some mucin proteins. Therefore l-threonine can be the Achilles heel of signet ring cell adenocarcinomas which are one of the most malignant and agressive cancers. A modified bioisoster of l-threonine, 4-fluoro l-threonine (its fluorine can be radioactive or not), can be used to selectively kill signet ring cancer cells without harming normal cells or for diagnostic purposes.

INTRODUCTION OF THE NEW LYMPHOPARIETAL INDEX FOR GASTRIC CANCER PATIENTS

Background:

The identification of prognostic factors of gastric cancer (GC) has allowed to predict the evolution of patients.

Aim:

Assess the reliability of the lymphoparietal index in the prediction of long-term survival in GC treated with curative intent.

Method:

Prospective study of the Universidad de Chile Clinical Hospital, between May 2004 and May 2012. Included all gastric cancer surgeries with curative intent. Exclusion criteria were: gastrectomies due to benign lesions, stage 4 cancers, R1 resections, palliative procedures, complete esophagogastrectomies and emergency surgeries.

Results:

A total of 284 patients were included; of the sample 65.4% were male,mean age of 64.5 years,75% were advanced cancers, 72.5% required a total gastrectomy, 30 lymph nodes harvest. Surgical morbidity and mortality were 17.2% and 1.7%. 5-year survival was 56.9%. The N+/T index could predict long-term survival in all de subgrups (p<0.0001), although had a reliable prediction in early GC (p=0.005), advanced GC (p<0.0001), signet ring cell GC (p<0.0001), proximal GC (p<0.0001) and distal GC (p<0.0001). The ROC curves N+/T index, LNR and T classification presented areas below the curve of 0.789, 0.786 and 0,790 respectively, without a significant statistical difference (p=0.96).

Conclusion:

The N+/T index is a reliable quotient in the prognostic evaluation of gastric adenocarcinoma patients who have been resected with curative intent.

Survival benefit of palliative gastrectomy followed by chemotherapy in stage IV gastric signet ring cell carcinoma patients: A large population-based study

Background

Stage IV gastric signet ring cell carcinoma (SRCC) is a type of malignant gastric cancer (GC) with poorer survival compared to metastatic non‐SRCC gastric cancer (NOS). However, chemotherapy alone was unable to maintain long‐term survival. This study aimed to evaluate survival benefit of palliative gastrectomy plus chemotherapy (PG+C) for metastatic gastric SRCC.

Methods

We obtained data on gastric cancer patients between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. Statistical methods included χ² tests, Kaplan‐Meier curves, COX models, propensity score matching (PSM) and subgroup analysis.

Results

Among 27 240 gastric cancer patients included, 4638 (17.03%) were SRCC patients. The proportion of patients with younger age, female gender, poorly differentiated grade and M1 stage was higher in SRCC than in NOS (P < .001). Multivariate analysis revealed that multiple metastatic sites (HR = 1.39, 95% CI: 1.14‐1.69, P = .001) was associated with increased mortality risk in metastatic SRCC. Median survival time was improved in metastatic SRCC receiving PG+C compared to PG/C alone (13 vs 7 months, P < .001). Notably, in subgroup analysis, 13 of 17 groups of metastatic SRCC patients with PG+C had prolonged overall survival compared to chemotherapy alone, especially for those with only one metastatic site (HR = 0.61, 95% CI: 0.51‐0.73, P < .001).

Conclusions

Our results suggested that there exists at least a selective group of stage IV gastric SRCC patients, who could benefit from palliative gastrectomy followed by chemotherapy compared to chemotherapy alone. Further prospective trials are needed to support our conclusion.

Differential gene expression in growth factors, epithelial mesenchymal transition and chemotaxis in the diffuse type compared with the intestinal type of gastric cancer

Gastric cancer (GC) is a highly heterogeneous disease and one of the major causes of cancer-related mortality worldwide. Diffuse-type gastric adenocarcinoma (or poorly cohesive- with independent cells) is characterized by aggressive behavior (rapid invasion, chemoresistance and peritoneal metastasis), as compared with intestinal-subtype adenocarcinoma. Diffuse subtype GC additionally has a substantially increasing incidence rate in Europe and the USA, and was often associated with younger age. Our objective was to analyze the expression and clinical significance of genes involved in several signaling pathways in diffuse-type GC. Tumors samples and non-malignant gastric tissues were obtained from patients with GC (diffuse-type and intestinal-subtype adenocarcinoma). The expression of 33 genes coding for proteins involved in four categories, growth factors and receptors, epithelial-mesenchymal transition, cell proliferation and migration, and angiogenesis was determined by reverse transcription-quantitative polymerase chain reaction. The expression of 22 genes was significantly upregulated in diffuse-type GC and two were downregulated (including CDH1) compared with normal tissues. Among these genes, acompared with intestinal-subtype adenocarcinoma, diffuse-type GC revealed elevated levels of IGF1 and IGF1R, FGF7 and FGFR1, ZEB2, CXCR4, CXCL12 and RHOA, and decreased levels of CDH1, MMP9 and MKI67. The expression of selected genes was compared with other genes and according to clinical parameters. Furthermore, TGF-β expression was significantly increased in linitis, a sub-population of diffusely infiltrating type associated with extensive fibrosis and tumor invasion. Our study identified new target genes (IGF1, FGF7, CXCR4, TG-β and ZEB2) whose expression is associated with aggressive phenotype of diffuse-type GC.

Expression of Glypican 3 is an Independent Prognostic Biomarker in Primary Gastro-Esophageal Adenocarcinoma and Corresponding Serum Exosomes

Exosomes are nano-sized membranous vesicles of endosomal origin that carry nucleic acids, lipids and proteins. The cargo of exosomes is cell origin specific and the release of these exosomes and uptake by an acceptor cell is seen as a vital element of cell-cell communication. Here, we sought to investigate the diagnostic and prognostic value of the expression of glypican 3 (GPC3) on primary gastro-esophageal adenocarcinoma (GEA) tissue (tGPC3) and corresponding serum exosomes (eGPC3). Circulating exosomes were extracted from serum samples of 49 patients with GEA and 56 controls. Extracted exosomes were subjected to flow cytometry for the expression of eGPC3 and GPC3 expression on primary GEA tissue samples was determined by immunohistochemistry and correlated to clinicopathological parameters. We found decreased eGPC3 levels in GEA patients compared to healthy controls (p < 0.0001) and high tGPC3 expression. This was significantly associated with poor overall survival (high vs. low eGPC3: 87.40 vs. 60.93 months, p = 0.041, high vs. low tGPC3: 58.03 vs. 84.70 months, p = 0.044). Cox regressional analysis confirmed tGPC3 as an independent prognostic biomarker for GEA (p = 0.02) and tGPC3 expression was validated in two independent cohorts. Our findings demonstrate that eGPC3 and tGPC3 can be used as potential diagnostic and prognostic biomarkers for GEA.

Pediatric gastric adenocarcinoma: A National Cancer Data Base review

PURPOSE

We sought to compare the presentation, management, and outcomes in gastric adenocarcinoma cancer for pediatric and adult patients.

METHODS

Using the 2004 to 2014 National Cancer Database (NCDB), patients ≤21 years (pediatric) were retrospectively compared to >21 years (adult). Chi-squared tests were used to compare categorical variables, and Cox regression was used to estimate hazard ratios (HR) for survival differences.

RESULTS

Of the 129,024 gastric adenocarcinoma cases identified, 129 (0.10%) occurred in pediatric patients. Pediatric cases presented with more advanced disease, including poorly differentiated tumors (81% vs 65%, p = 0.006) and stage 4 disease (56% vs 41%, p = 0.002). Signet ring adenocarcinoma comprised 45% of cases in the pediatric group as compared to 20% of cases in the adults (P < 0.001). Similar proportions in both groups underwent surgery. However, near-total gastrectomy was more common in the pediatric group (16% vs 6%, p < 0.001). The proportions of patients with negative margins, nodal examination, and presence of positive nodes were similar. There was no overall survival difference between the two age groups (HR 0.92, 95% Confidence interval 0.73-1.15).

CONCLUSION

While gastric adenocarcinoma in pediatric patients present with a more advanced stage and poorly differentiated tumors compared to adults, survival appears to be comparable.

TYPE OF STUDY

Retrospective cohort study.

LEVEL OF EVIDENCE

III.

State of the art for gastric signet ring cell carcinoma: from classification, prognosis, and genomic characteristics to specified treatments

Gastric cancer (GC) is responsible for 9% of cancer deaths worldwide. Over 950,000 new cases are diagnosed each year, and about 90% of them are in advanced stage, requiring chemotherapy. In Europe there has been research based on pre- and postoperative chemotherapy treatment, using 5-fluorouracil, epirubicin, cisplatin, capecitabine, and docetaxel. Chemotherapy significantly impairs the quality of life of patients; however, the final effects are not always satisfactory. There is scientific evidence that gastric mucus tumors and signet ring cell carcinomas have a pattern of specific signatures, that distinguish them from other gastric cancer subtypes, and may be associated with a poor response to systematic treatment. Signet ring cell carcinoma is less chemosensitive than others, and the increase in the percentage of signet ring cells correlates with resistance to chemotherapy. Perioperative chemotherapy in advanced signet ring cell carcinomas is an independent factor of poor prognosis and survival, which is explained by the toxicity of neoadjuvant treatment. Therefore, curative surgical resection enhanced by standardized lymphadenectomy remains the recommended gold standard in GC therapy. According to presented studies, early detection and aggressive treatments for this subtype of GC is a reasonable approach. This review paper is mostly addressed to physicians who are interested in updating to the state of the art concerning different subtypes of gastric carcinoma.

Clinicopathological differences in signet ring cell adenocarcinoma between early and advanced gastric cancer

BACKGROUND

Signet ring cell adenocarcinoma is a histological classification based on the WHO classification. The presence of this specific histological type is associated with a worse pathological appearance. The prognosis of signet ring cell adenocarcinoma in gastric cancer patients after curative surgery is still under debate.

METHODS

From January 1988 to December 2012, a total of 2971 patients, including 819 early and 2152 advanced gastric cancer patients underwent curative resection for gastric cancer. Among them, there were 185 cases of signet ring cell adenocarcinoma in early gastric cancer patients, while there were 570 cases in advanced gastric cancer patients.

RESULTS

The overall incidence of signet ring cell adenocarcinoma was 25.4%. Our results showed that the 5-year overall survival rates of early gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 90.7 and 83.2%, respectively (P = 0.001). The 5-year disease-free survival rates of early gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 87.4 and 81.6%, respectively (P = 0.003). The 5-year overall survival rates of advanced gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 32.1 and 37.9%, respectively (P = 0.041). The 5-year disease-free survival rates of advanced gastric cancer patients with signet ring cell adenocarcinoma and non-signet ring cell adenocarcinoma were 28.6 and 35.2%, respectively (P = 0.037). Signet ring cell adenocarcinoma was an independent predictor for overall survival in advanced gastric cancer (P = 0.017).

CONCLUSION

The clinical features and prognosis of signet ring cell adenocarcinoma are different between early and advanced gastric cancer. Signet ring cell adenocarcinoma is a poor prognostic factor in advanced gastric cancer after curative resection.

Deficiency of mismatch repair genes is less frequently observed in signet ring cell compared with non-signet ring cell gastric cancer

Signet ring cell (SRC) gastric cancer at advanced stage has poor prognosis. While a recent study reported nearly one-third of SRC cases contain tumors with deficient mismatch repair (MMR) genes, other studies in SRC have been inconclusive. To re-analyze the results, we performed immunohistochemical staining of MLH1, MSH2, MSH6 and PMS2 proteins in 38 SRC gastric tumors compared with 109 non-SRC (NSRC) tumors from 94 patients. In contrast to the previous study, all SRC gastric tumors normally expressed MMR proteins, whereas 22 of 109 of NSRC (20%) showed deficient MMR proteins. To reinforce our results, we referred to the Cancer Genome Atlas (TCGA) genomic database and found that only 6 (6%) of 99 samples with diffuse gastric tumors showed deficient MMR, whereas 64 (21%) of 304 in intestinal gastric tumors showed deficient MMR. Our results as well as the TCGA database indicated that MMR genes are infrequently inactivated in SRC gastric cancer. These findings indicate that SRC patients may not be the best candidates for immuno-oncology therapy.

Pitfalls in the Interpretation of Publications about Endoscopic Submucosal Dissection of Early Gastric Cancer with Undifferentiated-Type Histology

Endoscopic submucosal dissection (ESD) is a standard treatment for patients with gastrointestinal neoplasms with a negligible risk of lymph node metastasis. ESD enables en bloc resection of gastrointestinal neoplasms and organ preservation, thereby, avoiding surgical treatment. Although small (<2 cm) intramucosal early gastric cancer with undifferentiated-type histology (EGC-UH) without ulceration is included in the expanded criteria for ESD, controversies remain due to different biology and characteristics compared to EGC with differentiated-type histology. The authors previously presented studies about the technical feasibility of ESD for these lesions using a meta-analysis and retrospective multicenter analysis. However, many pitfalls were identified in the interpretation of studies analyzing histologic discrepancy, mixed-type histology, criteria-based analysis of therapeutic outcomes, interpretation of curative resection, and long-term clinical outcomes. In this review, the authors discuss pitfalls in the interpretation of publications on ESD for EGC-UH.

Signet ring cell component, not the Lauren subtype, predicts poor survival: an analysis of 198 cases of gastric cancer

AIM

Prognostic differences between major histologic gastric cancer groups, intestinal and diffuse are uncertain, since cellular components in each of them possibly have different behaviors.

MATERIALS & METHODS

We reviewed 198 gastric cancer patients charts diagnosed from January 2003 to December 2015 in a tertiary hospital. Multivariate Cox proportional survival models were used to evaluate the impact of histologic groups on overall survival.

RESULTS

About a third had the signet-ring cell carcinoma (SRCC). In a comparison of the different histologic subtypes, SRCC had the worst prognosis of all. The median durations of survival for patients with stage III and stage IV were 19.7 and 7.7 months, respectively.

CONCLUSION

Signet-ring cell component seem to have a relevant role in defining prognosis for gastric cancer.

Effect of Age on Prognosis of Gastric Signet-Ring Cell Carcinoma: A SEER Database Analysis

Background

Age is a prognostic factor for multiple malignancies. In this study, we aimed to assess the effect of age on the cancer-specific survival (CSS) of patients with gastric signet-ring cell carcinoma (SRC).

Material/Methods

Information on patients with gastric SRC was extracted from the Surveillance, Epidemiology, and End Results database. Chi-squared tests were used to demonstrate distribution differences, and Kaplan-Meier analysis and Cox regression models were used to analyze the impact of age on CSS.

Results

A total of 4596 patients were enrolled and divided into 3 subgroups according to age (<45, 45–74, and >74 years old). Higher percentages of T4, N2, and M1 disease were observed in the <45-year-old group (all P<0.001). Kaplan-Meier plots showed that the youngest group had the most favorable 5-year CSS rate (36.3%), which remained true after stratification according to tumor stage. Multivariate Cox regression models demonstrated a poorer survival outcome for >74-year-old than for <45-year-old patients (hazard ratio 1.841, 95% confidence interval 1.636–2.071; P<0.001).

Conclusions

Young age is associated with improved survival, even though younger patients generally present with a more advanced-stage disease.

Expression of VEGF with tumor incidence, metastasis and prognosis in human gastric carcinoma

OBJECTIVE

To analysis the expression of VEGF in gastric carcinoma cell and tumor tissue, our study determined the relationship between the expression of VEGF and tumor incidence, metastasis and prognosis in human gastric carcinoma.

METHODS

Treatment of ZD6474 at dose of 30 μmol/L was performed in gastric carcinoma cell BGC823. qPCR and Western-blot were used to analysis the mRNA and protein expression of VEGF. MTT, wound healing and Transwell experiments were conducted to study the effect of VEGF on tumor incidence, metastasis and prognosis. Sixty patients with gastric cancer were selected as the gastric cancer group, and 30 patients with gastric ulcer receiving main gastric resection were selected as control group. The survival curve of patients with gastric cancer in five years was recorded. The correlation between expression of VEGF to incidence, metastasis and prognosis of gastric cancer was evaluated by Cox multifactor regression.

RESULTS

The mRNA and protein expression of VEGF in treatment group were significantly lower than that of control group (P< 0.01). The results of MTT, wound healing and Transwell experiments were showed that the cell proliferation, migration and invasion capacity in treatment group were significantly reduced compared to that of the control group (P< 0.01). The 5-year survival rate for patients with VEGF positive expression was significantly decreased compared to the patients with VEGF expression negative (P< 0.01). The tumor size, differentiation, lymph node metastasis and tumor stage were statistically related to VEGF level (P< 0.05). The results of Cox regression multifactor analysis showed that lymph node metastasis, tumor staging and the expression of VEGF were significantly associated to the prognosis of gastric cancer patients (P< 0.05).

CONCLUSION

Our data demonstrated that the expression of VEGF was significantly related to the tumor incidence, metastasis and prognosis of patients with gastric cancer, which provides new leads to the diagnosis of gastric cancer.

Prognostic Stratification of Advanced Gastric Signet Ring Cell Carcinoma by Clinicopathological Factors and GALNT14 Genotype

Background: Gastric signet ring cell carcinoma (SRCC) is a histologic variant characterized by abundant intracytoplasmic mucin. Although it has been recognized that gastric adenocarcinoma harboring this feature has poorer prognosis, prognostic stratification within gastric SRCCs themselves has not been clearly defined. N-acetylgalactosaminyltransferase14 (GALNT14) genotype has been associated to poorer treatment outcome in mucinous type colorectal cancer. Here we incorporated clinicopathological factors and GALNT14 genotype to stratify prognosis of advanced gastric SRCC. Methods: Totally 347 gastric SRCC patients were retrospectively enrolled for GALNT14 genotyping. Clinicopathological factors were included for prognosis stratification. Results: Of the 347 patients, 341 underwent radical-intent gastrectomy and 6 received palliative gastrectomy. Kaplan-Meier analysis for overall survival indicated that Tumor-Node-Metastasis staging could only stratify the patients into three prognosis-distinguishable groups: group-1 (stage IA); group-2 (stage IB/IIA) and group-3 (the remaining Tumor-Node-Metastasis stages combined). Multivariate Cox-proportional hazard models for group-3 patients revealed GALNT14 "TT" genotype (P = 0.0482). Tumor size (P = 0.0009), node status (P <0.0001), metastasis status (P = 0.0096), and perineural invasion (P = 0.037) independently associated with unfavorable OS. Exploratory subgroup analysis showed that GALNT14"TT" genotype was associated with unfavorable OS in SRCCs with more aggressive phenotypes: node status >0 (P = 0.0013), lymphatic invasion (P = 0.021), vascular invasion (P = 0.0076) and perineural invasion (P = 0.0161). Accordingly, a scoring system was established capable of stratifying advanced gastric SRCC patients into three distinguishable prognostic subgroups. Conclusions: Gastric SRCC could be stratified into different prognostic subgroups by combining clinicopathological factors and GALNT14 genotype.

Evaluating TNM stage prognostic ability in a population-based cohort of gastric adenocarcinoma patients in a low-incidence country

OBJECTIVES

TNM stage is the preeminent cancer staging system and a fundamental determinant of disease prognosis. Our goal was to evaluate the predictive power of TNM stage for gastric adenocarcinoma (GAC), in a low-incidence country.

METHODS

A province-wide chart review of GAC patients diagnosed from April 1, 2005 to March 31, 2008 was conducted in Ontario and linked to routinely collected vital status data with a follow-up on March 31, 2012. TNM staging was classified using the sixth and seventh Union International for Cancer Control/American Joint Committee on Cancer editions. Kaplan-Meier and log-rank tests compared stage-stratified survival estimates. Discrimination was evaluated using Harrell's C statistic.

RESULTS

The cohort included 2366 patients. One- and 5-year survival was 43% and 17%. Using the sixth edition, 9% of patients had stage I disease, 5.4% stage II, 7.3% stage III, and 64% stage IV; 15% were not staged. Using the seventh edition, 9% were stage I, 7.7% stage II, 16% stage III, and 54% stage IV; 14% were not staged. Stage-stratified 5-year survival ranged from 68% to 7% with the sixth edition and from 70% to 4% with the seventh edition. Harrell's C statistic was 0.64 (0.63-0.65) for the broad sixth edition staging categories and 0.68 (0.67-0.69) for the broad seventh edition. Discriminative power was similar for the refined stage categories and across multiple subgroup analyses; it was best in non-metastatic patients.

CONCLUSION

Existing staging systems for GAC used in North America predict individualized prognosis poorly. The creation of a more complex prediction tool is necessary to provide accurate and precise prognostication information to oncologists, patients, and their families.

Prognostic significance of frequent CLDN18-ARHGAP26/6 fusion in gastric signet-ring cell cancer

Signet-ring cell carcinoma (SRCC) has specific epidemiology and oncogenesis in gastric cancer, however, with no systematical investigation for prognostic genomic features. Here we report a systematic investigation conducted in 1868 Chinese gastric cancer patients indicating that signet-ring cells content was related to multiple clinical characteristics and treatment outcomes. We thus perform whole-genome sequencing on 32 pairs of SRC samples, and identify frequent CLDN18-ARHGAP26/6 fusion (25%). With 797 additional patients for validation, prevalence of CLDN18-ARHGAP26/6 fusion is noticed to be associated with signet-ring cell content, age at diagnosis, female/male ratio, and TNM stage. Importantly, patients with CLDN18-ARHGAP26/6 fusion have worse survival outcomes, and get no benefit from oxaliplatin/fluoropyrimidines-based chemotherapy, which is consistent with the fact of chemo-drug resistance acquired in CLDN18-ARHGAP26 introduced cell lines. Overall, this study provides insights into the clinical and genomic features of SRCC, and highlights the importance of frequent CLDN18-ARHGAP26/6 fusions in chemotherapy response for SRCC.

Optimal management of resected gastric cancer

Although advances in medical treatment for gastric cancer (GC) have been made, surgery remains the mainstay of cure for patients with localized disease. Improvement in surgical modalities leads to increased chance of cure for resected patients, but a non-negligible number of patients eventually relapse. On this basis, it has been hypothesized that the addition of complementary systemic or local treatments (such as chemotherapy and radiotherapy) could help in improving patients' survival by reducing the risk of recurrence. Several studies have tried to identify the best approach in localized GC: some of them have assessed the role of perioperative chemotherapy [CT] with different drug combinations, while others have focused on the benefit obtained by addition of radiotherapy, whose role is still under investigation. In particular, the role of chemoradiotherapy, both in adjuvant and neoadjuvant settings, is still uncertain. In the last few years, several clinicopathological and molecular factors have been investigated and identified as potential prognostic markers in GC. Many of these factors could have influenced the outcome of patients receiving combined treatments in the abovementioned studies. Patients have not been generally distinguished by the site of disease (esophageal, gastric and junctional cancers) and surgical approach, making data difficult to be interpreted. The purpose of this review was to shed light on these highly controversial topics.

Efficacy of a docetaxel-5FU-oxaliplatin regimen (TEFOX) in first-line treatment of advanced gastric signet ring cell carcinoma: an AGEO multicentre study

Background

Triplet chemotherapy, with docetaxel-5FU-oxaliplatin (TEFOX), has yielded promising results in patients with advanced and operable gastric adenocarcinoma. This may prove useful in treating signet ring cell carcinoma (SRCC), which is known to be chemoresistant and has a poor prognosis. We therefore evaluated TEFOX in patients with untreated advanced SRCC.

Methods

Patients with metastatic or locally advanced non-resectable SRCC were treated with TEFOX. Chemotherapy was administered every 14 days, with combined docetaxel (50 mg/m²) and oxaliplatin (85 mg/m²) followed by 5FU (2400 mg/m²).

Results

Among 65 patients enrolled, including 17 with linitis plastica, ORR and DCR were 66.1% and 87.6%, respectively. Median PFS and OS were 9.7 months (95% CI [6.9–11.4]) and 14.3 months (95% CI [11.6–21.6]) respectively. Twenty-six patients (40%) initially considered as unresectable had secondary resection (n = 24) or radiotherapy (n = 2) with curative intent, with median PFS and OS of 12.4 and 26.2 months, respectively.

Conclusions

TEFOX appears to be effective as first-line treatment in advanced gastric SRCC and has an acceptable safety profile. It allowed a curative intent approach in 40% of patients. Considering the low chemosensitivity of SRCC reported with other chemotherapy regimens and pending for randomised studies, TEFOX might be an option in advanced gastric SRCC.

Prognostic value of metabolic parameters on preoperative 18F-fluorodeoxyglucose positron emission tomography/ computed tomography in patients with stage III gastric cancer

This study investigated the prognostic value of metabolic parameters determined by 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with stage III gastric cancer. Patients with pre-operative PET/CT and confirmed stage III after curative surgical resection were retrospectively enrolled. Parameters evaluated from pre-operative PET/CTwere maximum standardized uptake value (SUV_max) and peak SUV (SUV_peak) of primary tumor, SUV_max or SUV_peak of tumor to liver ratio (TLR_max and TLR_peak). Volumetric parameters, metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were also evaluated. These PET/CT parameters were compared with the overall survival (OS) and recurrence-free survival (RFS). From total of 133 consecutive patients, tumor recurrence was found in 54 patients (40.6%) and 53 died during the follow-up period (median, 43 mo; range 5-62). In univariate analysis, SUV_max, SUV_peak, TLR_max and TLR_peak were significantly associated with the OS and RFS. In multivariate analysis, high TLR_max and TLR_peak were significantly unfavorable prognostic factors for RFS (both P<0.05) even after adjusting for age, depth of tumor invasion, lymph node metastasis, and chemotherapy. MTV and TLG showed no statistically significant correlation with outcome. In conclusion, glucose metabolism of primary tumor measured by pre-operative PET/CT provides prognostic information, especially for recurrence, in stage III gastric cancer.

New therapeutic options opened by the molecular classification of gastric cancer

Gastric cancer (GC) is one of the most lethal and aggressive cancers, being the third cause of cancer related death worldwide. Even with radical gastrectomy and the latest generation of molecular chemotherapeutics, the numbers of recurrence and mortality remains high. This is due to its biological heterogeneity based on the interaction between multiple factors, from genomic to environmental factors, diet or infections with various pathogens. Therefore, understanding the molecular characteristics at a genomic level is critical to develop new treatment strategies. Recent advances in GC molecular classification provide the unique opportunity to improve GC therapy by exploiting the biomarkers and developing novel targeted therapy specific to each subtype. This article highlights the molecular characteristics of each subtype of gastric cancer that could be considered in shaping a therapeutic decision, and also presents the completed and ongoing clinical trials addressed to those targets. The implementation of the novel molecular classification system will allow a preliminary patient selection for clinical trials, a mandatory issue if it is desired to test the efficacy of a certain inhibitor to the given target. This will represent a substantial advance as well as a powerful tool for targeted therapy. Nevertheless, translating the scientific results into new personalized treatment opportunities is needed in order to improve clinical care, the survival and quality of life of patients with GC.

Signet Ring Cell Carcinoma of the Ampulla of Vater: A Rare Histopathological Variant

Signet ring cell carcinoma (SRCC) of the ampulla of Vater is an extremely rare tumor. Our case describes a 45-year-old female presenting with jaundice and pruritus. Computed tomography, endoscopy, and endoscopic retrograde cholangiopancreatography showed a tumor of the ampulla of Vater without distant metastasis. Histological biopsy confirmed a malignant tumor with SRCC characteristics and immunohistochemical staining revealed a mixed type profile (both intestinal and pancreatobiliary characteristics). A pylorus-preserving pancreatoduodenectomy was performed and the patient recovered without complications. Pathology results concluded a pT2N0 ampullary SRCC. SRCC of the ampulla of Vater is known to be highly malignant. After 13 months of follow-up, our patient showed no signs of recurrence.

Genomic profile of appendiceal goblet cell carcinoid is distinct compared to appendiceal neuroendocrine tumor and conventional adenocarcinoma

Goblet cell carcinoid (GCC) is a rare appendiceal tumor with unique morphologic features that shows glandular and neuroendocrine differentiation on immunohistochemistry. An additional component of adenocarcinoma (AC) can be present (GCC-AC). Both GCC and GCC-AC are staged and treated like AC. The histogenesis and genetic alterations underlying GCC and GCC-AC are unclear. Capture-based next-generation DNA sequencing targeting 479 cancer genes was performed on 19 appendiceal tumors: 4 GCC, 9 GCC-AC, 3 neuroendocrine tumors (NET), and 3 AC (2 conventional, 1 mucinous). Somatic coding mutations were not seen in any NET. Pathogenic (P)/likely pathogenic (LP) mutations were present in 1 GCC, 8 GCC-AC and all 3 AC cases. P/LP mutations in chromatin remodeling genes were seen in 4 (44.4%) GCC-AC cases, but not in NET, GCC or AC. In GCC-AC, P/LP mutations in ARID1A and RHOA were each present in 3 cases, and KDM6A and SOX9 mutations were each seen in 2 cases. APC and KRAS mutations were present in 1 conventional AC case, but were not observed in any GCC or GCC-AC. This limited series reveals mutations in SOX9, RHOA, and chromatin-modifier genes in goblet cell tumors, and shows that the mutational profile of GCC/GCC-AC is distinct from NET and conventional appendiceal AC.

Incidence, Survival, and Predictors of Lymph Node Involvement in Early-Stage Gastric Signet Ring Cell Carcinoma in the US

INTRODUCTION

The incidence, survival, and propensity for nodal metastasis in early-stage gastric signet ring cell carcinoma have not been defined in the United States. These data are critical determinants for treatment allocation.

METHODS

Cases of gastric signet ring cell carcinoma were extracted from the national SEER database for the years 2004-2013. Age-standardized incidence was derived. Survival was calculated using the Kaplan-Meier method. Univariate and multivariate analyses were performed to identify predictors of nodal metastasis. Exclusion criteria included neoadjuvant radiotherapy and lack of histologic or nodal data.

RESULTS

A total of 10,624 cases were initially identified. The analysis cohort included 506 cases with early T-stage N0M0 disease following exclusions. The incidence was 0.094 per 100,000 person-years. The 5-year survival rate was 82.8%. Tumor stage (p < 0.001) and size (p < 0.001) were independent predictors of nodal metastasis. The incidence of nodal involvement for T1a tumors <2 cm was 5.4% (p < 0.004).

CONCLUSION

The incidence of potentially resectable signet ring gastric carcinoma has not changed significantly over the past decade. While presenting with predominantly high-grade histology, early T-stage disease has a high survival rate. Small T1a tumors have low rates of nodal metastasis, suggesting that an endoscopic resection could be considered in this subset.