Secondary rectal linitis plastica caused by prostatic adenocarcinoma - magnetic resonance imaging findings and dissemination pathways: A case report.

BACKGROUND: Secondary rectal linitis plastica (RLP) from prostatic adenocarcinoma is a rare and poorly understood form of metastatic spread, characterized by a desmoplastic response and concentric rectal wall infiltration with mucosal preservation. This complicates endoscopic diagnosis and can mimic gastrointestinal malignancies. This case series underscores the critical role of magnetic resonance imaging (MRI) in identifying the distinct imaging features of RLP and highlights the importance of considering this condition in the differential diagnosis of patients with a history of prostate cancer. CASE SUMMARY: Three patients with secondary RLP due to prostatic adenocarcinoma presented with varied clinical features. The first patient, a 76-year-old man with advanced prostate cancer, had rectal pain and incontinence. MRI showed diffuse prostatic invasion and significant rectal wall thickening with a characteristic "target sign" pattern. The second, a 57-year-old asymptomatic man with elevated prostate-specific antigen levels and a history of prostate cancer exhibited rectoprostatic angle involvement and rectal wall thickening on MRI, with positron emission tomography/computed tomography PSMA confirming the prostatic origin of the metastatic spread. The third patient, an 80-year-old post-radical prostatectomy, presented with refractory constipation. MRI revealed a neoplastic mass infiltrating the rectal wall. In all cases, MRI consistently showed stratified thickening, concentric signal changes, restricted diffusion, and contrast enhancement, which were essential for diagnosing secondary RLP. Biopsies confirmed the prostatic origin of the neoplastic involvement in the rectum. CONCLUSION: Recognizing MRI findings of secondary RLP is essential for accurate diagnosis and management in prostate cancer patients.

Immunosuppressive tumor microenvironment in gastric signet-ring cell carcinoma.

Gastric signet-ring cell carcinoma (GSRCC) is a subtype of gastric cancer with distinct phenotype and high risk of peritoneal metastasis. Studies have shown that early GSRCC has a good prognosis, while advanced GSRCC is insensitive to radiotherapy, chemotherapy or immune checkpoint blockade therapy. With technological advancement of single-cell RNA sequencing analysis and cytometry by time of flight mass cytometry, more detailed atlas of tumor microenvironment (TME) in GSRCC and its association with prognosis could be investigated extensively. Recently, two single-cell RNA sequencing studies revealed that GSRCC harbored a unique TME, manifested as highly immunosuppressive, leading to high immune escape. The TME of advanced GSRCC was enriched for immunosuppressive factors, including the loss of CXCL13 +-cluster of differentiation 8+-Tex cells and declined clonal crosstalk among populations of T and B cells. In addition, GSRCC was mainly infiltrated by follicular B cells. The increased proportion of SRCC was accompanied by a decrease in mucosa-associated lymphoid tissue-derived B cells and a significant increase in follicular B cells, which may be one of the reasons for the poor prognosis of GSRCC. By understanding the relationship between immunosuppressive TME and poor prognosis in GSRCC and the underlying mechanism, more effective immunotherapy strategies and improved treatment outcomes of GSRCC can be anticipated.

Disappearing Signet Ring Cell Adenocarcinoma in Gastric Cancer Patients.

BACKGROUND: The incidence of diffuse-type gastric cancer is increasing steadily in the United States, Europe, and Asia. This subtype is known for aggressive clinical characteristics and transmural invasion. However, T1a diffuse-type cancers have been observed to have a better 5-year, disease-specific mortality than stage-matched intestinal tumors, supporting a clinical difference in these early-stage cancers. METHODS: Data on all living patients with T1a gastric adenocarcinoma with a finding of signet ring cell morphology on pathology and ≥1 year of follow-up from 2013 to 2023 at Memorial Sloan Kettering Cancer Center (MSK) was collected from a prospectively maintained database. Patients with known CDH1 or CTNNA1 mutations were excluded. RESULTS: In 7 of 30 patients, sporadic pathologically confirmed T1a signet ring cell (diffuse) cancer identified on initial biopsy was no longer detectable upon subsequent biopsy or resection with mean follow-up of 50 months. CONCLUSIONS: These cases allude to the distinct pathways of carcinogenesis in T1a signet ring cell cancers. Potential factors that may underlie the spontaneous regression of these T1a cancers include complete removal at initial biopsy, immune clearance, and lack of survival advantage conferred by signet ring cell genetic alterations in these cases. Given their more indolent behavior at an earlier stage, we suggest that these lesions can be closely followed by endoscopy in select circumstances with thorough disease assessment and an experienced care team.

Primary signet-ring cell carcinoma of the urinary bladder ‒ A rare bladder tumor.

AIM: Primary Signet Ring Cell Carcinoma (SRCC) of the bladder accounts for only 1%‒4% of all bladder malignancies. To date, few studies have been conducted to investigate the characteristics of SRCC. This study aimed to investigate the clinical features and treatments of SRCC and explore the independent risk factors of survival in SRCC patients. PATIENTS AND METHODS: A retrospective study was conducted on 32 eligible patients. The survival rate was calculated with the Kaplan-Meier method, and the COX proportional hazards model was used to investigate the independent risk factors of prognosis. RESULTS: In the present study, the 1-year and 2-year survival rates of SRCC patients were 53.1% and 9.4%, respectively. The TNM stage, tumor differentiation, and metastasis after treatment were risk factors for the prognosis of SRCC patients (p < 0.05), while surgical treatment, chemotherapy, and positive GATA3 expression were protective for prognosis (p < 0.05). Multivariate analysis showed that GATA3 was an independent protective factor for prognosis (p < 0.05), and T-stage was an independent risk factor (p < 0.05). CONCLUSIONS: Primary SRCC of the bladder is highly malignant and has a poor prognosis. Its clinical and imaging findings are usually non-specific. Early radical cystectomy and postoperative adjuvant systemic chemotherapy are helpful to improve the survival rate. T-stage is an independent risk factor for survival, and positive GATA3 expression is protective for primary SRCC of the bladder.

A rare case of primary signet-ring adenocarcinoma of anorectal region in a young patient: Diagnostic challenges and therapeutic outcomes.

Key Clinical Message: Primary signet-ring cell carcinoma of the anal canal and rectum is an extremely rare and aggressive malignancy. The present case underscores the importance of considering primary signet-ring cell carcinoma in differential diagnoses for young patients with chronic anorectal symptoms. It highlights the need for a multidisciplinary treatment approach (including surgery, chemotherapy, and radiotherapy) and comprehensive follow-up for managing this challenging condition and improving long-term patient outcomes. Abstract: Primary signet-ring cell carcinoma of the anal canal and rectum is an exceedingly rare subtype of colorectal adenocarcinoma, often originating as an extension of rectal adenocarcinoma. This malignancy constitutes a small fraction of colorectal cancers and is scarcely reported in medical literature. We present the case of an 18-year-old male with a three-year history of progressively worsening hematochezia, anorectal pain, and defecation-associated prolapse. Initial conservative treatments failed, leading to further investigations that revealed a palpable, nodular anorectal mass. Imaging studies (including CT and MRI), and biopsy confirmed poorly differentiated adenocarcinoma with signet-ring cell morphology. The tumor exhibited extensive lymphovascular invasion and involved perirectal lymph nodes, and was staged as pT3, N2a. Immunohistochemical staining was positive for CK 7, CK 20, and SATB2, supporting the primary anorectal origin. The treatment regimen included initial diversion colostomies for symptom relief, followed by neoadjuvant chemotherapy with a modified 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) regimen and concurrent chemoradiation with Xeloda. The patient subsequently underwent an abdominoperineal resection (APR), which confirmed the diagnosis and achieved curative resection. Postoperative complications included transient ileus and wound infection, which were managed with supportive care. This case underscores the diagnostic and therapeutic challenges posed by primary signet-ring cell carcinoma of the anorectal region, highlighting the need for a high index of suspicion and comprehensive diagnostic workup in atypical presentations. The multimodal treatment approach, incorporating surgery, chemotherapy, and radiotherapy, was crucial in managing this locally advanced tumor. The rarity and aggressiveness of this carcinoma necessitate a tailored treatment strategy to improve patient outcomes. Long-term follow-up, including regular imaging and surveillance, is vital for monitoring disease recurrence and evaluating treatment effectiveness.

Unmasking the silent killer: The hidden aggressiveness of signet-ring cell carcinoma in gallbladder cancer.

The prognostic significance of the signet-ring cell component in gallbladder carcinoma (GBC) has not been systematically evaluated. The aim of this study was to assess the similarities and differences between gallbladder signet-ring cell carcinoma (GBSRCA) and gallbladder adenocarcinoma (GBAC) in terms of clinicopathological features and long-term survival. Using the Surveillance, Epidemiology, and End Results (SEER) database, we analyzed 6,612 patients diagnosed with gallbladder cancer between 2000 and 2021. The cohort included 147 patients with GBSRCA and 6,465 with GBAC. Patients with GBSRCA were significantly younger, with 33.3% being age 60 or younger compared to 23.9% of patients with GBAC (p = 0.009). There was a higher proportion of females in the GBSRCA group (77.6%) compared to the GBAC group (70.1%, p = 0.049). GBSRCA was associated with a more advanced tumor stage (T3-T4: 56.5% vs. 44.4%, P = 0.004), higher rates of lymph node metastasis (43.5% vs. 28.0%, P < 0.001), and poorer differentiation status (poorly to undifferentiated: 80.3% vs. 29.7%, P < 0.001). Survival analysis revealed that patients with GBSRCA had significantly worse overall survival (OS) and cancer-specific survival (CSS) compared to patients with GBAC (p < 0.001). GBSRCA was an independent prognostic factor for OS (P = 0.001) in the entire cohort, while the T stage and N stage were independent prognostic factors for OS and CSS in patients with GBSRCA. Even after propensity score matching, patients with GBSRCA still had a poorer prognosis.

The "Forgotten" Subtypes of Breast Carcinoma: A Systematic Review of Selected Histological Variants Not Included or Not Recognized as Distinct Entities in the Current World Health Organization Classification of Breast Tumors.

Breast carcinoma is the most common cancer in women. Nineteen different subtypes of breast carcinomas are recognized in the current WHO classification of breast tumors. Except for these subtypes, there are a number of carcinomas with special morphologic and immunohistochemical features that are not included in the 5th WHO classification, while others are considered special morphologic patterns of invasive breast carcinoma of no special type. In this manuscript, we systematically review the literature on four different subtypes of invasive breast carcinoma, namely lymphoepithelioma-like breast carcinoma, breast carcinoma with osteoclast-like giant cells, signet-ring breast carcinoma, and metaplastic breast carcinoma with melanocytic differentiation. We describe their clinicopathological characteristics, focusing on the differential diagnosis, treatment, and prognosis.

Treatment Options for Signet Ring Cell Carcinoma of the Urinary Bladder: A Population-Based Study.

OBJECTIVES: Signet ring cell carcinoma (SRCC) of the urinary bladder is a rare and highly aggressive form of bladder cancer, with no widely agreed-upon treatment strategy. The aim of this study was to identify important factors influencing patient prognosis and to assess how various treatment approaches affect survival outcomes. METHODS: A retrospective study was conducted using data from the Surveillance, Epidemiology, and End Results (SEER) Program, including patients with bladder primary SRCC who were presented between 2000 and 2017. Univariate and multivariate Cox regression models were used to examine the impact of various factors on cancer-specific survival (CSS) and overall survival (OS). Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were applied to homogenize both groups. The impact of different treatment regimens on patient CSS and OS was analyzed using the Kaplan-Meier method. RESULTS: A total of 33 cases of non-muscular invasive SRCC and 210 cases of muscular invasive SRCC were included in this study. Multivariate analysis identified race, TNM stage, and surgical method as independent variables influencing both OS and CSS. In non-muscle invasive bladder SRCC patients, radical cystectomy showed no CSS benefit compared to transurethral resection of bladder tumors (P = 0.304). For muscle invasive SRCC, patients who underwent partial cystectomy had better OS and CSS compared to those who underwent radical cystectomy (P = 0.019, P = 0.024). However, after conducting a PSM analysis, the differences between the two surgical outcomes were not statistically significant (P = 0.504, P = 0.335). Lymphadenectomy, chemotherapy, and radiation did not show any benefit to the prognosis of patients. CONCLUSION: This study identified race, TNM stage, and surgical approach as significant independent predictors for SRCC outcomes. Simple radical cystectomy and partial cystectomy proved to be effective treatments for SRCC. The optimal treatment option still needs to be supported by a number of prospective research trials.

Epidemiology and prognostic nomogram for locally advanced gastric signet ring cell carcinoma: A population-based study.

BACKGROUND: Gastric signet ring cell carcinoma (GSRC) represents a specific subtype of gastric cancer renowned for its contentious epidemiological features, treatment principles, and prognostic factors. AIM: To investigate the epidemiology of GSRC and establish an improved model for predicting the prognosis of patients with locally advanced GSRC (LAGSRC) after surgery. METHODS: The annual rates of GSRC incidence and mortality, covering the years 1975 to 2019, were extracted from the Surveillance, Epidemiology, and End Results (SEER) database to explore the temporal trends in both disease incidence and mortality rates using Joinpoint software. The clinical data of 3793 postoperative LAGSRC patients were collected from the SEER database for the analysis of survival rates. The Cox regression model was used to explore the independent prognostic factors for overall survival (OS). The risk factors extracted were used to establish a prognostic nomogram. RESULTS: The overall incidence of GSRC increased dramatically between 1975 and 1998, followed by a significant downward trend in incidence after 1998. In recent years, there has been a similarly optimistic trend in GSRC mortality rates. The trend in GSRC showed discrepancies based on age and sex. Receiver operating characteristic curves, calibration curves, and decision curve analysis for 1-year, 3-year, and 5-year OS demonstrated the high discriminative ability and clinical utility of this nomogram. The area under the curve indicated that the performance of the new model outperformed that of the pathological staging system. CONCLUSION: The model we established can aid clinicians in the early prognostication of LAGSRC patients, resulting in improved clinical outcomes by modifying management strategies and patient health care.

Gastroesophageal signet ring cell carcinoma morbidity and mortality: A retrospective review.

BACKGROUND: Upper gastrointestinal (GI) signet ring cell carcinomas (SRCC) confer a poor prognosis. The benefit of operative intervention for this patient group is controversial in terms of overall survival. AIM: To investigate factors relating to survival in patients with upper GI SRCC. METHODS: A retrospective, tertiary, single-centre review of patients who were diagnosed with oesophageal, gastroesophageal junction and gastric SRCC was performed. The primary outcome was to compare mortality of patients who underwent operative management with those who had nonoperative management. Secondary outcomes included assessing the relationship between demographic and histopathological factors, and survival. RESULTS: One hundred and thirty-one patients were included. The one-year survival for the operative group was 81% and for the nonoperative group was 19.1%. The five-year survival in the operative group was 28.6% vs 1.5% in the nonoperative group. The difference in overall survival between groups was statistically significant (HR 0.19, 95%CI (0.13-0.30), P < 0.001). There was no difference in survival when adjusting for age, smoking status or gender. On multivariate analysis, patients who underwent surgical management, those with a lower stage of disease, and those with a lower Charlson Comorbidity Index (CCI) had significantly improved survival. CONCLUSION: Well-selected patients with upper GI SRCC appear to have reasonable medium-term survival following surgery. Offering surgery to a carefully selected patient group may improve the outcome for this disease.

Development and validation of a nomogram for predicting lymph node metastasis in early gastric cancer.

BACKGROUND: Lymph node metastasis (LNM) significantly impacts the treatment and prognosis of early gastric cancer (EGC). Consequently, the precise prediction of LNM risk in EGC patients is essential to guide the selection of appropriate surgical approaches in clinical settings. AIM: To develop a novel nomogram risk model for predicting LNM in EGC patients, utilizing preoperative clinicopathological data. METHODS: Univariate and multivariate logistic regression analyses were performed to examine the correlation between clinicopathological factors and LNM in EGC patients. Additionally, univariate Kaplan-Meier and multivariate Cox regression analyses were used to assess the influence of clinical factors on EGC prognosis. A predictive model in the form of a nomogram was developed, and its discrimination ability and calibration were also assessed. RESULTS: The incidence of LNM in the study cohort was 19.6%. Multivariate logistic regression identified tumor size, location, degree of differentiation, and pathological type as independent risk factors for LNM in EGC patients. Both tumor pathological type and LNM independently affected the prognosis of EGC. The model's performance was reflected by an area under the curve of 0.750 [95% confidence interval (CI): 0.701-0.789] for the training group and 0.763 (95%CI: 0.687-0.838) for the validation group. CONCLUSION: A clinical prediction model was constructed (using tumor size, low differentiation, location in the middle-lower region, and signet ring cell carcinoma), with its score being a significant prognosis indicator.

A prognostic framework for predicting lung signet ring cell carcinoma via a machine learning based cox proportional hazard model.

PURPOSE: Signet ring cell carcinoma (SRCC) is a rare type of lung cancer. The conventional survival nomogram used to predict lung cancer performs poorly for SRCC. Therefore, a novel nomogram specifically for studying SRCC is highly required. METHODS: Baseline characteristics of lung signet ring cell carcinoma were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression and random forest analysis were performed on the training group data, respectively. Subsequently, we compared results from these two types of analyses. A nomogram model was developed to predict 1-year, 3-year, and 5-year overall survival (OS) for patients, and receiver operating characteristic (ROC) curves and calibration curves were used to assess the prediction accuracy. Decision curve analysis (DCA) was used to assess the clinical applicability of the proposed model. For treatment modalities, Kaplan-Meier curves were adopted to analyze condition-specific effects. RESULTS: We obtained 731 patients diagnosed with lung signet ring cell carcinoma (LSRCC) in the SEER database and randomized the patients into a training group (551) and a validation group (220) with a ratio of 7:3. Eight factors including age, primary site, T, N, and M.Stage, surgery, chemotherapy, and radiation were included in the nomogram analysis. Results suggested that treatment methods (like surgery, chemotherapy, and radiation) and T-Stage factors had significant prognostic effects. The results of ROC curves, calibration curves, and DCA in the training and validation groups demonstrated that the nomogram we constructed could precisely predict survival and prognosis in LSRCC patients. Through deep verification, we found the constructed model had a high C-index, indicating that the model had a strong predictive power. Further, we found that all surgical interventions had good effects on OS and cancer-specific survival (CSS). The survival curves showed a relatively favorable prognosis for T0 patients overall, regardless of the treatment modality. CONCLUSIONS: Our nomogram is demonstrated to be clinically beneficial for the prognosis of LSRCC patients. The surgical intervention was successful regardless of the tumor stage, and the Cox proportional hazard (CPH) model had better performance than the machine learning model in terms of effectiveness.

Individualized prediction of conditional survival for colorectal signet-ring cell carcinoma patients.

Background: Conditional survival (CS) considers the time already survived after surgery and may provide additional survival information. The authors sought to construct and validate novel conditional survival nomograms for the prediction of conditional overall survival (OS) and cancer-specific survival (CSS) of colorectal signet-ring cell carcinoma (SRCC) patients. Methods: Patients diagnosed with stage I-III SRCC between 2010 and 2019 were identified from the Surveillance, Epidemiology, and End Results database. The formula calculating CS was: CS(x|y) = S(x+y)/S(x), where S(x) represents the survival at x years. CS nomograms were then constructed to predict the 5-year conditional OS and CSS, followed by internal validation. Results: A total of 944 colorectal SRCC patients were finally identified in this study. The 5-year OS and CSS improved gradually with additional survival time. Univariate and multivariate Cox regression analysis conducted in training set revealed that age, race, T stage, LNR, and perineural invasion were independent risk factors for both OS and CSS. Two nomograms with considerable predictive ability were successfully constructed [area under the curve (AUC) for OS: 0.788; AUC for CSS: 0.847] and validated (AUC for OS: 0.773; AUC for CSS: 0.799) for the prediction of 5-year OS and CSS, based on the duration of 1-4 years post-surgery survival. Conclusions: The probability of achieving 5-year OS and 5-year CSS in colorectal SRCC patients improved gradually with additional time. Conditional nomograms considering survival time will be more reliable and informative for risk stratification and postoperative follow-up.

Bladder metastasis originating from gastric signet-ring cell carcinoma: a case report.

Bladder metastasis of gastric adenocarcinoma is a rare phenomenon. Hereby, we report a case of a 52-year-old patient who presented with upper gastro-intestinal bleeding and ascites and was diagnosed with gastric signet-ring cell carcinoma. A CT scan revealed peritoneal infiltration and anterior parietal thickening of bladder wall. Cystoscopy showed three budding lesions of the anterior wall of the bladder. He had an endoscopic resection. Histology concluded that the bladder was infiltrated by a poorly differentiated carcinoma with independent cells consistent with a gastric origin. The patient was to be treated with palliative chemotherapy.

We report a case of a 52-year-old patient who presented with symptoms such as stomach bleeding and a buildup of fluid in the stomach (ascites). The doctors diagnosed the patient with gastric cancer. The doctors also noted a thickening in the wall of the bladder during a CT scan. After more investigations, they discovered that the cancer from the stomach had spread to the bladder (metastasis).

Is neoadjuvant chemotherapy followed by surgery the appropriate treatment for esophagogastric signet ring cell carcinomas? A systematic review and meta-analysis.

Background: The impact of neoadjuvant chemotherapy (nCTX) on survival and tumor response in patients with esophagogastric signet ring cell carcinoma (SRCC) is still controversial. Methods: Two independent reviewers performed a systematic literature search in Medline, CENTRAL, and Web of Science including prospective and retrospective two-arm non-randomized and randomized controlled studies (RCTs). Data was extracted on overall survival (OS) and tumor regression in resected esophagogastric SRCC patients with or without nCTX. Survival data was analyzed using published hazard ratios (HR) if available or determined it from other survival data or survival curves. OS and histopathological response rates by type of tumor (SRCC vs. non-SRCC) were also investigated. Results: Out of 559 studies, ten (1 RCT, 9 non-RCTs) were included in this meta-analysis (PROSPERO CRD42022298743) investigating 3,653 patients in total. The four studies investigating survival in SRCC patients treated with nCTX + surgery vs. surgery alone showed no survival benefit for neither intervention, but heterogeneity was considerable (HR, 1.01; 95% CI, 0.61-1.67; p = 0.98; I2 = 89%). In patients treated by nCTX + surgery SRCC patients showed worse survival (HR, 1.45; 95% CI, 1.21-1.74; p < 0.01) and lower rate of major histopathological response than non-SRCC patients (OR, 2.47; 95% CI, 1.78-3.44; p < 0.01). Conclusion: The current meta-analysis could not demonstrate beneficial effects of nCTX for SRCC patients. Histopathological response to and survival benefits of non-taxane-based nCTX seem to be lower in comparison to non-SRC esophagogastric cancer. However, certainty of evidence is low due to the scarcity of high-quality trials. Further research is necessary to determine optimal treatment for SRCC patients. Systematic Review Registration: https://www.crd.york.ac.uk/, PROSPERO (CRD42022298743).

Appendiceal Signet Ring Cell Carcinoma Presenting As Acute Appendicitis: A Case Report.

Appendiceal signet ring cell carcinoma is an exceedingly rare neoplasm which makes up only 4% of carcinomas of the appendix. It is a rare cause of abdominal pain which can mimic acute appendicitis. This case reports a 77-year-old female who presented to the emergency room with a complaint of right lower quadrant abdominal pain. After exploratory laparoscopy and histopathological studies, the patient was found to have peritoneal carcinomatosis and appendiceal signet ring cell carcinoma. This diagnosis unfortunately carries a relatively poor prognosis due to its aggressive nature. This study discusses the etiology, prevalence, clinical findings, and treatment of a rare cause of abdominal pain. This report sheds light on the importance of early detection and treatment of appendiceal signet ring cell carcinoma.

The effect of surgery and metastatic risk prediction in patients with gastrointestinal tract signet-ring cell carcinoma.

PURPOSE: This study aimed to assess the efficacy of surgery as a treatment option for patients with signet-ring cell carcinoma (SRCC) in the gastrointestinal tract (GI-SRCC). METHODS: Using the Surveillance, Epidemiology, and End Results database, patients with GI-SRCC who underwent surgery or received nonsurgical treatment were included. Propensity score matching (PSM) analysis was used to balance baseline characteristics and reduce bias. Overall survival (OS) was calculated in matching cohorts to estimate prognosis for patients with GI-SRCC. Nomogram was established to predict metastasis for patients with GI-SRCC. RESULTS: The study enrolled a total of 9428 patients with GI-SRCC, with 1689 patients in the nonsurgery group and 7739 patients in the surgery group. After 1:1 PSM, we analyzed 743 patients from each group. Our survival analyses revealed that surgery independently correlated with improved OS for patients with GI-SRCC (hazard ratio, 0.37; 95% CI, 0.33-0.42; P < .001). Subgroup analysis further confirmed the positive impact of surgery on the prognosis of patients with nonmetastatic GI-SRCC. Notably, distinct subsets of patients with metastasis, particularly those originating from the upper GI (esophagus, proximal stomach, and distal stomach) and left colon, demonstrated a significant improvement in OS after surgery. However, no significant survival difference was observed for patients with metastatic right colon and rectum SRCC. Using nomogram, we quantitatively assessed the risk of metastasis in patients with right colon and rectum SRCC, which exhibited robust predictive accuracy, with area under the curve values of 0.829. CONCLUSION: Our study highlighted surgery's positive impact on prognosis for both patients with nonmetastatic and metastatic upper GI-SRCC and left colon SRCC. Hence, we recommend surgery as a treatment option for these groups. In addition, for patients with metastatic right colon and rectum SRCC ineligible for surgery, our predictive nomogram can offer a convenient tool to aid early intervention and improve prognosis.

[68Ga]Ga-FAPI-04 PET/MR imaging strategy in management of Krukenberg tumors (KTs) from gastric signet-ring-cell carcinoma: to overcome limitation of [68Ga]Ga-FAPI-04 PET imaging in KTs.

PURPOSE: To compare performance of whole-body [68Ga]Ga-FAPI-04 and [18F]FDG PET imaging in the detection of Krukenberg tumors (KTs), primary site and extra-ovarian metastases of gastric signet-ring-cell carcinoma (GSRCC), and evaluate the value of [68Ga]Ga-FAPI-04 PET/MR imaging strategy and its potential impact on the management of KTs from GSRCC. METHODS: Twelve patients with twenty-three KTs from GSRCC, who underwent both [68Ga]Ga-FAPI-04 pelvic PET/MR and whole-body [68Ga]Ga-FAPI-04 and [18F]FDG PET imaging were retrospectively analyzed. [68Ga]Ga-FAPI-04 and [18F]FDG uptakes were compared by using Wilcoxon signed-rank test or paired t test. McNemar's test was used to compare lesion detectability between two modalities. Two-tailed P<0.05 was considered statistically significant. Immunohistochemistry staining was utilized to analyze the fibroblast activation protein (FAP) expression in KTs. RESULTS: A total of 12 patients with 23 KTs from GSRCC (8 synchronous and 4 metachronous) were evaluated. [68Ga]Ga-FAPI-04 was superior to [18F]FDG PET in detecting primary sites of GSRCC (100% [11/11] vs. 18.2% [2/11], p = 0.002), involved lymph nodes (90.9% [10/11] vs. 54.5% [6/11], p = 0.046) and peritoneal metastases (100% [12/12] vs. 41.7% [5/12], p = 0.008), with higher SUVmax and TBR (all p < 0.005). Both tracers had limited value in identifying KTs, with 100% false negative rate on [68Ga]Ga-FAPI-04 PET and a low detection rate of 8.7% on [18F]FDG PET. Fap immunohistochemistry showed negative or slight FAP expression in neoplastic signet ring cells and ovarian stroma. [68Ga]Ga-FAPI-04 PET/MR imaging strategy greatly improved the detection rate of Krukenberg tumors (87%, 20/23). After adding diffusion-weighted imaging (DWI), the detection rate was further improved (87.5% vs. 100%, p = 0.083). [68Ga]Ga-FAPI-04 PET/MR imaging strategy either upgraded TNM staging or changed treatment management in twelve patients. CONCLUSIONS: [68Ga]Ga-FAPI-04 PET outperformed [18F]FDG PET in detecting primary site and most extra-ovarian metastases of GSRCC, but both tracers had limited value in identifying Krukenberg tumors. Pelvis MRI should be applied to compensate the limitation of [68Ga]Ga-FAPI-04 PET imaging to identify Krukenberg tumours. The [68Ga]Ga-FAPI-04 PET/MR imaging strategy has the potential to impact treatment decisions for GSRCC patients with KTs.