Immunotherapies for well-differentiated grade 3 gastroenteropancreatic neuroendocrine tumors: A new category in the World Health Organization classification.

According to the 2019 World Health Organization (WHO) classification, well-differentiated grade 3 (G3) gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) are a new category of cancer of the digestive system. G3 GEP-NET research and treatment are not as robust as those of lower grade (G1/2) NETs and poorly differentiated neuroendocrine carcinomas (NECs). Previously, the management of high-grade NETs was mainly based on NEC therapies, as high-grade NETs were classified as NECs under the previous WHO classification. Despite this, G3 GEP-NETs are significantly less responsive to platinum-based chemotherapy regimens than NECs, due to their distinct molecular pathogenesis and course of pathological grade transition. Patients with advanced G3 GEP-NETs, who have progressed or are intolerant to chemotherapy regimens such as capecitabine plus temozolomide, have limited treatment choices. Immunotherapy has helped patients with a variety of cancers attain long-term survival through the use of immune checkpoint inhibitors. Immunotherapies, either alone or in combination with other therapies, do not have a clear function in the treatment of G3 GEP-NETs. Currently, the majority of immunotherapy studies, both prospective and retrospective, do not reliably differentiate G3 GEP-NETs from NECs. By contrast, a significant number of studies include non-GEP neuroendocrine neoplasms (NENs). Therefore, there is an urgent need to summarize and evaluate these data to provide more effective therapeutic approaches for patients with this rare tumor. The purpose of this mini-review was to screen and summarize information on G3 GEP-NETs from all studies on NENs immunotherapy.

Successful treatment of metastatic colorectal cancer with synchronous BRAF V600E mutation and dMMR with BGB-A317.

Metastatic colorectal cancer with BRAF mutation is a type of highly invasive malignant tumor with poor prognosis and few treatment options. Here, we report a case of a BRAF-mutant and DNA mismatch-repair deficiency colorectal cancer patient with postoperative recurrence as well as abdominal cavity and pelvic metastasis, whose condition was relieved continuously after treatment with a new anti-PD-1 antibody, BGB-A317.

Icotinib plus gemcitabine for metastatic pancreatic cancer: a case report.

A large majority of patients diagnosed with pancreatic cancer have advanced metastatic disease with unresectable malignancies. Despite treatment advances, the survival benefit from chemotherapeutic regimens and targeted drugs is limited. Moreover, their application is limited in China because of high toxicity and cost. Recently, inhibitors of epidermal growth factor receptor activity have shown promise for the treatment of solid cancers when used in combination with standard therapy. However, these drugs have not been evaluated extensively for the treatment of pancreatic cancer. Here, we report the treatment of a 64-year-old male with metastatic pancreatic cancer using a novel regimen of icotinib with gemcitabine. Marked shrinkage of the mass was observed after two treatment cycles, and partial remission was achieved. The abdominal pain was relieved. The adverse effects were tolerable and treatment cost was acceptable. This is the first reported case for the treatment of advanced pancreatic cancer with icotinib plus gemcitabine and demonstrates a promising therapeutic alternative.

Oxaliplatin-based adjuvant chemotherapy without radiotherapy can improve the survival of locally-advanced rectal cancer.

OBJECTIVE: To assess the impact of oxaliplatin-containing adjuvant chemotherapy on the survival of patients with locally-advanced rectal cancer. METHODS: Data on patients with pathologically-confirmed T3/4 or N1/2 rectal cancer who accepted radical surgery at our center from January 2002 to June 2009 were reviewed retrospectively. The patients' 5-year overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were analyzed by comparing those who accepted radical surgery only (Group S) with those who accepted radical surgery and oxaliplatin-containing adjuvant chemotherapy (Group SO). RESULTS: A total of 236 patients were analyzed (Group S 135; Group SO 101). Group S patients were older and had a higher proportion with stage II disease and more perioperative complications than those in Group SO (P<0.05). The OS and DSS of patients with stage III disease under 50 years of age or with mucinous adenocarcinoma were higher in Group SO than Group S (P<0.05). In addition, the OS of patients with stage N2b disease was higher in Group SO than Group S (P = 0.016), and the OS of patients with stage N1a or N2b disease who received more than 8 weeks of oxaliplatin-containing chemotherapy was also higher in Group SO than Group S (P<0.05). Although the OS and DSS of patients with stage II disease in Group SO showed a tendency towards improvement, the differences between the groups were not statistically significant. CONCLUSION: Adjuvant oxaliplatin-containing chemotherapy can improve the survival of patients with locally-advanced low and middle rectal cancers in comparison with observation. Randomized, prospective trials are warranted to confirm this benefit of oxaliplatin for rectal cancer.

Prognostic and survival analysis of 837 Chinese colorectal cancer patients.

AIM: To develop a prognostic model to predict survival of patients with colorectal cancer (CRC). METHODS: Survival data of 837 CRC patients undergoing surgery between 1996 and 2006 were collected and analyzed by univariate analysis and Cox proportional hazard regression model to reveal the prognostic factors for CRC. All data were recorded using a standard data form and analyzed using SPSS version 18.0 (SPSS, Chicago, IL, United States). Survival curves were calculated by the Kaplan-Meier method. The log rank test was used to assess differences in survival. Univariate hazard ratios and significant and independent predictors of disease-specific survival and were identified by Cox proportional hazard analysis. The stepwise procedure was set to a threshold of 0.05. Statistical significance was defined as P < 0.05. RESULTS: The survival rate was 74% at 3 years and 68% at 5 years. The results of univariate analysis suggested age, preoperative obstruction, serum carcinoembryonic antigen level at diagnosis, status of resection, tumor size, histological grade, pathological type, lymphovascular invasion, invasion of adjacent organs, and tumor node metastasis (TNM) staging were positive prognostic factors (P < 0.05). Lymph node ratio (LNR) was also a strong prognostic factor in stage III CRC (P < 0.0001). We divided 341 stage III patients into three groups according to LNR values (LNR1, LNR ≤ 0.33, n = 211; LNR2, LNR 0.34-0.66, n = 76; and LNR3, LNR ≥ 0.67, n = 54). Univariate analysis showed a significant statistical difference in 3-year survival among these groups: LNR1, 73%; LNR2, 55%; and LNR3, 42% (P < 0.0001). The multivariate analysis results showed that histological grade, depth of bowel wall invasion, and number of metastatic lymph nodes were the most important prognostic factors for CRC if we did not consider the interaction of the TNM staging system (P < 0.05). When the TNM staging was taken into account, histological grade lost its statistical significance, while the specific TNM staging system showed a statistically significant difference (P < 0.0001). CONCLUSION: The overall survival of CRC patients has improved between 1996 and 2006. LNR is a powerful factor for estimating the survival of stage III CRC patients.

[Translational medicine of colorectal cancer].

Translational medicine is a systemic project because it is patient and clinical problems oriented, aiming at research results application, and involves multidisciplinary cooperation. Studies on molecular events in the precancerous stage, early stage and metastasis of colorectal cancer (CRC) are the CRC hot research topics currently. Investigations on the earliest molecular events can help to find out the markers which may improve the effect of CRC screening and predict CRC liver metastasis and prognosis. Based on the concept of micro environment, molecular targeted drugs to interfere with metastasis and invasion and new concepts of surgical resection margin and neoadjuvant therapy will gain recognition from clinicians.

SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK are prognosis-related in colorectal cancer.

AIM: To investigate the expression of markers that are correlated with the prognosis of colorectal cancer (CRC) patients. METHODS: One hundred and fifty-six CRC patients were followed up for more than 3 years after radical surgery. Immunohistochemical (IHC) analysis was performed to detect the expression of 14 pathway-related markers (p53, APC, p21ras, E-cadherin, endothelin-B receptor, Shp2, ADCY-2, SPARCL1, neuroligin1, hsp27, mmp-9, MAPK, MSH2 and rho) in specimens from these patients. Bioinformatics analysis involving a Support Vector Machine (SVM) was used to determine the best prognostic model from combinations of these markers. RESULTS: Seven markers (SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK) were significantly related to the prognosis and clinical pathological features of the CRC patients (P < 0.05). Prognostic models were established through SVM from combinations of these 7 markers and proved able to differentiate patients with dissimilar survival, especially in stage II/III patients. According to the best prognostic model, the p53/SPARCL1 model, patients having high p53 and low SPARCL1 expression had about 50% lower 3-year survival than others (P < 0.001). CONCLUSION: SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK are potential prognostic markers in CRC. A p53/SPARCL1 bioinformatics model may be used as a supplement to tumor-nodes-metastasis staging.

Clinical significance of K-ras and BRAF mutations in Chinese colorectal cancer patients.

AIM: To identify and assess mutations in the K-ras and BRAF genes in a cohort of Chinese patients with colorectal cancer (CRC) for their association with various clinicopathological parameters and prognosis. METHODS: Genomic DNA was isolated from frozen tissues. Pyrosequencing analysis was conducted to detect mutations in the K-ras (codons 12, 13, and 61) and BRAF genes (codon 600). Statistical analysis was carried out using SPSS-15.0 software. RESULTS: Among the 118 colorectal cancer patients, we detected 41 (34.7%) mutations in the K-ras gene. Mutation frequencies at codon 12 and codon 13 were 23.7% (28/118) and 10.2% (12/118), respectively. Only one patient harbored a point mutation at codon 61 (0.8%, 1/118). Gender was the only factor that showed an obvious relationship with K-ras gene mutation (female 44.7% vs male 28.2%, P = 0.037). Other clinicopathological features, such as age, location of the tumor, tumor differentiation, Tumor, Node and Metastases classification, and the Union for International Cancer Control staging, showed no positive relationship with K-ras gene mutations. No significant correlation was observed between the presence of K-ras mutations (codons 12, 13, and 61) and the survival of the patients. BRAF mutations were rare, and only two patients (1.7%) harbored a detectable mutation at codon 600. CONCLUSION: K-ras gene mutation is a common event in our 118 Chinese CRC patients, with an obvious relationship with gender. However, it seems not to be an independent prognostic factor in CRC patients. The BRAF gene is rarely mutated in Chinese CRC patients.

[Effects of osteopontin on gap junctional intercellular communication in colon cancer cell lines].

OBJECTIVE: Liver metastasis is a major cause of mortality in patients with colorectal cancer. However, the mechanisms underlying this process remain largely unknown. Osteopontin (OPN) is a secreted phosphorylated glycoprotein known to be involved in tumor migration and metastasis. Gap junction intercellular communication (GJIC) is a pathway of direct cell to cell communication. This study analyzed gap junctional intercellular communication (GJIC) changes in colon cancer SW-480 cell lines after osteopontin had been transfected in. METHODS: Transfect sense-osteopontin eukaryotic expression plasmids into SW-480 cell lines and detect the GJIC changes in two different cell lines by flurescence redistribution after photobleaching (FRAP). RESULTS: Compared with control, signal exchange is impaired and GJIC function is inhibited in SW-480-pcDNA3.1(+)-OPN cell lines. FRAP after 5 min in SW-480-pcDNA3.1(+)-OPN is 24.65% ± 4.08%,the control SW-480-pcDNA3.1(+) is 44.74% ± 6.23%,P < 0.001;FRAP after 10 min in SW-480-pcDNA3.1(+)-OPN is 25.98% ± 4.48%, while SW-480-pcDNA3.1 is up to 64.92% ± 5.39%,P < 0.001. CONCLUSION: OPN could inhibit GJIC function of colon cells to accelerate the metastatic process in colorectal cancer.

[K-ras gene mutation in colorectal cancer and its clinicopathologic significance].

OBJECTIVE: To establish a simple, rapid and economical method in detecting mutations of oncogene K-ras and to investigate its mutations in colorectal cancer tissues and its relationship with clinicopathologic characteristics of colorectal carcinoma. METHODS: Forty colorectal cancer tissues were tested for K-ras mutations at codon 12 and codon 13 using polymerase chain reaction (PCR) followed by direct sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) followed by sequence analysis. The other 113 colorectal cancer tissues were tested for K-ras mutations at codon 12 and codon 13 using PCR-RFLP followed by sequence analysis only. The mutation results were analyzed with the corresponding clinical pathological data. RESULTS: Among 40 colorectal cancer cases, none of K-ras mutations at codon 12 and codon 13 was detected by PCR followed by direct sequencing. However, K-ras mutations were found in 11 cases (11/40, 27.5%) by PCR-RFLP followed by sequence analysis, including 8 cases at codon 12 and 3 cases at codon 13 respectively. Among 153 colorectal cancer cases, point mutations were detected by PCR-RFLP followed by sequence analysis in 58 cases (37.9%). Point mutations at codon 12 were found in 46 cases and 12 cases at codon 13. Mutations with the highest frequency were G→A transitions (25/58, 43.1%) at codon 12. No significant correlation was observed between mutations of K-ras and gender, invasive depth, tumor differentiation, number of invaded lymph nodes, distant metastasis and clinical stage (P > 0.05). Mutation of oncogene K-ras at codon 12 and codon 13 was closely related with age and tumor location (P < 0.05). The incidence of K-ras mutation was significantly higher in younger patients and in patients with ascending colon cancer. CONCLUSIONS: PCR-RFLP followed by sequence analysis is a rapid, simple, sensitive and low-cost method. It is a suitable technology for detecting hot-spot mutations in the K-ras oncogene. Mutation of oncogene K-ras at codon 12 and codon 13 is a common molecular event in colorectal carcinogenesis, which might be related with age and tumor location.

Comparative features of colorectal and gastric cancers with microsatellite instability in Chinese patients.

OBJECTIVE: The purpose of this study was to determine the unique and universal features of microsatellite instability-high (MSI-H) colorectal cancer (CRC) and MSI-H gastric cancer (GC) in the Chinese population. METHODS: A new panel of mononucleotide MSI markers, BAT25, BAT26, NR21, NR24, and MONO-27, was used to define MSI status in 303 CRC and 288 GC subjects. Clinicopathological features of both types of MSI-H tumors were analyzed. Methylation analysis in the hMLH1 promoter region by methylation specific polymerase chain reaction (PCR) and mutation detection of hMSH2/hMLH1 genes by denaturing high-performance liquid chromatography (DHPLC) were carried out simultaneously. RESULTS: MSI-H CRCs and MSI-H GCs account for 11.9% and 8.0% of unselected sporadic CRCs and GCs, respectively. MSI-H CRCs are strongly characterized by early onset, right-side location, low differentiation, mucinous tumor, less infiltration, less lymphatic metastasis, and more often familial tumor. MSI-H GCs only showed site preference for the antrum and less lymphatic metastasis. Genetic and epigenetic analyses were positive in 6/36 MSI-H CRCs and 0/23 MSI-H GCs with pathological mutation in major mismatch repair genes, and in 7/36 MSI-H CRCs and 18/23 MSI-H GCs with methylated hMLH1 promoter (P<0.01), respectively. CONCLUSIONS: Although there are many differences in the genetic basis and clinicopathological features between MSI-H CRC and MSI-H GC, when compared with their microsatellite stable (MSS) counterparts, site preference and lymphatic metastasis are features common to both types of MSI-H tumors.

Effect of SNC19/ST14 gene overexpression on invasion of colorectal cancer cells.

AIM: To study the effect of SNC19/ST14 gene overexpression on invasion in vitro of colorectal cancer cells. METHODS: The adhesion of SNC19/ST14 gene-transfected cells to ECM was measured by MTT assay. The cell movement was evaluated by wound healing assay. Cell invasion and migration were determined by invasion assay in vitro. RESULTS: SNC19/ST14 gene overexpression could enhance invasion of colorectal cancer cells in vitro significantly and influence early cell adherence to ECM, but could not change cell movement significantly. CONCLUSION: SNC19/ST14 gene overexpression increases the local invasion of colorectal cancer cells in vitro.