Newly recognized extratumoral features of colorectal cancer challenge the current tumor-node-metastasis staging system

Prognostic Value of Tumor Deposits in Patients with Colorectal Cancer

Tumor nodules or tumor deposits (TDs) are a histopathological prognostic factor that are associated with a negative evolutionary course in patients with colorectal cancer (CRC). There are still controversial aspects of TDs, including how they should be integrated into the TNM classification system. The objective of this study was to analyze the predictive value of TDs for cancer-related survival (CRS) and time-to-recurrence survival (TTR) and to evaluate the prognostic value of TDs in patients whose tumors also presented lymph node metastasis (LNM). In this retrospective observational study, all patients treated for CRC between January 2010 and December 2020 at the same hospital were included. CRS and TTR were classified by tumor stage. The results were compared between patients whose tumors had TDs and patients whose tumors did not. A total of 1426 patients met the criteria for inclusion in the analysis. TDs were detected in 178 patients (12.5%): 60 had tumors without LNM, and 118 had LNM. Patients with TD tumors had a lower CRS at 60 months after diagnosis (42% vs. 82%; p < 0.001) and a shorter TTR (34% vs. 79%; p < 0.001). Cox multiple regression analysis revealed that the presence of TD was associated with an increased risk of death from CRC (HR: 1.820; 95% CI: 1.327-2.496) and an increased risk of recurrence (HR: 2.315; 95% CI: 1.743-3.073). In each N stage category, the CRS was significantly lower in the subgroup with TD+: in patients with N1a tumors, the CRS was 44% when TD+ vs. 70% when TD- (p = 0.019); in the N1b group it was 36% vs. 66% (p < 0.001); in the N2a group it was 34% vs. 58% (p = 0.012); and in N2b tumors it was 23% vs. 53% (p = 0.031). The present study shows that the information on the presence of TDs is complementary to that provided by LNM and allows the identification of subgroups of patients in each N stage determined by two metrics, CRS and TTR. TDs should be included in the definition of TNM system categories in patients who simultaneously present with LNM.

The tumor-stroma ratio and the immune microenvironment improve the prognostic prediction of pancreatic ductal adenocarcinoma

Tumor-infiltrating immune cells and fibroblasts are significant components of the tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC), and they participate in tumor progression as closely as tumor cells. However, the relationship between the features of the TME and patient outcomes and the interactions among TME components are still unclear. In this study, we evaluated the PDAC TME in terms of the quantity and location of cluster of differentiation (CD)4⁺ T cells, CD8⁺ T cells, macrophages, stromal maturity, and tumor-stroma ratio (TSR), as evaluated by immunohistochemical staining of serial whole-tissue sections from 116 patients with PDAC. The density of T cells and macrophages (mainly activated macrophages) was significantly higher at the invasive margins (IMs) than at the tumor center (TC). CD4⁺ T cells were significantly association with all the other tumor-associated immune cells (TAIs) including CD8, CD68 and CD206 positive cells. Tumors of the non-mature (intermediate and immature) stroma type harbored significantly more CD8⁺ T cells at the IMs and more CD68⁺ macrophages at the IMs and the TC. The density of CD4⁺, CD8⁺, and CD206⁺ cells at the TC; CD206⁺ cells at the IMs; and tumor-node-metastasis (TNM) staging were independent risk factors for patient outcomes, and the c-index of the risk nomogram for predicting the survival probability based on the TME features and TNM staging was 0.772 (95% confidence interval: 0.713-0.832). PDAC harbored a significantly immunosuppressive TME, of which the IMs were the hot zones for TAIs, while cells at the TC were more predictive of prognosis. Our results indicated that the model based on the features of the TME and TNM staging could predict patient outcomes.

Risk factors predict microscopic extranodal tumor deposits in advanced stage III colon cancer patients

BACKGROUND

Colorectal cancer is a frequent cause of cancer-related mortality in patients with lymph node or distant metastases. Pericolonic tumor deposits (TDs) are considered prognostically distinct from lymph node metastases.

AIM

To investigate risk factors for extranodal TDs in stage III colon cancer.

METHODS

This was a retrospective cohort study. We selected 155 individuals diagnosed with stage III colon cancer from the database of the Cancer Registry of the Tri-Service General Hospital. The patients were allocated into the groups with/without N1c. Multivariate Cox regression analysis and Kaplan-Meier method were done. The primary outcomes investigate the association between the covariates and extranodal TDs, and prognostic significance of the covariates regarding the survival.

RESULTS

There were 136 individuals in the non-N1c group and 19 individuals in the N1c group. Patients with lymphovascular invasion (LVI) had a higher risk of TDs. Overall survival rates of patients with and without LVI were 6.64 years and 8.61 years, respectively (P = 0.027). The N1c patients without LVI had higher overall survival than those who with LVI (7.73 years vs 4.42 years, P = 0.010).

CONCLUSION

Patients having stage III colon cancer with LVI have a higher probability of having TDs than those with stage III colon cancer without LVI. Stage III colon cancer patients with TDs and LVI could have poor prognosis and outcome.

Role of one-step nucleic acid amplification in colorectal cancer lymph node metastases detection

Current histopathological staging procedures in colorectal cancer (CRC) depend on midline division of the lymph nodes (LNs) with one section of hematoxylin and eosin staining. Cancer cells outside this transection line may be missed, which could lead to understaging of Union for International Cancer Control Stage II high-risk patients. The one-step nucleic acid amplification (OSNA) assay has emerged as a rapid molecular diagnostic tool for LN metastases detection. It is a molecular technique that can analyze the entire LN tissue using a reverse-transcriptase loop-mediated isothermal amplification reaction to detect tumor-specific cytokeratin 19 mRNA. Our findings suggest that the OSNA assay has a high diagnostic accuracy in detecting metastatic LNs in CRC and a high negative predictive value. OSNA is a standardized, observer-independent technique, which may lead to more accurate staging. It has been suggested that in stage II CRC, the upstaging can reach 25% and these patients can access postoperative adjuvant chemotherapy. Moreover, intraoperative OSNA sentinel node evaluation may allow early CRC to be treated with organ-preserving surgery, while in more advanced-stage disease, a tailored lymphadenectomy can be performed considering the presence of aberrant lymphatic drainage and skip metastases.

MicroRNA-196b-5p promotes malignant progression of colorectal cancer by targeting ING5

Background

miR-196b-5p expression is deregulated in many malignant tumors. Although miR-196b-5p has been implicated in the malignant transformation of colorectal cancer, its role in this specific type of cancer has not been fully explored. Thus, the present study was aimed to examine the cellular function of miR-196b-5p and its role in malignant biological behavior in colorectal cancer.

Methods

miR-196b-5p expression was measured in colorectal cancer tissues and cell lines using quantitative real-time PCR. Cell counting kit-8 (CCK-8) assay and Transwell assay were used to detect proliferation, migration, and invasion in cell lines, whereas flow cytometry was applied to study apoptosis. Western blot analysis was performed to measure the protein levels. Dual luciferase reporter assay was used to investigate the interaction between miR-196b-5p and ING5. Tumor formation was evaluated in mice.

Results

MiR-196b-5p was abundantly expressed in colorectal cancer tissues and cell lines, whereas ING5 was expressed at low levels. MiR-196b-5p was successfully overexpressed or knocked down in colorectal cancer cells. We found that miR-196b-5p overexpression significantly accelerated the proliferation, cell cycle, migration and invasion, while inhibited cell apoptosis in colorectal cancer cells. However, miR-196b-5p inhibitor showed the opposite effects. Moreover, ING5 overexpression or knockdown was successfully performed in colorectal cancer cells. ING5 overexpression suppressed proliferation, migration, invasion, the phosphorylation of PI3K, Akt as well as MEK, and promoted cell apoptosis, which could be reversed by ING5 knockdown. Additionally, ING5 was identified as a target of miR-196b-5p through bioinformatics analysis and a luciferase activity assay. Furthermore, ING5 knockdown could attenuate the decrease in proliferation, migration, invasion, and the protein levels of p-PI3K, p-Akt, and p-MEK, which were induced by miRNA-196b-5p inhibitor. Besides, miR-196b-5p knockdown inhibited tumor growth, whereas ING5 knockdown elevated it in vivo.

Conclusions

In conclusion, miR-196b-5p promotes cell proliferation, migration, invasion, and inhibits apoptosis in colorectal cancer by targeting ING5.

Comparison of Oncologic Outcomes in Laparoscopic versus Open Surgery for Non-Metastatic Colorectal Cancer: Personal Experience in a Single Institution

The oncologic merits of the laparoscopic technique for colorectal cancer surgery remain debatable. Eligible patients with non-metastatic colorectal cancer who were scheduled for an elective resection by one surgeon in a medical institution were randomized to either laparoscopic or open surgery. During this period, a total of 188 patients received laparoscopic surgery and the other 163 patients received the open approach. The primary endpoint was cancer-free five-year survival after operative treatment, and the secondary endpoint was the tumor recurrence incidence. Besides, surgical complications were also compared. There was no statistically significant difference between open and laparoscopic groups regarding the average number of lymph nodes dissected, ileus, anastomosis leakage, overall mortality rate, cancer recurrence rate, or cancer-free five-year survival. Even though performing a laparoscopic approach used a significantly longer operation time, this technique was more effective for colorectal cancer treatment in terms of shorter hospital stay and less blood loss. Meanwhile, fewer patients receiving the laparoscopic approach developed postoperative urinary tract infection, wound infection, or pneumonia, which reached statistical significance. For non-metastatic colorectal cancer patients, laparoscopic surgery resulted in better short-term outcomes, whether in several surgical complications and intra-operative blood loss. Though there was no significant statistical difference in terms of cancer-free five-year survival and tumor recurrence, it is strongly recommended that patients undergo laparoscopic surgery if not contraindicated.

Tumor budding for predicting prognosis of resected rectum cancer after neoadjuvant treatment

BACKGROUND

Rectum cancer is a type of colorectal cancer. Its etiology and etiopathogenesis are similar to other colon diseases. We aimed to evaluate the tumor budding for predicting prognosis of resected rectum cancer patients.

METHODS

We retrospectively collected the data of 75 operated rectum adenocarcinoma patients who were treated neoadjuvant chemoradiotherapy between 2013 and 2018 in Umraniye Research and Training Hospital and Acıbadem University Medical Oncology Outpatient Clinic. Tumor budding was investigated as a prognostic factor for disease-free survival.

RESULTS

This study included 75 rectum cancer patients and 51 were male (68%). Median age was 56 (range 19 to 77 years). There were 29 (39%) and 46 (61%) patients in tumor budding low-intermediate and high groups respectively. In multivariate analysis, tumor budding was found to be an independent prognostic factor for disease-free survival (p = 0.00).

CONCLUSIONS

According to our study, having high tumor budding suggests a high likelihood of relapse. Therefore, we might need additional follow-up protocol in these patients.