A national evaluation of adjuvant chemotherapy in pT4N0M0 colon cancer from the National Cancer Database

Associations of Social Vulnerability and Race-Ethnicity With Gastrointestinal Cancers in the United States

BACKGROUND

National social determinant of health (SDoH) studies on gastrointestinal cancers (GIC) have observed single GIC-types for surgery but not across all GIC-types, non-surgical treatments outcomes, or mortality. The Social Vulnerability Index (SVI), a validated large-data SDoH-tool, quantifiably characterizes the interrelatedness of SDoH-impact through dynamic, region-contextualized measures.

METHODS

This retrospective cohort study assessed GIC patients (20+ years) between 2013 and 2017 from the Surveillance, Epidemiology, and End Results (SEER) database for total and subcomponent social vulnerability associations across 15 SDoH-variables encompassing themes of socioeconomic status, minority-language status, household composition, and housing-transportation measured by the Social Vulnerability Index (SVI). These are measured and contextualized from all US counties. Univariate logistic and linear regressions of these vulnerability associations with treatment receipt (chemotherapy, radiation, primary surgery) and survival were performed for the entire cohort and across race/ethnicity strata.

RESULTS

With increasing overall social vulnerability, 287,248 patients (162,387 [56.5%] male; 185,250 [64.6%] white) demonstrated decreased receipt of chemotherapy (lowest, pancreas-OR, 0.90; 95% CI, 0.88-0.93), radiotherapy (hepatic-OR, 0.87; 95% CI, 0.85-0.89) and surgery (esophagus-OR, 0.90; 95% CI, 0.87-0.92) for 13/14, 10/14, and 8/14 GIC-types, respectively. Survival period decreases upwards of 21.3% (biliary tract: 6.9-5.4 months) were observed across 7/14 GICs. Treatment receipt and survival decreases were exacerbated for non-White patients for 9/14 GICs. Socioeconomic status, minority-language, household composition, and housing-transportation vulnerabilities differentially contributed to these trends.

DISCUSSION

Social vulnerability was associated with worse prognostic and treatment disparities, with certain SDoH-types differentially contributing to these detrimental trends per GIC-type while associations were exacerbated among non-White race/ethnic patients. These real-world contexts present actionable targets for further initiatives to combat GIC disparities.

Staging Paradox and recurrence pattern among stage IIB, IIC, and IIIA Colon cancers: a retrospective cohort study

PURPOSE

The survival rates of patients with stage IIB and IIC colon cancer are paradoxically inferior to that of patients with stage IIIA colon cancer. This study aimed to examine the oncological outcomes and investigate the factors that could affect the staging paradox among stage IIB, IIC, and IIIA colon cancers based on a 9-year cancer database.

METHODS

Patients with stage IIB (pT4aN0M0), IIC (pT4bN0M0), or IIIA (pT1-2N1M0) colon cancer were retrospectively selected from a prospectively maintained medical database from January 2011 to December 2019. Factors that might influence the staging paradox, including radicality, harvested lymph nodes, and chemotherapy administration, were examined.

RESULTS

A total of 282 patients (stage IIB, n = 59; stage IIC, n = 46; and stage IIIA, n = 177) were enrolled. Patients with stage IIB/C cancer demonstrated higher carcinoembryonic antigen levels, larger tumor size, more frequent tumor obstruction, and higher locoregional recurrence than those with stage IIIA cancer. With respect to 10-year locoregional recurrence-free survival and cancer-specific survival, patients with stage IIB and IIC cancers had significantly lower survival rates than did those with stage IIIA cancer (73.7% vs. 66.3% vs. 91.2%, P = 0.0003; 5.4% vs. 10.9% vs. 11.2%, P = 0.0023). The staging paradox persisted in patients who underwent R0 resection, had harvested lymph nodes ≥ 12, and received chemotherapy, as confirmed by multivariate regression analysis.

CONCLUSIONS

Based on the inferior oncological outcomes and higher locoregional recurrence rate, this study highlighted the need for intensified cytotoxic chemotherapy specific to this recurrence pattern for patients with stage IIB/C colon cancer.

Methyltransferase DNMT3B promotes colorectal cancer cell proliferation by inhibiting PLCG2

Aberrant DNA methylation patterns in the promoter region of PLCG2 are associated with dysregulated signaling pathways and cellular functions. Its role in colorectal cancer cells is still unknown. In this study, qRT-PCR is used to measure DNMT3B expression in colorectal cancer. Western blot analysis and immunohistochemistry are used to analyze DNMT3B and PLCG2 protein levels in colorectal tissues and cell lines. Cell Counting Kit-8 (CCK-8) and colony formation assays are used to assess the proliferation of colorectal cancer cells. Methylation-specific PCR (MSP) and bisulfite-sequencing PCR (BSP) are used to measure DNA methylation level. Our results show that DNMT3B is overexpressed in colorectal cells in the TCGA datasets according to Kaplan-Meier plots. DNMT3B is significantly overexpressed in tumor tissues compared to that in adjacent nontumor tissues. Western blot analysis results demonstrate high expression of DNMT3B in tumor tissues. Compared to normal colonic epithelial cells, colorectal cancer cell lines exhibit elevated level of PLCG2 methylation. Overexpression of PLCG2 effectively prevents the growth of colorectal cancer xenograft tumors in vivo. PLCG2 is identified as a key downstream regulatory protein of DNMT3B in colorectal cancer. DNMT3B inhibits PLCG2 transcription through methylation of the PLCG2 promoter region. DNMT3B controls colorectal cancer cell proliferation through PLCG2, which is useful for developing therapeutic approaches that target PLCG2 expression for the treatment of colorectal cancer.

The Causes Behind the Survival Paradox in Non-Metastatic Colorectal Cancer Patients and its Impact on the Treatment Regimen: A Retrospective Cohort Study

BACKGROUND

The survival paradox (ie, the prognosis of the population at earlier tumor stages is worse than that of the population at later stages) has been observed in colorectal cancer based on the American Joint Committee on Cancer Tumor-Nodes-Metastases staging system. We aimed to clarify the reason for the survival paradox and its impact on patient treatment.

METHODS

We conducted a retrospective study analyzing eligible patients with colorectal cancer from the Surveillance, Epidemiology, and End Results database and Zhejiang Cancer Hospital between 2010 and 2019. Adjusting for confounders using propensity score matching allowed confirmation of the effect of staging on the survival paradox.

RESULTS

Based on the Surveillance, Epidemiology, and End Results database, the subgroups with survival paradox might be IIB/C versus IIIA, IIA versus IIIA, and T4N0 (IIB/C) versus T3N1 (IIIB). After propensity score matching, stage IIB/C still had a worse prognosis than stage IIIA (5-year overall survival: 69.3% vs 78.5%, P < .001). Interestingly, the proportion of stage IIIA people receiving chemotherapy was higher than that of stage IIB/C (P < .001), and logistic regression models showed that staging was the reason for deciding whether a patient receives chemotherapy or not. These phenomena between stage IIB/C and IIIA were verified in the local database.

CONCLUSION

These results suggested that the survival paradox was mainly due to underestimation of stage T4 weights or overestimation of stage N1 weights, and the low proportion of chemotherapy in patients with T4N0M0 colorectal cancer (proven to be more malignant than stage IIIA) might be related to the assignment to earlier stages, resulting in a lack of attention and poor compliance to chemotherapy in these patients.

Adjuvant chemotherapy in stage 1 colon cancer: Patient characteristics and survival analysis from the national cancer database

BACKGROUND

A subset of patients in ACS-NCDB with stage-1 colon cancer received adjuvant chemotherapy (AC), in contrast to national guidelines. This study aimed to define this population and evaluate associations between AC and survival.

METHODS

Patients with T1-2N0 colon cancer from 2004 to 2016 were separated into AC and non-AC groups. Adverse pathological features (APF) included T2, poor differentiation, lymphovascular invasion, positive margin, and inadequate lymph nodes (<12). Cox proportional hazard models were used to estimate prognostic factors for overall survival (OS).

RESULTS

A total of 1745 of 139,857 patients (1.2 %) received AC. Receiving AC was associated with male sex (p = 0.02), uninsured (p < 0.01), low income (p = 0.02), or having ≥2 APFs (p < 0.001). In the total cohort, AC was associated with increased mortality (HR 1.14 [1.04-1.24] P < 0.01). On subset analysis, AC was associated with improved OS for patients with ≥2 APFs (log-rank P=<0.001), and decreased mortality when adjusted for covariates (HR 0.81 [0.69-0.95] P=<0.01). The most significant predictor of mortality was old age (HR 3.78 [3.67, 3.89] p ≤ 0.01), followed by higher Charlson Comorbidity Index (HR 1.73 [1.69, 1.76] (p ≤ 0.01), and higher APF score (HR 1.46 [1.42, 15.2] p ≤ 0.01).

CONCLUSION

AC was associated with decreased survival in the total cohort of stage 1 colon cancer patients, but was associated with improved survival for patients with multiple APFs.

Squalene epoxidase promotes the chemoresistance of colorectal cancer via (S)-2,3-epoxysqualene-activated NF-κB

BACKGROUND

While de novo cholesterol biosynthesis plays a crucial role in chemotherapy resistance of colorectal cancer (CRC), the underlying molecular mechanism remains poorly understood.

METHODS

We conducted cell proliferation assays on CRC cells with or without depletion of squalene epoxidase (SQLE), with or without 5-fluorouracil (5-FU) treatment. Additionally, a xenograft mouse model was utilized to explore the impact of SQLE on the chemosensitivity of CRC to 5-FU. RNA-sequencing analysis and immunoblotting analysis were performed to clarify the mechanism. We further explore the effect of SQLE depletion on the ubiquitin of NF-κB inhibitor alpha (IκBα) and (S)-2,3-epoxysqualene on the binding of IκBα to beta-transducin repeat containing E3 ubiquitin protein ligase (BTRC) by using immunoprecipitation assay. In addition, a cohort of 272 CRC patients were selected for our clinical analyses.

RESULTS

Mechanistically, (S)-2,3-epoxysqualene promotes IκBα degradation and subsequent NF-κB activation by enhancing the interaction between BTRC and IκBα. Activated NF-κB upregulates the expression of baculoviral IAP repeat containing 3 (BIRC3), sustains tumor cell survival after 5-FU treatment and promotes 5-FU resistance of CRC in vivo. Notably, the treatment of terbinafine, an inhibitor of SQLE commonly used as antifungal drug in clinic, enhances the sensitivity of CRC to 5-FU in vivo. Additionally, the expression of SQLE is associated with the prognosis of human CRC patients with 5-FU-based chemotherapy.

CONCLUSIONS

Thus, our finding not only demonstrates a new role of SQLE in chemoresistance of CRC, but also reveals a novel mechanism of (S)-2,3-epoxysqualene-dependent NF-κB activation, implicating the combined potential of terbinafine for 5-FU-based CRC treatment.