Gallstones, Body Mass Index, C-Reactive Protein, and Gallbladder Cancer: Mendelian Randomization Analysis of Chilean and European Genotype Data

BACKGROUND AND AIMS

Gallbladder cancer (GBC) is a neglected disease with substantial geographical variability: Chile shows the highest incidence worldwide, while GBC is relatively rare in Europe. Here, we investigate the causal effects of risk factors considered in current GBC prevention programs as well as C-reactive protein (CRP) level as a marker of chronic inflammation.

APPROACH AND RESULTS

We applied two-sample Mendelian randomization (MR) using publicly available data and our own data from a retrospective Chilean and a prospective European study. Causality was assessed by inverse variance weighted (IVW), MR-Egger regression, and weighted median estimates complemented with sensitivity analyses on potential heterogeneity and pleiotropy, two-step MR, and mediation analysis. We found evidence for a causal effect of gallstone disease on GBC risk in Chileans (P = 9 × 10-5 ) and Europeans (P = 9 × 10-5 ). A genetically elevated body mass index (BMI) increased GBC risk in Chileans (P = 0.03), while higher CRP concentrations increased GBC risk in Europeans (P = 4.1 × 10-6 ). European results suggest causal effects of BMI on gallstone disease (P = 0.008); public Chilean data were not, however, available to enable assessment of the mediation effects among causal GBC risk factors.

CONCLUSIONS

Two risk factors considered in the current Chilean program for GBC prevention are causally linked to GBC risk: gallstones and BMI. For Europeans, BMI showed a causal effect on gallstone risk, which was itself causally linked to GBC risk.

Total neoadjuvant chemotherapy with FLOT scheme in resectable adenocarcinoma of the gastro-oesophageal junction or gastric adenocarcinoma: impact on pathological complete response and safety

Background

Gastric cancer is the fifth cause of cancer incidence worldwide. Multidisciplinary approaches that improve the survival are needed. Perioperative chemotherapies show improvement in pathological complete remission (pCR) and overall survival (OS), but less than 50% of the patients completed the chemotherapeutic regimen. The recent 5-fluorouracil, leucovorin, oxaliplatin, docetaxel-4 (FLOT4) study shows OS 50 months and pCR 16.6%, but only 46% of the patients completed pre- and postoperative treatment. This case series report evaluated pCR and safety in patients that received complete preoperative chemotherapeutic with FLOT.

Methods

Patients received eight cycles FLOT regimen before surgery. Each cycle comprised 50 mg/m² docetaxel intravenous (iv) on day 1, 85 mg/m² oxaliplatin iv on day 1, 200 mg/m² leucovorin iv on day 1 and 2,600 mg/m² 5-fluorouracil iv in a 24-hour infusion on day 1, every 2 weeks.

Results

Fifty-nine patients were evaluated, 58 patients received preoperative cycles. Thirty-one patients received all eight cycles of preoperative therapy. 65.5% patients presented any major adverse event. Thirty-nine patients underwent surgery. Thirty-three biopsy reports were obtained. Six patients (18.2%) presented pCR, 13 patients (39.4%) had no lymph node involvement. OS was 21.32 months. Patients with histology of signet ring carcinoma cells had a shorter survival than other histologies.

Conclusion

Total neoadjuvant with FLOT chemotherapy presents an adequate safety profile, a similar pathologic regression rate, and a slightly higher rate of completing treatment to report in perioperative FLOT regimen studies. A prospective clinical study with suitable diagnostic, staging tools and an adequate follow-up may prove total neoadjuvant chemotherapy’s efficacy.

ABCB1/4 gallbladder cancer risk variants identified in India also show strong effects in Chileans

BACKGROUND

The first large-scale genome-wide association study of gallbladder cancer (GBC) recently identified and validated three susceptibility variants in the ABCB1 and ABCB4 genes for individuals of Indian descent. We investigated whether these variants were also associated with GBC risk in Chileans, who show the highest incidence of GBC worldwide, and in Europeans with a low GBC incidence.

METHODS

This population-based study analysed genotype data from retrospective Chilean case-control (255 cases, 2042 controls) and prospective European cohort (108 cases, 181 controls) samples consistently with the original publication.

RESULTS

Our results confirmed the reported associations for Chileans with similar risk effects. Particularly strong associations (per-allele odds ratios close to 2) were observed for Chileans with high Native American (=Mapuche) ancestry. No associations were noticed for Europeans, but the statistical power was low.

CONCLUSION

Taking full advantage of genetic and ethnic differences in GBC risk may improve the efficiency of current prevention programs.

Viable Pregnancy in a patient with metastatic melanoma treated with double checkpoint immunotherapy

Metastatic cancers during pregnancy have historically been associated with dismal outcomes, with greater rates of tumor progression in part because of diminished treatment alternatives. Immunotherapy with T-cell checkpoint inhibitors has significantly impacted the survival of several metastatic tumors. However, given their mechanism of action, immune-related adverse events can occur, especially with combined immunotherapy treatments. During pregnancy, checkpoint pathways have a major role, providing immune tolerance to the fetal allograft. Furthermore, evidence suggests that inhibition of this pathway may be associated with an increased risk of miscarriage. We describe, to our knowledge, the first case reported in the literature of a patient 7 weeks pregnant, diagnosed with metastatic melanoma and treated with nivolumab plus ipilimumab. We also present the associated immune-related side effects and their treatment, as well as the oncologic results that lead to favorable pregnancy outcome.