154P - The impact of proton pump inhibitors in the prognosis of patients with non-metastatic nasopharyngeal carcinoma

Background

The gut microbiome may be potentially disrupted by commonly used drugs, such as proton pump inhibitors (PPI), with possible impact in the immunologic response to cancer therapies. In this work we aimed to assess the impact of taking PPI in the outcome of patients with non-metastatic nasopharyngeal carcinoma (NPHC), treated at an oncological center.

Methods

We conducted a retrospective and observational study that included newly diagnosed subjects with non-metastatic NPHC, diagnosed between October 2012 and November 2019, and treated in our centre with a curative strategy that included radiotherapy (RT). Demographic and clinical variables were evaluated and patients were categorized as taking PPI at baseline/initiated PPI before the start of RT or not. Oncologic outcomes evaluated included disease-free survival (DFS) and overall survival (OS). OS and DFS were evaluated by the Kaplan-Meier method and prognostic features were assessed by univariate and multivariate Cox regression.

Results

We included 83 patients, of which 56 (67.5%) were males and 60 (72.3%) had at least 45 years-old. Fifty-nine (71.1%) had stage ≥ III and 35 (42.2%) were treated only with chemoradiotherapy, while 14 (16.9%) also received neoadjuvant chemotherapy and 26 (31.3%) adjuvant chemotherapy. Twenty-three (27.7%) were taking PPI at baseline or initiated it before the start of RT. On the multivariate analysis age ≥ 45 years [HR 6.07 (95% CI: 1.36-27.06), p=0.018] and taking PPI [HR 2.66 (95% CI: 1.07-6.60), p=0.035] were associated with worst DFS. Concerning OS, age ≥ 45 years [HR 9.90 (95% CI: 1.24-79.11), p=0.031], stage ≥ III [HR 5.17 (95% CI: 1.11-23.98), p=0.036] and taking PPI [HR 4.14 (95% CI: 1.47-11.68), p=0.007] were associated with a worst outcome.

Conclusions

In our sample, taking PPI at baseline or initiate it before the start of RT was associated with worst prognosis in non-metastatic NPHC patients. Further studies are still needed to assess the impact of drugs with potential to disrupt the gut microbiome on the outcome of non-metastatic NPHC patients.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.