Antibiotics may prevent chemoresistance in metastatic pancreatic cancer

According to a study published in , antibiotics may prevent bacteria-mediated chemotherapy resistance in patients with metastatic pancreatic cancer. JAMA network open.

The study showed that gemcitabine-treated patients had improved overall survival (OS) and cancer-specific survival (CSS) when receiving antibiotics.

This retrospective study included 3850 patients with unresectable metastatic pancreatic ductal adenocarcinoma. They were treated with gemcitabine (81.8%) or fluorouracil (18.2%) as first-line therapy from 2007 to 2017.

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Researchers matched 1672 patients who received antibiotics with 1672 who did not. Antibiotics were administered months before or after starting chemotherapy. The patient received either one injection of antibiotics or oral antibiotics for at least 5 days.

Antibiotics significantly improved OS and CSS in both the overall matched cohort and gemcitabine-treated patients. Patients treated with fluorouracil, on the other hand, did not derive any benefit from antibiotics.

Across the cohort, median OS was 7.3 months for patients who received antibiotics and 6.8 months for those who did not (hazard ratio [HR]0.93; 95% CI, 0.86–0.99; P. =.03). Additionally, patients receiving antibiotics had an 11% improvement in CSS (HR, 0.89; 95% CI, 0.82-0.96; P. =.004).

In the gemcitabine-treated arm, median OS was 7.1 months for patients who received antibiotics and 6.5 months for those who did not (HR, 0.89; 95% CI, 0.83-0.96;

P. =.003). Patients receiving this group of antibiotics had a 16% improvement in CSS (HR, 0.84; 95% CI, 0.77-0.92; P. <.001).

In the fluorouracil-treated arm, median OS was 8.6 months for patients who received antibiotics and 9.2 months for those who did not (HR, 1.08; 95% CI, 0.90-1.29; P. =.41). There was no significant difference in CSS between patients who received antibiotics and those who did not (HR, 1.12; 95% CI, 0.90-1.36; P. =.29).

The researchers also evaluated the role of antibiotic class and route of administration. They found that non-penicillin beta-lactams were associated with an 11% reduction in mortality risk (HR, 0.89; 95% CI, 0.81-0.97; P. =.01) when compared to all other antibiotic classes. In addition, there was a trend towards a lower risk of death with injectable antibiotics compared with oral antibiotics (HR, 0.91; 95% CI, 0.82-1.00; P. =.05).

These results “suggest that antibiotics may modulate bacterial-mediated gemcitabine resistance and improve PDAC. [pancreatic ductal adenocarcinoma] results,” the researchers concluded.

Disclosure: Some study authors have declared affiliations with biotechnology, pharmaceutical, and/or device companies. See the original reference for the full list of disclosures.

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