Background
A cancer-protective role of renin-angiotensin system inhibitors (RASIs) has been demonstrated in epidemiological studies, including increased overall survival (OS), cancer-specific survival (CSS), and reduced risk of cancer, recurrence and metastasis. These studies investigated the use of traditional RASIs (b-blockers, angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs)). Protective effects have been observed for medications inhibiting regulatory pathways converging onto the RAS, such as metformin and cyclo-oxygenase inhibitors (COXIs). There is paucity of studies exploring the effect of RASIs in oral cavity squamous cell carcinoma (OCSCC).
Methods
All patients undergoing major head and neck surgery for OCSCC at Hutt Hospital between 1996 to 2021 were identified from our Head and Neck Database and included. Analysis was performed for those on RASIs (ACEI, ARB, b-blocker, metformin and/or COXI) and not on RASIs at time of surgery. Subgroup analysis was performed with number of RASIs taken.
Results
Of 355 patients included, 211 and 144 patients were in the non-RASI and RASI groups, respectively. No significant difference in recurrence-free survival (RFS) (116.1 months, 95% CI 99.4-132.7 vs 99.4 months, 95% CI 82.0-116.9, p=0.992), OS (106.5 months, 95% CI 88.4-124.5 vs 88.4 months, 95% CI 73.0-103.8, p=0.274), and CSS (182.7 months, 95% CI 160.6-204.8 vs 155.9 months, 95% CI 130.9-180.8, p=0.725), was observed between non-RASI and RASI groups respectively. A non-significant decrease in RFS was observed with increasing number of RASIs used.
Conclusion
RASI use in patients undergoing major head and neck surgery +/- radiotherapy for OCSCC is associated with no significant difference in OS, RFS or CSS compared to the non-RASI group, but this was limited by sample size. A decrease in RFS is observed with increasing number of RASIs taken, potentially reflecting confounding comorbidities of this cohort. Further studies are warranted to explore the role of RASI in OCSCC.