Background and purpose: In cases of simultaneous chemoradiotherapy (CRT), early recognition of toxic side effects is important, as drug discontinuation may prevent further injury. It appears favorable to undertake further steps to investigate whether patient subgroups behave differently depending on their toxicity profile.
Methods: We retrospectively analyzed 125 consecutive patients with non-metastasized carcinoma of the head and neck who were treated with CRT (cisplatin 40 mg/m2 weekly) in 2013/2014. Patients were planned to receive six cycles of cisplatin. Statistical analyses were performed using the chi2 test, t-test, Kaplan-Meier method, and the log-rank test, as appropriate.
Results: Eighty-six patients did not reach the intended sixth cycle (68.8%; 60.0% of whom were ≥60 years, p < 0.05). Acute kidney injury (glomerular filtration rate <60 mL/min/1.73m2) was the most common reason for drug discontinuation (26.7%; 82.6% of whom were ≥60 years; p < 0.01), followed by leukopenia <3/nL (23.3%; 75% of whom were <60 years; p < 0.01) and infection (11.6%). Patients who underwent ≥5 cycles were associated with prolonged overall survival and metastasis-free survival after CRT (p < 0.02; median follow-up 24 months), especially patients <60 years.
Conclusion: Acute kidney injury was the most common side effect in patients ≥60 years, whereas leukopenia characteristically occurred significantly more often in younger patients. Discontinuing cisplatin during CRT was associated with a worse outcome, especially in patients <60 years.
Keywords: Compliance; Cumulative dose; Head and neck neoplasms; Kidney injury; Leukopenia; Survival.