Radio-chemotherapy is a common treatment for locally advanced squamous cell head-and-neck cancers (LA-SCCHN). Cisplatin (100 mg/m(2)) every 3 weeks is very common but associated with considerable toxicity. Therefore, cisplatin programs with lower daily doses were introduced. There is a lack of studies comparing lower-dose programs. In this study, 85 patients receiving radio-chemotherapy with 20 mg/m(2) cisplatin on 5 days every 4 weeks (group A) were retrospectively compared to 85 patients receiving radio-chemotherapy with 30-40 mg/m(2) cisplatin weekly (group B). Groups were matched for nine factors including age, gender, performance score, tumor site, T-/N-category, surgery, hemoglobin before radio-chemotherapy, and radiation technique. One- and 3-year loco-regional control rates were 83 and 69 % in group A versus 74 and 63 % in group B (p = 0.12). One- and 3-year survival rates were 93 % and 73 % in group A versus 91 and 49 % in group B (p = 0.011). On multivariate analysis, survival was significantly better for group A (HR 1.17; p = 0.002). In groups A and B, 12 and 28 % of patients, respectively, did not receive a cumulative cisplatin dose ≥180 mg/m(2) (p = 0.016). Toxicity rates were not significantly different. On subgroup analyses, group A patients had better loco-regional control (p = 0.040) and survival (p = 0.005) than group B patients after definitive radio-chemotherapy. In patients receiving adjuvant radio-chemotherapy, outcomes were not significantly different. Thus, 20 mg/m(2) cisplatin on 5 days every 4 weeks resulted in better loco-regional control and survival in patients receiving definitive radio-chemotherapy and may be preferable for these patients. Confirmation of these results in a randomized trial is warranted.
