Weekly versus Three-Weekly Cisplatin-based Concurrent Chemoradiotherapy as definitive treatment in Head and Neck Cancer- Where do we stand?

PURPOSE: To compare toxicity, compliance, and early response of weekly and 3-weekly cisplatin administration concurrent with radiotherapy as definitive treatment in locally advanced squamous cell carcinoma head and neck. MATERIALS AND METHODS: Patients with histologically proven stage III - IV B head and neck carcinoma presenting from June 2013 to March 2014 were randomly assigned to weekly (35 mg/m2, 6 cycles; arm A) and 3 weekly (100 mg/m2, 3 cycles; arm B) cisplatin with concurrent radiotherapy. RESULTS: 60 patients were randomly assigned to treatment, 30 in each arm. Median follow-up was 8 months (range 4-13). There was no significant difference in grade 3 mucositis between the two arms (75.9% vs 70%, p = 0.20). Grade 3 neutropenia was more frequent in arm B (55.2% vs 26.7%, p = 0.01). Hypomagnesemia was the commonest electrolyte imbalance and it was significantly higher in arm B (60% vs 20%, p = 0.001). Completion rate of scheduled chemotherapy cycles was higher for patients receiving weekly regimen. Response at 3 months was similar for all the patients {Complete Response (66.7% vs 62.1%), p = 0.200}. Our data suggested that there is a reduced need of hospitalization and supportive care measures for patients receiving weekly cisplatin with RT (p = 0.05). CONCLUSIONS: Weekly cisplatin 35 mg/m2 chemotherapy concurrent with radiotherapy is equally effective and less toxic in terms of neutropenia, hypomagnesemia and need for supportive measures than the conventional 3 weekly cisplatin 100 mg/m2 regimen.

Interspecies scaling of a camptothecin analogue: human predictions for intravenous topotecan using animal data.

As a class, camptothecin analogues via market entry of topotecan and irinotecan, have shown promise for the treatment of various solid tumours. Topotecan, in particular, was chosen as the substrate for allometric scaling and prediction of human parameter values for both total clearance (CL) and volume of distribution (V(ss)). The availability of published data in mouse, rat, dog, and monkey paved the way for interspecies scaling via allometry. Although it appeared that at a minimum mouse, rat, and dog would reasonably fit in a three-species allometry scale-up, the inclusion of monkey data enabled a better prediction of the human parameter values for total topotecan-e.g., CL: allometric equation: 1.5234W(0.7865); predicted value = 43.04 l h(-1): observed CL = 24-53 l h(-1); V(ss): allometric equation: 1.1939W(1.0208); predicted value = 91.29 litres: observed V(ss) = 66-146 litres. The proximity of the allometric exponent values of CL (0.7885) and V(ss) (1.0208) to the suggested values of 0.75 and 1.00 was not only encouraging, but also confirmed the applicability of interspecies scaling approach for topotecan. The data suggest that allometric scaling approaches with suitable correction factors could potentially be used to predict the human pharmacokinetics of novel CPT analogues prospectively.