Correlation between different carboplatin dosing patterns and its toxicity analysis in patients with advanced lung cancers: A retrospective study

OBJECTIVE: To evaluate the current NCI-CTEP recommendation and the clinical use of Calvert Formula-derived carboplatin dosing pattern in the treatment of advanced lung cancer patients and assess carboplatin-related toxicity in relation to the degree of dose fluctuation. METHODOLOGY: This retrospective study involved all histologically confirmed inoperable lung cancer patients receiving palliative-intent carboplatin or carboplatin-combination chemotherapy from 2012 to 2016 at Kingston Health Sciences Centre. The carboplatin dosing pattern and carboplatin-related toxicity were collected and analysed on SPSS IBM for Windows version 24.0 (IBM Corp., Armonk, NY, USA). Results were expressed in percentages and P values. RESULTS: Our findings ( N = 75) suggested that 24% of patients had a high-degree of fluctuation in carboplatin dose (>10% variation from initial dose) if carboplatin dose was readjusted with each new creatinine. In practice, 16% of patients had a fluctuation of greater than 10% in ordered dose in the absence of planned dose reductions. Our study found no significant association between prescribed high-risk dosing fluctuation (>10% increased from initial dose) and carboplatin-related toxicities. DISCUSSION AND CONCLUSION: In contrast to some prescribing recommendations such as NCI-CTEP, our study suggested that most medical oncologists incorporate new serum creatinine in calculating carboplatin dose for each cycle. Only 9% of patients were treated with a fixed dosing pattern (i.e. no fluctuation). Nonetheless, no significant associations were found between high-risk carboplatin dosing fluctuation and its-related toxicity. Whether such practice was due to the forcing function of the computer order entry system (CPOE), or conscious decisions by medical oncologists was unknown. Further analysis in evaluating physicians' preferences and influencing factors on dosing pattern decision would be recommended.