Search

Key Points Question What are the survival and toxicity outcomes associated with platinum plus low-dose, long-term fluorouracil compared with other chemotherapy regimens? Findings This cohort study of 1397 consecutive patients from 2006 to 2017 with metastatic nasopharyngeal carcinoma found that administration of platinum plus infusion of low-dose, long-term fluorouracil was associated with similar overall survival but better subsequent-line, treatment-free survival than other conventional chemotherapy regimens. Meaning Findings from this study suggest that platinum plus low-dose, long-term fluorouracil may be an optional treatment regimen to control disease progression for patients with metastatic nasopharyngeal carcinoma., Importance The treatment of metastatic nasopharyngeal carcinoma (mNPC) is a major challenge because of drug resistance and the toxic effects of chemotherapy. Objective To evaluate the survival and toxicity outcomes and safety associated with the use of a modified low-dose fluorouracil protocol compared with standard regimens recommended in current guidelines for treatment of mNPC. Design, Setting, and Participants This retrospective cohort study was based on data retrieved from electronic medical records from Sun Yat-sen University Cancer Center in China for 1397 patients with mNPC diagnosed from January 1, 2006, to December 31, 2017. Data analyses were conducted from October 1, 2020, to May 1, 2021. Exposures Patients received chemotherapy, including platinum plus low-dose, long-term fluorouracil (PFLL); cisplatin plus standard dose, short-term fluorouracil (PFSS); cisplatin plus gemcitabine (GP); cisplatin plus taxane (TP); and cisplatin plus taxane plus fluorouracil (TPF). Main Outcomes and Measures The main outcomes included overall survival (OS); subsequent-line, treatment-free survival (sTFS), defined as the period from metastasis to the date requiring subsequent-line treatment or death; and the survival to toxicity ratio (STR), defined as person-year rate of OS divided by person-year rate of severe hematologic toxic effects. Cox regression models were used to compare the outcomes of patients receiving PFLL vs other regimens, adjusting for baseline characteristics. Results Of 1397 patients with mNPC included in this study (1152 men; median age, 46 years [range, 18-70 years]) 134 received PFLL, 203 received GP, 330 received PFSS, 366 received TP, and 364 received TPF. A total of 764 patients died (75 in treatment group PFLL; 107 in group GP; 204 in group PFSS; 207 in group TP; and 171 in group TPF), and 979 patients had subsequent-line treatment or died, whichever occurred first (PFLL, 77; GP, 144; PFSS, 262; TP, 269; and TPF, 227). The median follow-up was 46.9 months (IQR, 25.4-82.4 months), and the 5-year OS rate among patients who received PFLL was 25.4% (95% CI, 16.7%-38.8%), which was not significantly different from that among patients who did not receive PFLL (30.2%; 95% CI, 27.1%-33.5%; P = .13) or who received GP (25.1%; 95% CI, 18.1%-35.0%; P = .81), PFSS (23.6%; 95% CI, 18.5%-30.0%; P = .80), or TP (28.1%; 95% CI, 22.8%-34.7%; P = .99) but was lower than that for patients who received TPF (40.4%; 95% CI, 34.7%-47.1%; P = .001). The 5-year sTFS among patients who received PFLL (24.1%; 95% CI, 15.4%-37.6%) was significantly higher than that among patients who did not receive PFLL (18.5%; 95% CI, 16.1%-21.3%; P = .005) or who received GP (14.3%; 95% CI, 9.1%-22.5%; P = .001) but similar to that for patients who received TPF (28.0%; 95% CI, 23.0%-34.0%; P = .74). The STR of PFLL was 0.81, substantially better than that of GP (0.41) and TPF (0.65). Conclusions and Relevance The results of this cohort study suggest that, compared with the use of standard treatment regimens, administration of PFLL was associated with similar OS but prolonged sTFS. PFLL also had better STR than other regimens, which could indicate less severe toxic effects. Thus, PFLL may be an option for first-line treatment of mNPC., This cohort study uses real-world evidence to assess the survival outcomes and hematologic toxic effects associated with the use of a low-dose, long-term infusion protocol for administration of fluorouracil vs standard regimens recommended in current guidelines for treatment of patients with metastatic nasopharyngeal carcinoma.