Advancing Education, Research, and Quality of Care for the Head and Neck oncology patient.
Introduction: Medullary thyroid cancer (MTC) comprises 4% of thyroid cancers but has worse survival outcomes than well-differentiated types such as papillary or follicular thyroid carcinomas. While surgical resection is the mainstay of treatment for MTC, few studies have examined the optimal timing for intervention.
Objective: This study evaluates the impact of time to treatment on overall survival (OS) and disease-specific survival (DSS) outcomes in patients with MTC.
Methods: Patients diagnosed with MTC between 2000 to 2021 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Patients were separated into groups based on the time from diagnosis to treatment: within one month, between one and two months, and after two months. Additional covariates included age, gender, race, cancer stage, year of diagnosis, and treatment mode (surgery, radiation, and/or chemotherapy). OS and DSS outcomes based on time to treatment were analyzed using Kaplan-Meier curves and logistic regression. Odds ratios (OR) and 95% confidence intervals (CI) were also generated.
Results: A total of 4066 patients diagnosed with MTC were identified, of which 3555 received treatment and had available time to treatment data allowing for inclusion in this study. The mean age (SD) was 54 (17.1) years, with 42% being male. The mean time to treatment was 27 (42.6) days, and the mean survival time was 89.6 (67.4) months. Among these patients, OS rates were 80.1% at ten years and 77.1% at fifteen years, while DSS rates were 89% at ten years and 87.9% at fifteen years.
Overall Survival: Kaplan-Meier analysis revealed patients treated earlier exhibited a significant stepwise improvement in overall survival among patients treated within 1 month, between 1 and 2 months, and after 2 months. Patients treated earlier demonstrated improved survival in both ten-year OS (p=0.005) and fifteen-year OS (p=0.004). On logistic regression analysis, after adjusting for age and tumor stage, a delay in treatment was significantly associated with worsened ten-year OS (OR: 1.003, 95% CI [1.001-1.005]) and fifteen-year OS (OR: 1.004, 95% CI [1.001-1.006]).
Disease-Specific Survival: Kaplan-Meier analysis revealed that patients treated within one month of diagnosis were significantly more likely to survive in both ten-year DSS (p=0.013) and fifteen-year DSS (p=0.005) than those treated later. Logistic regression analysis, adjusting for age and tumor stage, further confirmed that delay in time to treatment initiation significantly decreased ten-year DSS (OR: 1.004, 95% Cl [1.001-1.007]) and fifteen-year DSS (OR: 1.003, 95% Cl [1.001-1.006]).
Conclusion: Timely treatment within one month of diagnosis significantly improves both OS and DSS in patients with MTC. Delays in treatment initiation are associated with a modest but statistically significant decrease in survival at ten- and fifteen-years, underscoring the importance of early intervention. Future studies should elucidate the source of delay to guide deployment of resources and infrastructure to address these delays.