Rare complications of multikinase inhibitor treatment

ABSTRACT Objective: The advent of multikinase inhibitor (MKI) therapy has led to a radical change in the treatment of patients with advanced thyroid carcinoma. The aim of this manuscript is to communicate rare adverse events that occurred in less than 5% of patients in clinical trials in a subset of patients treated in our hospital. Subjects and methods: Out of 760 patients with thyroid cancer followed up with in our Division of Endocrinology, 29 (3.8%) received treatment with MKIs. The median age at diagnosis of these patients was 53 years (range 20-70), and 75.9% of them were women. Sorafenib was prescribed as first-line treatment to 23 patients with differentiated thyroid cancer and as second-line treatment to one patient with advanced medullary thyroid cancer (MTC). Vandetanib was indicated as first-line treatment in 6 patients with MTC and lenvatinib as second-line treatment in two patients with progressive disease under sorafenib treatment. Results: During the follow-up of treatment (mean 13.7 ± 7 months, median 12 months, range 6-32), 5/29 (17.2%) patients presented rare adverse events. These rare adverse effects were: heart failure, thrombocytopenia, and squamous cell carcinoma during sorafenib therapy and squamous cell carcinoma and oophoritis with intestinal perforation during vandetanib treatment. Conclusions: About 3 to 5 years after the approval of MKI therapy, we learned that MKIs usually lead to adverse effects in the majority of patients. Although most of them are manageable, we still need to be aware of potentially serious and rare or unreported adverse effects that can be life-threatening.

Riesgo dinámico en pacientes con cáncer diferenciado de tiroides no ablacionados / Dynamic risk assessment in patients with differentiated thyroid cancer without remnant ablation

En la actualidad, el enfoque terapéutico y el seguimiento de los pacientes con carcinoma diferenciado de tiroides (CDT) es individualizado de acuerdo con el riesgo de recurrencia de la enfermedad, con una menor tendencia a ablacionar a pacientes de bajo riesgo de recurrencia. Por otro lado, la evaluación de las respuestas al tratamiento se validó en pacientes tratados con tiroidectomía total (TT) y ablación con radioyodo (RAI), pero son escasos los estudios en pacientes no ablacionados. Los objetivos de este estudio fueron describir las características de una población de pacientes con CDT no ablacionados y validar las respuestas al tratamiento durante el seguimiento. Se incluyó a 88 pacientes con un seguimiento mínimo de 12 meses. El 87,6% eran mujeres y la edad promedio en el momento del diagnóstico fue de 47,5 años. Basados en el Consenso Intersocietario Argentino, el 97,7% de la cohorte fue clasificada como de bajo riesgo y el 2,3% como de riesgo intermedio de recurrencia. Los pacientes presentaron una respuesta inicial excelente en el 73% de los casos, con un estado sin evidencia de enfermedad al final del seguimiento en el 85,5%. Una minoría de los pacientes (1%) presentó una respuesta inicial estructural incompleta, la cual fue similar al final del seguimiento (1%). Por otro lado, el 26% de los pacientes presentó una respuesta inicial indeterminada, aunque solo el 13,5% permaneció con esta respuesta al final del seguimiento. Nuestros datos validan las respuestas al tratamiento en pacientes con CDT que recibieron TT no ablacionados como una herramienta efectiva para la estratificación del riesgo dinámico. Los pacientes apropiadamente seleccionados tratados sin RAI tienen un excelente pronóstico, con una baja frecuencia de respuesta estructural incompleta en el seguimiento, inclusive menor que la de los pacientes de bajo riesgo ablacionados.

The therapeutic approach and the follow-up of patients with differentiated thyroid cancer (DTC) is currently individualised according to the risk of recurrence, with a lower tendency to perform remnant ablation (RA) in patients with low risk of recurrence. While response to therapy assessment has been validated for DTC patients treated by total thyroidectomy (TT) and RA, it has not been widely confirmed in patients treated with TT without RA. The aims of this study were to describe the characteristics of the population of patients treated with TT without RA, and to validate the response to therapy. The study included 88 patients followed-up for at least 12 months after surgery. In the entire cohort, 87.9% were female and the mean age was 47.5 years old. Based on the Argentine Intersociety Consensus, 97.7% and 2.3% were classified as low risk and intermediate risk of recurrence, respectively. Patients had an initial excellent response to treatment in 73% of cases, with a disease-free status at the end of follow-up of 85.5%. A minority of patients (1%) presented with an initial structural incomplete response, which was similar at the end of follow-up (1%). On the other hand, 26% of the patients had an initial indeterminate response, although only 13.5% remained with this response at the end of follow-up. These results validate the responses to treatment in DTC patients treated with TT without RA as an effective tool for the dynamic risk stratification. Patients appropriately selected who did not receive RA have an excellent outcome, with a low frequency of structural incomplete response, even lower than that observed in low risk ablated patients.

Undetectable pre-ablation thyroglobulin levels in patients with differentiated thyroid cancer: it is not always what it seems / Níveis indetectáveis de tireoglobulina pré-ablação em pacientes com câncer de tireoide: nem sempre é o que parece

OBJECTIVE: To establish the frequency of U Tg (undetectable pre-ablation thyroglobulin) in TgAb- negative patients and to evaluate the outcome in the follow-up. SUBJECTS AND METHODS: We retrospectively reviewed 335 patients' records. Twenty eight patients (9%) had U Tg. Mean follow-up was 42 ± 38 months. All subjects had undergone total thyroidectomy, and lymph nodes were positive in 13 (46%) patients. Tg and TgAb levels were measured 4 weeks after surgery by IMA technology in hypothyroid state. No evidence of disease (NED) status was defined as undetectable (< 1 ng/mL) stimulated Tg and negative Tg-Ab and/or negative WBS, together with normal imaging studies. RESULTS: Seventeen patients (61%) were considered with NED. Four patients (14%) had persistent disease (mediastinum, n = 1, lung n = 2, unknown n = 1), and 7 (25%) had detectable TgAb by other method during their follow-up. CONCLUSIONS: U Tg levels usually is associated to a complete surgery. However, in a low percentage of patients, this may be related to false negative Tg or TgAb measurement.

OBJETIVO: Estabelecer a frequência de U Tg (tireoglobulina indetectável pré-ablação) em pacientes com TgAb negativo e avaliar o prognóstico no seguimento. SUJEITOS E MÉTODOS: Foram analisados retrospectivamente 335 registros de pacientes. Vinte e oito pacientes (9%) tiveram U Tg. O acompanhamento médio foi de 42 ± 38 meses. Todos os participantes receberam uma tireoidectomia total, e os linfonodos foram positivos em 13 (46%) pacientes. Tg e TgAb foram medidos quatro semanas após a cirurgia pelo método IMA em estado de hipotireoidismo. A não evidência de doença (NED) foi definida como níveis indetectáveis (<1 ng/mL) de Tg estimulada com anticorpos anti-Tg negativos e/ou PCI negativo, com estudos de imagem normais. RESULTADOS: Dezessete pacientes (61%) foram considerados com NED. Quatro pacientes (14%) tiveram doença persistente (mediastino, n = 1, pulmão n = 2, n = desconhecido 1), e 7 (25%) apresentavam anticorpos anti-Tg detectáveis por outro método durante acompanhamento. CONCLUSÕES: U Tg geralmente indica uma cirurgia completa. No entanto, em uma pequena porcentagem de pacientes, pode estar relacionada com uma medida de Tg ou de anticorpos anti-Tg falsamente negativos.