Retrospective analysis of definitive radiotherapy for neck node metastasis from unknown primary tumor: Japanese Radiation Oncology Study Group study

Abstract

Objective: To investigate the optimal treatment method and risk factor of neck node metastasis from unknown primary tumors (NUP) treated by radiotherapy. Methods: Retrospective case study based on a multi-institutional survey was conducted by the Japanese Radiation Oncology Study Group. Patients pathologically diagnosed as having NUP from 1998 to 2007 were identified. Univariate and multivariate analyses of overall survival (OS), progression free survival (PFS), neck progression free survival (NPFS) and mucosal progression free survival (MPFS) were evaluated. Results: In total, 130 patients with median age of 65 years were included. Nodal stages N1, N2a, N2b and N2c were observed for 10, 26, 43, 12 and 39 patients, respectively. All the patients received radiotherapy (RT) with neck dissection in 60 and with chemotherapy in 67 cases. The median doses to the metastatic nodes, prophylactic neck and prophylactic mucosal sites were 60.0, 50.4 and 50.4 Gy, respectively. The median follow-up period for surviving patients was 42 months. Among 12 patients, occult primary tumors in the neck region developed after radiotherapy. The 5-year OS, PFS, NPFS and MPFS were 58.1%, 42.4%, 47.3% and 54.9%, respectively. Univariate analysis showed that lower N stage (N1-2b), non-bulky node (<6 cm) and negative extracapsular extension (ECE) status were the factors associated with favorable OS, PFS, NPFS and MPFS. Radical surgery proved to be a favorable factor of OS, NPFS and MPFS. On multivariate analysis, lower N stage and negative ECE status were correlated with improved survival.

Clinical characteristics and outcomes of cervical lymph node metastasis from unknown primary sites: a single institution’s 14-year experience

“…They conclude that patients with N1 cancer without extracapsular extension (ECE) can be managed by surgery alone, whereas those with advanced disease and/or ECE are candidates for postoperative adjuvant radiation therapy. These findings are supported by a study by Yamazaki [ 25 ], which has reported negative ECE status is a factor associated with favorable OS and PFS. ECE is an unfavorable prognostic factor of neck recurrence, cause-specific survival, and overall survival.…”

Metástasis cervical con primario desconocido, cambios en los paradigmas. Revisión sobre el enfrentamiento clínico, estudio y tratamiento

“…Al momento de definir el tratamiento para nuestros pacientes, es necesario tener en cuenta los principales factores pronósticos en la MCCPD. Dentro de los factores significativos para tener una mejor sobrevida global y una supervivencia sin recurrencias son la ausencia de diseminación extracapsular, el estado de resección (R0 versus R1/R2), el nivel de ganglios linfáticos comprometidos en el cuello (I-III versus IV-V) y una mayor puntuación en el índice de Karnofsky 2,6,11 .…”

“…Enfermedad del cuello poco avanzada, como los casos de N1 y N2a sin extensión extracapsular (ECE) en el examen histopatológico, muchos estudios informaron un excelente control regional tanto con cirugía exclusiva como con RT exclusiva 4,11,13 . Una posible ventaja de la RT sobre la cirugía es que permite el tratamiento de sitios de la mucosa en riesgo con una dosis subclínica de radiación 4 .…”

“…Enfermedad de cuello avanzada o con el antecedente de una biopsia incisional o escisional de cuello, la terapia de modalidad combinada parece ser lo más indicado, pero no hay certeza sobre cuál es el mejor momento para realizar la cirugía y la RT 4,11,13,15 . Al momento del diagnóstico de MCCPD, la etapa N en la mayoría de los casos está N2a, N2b y N2c, con un tamaño medio de ganglios linfáticos de 3,5-5 cm.…”

“…Por lo tanto, la mayoría de los pacientes con MC-CPD reciben tratamiento combinado en forma de resección seguida de radiación adyuvante (quimioterapia) o quimiorradiación primaria (disección cervical posterior a la terapia). En términos de resultados y según la evidencia existente, no está claro cuál representa la mejor opción y la decisión se toma caso a caso en comité oncológico 4,11 .…”