Age-Dependent Metastatic Spread and Survival: Cancer of Unknown Primary as a Model

Abstract

In order to describe a novel approach for the clinical study of metastases, we provide here age-specific incidence and survival data for cancer of unknown primary (CUP). Metastases in various organs are found at CUP diagnosis, which have implications for prognosis, and we hypothesize similar prognostic implications for metastases found at diagnosis of primary cancers. We identified 33,224 CUP patients from the Swedish Cancer Registry and calculated incidence rates (IRs) for CUP development. Cox proportional hazards regression models were performed to estimate hazard ratios (HRs) for relative survival in CUP patients compared to the general population. In age-group specific analyses, a maximal IR was reached at age 85–89 years, followed by a marked decline to age 90+ (7-fold in men and 3-fold in women). The overall HR for relative survival declined systematically by age. CUP may be applied as an epidemiological age-incidence model for cancer metastases providing evidence in line with autopsy data that the metastatic potential, as shown by the incidence of CUP, appears to weaken markedly at age 85 years, depending on metastatic locations. The relative death rates were highest among young patients, which was probably entirely due to the low death rates in young background population.

Cancer of Unknown Primary: A Review on Clinical Guidelines in the Development and Targeted Management of Patients with the Unknown Primary Site

“…Based on data from the studies, the prognosis of CUP is depressing with the median survival at three to six months in earlier studies, but according to recent studies, median survival is less than one year [8-9]. Site of metastasis and histology are two essential factors in the prognosis of CUP [10]. The incidence of CUP is highest in patients of age between 60-75 years [2].…”

“…The incidence of CUP is highest in patients of age between 60-75 years [2]. In another study, the highest incidence ratio was at age 85-89 years, followed by a significant decrease by age ninety-plus (7-fold in men and 3-fold in women) [10].…”

“…Multiple metastases at presentation are common involving liver, abdomen, brain, thorax, bones, and lungs [10]. Peak incidence in abdomen and liver metastasis is seen in age 80-89-year-old individual.…”

Cáncer metastásico con primario desconocido. Una revisión

“…Esas metástasis afectan 3 o más órganos en un tercio de los pacientes al diagnóstico (8). Los sitios más frecuentes de las metástasis incluyen el abdomen e hígado, seguidos del tórax, cuello y huesos (11). Desde el punto vista histológico, puede clasificarse en 5 subtipos: el subtipo más frecuente es el adenocarcinoma bien y moderadamente diferenciado (60%), seguido del adenocarcinoma o carcinoma mal diferenciado (29%), carcinoma escamocelular (5%) y las neoplasias malignas mal diferenciadas (5%) (1).…”

Manejo Quirúrgico del Carcinoma Metastásico de Primario Desconocido de Cabeza y Cuello

“…Al momento del diagnóstico, en un tercio de los pacientes, tres o más órganos presentan metástasis [3]. Siendo el abdomen, hígado, tórax, cuello y huesos en orden de frecuencia los sitios más comunes de metástasis [4]. La supervivencia posterior al diagnóstico oscila de 11 semanas a 11 meses con una media de 3 meses [5,6].…”