Epidemiology of bone tumors in Mexico City: retrospective clinicopathologic study of 566 patients at a referral institution

Abstract

A retrospective analysis of all bone tumors accessioned at a large referral center (Instituto Nacional de Rehabilitacion) in Mexico City between 2000 and 2005 is presented. A total of 6216 biopsies and surgical resection specimens were reviewed during this period, of which 566 corresponded to bone tumors. Benign bone tumors accounted for 71.6% of cases and malignant bone tumors for 28.4%. The tumors affected men in 53.7% of cases and women in 46.3% of cases, with an average age at presentation of 25 years. The femur was the most common location of the tumors (39.9%), followed by the tibia (17.7%) and humerus (11.8%). The commonest malignant bone tumors were osteosarcoma (46.6%) and chondrosarcoma (8.7%). Of malignant bone tumors, 18.6% corresponded to metastases of carcinomas from internal organs and 8.1% were multiple myeloma. The most common benign bone tumor was osteochondroma (43.7%) followed by giant cell tumor of bone (14.6%) and enchondroma (10.1%). The age distribution showed a peak in children and adolescents comprised predominantly of benign lesions and a second peak in young adults that corresponded to malignant bone tumors (principally osteosarcoma). Malignant bone tumors most often involved the femur, vertebra, and tibia. Our results parallel the findings previously reported in the world literature and show a similar distribution and epidemiology as in other developed and underdeveloped countries. Geographic location does not appear to represent a risk factor for any particular type of bone tumor and does not affect the age distribution, location, or histopathologic type of the lesions.

Introduction

Malignant neoplasms represent a major health problem in Mexico, not only due to their morbidity and mortality but also due to the specific risk factors, environmental issues, and genetic background of the local population. Cancer represents the second leading cause of death in advanced countries, and it is the third cause of mortality for adults in developing countries. By the year 2002, it was estimated that there were 10.9 million new cancer cases, 6.7 million cancer deaths, and 24.6 million persons affected by cancer. It has been estimated that by the year 2020, there will be 16 million persons affected with the disease, of whom approximately two thirds will live in developing or underdeveloped countries [1].

According to the Mexican Histopathologic Registry of Malignant Neoplasms (Registro Histopatológico de Neoplasias Malignas en México), cancer is one of the diseases that has shown a steep rise in incidence since the year 2000 in the metropolitan area of Mexico City (Mexico, DF). Since the year 2000, 108 064 cases of malignant neoplasms have been accessioned in the registry, of which 35% occurred in men and 65% women [1]. The most common organs affected were the skin (13%), cervix (13%), breast (11%), prostate (6%), and stomach (3%) [1]. No current information, however, is available regarding the epidemiology of bone tumors in the Mexican population.

Primary bone tumors are rare, yet they account for a major source of mortality and morbidity among patients with cancer. The geographic distribution of bone tumors throughout the world appears to be quite variable, with a very low incidence reported in some Asian countries such as India, Japan, and China as well as in most of Latin America. In the United States, there seems to be an increased incidence among patients of African American and Caribbean descent over whites [2], [3].

There is limited information regarding the epidemiology of bone tumors in Mexico. The Mexican Histopathologic Registry of Malignant Neoplasms only cites an incidence of 0.07 per 100 000 population for malignant bone tumors, corresponding to roughly 0.1% of all malignant neoplasms affecting the local population. The objective of this study was to review the incidence, age and sex distribution, histologic type, and location of benign and malignant bone tumors at a large referral hospital serving a large metropolitan area in Mexico City (DF).