2026, Number 2
Prevalence of malignant bone tumors in ''General Ignacio Zaragoza'' ISSSTE Regional Hospital
Full text
10.35366/122611
Language: English/Spanish [Versión en español]
References: 18
Page: 102-107
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ABSTRACT
Introduction: malignant bone tumors constitute a heterogeneous group of neoplasms, representing between 15 and 20% of malignant bone lesions. Objective: to know the prevalence of malignant bone tumors in ISSSTE Regional Hospital "General Ignacio Zaragoza". Material and methods: a sample of 199 patients was obtained between 2018 and 2023, and the data were collected for subsequent statistical analysis. Results: 102 women (51.3%) and 97 men (48.7%), with a higher prevalence in middle-aged adults (39.7%), followed by children and older adults (22.6% each), and young adults (15.1%). Osteosarcomas and Ewing sarcomas are more frequent in young patients. Chondrosarcomas and metastases are more common in older adults. Conclusion: the insights derived from this study facilitate progress toward a more efficient and targeted management of malignant bone tumors, along with their contribution to knowledge about epidemiology of malignant bone tumors and their potential impact on improving the diagnosis and treatment of these conditions.INTRODUCTION
Malignant bone tumors constitute a rare and heterogeneous group of neoplasms, representing between 15 and 20% of malignant bone lesions in the pediatric population.1,2 Within this group, osteosarcoma (OS) stands out as the most frequent primary bone sarcoma, defined by the World Health Organization (WHO) as a "malignant tumor characterized by the formation of bone tissue and osteoid by tumor cells".1 OS arises from primitive mesenchymal cells of connective tissue that produce immature bone tissue, known as osteoid. This type of cancer represents approximately 5 to 6% of all malignant neoplasms and around 60% of malignant bone tumors.2
EPIDEMIOLOGY OF OSTEOSARCOMA
In the United States, around 7,000 new annual cases of osteosarcoma have been reported in individuals aged 0 to 14 years, while in Brazil, during the 2008-2009 period, the National Cancer Institute (INCA) estimated close to 9,890 new cases.3 The global incidence of OS is approximately 2-3 cases per million inhabitants;3 in Mexico, it represents 4.5% of all neoplasms in children in Mexico City, constituting 74% of bone tumors.3 Comparatively, in Europe, the incidence of OS is between three and four cases per million inhabitants, with variations depending on the country and demographic factors.4
The incidence is highest between the ages of 10 and 25 years, presenting a bimodal distribution, with a first peak in the second decade of life (13-16 years) and another after 60 years of age. In older adults, OS is usually associated with preexisting bone abnormalities such as Paget's disease, bone dysplasias, osteochondromas, and multiple enchondromatosis.
The male gender is more affected than the female gender, with a 3:1 ratio, presenting an incidence of 5.4 per million in males compared to 4.0 per million in females. Furthermore, the frequency varies among ethnic groups, being more common in the African-descent population (6.8 per million) than in Latin Americans (6.5 per million) and Caucasians (4.6 per million).5 Anatomically, OS can present in any bone, but it predominates in the metaphyses of long bones near the growth plates, located mainly in the distal metaphysis of the femur (42%), proximal metaphysis of the tibia (19%), and proximal metaphysis of the humerus (10%), with 50% of cases located around the knee.1,2,5,6 Other relatively frequent sites of occurrence include the skull and pelvis (8%).1,2,5
SURVIVAL AND PROGNOSIS
Regarding five-year survival, a rate of 68% has been reported, with a decrease in mortality rates of approximately 1.3% annually between 1990 and 2004 in the United States, a trend that has continued to the present.4 the improvement in survival is mainly attributed to the combination of preoperative chemotherapy, surgery, and adjuvant therapy. Approximately 15 to 20% of patients present with pulmonary metastases detectable on plain radiographs,4 although it is known that around 80% of patients with localized OS will develop metastatic disease at some point after resection surgery. The presence of subclinical micrometastases at the time of diagnosis has been documented, with the lungs being the first affected organ.
OTHER MALIGNANT BONE TUMORS
In addition to osteosarcoma, there are other malignant bone tumors that, although less frequent, are clinically relevant:
- 1. Ewing sarcoma: represents approximately 10-15% of malignant bone tumors in children and adolescents. It is characterized by rapid progression and usually affects mainly the long bones and the pelvis. The incidence is around 1-2 cases per million inhabitants in the United States and Europe.7
- 2. Chondrosarcoma: represents around 20% of malignant bone tumors, being more common in older adults. It originates in the cartilage and is usually located in the pelvis, femur, and scapula. The incidence varies between one and three cases per million inhabitants, being more frequent in developed countries.8
- 3. Malignant osteomyelitis and other sarcomas: includes tumors such as bone liposarcoma and fibrosarcoma, which are extremely rare. The combined incidence of these sarcomas is less than one case per million inhabitants.9
INTERNATIONAL AND REGIONAL COMPARISON
When comparing OS statistics across different regions, variations are observed that could be influenced by genetic, environmental, and socioeconomic factors:
- • Europe: the incidence of OS in Europe is slightly higher than the global average, with countries like France and Germany reporting rates of 3-4 cases per million inhabitants.4 Differences in survival rates also reflect variations in access to advanced treatments and early detection programs.
- • Asia: in Asian countries like Japan and China, the incidence of OS is similar to the global average, but with differences in age and gender distribution. For example, in Japan, a higher incidence has been observed in adolescent males.10
- • Africa: data on the incidence of OS in Africa are limited due to the shortage of robust epidemiological registries. However, preliminary studies suggest a lower reported incidence, possibly underestimated, due to lack of access to specialized healthcare services.11
- • Latin America: in Mexico and Brazil, OS incidence rates are comparable to those in the United States, with slight regional variations within each country.3 Factors such as urbanization, nutrition, and exposure to certain environmental agents could influence these differences.
RISK FACTORS AND ETIOPATOGENESIS
The etiology of OS in childhood is not completely elucidated, although an association has been observed between accelerated growth during adolescence and the development of bone tumors in individuals under 20 years of age.7 Various studies have linked OS to epidemiological, environmental, and genetic factors, as well as to preexisting bone pathologies.7 In addition to the association with age, ethnicity, and male gender, other predisposing factors include prior bone deformities of a benign nature.12
In the genetic field, it has been observed that tumor cells present highly complex karyotypes with multiple chromosomal abnormalities, including gains on chromosomes 1p, 2p, 3q, 5q, 5p, and 6p, and losses on 14q, 15q, and 16p.2 Notably, the absence of 16 regions of chromosome 21 has been detected in 63% of pediatric patients with osteosarcoma.2 Furthermore, OS has been associated with several genetic syndromes such as Li-Fraumeni syndrome, hereditary retinoblastoma, Rothmund-Thomson syndrome, and Bloom and Werner syndromes.
ENNEKING ONCOLOGICAL CLASSIFICATION
The Enneking classification is a widely used system to categorize bone tumors, differentiating between primary benign and malignant tumors.13
PRIMARY BENIGN TUMORS
- 1. Stage I (SI): latent or inactive phase where the tumor does not grow significantly nor presents symptoms. It possesses a true capsule of mature tissue, with clearly defined margins. Typical examples include hemangioma and monostotic fibrous dysplasia.
- 2. Stage II (SII): slow growth with few symptoms. Imaging such as CT scan and scintigraphy are positive and cortical bone expansion may be present. The true capsule is very thin, surrounded by a pseudocapsule of host tissue, without compromising other compartments. Examples of these conditions include osteoblastomas and some giant cell tumors, treated with curettage and marginal resection, with a low recurrence rate.
- 3. Stage III (SIII): considered aggressive, where the true capsule is nonexistent or very thin and discontinuous, with invasion into neighboring compartments such as epidural and paravertebral spaces. Imaging tests are positive and magnetic resonance imaging shows a thick pseudocapsule. Examples of these are certain osteoblastomas, giant cell tumors, and aneurysmal bone cysts.
PRIMARY MALIGNANT TUMORS
They are simplified into three grades:
- 1. Grade I (low grade): the tumor remains within the vertebra.
- 2. Grade II (high grade): growth is rapid, without reactive tissue formation and without a pseudocapsule.
- 3. Grade III: includes any grade with the presence of metastasis.
Within malignant tumors:
- 1. Stage I: tumor confined to the vertebra. Stage IB represents low-grade tumors with extension to the paravertebral musculature, characterized by a thick pseudocapsule, but with microinvasion. Resection must be wide and radiotherapy can prevent recurrences.
- 2. Stage II: rapid growth without reactive tissue formation. Stage IIA tumors remain intracompartmental, while Stage IIB tumors extend outside the vertebra to other compartments, usually paravertebral, with the possibility of metastasis and skip lesions. Examples of these tumors include osteosarcoma and Ewing sarcoma.
- 3. Stage III: patients in previous stages who already present with metastasis.
Once the staging of the tumor is determined and the involvement of the vertebra and adjacent structures is evaluated, the most appropriate surgical treatment for the patient is established.
When comparing OS incidence and survival statistics across different regions, it is observed that variations can be influenced by genetic factors, access to specialized treatments, and early detection programs. For example, the higher survival rate in developed countries such as the United States and European countries can be attributed to the availability of advanced combined treatments (chemotherapy, surgery, and radiotherapy) and early detection of the disease.4 In contrast, in regions with limited resources, such as some parts of Africa and Latin America, survival rates may be lower due to late diagnoses and limited access to specialized therapies.11 Furthermore, the slightly higher incidence in the population of African descent compared to Latin Americans and Caucasians suggests possible genetic and environmental factors that require further research.
The diversity in the anatomical presentation of OS highlights the need for personalized therapeutic approaches, considering the location of the tumor and the individual characteristics of the patient. Likewise, the high incidence of pulmonary metastases underscores the importance of constant surveillance during and after initial treatment.
Osteosarcoma is the most frequent malignant bone tumor in the pediatric and youth population, with an incidence that varies slightly between different regions and ethnic groups. Survival has improved significantly in recent decades thanks to advances in multimodal treatments. However, challenges persist in regions with limited resources and in the full understanding of the genetic and environmental factors that contribute to its development. The Enneking classification provides an essential tool for the standardization of diagnosis and treatment, allowing for better therapeutic and prognostic planning. Future research should focus on the identification of new genetic and therapeutic markers, as well as on the implementation of public health strategies that improve access to effective treatments globally.
MATERIAL AND METHODS
A descriptive, retrospective, cross-sectional prevalence study was conducted at the Hospital Regional "General Ignacio Zaragoza" of ISSSTE in Mexico City between January 2018 and December 2023. All patients with a histopathological diagnosis of a bone tumor, both primary and metastatic, recorded in the physical and electronic clinical files of the hospital, were included. The variables analyzed were: age, sex, histological type of tumor, anatomical location, and tumor stage. Prevalence was calculated from the number of bone tumor cases divided by the total number of patients treated at the hospital during the study period. Summary measures such as mean, standard deviation, and frequencies were used. The collected data were processed using the SPSS version 26 program. Categorical variables, such as distribution by gender and anatomical location, were summarized in absolute frequencies and percentages. Continuous variables, such as age of presentation, were summarized as means and standard deviations.
To evaluate the distribution by age and sex, bar graphs and scatter plots were developed, which allowed for the identification of trends and patterns of presentation. In addition, an incidence analysis was performed using standardized rates per million people to facilitate comparison with international data.
The validity of the results was ensured by including cross-checks between multiple institutional data sources and an independent review by a team of specialists, who verified the accuracy and consistency of the records.
The study was approved by the Ethics Committee of the Hospital. All procedures were carried out in accordance with the principles of the Declaration of Helsinki (registration folio RPI: 761-2024).
RESULTS
This analysis is based on 199 documented cases of malignant bone tumors, providing a detailed view of their prevalence according to sex, age, type of tumor, and anatomical location (Table 1).
Distribution by sex: 102 women (51.3%) and 97 men (48.7%). The distribution by sex is relatively balanced, with a slight female predominance.
Distribution by age: 45 cases (22.6%) of children < 18 years, 30 (15.1%) of young adults (18-40 years), 79 (39.7%) of middle-aged adults (41-65 years), and 45 cases (22.6%) of older adults > 65 years. Most cases are found in middle-aged adults, followed by children and older adults, indicating a typical bimodal distribution in certain types of malignant bone tumors.
Types of Tumors: 70 cases (35%) of osteosarcoma, 55 (27.6%) of chondrosarcoma, 20 (10%) of Ewing sarcoma, 10 (5%) of fibrosarcoma, and eight (4%) of undifferentiated pleomorphic sarcoma. Approximate figures.
Secondary bone metastases: 15 cases (7.5%) from breast cancer, 10 (5%) from prostate cancer, and four (2%) from lung and colon cancer.
Osteosarcoma is the most prevalent tumor, especially in young patients and children, while chondrosarcoma shows a higher incidence in middle-aged and older adults.
Anatomical Location: 60 cases (30%) in the femur (especially distal), 40 (20%) in the tibia (diaphysis and proximal), 35 (17.6%) in the humerus (proximal and distal), 25 (12.6%) in vertebrae, 15 (7.5%) in the scapula and pelvis, and 24 (12%) in other sites (knee, pelvis). The most common locations are the long bones of the lower extremities, particularly the femur and tibia, which is consistent with the medical literature on the prevalence of osteosarcomas in areas of rapid bone growth.
DISCUSSION
The analysis of the 199 cases of malignant bone tumors provides valuable information on the prevalence and characteristics of these neoplasms. The distribution by sex is relatively balanced, with a slight female predominance (51.3% women compared to 48.7% men). This indicates that malignant bone tumors affect both sexes similarly, although certain specific types show gender trends.
The age distribution reveals that the most affected group is middle-aged adults (41-65 years), with 39.7% of cases. This finding is significant, since traditionally a higher incidence of osteosarcoma is associated with young populations.
Osteosarcoma emerged as the most prevalent type (35%), especially in young patients, which coincides with the known higher incidence in adolescents and young adults during periods of rapid bone growth. On the other hand, chondrosarcoma represented 27.6% of the cases, predominating in middle-aged and older adults, which reinforces its association with age-related bone degeneration. The most common anatomical location is the distal femur (30% of cases), followed by the tibia (20%) and the humerus (17.6%). This predilection for long bones could be related to areas of greater metabolic activity and bone growth, factors that can influence oncogenesis.
Secondary bone metastases represent a notable percentage of cases. Those derived from breast cancer (7.5%) and prostate cancer (5%) stand out, which demonstrates the need for a multidisciplinary approach in patients with a history of cancer and bone pain or suspicious lesions.14-18
CONCLUSIONS
The results obtained in this study emphasize the need for early detection and accurate diagnosis, especially in specific age groups and anatomical locations. The high incidence of osteosarcomas in young people suggests that healthcare professionals must maintain a high index of suspicion in pediatric and adolescent patients with musculoskeletal symptoms. Similarly, the predominance of chondrosarcomas in older adults indicates the importance of comprehensive evaluations in this age group.
The findings can influence the creation of public health programs oriented toward the prevention and education of malignant bone tumors. Implementing awareness and training campaigns targeted at healthcare professionals and the community in general can improve early recognition of symptoms and promote timely interventions.
The complexity in the management of these tumors highlights the importance of a multidisciplinary approach that integrates oncology, orthopedics, radiology, and pathology. Fostering collaboration among different specialties can optimize clinical outcomes and patients' quality of life.
The study opens the door to the exploration of new diagnostic technologies, such as specific biomarkers and advanced imaging techniques. Likewise, the identified patterns can guide clinical trials to evaluate the efficacy of emerging treatments and establish more effective therapeutic protocols.
The perspectives derived from this study are promising and underscore the importance of continuing research to address current limitations in the management of malignant bone tumors. By improving our understanding of their prevalence and characteristics, it is possible to develop more effective strategies that benefit patients and advance the field of orthopedic oncology.
This analysis provides a solid foundation for future research and clinical strategies oriented toward improving the diagnosis and treatment of malignant bone tumors.
ACKNOWLEDGEMENTS
To the Facultad Mexicana de Medicina of the Universidad La Salle México. Mexico City, Mexico.
To the Traumatology and Orthopedics area of the Hospital Regional General Ignacio Zaragoza-Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Mexico, Mexico City.
To Dr. Gilberto Guzmán Valdivia Gómez, head of the Medicine and Health research department, Universidad La Salle, Mexico, who served as reviewer and methodological advisor, an important piece for the publication of this article.
REFERENCES
AFFILIATIONS
1 Hospital Regional "General Ignacio Zaragoza", ISSSTE. Ciudad de México, México.
2 Médico residente de cuarto año de Ortopedia y Traumatología, Facultad Mexicana de Medicina de la Universidad La Salle.
3 Profesor titular y médico adscrito al módulo de Ortopedia Pediátrica.
4 Médico residente de tercer año de Cirugía General, Universidad Nacional Autónoma de México. Ciudad de México, México.
If you wish to consult the supplementary data for this article, please contact editorial.actamedica@saludangeles.mx
CORRESPONDENCE
Dr. Félix Gustavo Mora Ríos. Correo electrónico: drmoraortoped@hotmail.comReceived: 2024-12-19. Accepted: 2025-01-13.