Essential Aspects of Cancer: A Narrative Review

Abstract

Cancer is a disease of significant global burden, characterized by the uncontrolled growth of cells with the capacity for invasion and metastasis. Its origin is linked to genetic and epigenetic alterations that disrupt the balance between proto-oncogenes and tumor suppressor genes, enabling autonomous cell proliferation and clonal evolution toward more aggressive phenotypes. During this process, cells acquire properties known as the hallmarks of cancer, which explain its progression and therapeutic resistance.

Pathology is the cornerstone discipline in oncologic diagnosis. Through histological, cytological, immunohistochemical, and molecular assessments, it enables the identification of tumor type, its degree of differentiation, invasiveness, and characteristics with therapeutic potential. Tools such as immunohistochemistry, genomic sequencing, and liquid biopsy have expanded diagnostic, prognostic, and personalized therapeutic possibilities.

Tumors are classified according to their cellular lineage and biological behavior as benign or malignant. Benign tumors exhibit slow growth, are well circumscribed, and do not metastasize. Malignant tumors, on the other hand, display anaplasia, local invasion, and distant dissemination. Understanding key terms such as differentiation, dysplasia, carcinoma in situ, invasion, and metastasis is fundamental for appropriately interpreting pathological findings.

From a clinical perspective, the general practitioner plays a crucial role in early detection, initial interpretation of warning signs, and timely referral. Moreover, they should understand the basic principles of modern oncology to effectively support the diagnostic and therapeutic process. Strengthening these competencies at the primary care level is essential to improve access, treatment quality, and health outcomes for cancer patients.