Modern cancer therapy is multidisciplinary, involving coordinated care by surgeons, medical oncologists, radiation oncologists, reconstructive surgeons, pathologists, radiologists, and primary care physicians.
Understanding cancer biology is essential to successfully implement personalized cancer therapy.
The following alterations are critical for malignant cancer growth: self-sufficiency of growth signals, insensitivity to growth-inhibitory signals, evasion of apoptosis, potential for limitless replication, angiogenesis, invasion and metastasis. Reprogramming of energy metabolism and evading immune destruction.
ONCOLOGY AND SURGICAL PRACTICE
As the population ages, oncology is becoming a larger portion of surgical practice. The surgeon often is responsible for the initial diagnosis and management of solid tumors. Knowledge of cancer epidemiology, etiology, staging, and natural history is required for initial patient assessment, as well as to determination of the optimal surgical therapy.
Modern cancer therapy is multidisciplinary, involving the coordinated care of patients by surgeons, medical oncologists, radiation oncologists, reconstructive surgeons, pathologists,radiologists, and primary care physicians. Primary (or definitive) surgical therapy refers to en bloc resection of tumor with adequate margins of normal tissues and regional lymph nodes as necessary. Adjuvant therapy refers to radiation therapy and systemic therapies, including chemotherapy, immunotherapy, hormonal therapy, and, increasingly, biologic therapy. The primary goal of surgical and radiation therapy is local and regional control. On the other hand, the primary goal of systemic therapy is systemic control by treatment of distant foci of subclinical disease to prevent distant recurrence. Surgeons must be familiar with adjuvant therapies to coordinate multidisciplinary care and to determine the best sequence of therapy.
Recent advances in molecular biology are revolutionizing medicine. New information is being translated rapidly into clinical use, with the development of new prognostic and predictive markers and new biologic therapies. Increasingly cancer therapy is getting personalized, incorporating information about each patient’s tumor characteristics, patient’s own genome, as well as host immune responses and tumor microenvironment, into clinical decision-making. It is therefore essential that surgeons understand the principles of molecular oncology to appropriately interpret these new contributions and incorporate them into practice.
Basic Principles of Cancer Epidemiology
The term incidence refers to the number of new cases occurring. Incidence is usually expressed as the number of new cases per 100,000 persons per year. Mortality refers to the number of deaths occurring and is expressed as the number of deaths per 100,000 persons per year. Incidence and mortality data are usually available through cancer registries. Mortality data are also available as public records in many countries where deaths are registered as vital statistics, often with the cause of death. In areas where cancer registries do not exist, mortality data are used to extrapolate incidence rates. These numbers are likely to be less accurate than registry data, as the relationship between incidence and cause-specific death is likely to vary significantly among countries owing to the variation in health care delivery.