Oxford American handbook of oncology. Second Edition. Oxford University Press (2015)
An understanding of tumor biology is essential in the planning of surgical treatment for cancer. The biology of solid tumors is diverse and often unpredictable. Even in patients where the primary tumor appears localized by radiographic evaluation, locally advanced disease or distant metastases may still be present, highlighting the need for rigorous preoperative staging. The three principal methods of spread are as follows:
- Direct extension
- Lymphatic involvement
Most cancers have the potential to disseminate by all three methods, although one method of spread may be predominant.
Breast and colorectal cancer exhibit both blood and lymphatic spread, whereas cancers arising in the upper gastrointestinal tract and the neck metastasize via the lymphatic system. Even cancers arising from the same cell type behave differently: papillary and follicular tumors of the thyroid give rise to lymphatic and hematogenous metastases, respectively.
Different surgical approaches will be required depending on tumor type.
Before performing surgery for curative intent, appropriate preoperative staging must be performed, including a complete history and physical examination, appropriate laboratory tests, and radiographic evaluation.
The specific laboratory and radiographic tests used depend on the tumor type and clinical stage of the patient.
Recently, positron emission tomography (PET) has been demonstrated to improve the preoperative detection of distant metastatic disease, reducing the incidence of futile surgical exploration for patients with many (but not all) tumor types.
For many patients, multidisciplinary evaluation including (but not necessarily limited to) surgical, medical, and radiation oncologists will improve outcomes. In addition, appropriate knowledge and use of staging and treatment guidelines, such as those from the National Comprehensive Cancer Network (NCCN), have also been demonstrated to improve results.