Oxford American handbook of oncology. Second Edition. Oxford University Press (2015)
Diagnosis and staging algorithms have been well described (NCCN Guidelines), and these should be followed closely in the majority of patients with known or suspected cancer.
The use of ultrasound, computerized tomography (CT), PET, and magnetic resonance imaging (MRI), as well as the performance of percutaneous (or transluminal) biopsy, allows the preoperative diagnosis of cancer to be made in most cases. These radiographic techniques may be interpreted to determine the clinical stage of a patient prior to surgical staging or therapy. Surgical procedures may be used for diagnostic and staging purposes, either before resection or to plan nonoperative therapy.
Although fine-needle aspiration and core biopsy often provide the diagnosis of cancer, it is important that the physician, pathologist, or radiologist performing these investigations direct their needle bearing in mind the possibility of tumor seeding.
Tumor seeding is not a problem with a fine-needle aspiration generally, but it may be more of a problem with core biopsy, especially with soft tissue sarcomas. Here, the needle track should be placed after discussion with the surgeon so that the needle track will be excised in the definitive surgery.
The surgeon may still be required to perform either an incisional or an excisional biopsy. In the former, compromise to the future definitive operation must not occur. The excisional biopsy should in many cases be carried out by the appropriate specialist who will be carrying out the definitive surgery. This applies particularly in melanoma where there is controversy over the excision margins (depending upon the depth of the melanoma).
When taking biopsies for diagnostic purposes, the surgeon should be aware of the quantity required for diagnosis and the appropriate conditions for storage of the biopsy. Tissue samples will need to be sent “fresh” if electron microscopy or other specialized stains or cytogenetics are required.
Some pathologic evaluations (such as receptor expression) require a certain minimum amount of tissue, and aspiration specimens for cytologic analysis may be inadequate. Diagnostic surgical procedures may provide specimens other than the primary tumor, including the adjacent lymph nodes, to stage the tumors most effectively.
A variety of surgical procedures may be used to effectively stage patients before resection or before induction therapy, or to plan definitive or palliative nonoperative therapy. For example, mediastinoscopy may be used to assess mediastinal lymph node involvement in patients with lung cancer, to determine whether resection (stages I or II), induction chemotherapy followed by resection (stage IIIA), or chemoradiotherapy (stage IIIB) should be used.
MIS procedures, such as laparoscopy or thoracoscopy, are also used in the diagnosis and staging of malignancy. Although image-directed biopsy can give a diagnosis in a large proportion of patients, some areas are not easily amenable.
MIS may be used for staging the following malignancies before definitive surgery: esophageal cancer, gastric cancer, pancreatic cancer, liver cancer, prostatic cancer, and ovarian cancer.
Sentinel node biopsy
Sentinel node biopsy is a minimally invasive technique that has been used for several years for patients with breast cancer or melanoma.
After injection of the primary tumor with a dye or a radioisotope, the “sentinel” lymph node (that which would be most likely to harbor metastatic disease) is identified and removed. Thereafter, if the gland is positive (on frozen section), the surgeon will proceed to complete resection of the regional nodes.