In theory, non-hematological cancers can be cured if entirely removed by surgery, but this is not always possible. When the cancer has metastasized to other sites in the body prior to surgery, complete surgical excision is usually impossible. In the Halstedian
model of cancer progression, tumors grow locally, then spread to the
lymph nodes, then to the rest of the body. This has given rise to the
popularity of local-only treatments such as surgery for small cancers.
Even small localized tumors are increasingly recognized as possessing
metastatic potential.
Examples of surgical procedures for cancer include mastectomy for breast cancer, prostatectomy for prostate cancer, and lung cancer surgery
for non-small cell lung cancer. The goal of the surgery can be either
the removal of only the tumor, or the entire organ. A single cancer cell
is invisible to the naked eye but can regrow into a new tumor, a
process called recurrence. For this reason, the pathologist
will examine the surgical specimen to determine if a margin of healthy
tissue is present, thus decreasing the chance that microscopic cancer
cells are left in the patient.
In addition to removal of the primary tumor, surgery is often necessary for staging, e.g. determining the extent of the disease and whether it has metastasized to regional lymph nodes. Staging is a major determinant of prognosis and of the need for adjuvant therapy.
Occasionally, surgery is necessary to control symptoms, such as spinal cord compression or bowel obstruction. This is referred to as palliative treatment.
If surgery is possible and appropriate, it is commonly performed
before other forms of treatment, although the order does not affect the
outcome.[6] In some instances, surgery must be delayed until other treatments are able to shrink the tumor.
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