Introduction to Surgical Oncology

By: E. Loren Buhle, Jr. Ph.D.
Copyright, 1994

Surgery is the oldest form of cancer therapy and remains one of the most important treatment components for solid tumors. Surgery alone can be curative in patients with localized disease, but because many patients (~70%) have evidence of micro-metastases at diagnosis, combining surgery with other treatment modalities is usually necessary to achieve higher response rates.

Continuing advances in cancer surgery have improved patient outcomes and permitted more complex operative procedures. These include:

improved technical ability to perform complex, radical surgeries, as well as greater understanding about the appropriate applications of radical surgery;
the use of radiolabelled monoclonal antibodies to facilitate the excision of the entire tumor;
the use of antibiotic therapy to reduce morbidity secondary to infection;
advanced technology in surgical intensive care units resulting in increased survival after radical surgical procedures; and
new techniques and improved prosthetics to decrease disability and disfigurement caused by radical surgery.

Knowledge of the natural history of cancer -- especially of the patterns of metastases -- provides a more scientific basis for the selection and combination of treatment modalities. For example, the Halstead radical mastectomy was the treatment of choice for breast cancer in 1890 and remained the primary treatment well into the 1960s. Today, information about the progression of breast disease and its often systemic involvement cancer progresses and the knowledge that breast cancer is often a systemic involvement at the time of presentation has changed the surgical approach to this disease. Breast cancer surgery has become less radical and is frequently followed by a radiation or chemotherapy (or both).

Principles of Cancer Surgery

A number of principles are used by the surgical oncologist in the management of malignant disease:

Slow growing cancers are the most amenable to surgical treatment.
The initial surgery for malignancy is more successful than secondary operations for recurrence. This is the guiding principle behind many radical surgeries.
A margin of normal tissue must be excised to assure an adequate resection.
Clinical staging to determine the extent of disease should be completed before definitive surgery, if possible.
Removal of the tumor with adjacent lymph nodes is preferable to simple tumor excision (if no serious disfigurement results).
The patient must find the potential impairment resulting from the surgery acceptable.
Reconstruction and rehabilitation are essential components of cancer surgery and postoperative care.

Types of Cancer Surgery

Surgical procedures for malignancies may be divided into the following categories: diagnostic, staging, definitive (curative), preventative, reconstructive, palliative, and supportive. Surgical procedures are also used in the management of some oncological emergencies.

Diagnostic

Tissue biopsy is essential to confirm the diagnosis and identify the specific type of cancer (histology). Each histologic disease type responds differently to treatment; this is a factor in planning surgical and adjuvant therapy.

Several biopsy techniques are used to confirm diagnosis. These include: aspiration biopsy, needle biopsy, excisional biopsy, and incisional biopsy. The approach used depends on the type of tumor suspected, its size, location, and characteristics of growth. Patients will need to be taught to care for the biopsy site and to report any complications, such as bleeding or signs of infection.

In addition to confirming the histological diagnosis of the primary cancer, biopsy techniques are also used to diagnose opportunistic infections in immunosuppressed patients.

Biopsy Procedures Used in the Diagnosis of Cancer

Type

Definition

Note

Aspiration Aspiration of cells and tissue fragments through a needle that has been guided to a suspected malignant tissue. Cytologic analysis can provide a tentative diagnosis. Since the tumor can be missed, only a positive test is diagnostically significant.

Needle Obtaining a core of tissue through a specially designed needle introduced into suspected malignant tissue. Sufficient for the diagnosis of most tumors. Differentiating benign and reparative lesions from malignancies is often difficult with soft tissue and body sarcomas. Since the tumor can be missed, only a positive test is diagnostically significant.

Incisional Removal of a small wedge of tissue from a large tumor mass. Preferred method for diagnosis soft tissue and bony sarcomas.

Excisional Excision of the entire suspected tumor tissue. Procedure of choice for small, accessible tumors when they can be done without compromising the ultimate surgical procedure.

Staging

Staging surgeries are performed to determine the extent of disease. The information obtained helps the oncologist select the surgical procedure and additional therapy most appropriate for that stage of the disease. Exploratory surgery is commonly used to stage disease in patients with lymphomas or ovarian cancers. During staging operations, abdominal organs are exposed and palpated for gross evidence of disease. Multiple biopsies are taken from the peritoneal cavity.

In cases of metastatic diease, where surgery alone would not be curative and other treatment modalities will be used, stating surgery permits the determination of the exact extent of the disease. Preparations may also be made for further treatment or observations; for example, implanting radio-opague clips for tumor delination during staging surgery. This tailoring spare the patient the morbidity associated with more radical or unnecessary procedures that may be beneficial at certain stages but not others.

Definitive

The goal of definitive surgery is to excise as much of the tumor as possible. During a curative surgery, the entire tumor, associated lymphatics, a a margin of surrounding tissue are removed as one speciment. This decreases the possibility of seeding normal tissue with cancer cells. Surgery can be curative for early-stage cervical, breast, skin, and vulvar cancers, among others. Ultimately, the selection of the appropriate surgical procedure considers the size of the tumor, its anatomic extent, and the patient's physiological status.

When patients have large or unresectable tumors, cytoreductive or debulking surgery may be performed. Reducing the tumor mass in certain cancers can increase the effectiveness of subsequent radiation or chemotherapy, both of which aremo most effective against small numbers of cancer cells. For example, cytoreductive surgery has proven beneficial for ovarian cancer and Burkitt's lymphoma. This approach to treatment is generally beneficial only in cancers where other treatment modalities are effective in controlling residual disease.

Surgery may also be useful to manage metastatic disease. When metastasis is confined to solitary lesions or a few nodules -- as it may be to the lung, brain or liver -- surgical removal of these specific areas is frequently of value.

Two other surgical techniques are used in select clinical situations. Cryosurgery, where malignant cells are destroyed by the application of liquid nitrogen, may be used for cancers of the oral cavity, skin and prostate. Laser surgery is another procedure used for the local excisions of laryngeal cancers and in the treatment of cervical dysplasias. It is also used in surgeries where excessive bleeding may be a problem.

Preventive

Surgery plays a limited role in the prevention of malignancy. Surgical intervention may be indicated for a patient with a strong family history of cancer, an underlying condition, or congenital predisposition that increases the risk of developing cancer. For example, colectomy may be recommended for a patient with ulcerative colitis or a history of familial polyposis who has an increased risk of developing colon cancer. Occasionally, prophylactic subcutaneous mastectomies are considered for women with a very strong family history of breast cancer and previous fibrocystic disease. Before any prophylactic surgery, patients should be informed of the statistical risks of developing malignancy as well as the risks and benefits of prophylactic surgery.

Reconstruction

Reconstructive surgery is becoming more common to repair anatomical defects and improve function and cosmetic appearance following radical surgery. Reconstructive techniques that minimize deformity and improve the quality of life include: breast reconstruction after mastectomy, restoration of acceptable appearance after head and neck surgery, the use of artificial joints after surgery for sarcoma, and the use of penile implants after urological organ surgery.

Palliative

Surgery can be effective in relieving symptoms in more advanced stages of cancer. For example, when pain cannot be controlled through pharmacoogic or behavioral interventions, the nerve pathways can be surgically interrupted. Surgery is also indicated in patients with obstructions related to local expansion of the tumor. Common sites of obstruction are the bowel in colorectal and ovarian cancer, biliary obstruction in hepatobiliary tumors, and urinary tract obstruction from cancers of the cervix, ovary, bladder, prostate and rectum.

Supportive Care

Several surgical inteverentions are useful in the supportive care of oncology patients. Venous access devices may be surgically inserted for administration of chemotherapy or parenteral nutrition and blood drawing. Ventricular reservoirs permit direct delivery of chemotherapy to the cerebrospinal fluid. Gastrostomy and jejunostomy tubes can be placed in patients with gastrointestinal malignancies to provide enteral nutrition.

Type	Definition	Note
Aspiration	Aspiration of cells and tissue fragments through a needle that has been guided to a suspected malignant tissue.	Cytologic analysis can provide a tentative diagnosis. Since the tumor can be missed, only a positive test is diagnostically significant.
Needle	Obtaining a core of tissue through a specially designed needle introduced into suspected malignant tissue.	Sufficient for the diagnosis of most tumors. Differentiating benign and reparative lesions from malignancies is often difficult with soft tissue and body sarcomas. Since the tumor can be missed, only a positive test is diagnostically significant.
Incisional	Removal of a small wedge of tissue from a large tumor mass.	Preferred method for diagnosis soft tissue and bony sarcomas.
Excisional	Excision of the entire suspected tumor tissue.	Procedure of choice for small, accessible tumors when they can be done without compromising the ultimate surgical procedure.