Surgery is part of the standard treatment for the majority of patients with gastric cancer. However, since gastric cancer is not exclusively treated by surgery, it is important for patients to be treated at a medical center that can offer multi-modality treatment involving surgeons, medical gastroenterologists, radiation oncologists, medical oncologists and nutritionists.
SURGICAL TREATMENT OF GASTRIC CANCER
Individuals with gastric cancer are frequently treated with surgical removal of the stomach (called a gastrectomy), to remove the cancer and prevent recurrence (or return) of the cancer. Lymph nodes (parts of the body’s lymph system) around the stomach are also removed and examined to determine whether or not the cancer has spread to these areas. Depending on the stage (extent of disease) of the cancer, the majority of patients will also be treated with chemotherapy drugs and/or radiation therapy.
A complete removal of the primary cancer and the lymphatic drainage of the cancer is the primary goal of any surgical treatment for gastric cancer. Patients with gastric cancer may have a total or partial removal of the stomach. When patients undergo a partial removal of the stomach, the remaining portion of the stomach is re-attached to the upper part of the small intestine (duodenum) or to the middle part of the small intestine (jejunum) or to the esophagus. Cure rates for gastric cancer are related to the extent of cancer at the time of diagnosis.
During a total gastrectomy, the entire stomach is removed and the two remaining ends of the gastrointestinal tract are reconnected. This is the most common operation for cancer of the upper stomach. For cancers of the middle and lower stomach, an incision is made in the abdomen and the entire operation can be carried out without entering the chest. The usual operation for cancer of the upper stomach, called the cardia, is an incision that involves entering both the abdomen and the chest. An alternative approach is a single incision in the abdomen with an incision through the diaphragm (transhiatal approach). The transhiatal approach for total gastrectomy for cancer of the upper stomach is a safe alternative to the standard thoracoabdominal technique and avoids entering the chest and the associated complications.
Treatment of patients with cancer of the lower part of the stomach has frequently involved the complete removal of the stomach. An alternative operation is removal of only the part of the stomach involved with cancer with preservation of the upper stomach. This is called a subtotal gastrectomy. The less extensive operation is associated with better nutrition and quality of life than total gastrectomy.
Early cancers (Stage 0 and I) can often be removed through an endoscope passed through the esophagus. Another procedure, called laparoscopic surgery, is performed through an endoscope passed into the abdomen through a small incision. Studies conducted thus far suggest that laparoscopic surgery is safe and effective for selected patients; additional, larger studies are needed before firm conclusions can be drawn. The primary advantage of laparoscopic surgery is more rapid recovery after surgery.
EXTENT OF SURGERY
Lymphocytes and the lymph system are part of the body’s immune system that protects the body from disease and infection. The lymph system consists of small bean-shaped “lymph nodes” connected by ducts, which are extensively located throughout the gastrointestinal tract. When cancer originates in the stomach, cancer cells may spread through the lymph nodes to other parts of the body.
In some, but not all clinical studies, improved survival is associated with more extensive removal of the lymph nodes. This has led some surgeons to recommend removing the maximum number of lymph nodes during surgery. However, this more extensive surgery is often associated with increased complications. Thus, controversy remains regarding the appropriate extent of lymph node removal.
ADJUVANT THERAPY (TREATMENT AFTER SURGERY)
It is important to understand that some patients with gastric cancer already have small amounts of cancer that have spread beyond the stomach and cannot be detected with any of the currently available tests. Undetectable areas of cancer are referred to as micrometastases. It is the presence of micrometastases that causes cancer recurrence following treatment with surgery alone. For some patients, additional treatment aimed at these micrometastases can improve duration of survival and potential for a cure. The delivery of cancer treatment following local treatment with surgery is referred to as adjuvant therapy. Adjuvant therapy for gastric cancer typically involves chemotherapy, sometimes in combination with radiation therapy.
NEOADJUVANT THERAPY (TREATMENT BEFORE SURGERY)
Some patients may receive treatment with chemotherapy (with or without radiation therapy) prior to surgery. This treatment can help to reduce the extent of cancer, making it easier to remove the cancer during surgery. Patients who receive chemotherapy prior to surgery often receive chemotherapy after surgery as well.
STRATEGIES TO IMPROVE TREATMENT
The progress that has been made in the treatment of gastric cancer has resulted from improved patient participation in clinical studies. Future progress in the treatment of gastric cancer will result from continued participation in appropriate studies. Currently, there are several areas of active exploration aimed at improving the treatment of gastric cancer.
Supportive Care: Supportive care refers to treatments designed to prevent and control the side effects of cancer and its treatment. Side effects not only cause patients discomfort, but also may prevent the optimal delivery of therapy at its planned dose and schedule. In order to achieve optimal outcomes from treatment and improve quality of life, it is imperative that side effects resulting from cancer and its treatment are appropriately managed. For more information, go to Managing Side Effects.
Extensive Lymph Node Resection: Controversy remains concerning how many lymph nodes should be removed during surgery. Clinical trials comparing more extensive to less extensive removal of lymph nodes are ongoing.
Adjuvant Therapy: The administration of additional treatment after surgery for the purpose of decreasing the risk of cancer recurrence is referred to as adjuvant therapy. Clinical trials have demonstrated an improvement in survival when adjuvant therapy is used to treat all stages of gastric cancer except stage IA. Clinical trials are ongoing to determine the optimal adjuvant therapy.
Huscher CG, Mingoli A, Sgarzini G et al. Laparoscopic versus open subtotal gastrectomy for distal gastric cancer: five-year results of a randomized prospective trial. Annals of Surgery. 2005;241:232-7.