Types of Cancer

Stage I Gastric Cancer

Overview

Patients with stage I gastric cancer have cancer that invades beneath the surface layer of cells lining the stomach, but not into the muscle wall of the stomach. When there is no lymph node involvement or distant spread of cancer, the cancer is referred to as stage IA cancer. When the cancer invades beneath the surface layer of cells and has spread to 1-6 lymph nodes or invades into the muscle of the wall of the stomach without regional lymph node or distant spread, it is referred to as stage IB cancer.

A variety of factors ultimately influence a patient’s decision to receive treatment of cancer. The purpose of receiving cancer treatment may be to improve symptoms through local control of the cancer, increase a patient’s chance of cure, or prolong a patient’s survival. The potential benefits of receiving cancer treatment must be carefully balanced with the potential risks of receiving cancer treatment.

The following is a general overview of the treatment of stage I gastric cancer. Circumstances unique to your situation and prognostic factors of your cancer may ultimately influence how these general treatment principles are applied. The information on this Web site is intended to help educate you about your treatment options and to facilitate a mutual or shared decision-making process with your treating cancer physician.

Most new treatments are developed in clinical trials. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Participation in a clinical trial may offer access to better treatments and advance the existing knowledge about treatment of this cancer. Clinical trials are available for most stages of cancer. Patients who are interested in participating in a clinical trial should discuss the risks and benefits of clinical trials with their physician. To ensure that you are receiving the optimal treatment of your cancer, it is important to stay informed and follow the cancer news in order to learn about new treatments and the results of clinical trials.

Surgery or multi-modality treatment with surgery, chemotherapy and/or radiation is the primary treatment for stage I gastric cancer. Chemotherapy and/or radiation therapy without surgery is usually reserved for patients who are not able or do not wish to undergo major surgery.

Surgery as Primary Treatment

It is important for patients with gastric cancer to consider receiving treatment at a large medical center because improved survival rates have been reported at these facilities. Large medical centers have reported five-year survival rates as high as 95% for stage IA and approximately 80% for stage IB gastric cancer following surgical resection and extensive lymph node removal. However, in a large study that involved over 50,000 patients with all stages of gastric cancer treated between 1985 and 1996 in many different medical centers, the 5 and 10-year survival rates for patients with stage IA and IB cancer were only 78% and 50%, respectively. There are several reasons that could account for the large differences in survival between “large centers” and this single report evaluating survival rates across a majority of cancer centers in the United States. Factors such as the experience of the surgical team, the extent of lymph node removal performed and the types of patients treated at the center could all play a role in these differences. Patients who had 15 or more lymph nodes removed during surgery experienced longer survival than patients who had fewer lymph nodes removed. Many patients in this study had fewer then 15 lymph nodes removed, which may be less than optimal. This study also suggests variation in outcomes between medical centers. Patients with stage I gastric cancer should consider treatment at a medical center with a surgical team that has experience and treats a large number of patients with gastric cancer each year. To learn more about surgical treatment, go to Surgery and Gastric Cancer.

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 into the lymph nodes 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. An effective treatment is needed to cleanse the body of micrometastases in order to improve a patient’s duration of survival and potential for a cure. The delivery of cancer treatment following local treatment with surgery is referred to as adjuvant therapy and may include chemotherapy, radiation therapy and/or biologic therapy.

Several clinical trials have suggested that chemotherapy administered after surgery may prevent some cancer recurrences; however results from other clinical trials have not shown this effect. In order to determine the effectiveness of chemotherapy after surgery in preventing recurrences, doctors in Canada analyzed results from 13 major clinical trials that compared adjuvant chemotherapy treatment to no additional treatment following surgery for gastric cancer. They found a modest benefit for patients treated with adjuvant chemotherapy. The results indicated that 65% of patients treated with surgery alone experienced a recurrence and died, compared to approximately 61% of patients receiving adjuvant chemotherapy. The greatest benefit appeared to be in patients treated with more modern chemotherapy drugs. Over the past few years, several new chemotherapy drugs have been developed that appear to have more anti-cancer activity and are being evaluated in clinical trials.

Results from a large multi-institutional clinical study also indicate that adjuvant therapy significantly improves survival for patients with gastric cancer and should become the standard of care for this disease. The trial involved over 500 patients with gastric cancer who received surgery alone or surgery plus a combination of chemotherapy and radiation. All patients in the study underwent surgery to remove their cancer and had no evidence of cancer remaining following the surgical procedure. Half of the patients then received adjuvant combination chemotherapy consisting of 5-fluorouracil and leucovorin plus radiation. Three years following therapy, 50% of patients treated with surgery followed by adjuvant chemotherapy and radiation survived, compared with only 41% of patients treated with surgery alone. Three years following treatment, 48% of patients treated with adjuvant therapy survived without a cancer recurrence, compared to only 31% treated with surgery alone. The average duration of survival following surgery was 27 months, compared with 36 months for patients receiving surgery and adjuvant therapy.

Another clinical trial evaluated adjuvant chemotherapy without radiation in gastric cancer patients. All patients in this trial had cancer that had spread to nearby lymph nodes and were eligible for curative surgery. Half of the patients received combination chemotherapy consisting of epidoxorubicin, leucovorin and 5-fluorouracil for 7 months following surgery while the other half of patients received no adjuvant therapy (control group). Five years following therapy, 30% of the patients receiving adjuvant chemotherapy were still alive, compared with only 13% from the control group. The average survival time following treatment was 31 months for patients receiving adjuvant chemotherapy and only 18 months for the control group.

Results from both of these clinical trials are consistent with previous studies indicating that adjuvant therapy improves outcomes for patients with gastric cancer. The researchers in these studies have concluded that surgery following adjuvant therapy for stage I to IV gastric cancer reduces cancer recurrences and improves overall survival compared with surgery alone. Adjuvant therapy is considered the standard treatment for patients with gastric cancer for whom all detectable cancer can first be removed by surgery.

Strategies to Improve Treatment

The progress that has been made in the treatment of gastric cancer has resulted from the use of multi-modality treatment and improved patient and physician 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 Supportive Care.

New Adjuvant Regimens: Development of new multi-drug chemotherapy treatment regimens that incorporate new or additional anti-cancer therapies is an active area of clinical research carried out in phase II clinical trials. Adjuvant therapy may consist of chemotherapy alone or in combination with radiation therapy or biological agents.

Chemotherapy Combined with Biologic agents: Combining chemotherapy with biologic agents is the focus of intensive investigation and there are many such clinical trials ongoing in patients with other cancers.

In a recent clinical trial, the regimen of hydroxyurea, fluorouracil and alpha-2a Interferon was evaluated in 30 patients with advanced gastric cancer. There were 2 complete (7%) and 11 (37%) partial responses. This response rate is as good or better than any other previously reported regimen suggesting some activity for Interferon for the treatment of gastric cancer.

Neoadjuvant Therapy: The practice of administering chemotherapy before surgery is referred to as neoadjuvant. In theory, neoadjuvant chemotherapy can decrease the size of the cancer, thereby making it easier to remove with surgery. With the development of new chemotherapy regimens, new clinical trials of neoadjuvant therapy performed in patients with gastric cancer are currently ongoing.

Multiple Drug Resistance Inhibitors: Gastric cancer can be drug resistant at the outset of treatment or develop drug resistance after treatment. Several drugs are being tested to determine if they will overcome or prevent the development of multiple drug resistance in gastric cancer and other cancers.

Gene Therapy: Currently, there are no gene therapies approved for the treatment of gastric cancer. Gene therapy is defined as the transfer of new genetic material into a cell for therapeutic benefit. This can be accomplished by replacing or inactivating a dysfunction gene or replacing or adding a functional gene into a cell to make it function normally. Gene therapy has been directed towards the control of rapid growth of cancer cells, control of cancer death or efforts to make the immune system kill cancer cells. A few gene therapy studies are being carried out in patients with refractory gastric cancer. If successful, these therapies could be applied to patients with earlier stage disease.