Complications of Stomach Cancer Treatments
The treatment of stomach cancer is associated with several immediate and long term complications. Surgical resection (refer to stomach cancer surgery) is associated with bleeding, leakage from the anastomosis (joining of gut following gastrectomy), and damage to surrounding structures. Palliative surgeries are can also end up with fatal anastomotic leak.
A long term complication of surgical removal of the stomach is dumping syndrome, which is characterized by diarrhea, abdominal cramps and sometimes palpitations following a meal. This usually results from a sudden release of some gastrointestinal hormones due to rapid movement of the ingested food to the intestines. Long term complications can also result in malabsorption of vitamin B12, iron and calcium, which may require monitoring and supplementation.
Chemotherapy is associated with a wide range of adverse effect including :
- hair loss
- edema (swelling)
- bone marrow suppression (neutropenia, low platelet counts)
- febrile neutropenia
Drugs like docetaxel are known to cause allergic reactions. Cisplatin is associated with severe nausea and vomiting and oxaliplatin is associated with peripheral neuropathy. Toxicity of combination chemotherapy is slightly higher than the single-drug therapy and is also associated with higher treatment-related mortality. Some regimens like irinotecan-based and oxaliplatin-based are less toxic compared to the cisplatin or flurouracil-based regimens.
Stomach Cancer Prognosis
The prognosis for stomach cancer depends on the stage at which the diagnosis is made. An earlier diagnosis translates into a better prognosis. Good screening systems are the cornerstone of early diagnosis and high risk patients should consider undergoing regular screening. Surgical resection of the tumor at an early stage is the only curative treatment for gastric cancer. Additional treatment given in the form of adjuvant or neoadjuvant chemotherapy can further improve the results.
Approximately 30% of patients undergoing curative surgical resection survive beyond 5 years. The overall 5-year survival rate including all patients across all stages of gastric cancer is less than 10%. Surgical resection may be curative in early gastric cancer confined to the mucosa and submucosa. Anatomic location is another important prognostic factor. The cancers of the distal end of the stomach have a better prognosis than cancers of the proximal or the cardiac end of stomach. Prognosis is relatively poor for the diffuse-type in general and especially in those with linitis plastica. Other factors affecting the prognosis of stomach cancer include age, tumor size and depth.
In countries like Japan where mass screening techniques are employed due to the high incidence of stomach cancer, tumors are detected while still confined to the mucosa and submucosa. The 5 year survival rate increases sharply, as high as 50%, due to early detection. However, the most important factor affecting the prognosis is the stage of the cancer and lymph node status (number of positive lymph nodes).