What is the treatment for gastric cancer?

In response to a question on healthshare.com.au

Treatment for gastric cancer depends very much on the stage of the disease, particularly on whether the cancer is localised to the stomach or whether it has spread to other areas.

Treatment for localised gastric cancer usually involves a combination of chemotherapy and surgery, and also radiotherapy in some cases. Often the process will involve chemotherapy, surgery, then further chemotherapy and possibly radiotherapy. Early stomach cancers can sometimes be treated with surgery alone.

Treatment for advanced or metastatic cancer, in particular cancer which is thought to be incurable, centers around ensuring the best quality of life possible for as long as possible. Treatment will be guided by the problems that the cancer is causing - for example, blockage of the stomach (gastric outlet obstruction) occasionally requires surgery but will often be treated better with drainage tubes or with stents that open up the blockage from within. Chemotherapy can often slow the rate of progression of the cancer, but not always, and chemotherapy has its own complications that need to be considered.

Treatment should be discussed by a multidisciplinary team of surgeons, oncologists, radiation oncologists and other specialists to ensure that all options are considered, and that any relevant clinical trials are considered. Clinical trials compare different treatment options in the hope of improving treatments in the future; a list of currently open trials can be found here: https://gicancer.org.au/clinical-trial/status/in-development/ [LINK UPDATED APRIL 2021]

Surgery can be laparoscopic (keyhole) or open (large incision). Not all surgeons perform laparoscopic stomach surgery.

Have a look also at the answers to this related question:
http://www.healthshare.com.au/questions/46656-surgery-for-gastric-cancer-what-is-the-success-rate-and-what-should-a-patient-expect-following-the-procedure#answers-49561