**Acknowledgements**

"evidence-based medicine" from 1980s. This period covered the correct diagnosis and scientifically based (proved) therapy in terms of medicine. In the early years of this period, the drug actions were observed (later tested) on healthy human beings and in patients with different diagnosis. Following the first years appeared the randomized, prospective, multicentric, and multiclinical studies, and thereafter these studies were carried out in

The international organization of human drug research has been absolutely required the involvement of different nations from the different continents in the same studies (multinational) studies. One of the many factors the selections of patients including the same study other problems (age, body weight, correct diagnosis, the same stadiums of the disease, correct laboratory parameters, genders, nutritional habits, used drugs, etc.). The selections of the patients into the different drug therapies had been carried out randomly. Physicians (who actively participated in carrying out these observations) were not informed on therapeutically applied drugs (similarly to the patients), because these studies were done in accordance to

These observations were done absolutely in accordance to earlier and the strictly prepared protocols (time of drug administration, collection of biological samples (blood and urine), relevant examinations, food and fluid consumption, etc.), and the protocols were previously permitted by the national authorities (respecting the ethical and medical aspects, cost and

The critical evaluation of efficiencies of different drugs (or drug combinations) included the very complicated computer participation in the pharmacological research. Meanwhile, the detailed therapeutic effects resulted in the "meta-analysis" of drug (or drug-combination) actions.

The results of these examinations led us to plan a "generally accepted therapeutically used

Medically, we have to understand that these studies depended on the results obtained in huge number of human observations; however, an actually present patient was only one from the patients participated in whole ones of the big studies. Surprisingly, the results obtained in one patient differed from those obtained in big randomized studies. Of course, the physicians recalled the insufficient complaints of patients or some other causes. Later on, many other possibilities existed to explain the insufficient medical therapies, and their became to be clear by the new results of molecular biology, genetics, immunology, immunohistochemistry, and of new development of medical science (molecular pharmacology, biochemical pharmacology

In this century, the development of medical sciences has been in an extremely high speed in different fields (including the basic research and clinical research), which produced an abnor-

We have to realize that oncology is one of these fields indicating rapid changes from day to day. Consequently, the diagnostic and therapeutic possibilities in our hand are changing day to day. This is an absolutely new challenge to physicians and this offers new possibilities for

form" of drug therapy in the everyday medical treatment (guidelines).

mally increased quantity and quality of our knowledge.

huge number of patients suffering from the same disorders.

previously permitted protocol(s).

4 Gastric Cancer

pharmacogenetics, etc.).

the patients.

benefit, dangers of treated patients, etc.).

The editors thank very much the excellent cooperations of the contributors in this book at the time of book edition.

The editors are especially thankful for the excellent support given by Ms. Ana Pantar (Senior Commissioning Editor) and by Ms. Mirena Čalmić (Publishing Process Manager) and Mr. Teo Kos (Publishing Process Manager) from Intech Open Access Publisher; without their help, the publication of this book would not be possible.
