Research conducted by Prof. Dan Aderka from Sheba Medical Center, Tel Hashomer found that various combinations of biological medicine and chemotherapy, depending on the type of tumor, affect the life expectancy of Colorectal Cancer (CRC) patients, according to an Israel Hayom report.Colorectal Cancer is also known as bowel cancer and colon cancer.The study resolves a decade-long controversy over the treatment of a third (35%) of metastatic CRC patients, patients whose tumor contains receptors of EGFR (Epidermal Growth Factor Receptor).The controversy in question surrounded the difference between medicinal regimens for CRC used with the chemotherapy treatment. The main difference had been whether to use Avastin first and then Erbitux, or the other way around. Earlier research conducted showed conflicting results for each approach.Aderka conducted his research at the Oncology wing at Sheba along with fellow associates from abroad. The research had also been published at The Lancet Oncology, among the world's oldest, most prestigious and best known general medical journals, according to the Population Media Center.Prof. Aderka's research settled the argument and showed that the different use of medicines directly affects the life expectancy for CRC patients.The research conducted on patients with an incurable tumor, classified the patients into four different groups according to their type of tumor.In one of the focus groups, the use of Avastin along with chemotherapy increased the patients' life expectancy by an average of 21 months, whereas the use of Erbitox, applied with the same chemotherapy treatment, increased the life expectancy by an average of 40 months.A research group with a different type of CRC tumor showed that the use of Avastin increased the life expectancy of those patients by an average of 22 months, whereas consummation of Erbitox only increased their life expectancy by an average of 11 months."The different results obtained with the same biological material for the same type of tumor stemmed from the simultaneous combination of various chemotherapy drugs: in one study, the chemotherapy worked together with the biological drugs against the tumor, while in the other the chemical stimulated the secretion of substances that neutralized biological activity, which reduced its effectiveness," Aderka told Israel Hayom."For years, we did not know how to maximize the potential of the drugs, and we did not care with which of the two biological drugs we started the treatment. We thought that applying one treatment was suitable for all patients," Aderka explained. "If the right combination of drugs was applied, the patient's life expectancy would be extended. Whereas if another combination had been used – his life expectancy would not be extended. In one case, we even observed that a combination of a biological drug and chemotherapy in one of the tumor types reduces the effectiveness of the biological drug and not the other way around, as we have thought for years."Aderka is the head of the Gastrointestinal Cancer Service at Sheba and a chief specialist in the field of digestive system oncology. He is the member of the Israeli Association of Clinical Oncology and Radiotherapy (ISCORT), the American Society of Oncology (ASCO) and the European Oncology Society (ESMO).